阅读说明：本技术 电化学电池和用于制造该电化学电池的方法 (Electrochemical cell and method for manufacturing the same ) 是由 S·斯托克 E·皮特利克 R·哈德 D·恩斯林 B·贝克 于 2020-05-19 设计创作，主要内容包括：电化学电池(100)包括电极-隔膜复合体(101),该电极-隔膜复合体具有阳极(115)、至少一个隔膜(116、117)和阴极(118)。阳极(115)和阴极(118)分别包括集流体(115a、118a),该集流体具有由至少一种金属组成的表面,该表面加载有由电极活性材料构成的至少一个层(115b、118b)。集流体(115a、118a)的表面包括至少一个空闲区域(115c、118c),该至少一个空闲区域未加载该电极活性材料。代替于此,这些表面在该至少一个空闲区域(115c、118c)用支撑材料(119)涂层,该支撑材料比用它涂层的表面更加耐热。在制造电池(100)时,在制造电极-隔膜复合体(101)之前或之后,可以将支撑材料(119)涂覆到该至少一个空闲区域(115c、118c)上或者在那里形成该支撑材料。(An electrochemical cell (100) includes an electrode-separator composite (101) having an anode (115), at least one separator (116, 117), and a cathode (118). The anode (115) and the cathode (118) each comprise a current collector (115 a, 118 a) having a surface consisting of at least one metal, which is loaded with at least one layer (115 b, 118 b) of an electrode active material. The surface of the current collector (115 a, 118 a) comprises at least one free area (115 c, 118 c) which is not loaded with the electrode active material. Instead, the surfaces are coated in the at least one free area (115 c, 118 c) with a support material (119) which is more heat-resistant than the surface coated therewith. In the production of the battery (100), a support material (119) can be applied to the at least one free region (115 c, 118 c) or formed there, before or after the production of the electrode-separator composite (101).)

1. An electrochemical cell (100) having the following features:

a. the battery comprises an electrode-separator complex (101) having an anode (115), at least one separator (116, 117) and a cathode (118); and also

b. The anode (115) comprises an anode current collector (115 a) having a surface consisting of at least one metal, said surface being loaded with at least one layer (115 b) of a negative electrode active material; and also

c. The cathode (118) comprises a cathode current collector (118 a) having a surface consisting of at least one metal loaded with at least one layer (118 b) of positive electrode active material; and also

d. The surface of the anode current collector (115 a) and/or the surface of the cathode current collector (118 a) comprising at least one free area (115 c; 118 c) which is not loaded with a respective electrode active material,

and has the following additional features:

e. within the at least one free area (115 c; 118 c), the surface of the anode current collector (115 a) and/or the surface of the cathode current collector (118 a) is coated with a support material (119) that is more heat resistant than the surface coated therewith.

2. The electrochemical cell of claim 1, having the additional features of:

a. the at least one metal forming the surface of the anode current collector (115 a) comprises at least one member from the group consisting of copper, copper alloys, titanium alloys, nickel alloys, and stainless steel;

b. the anode current collector (115 a) is composed of the at least one metal;

c. the anode current collector (115 a) is a metal foil, a metal foam, a woven fabric or a metal mesh;

d. the at least one metal forming the surface of the cathode current collector (118 a) comprises at least one member from the group consisting of aluminum, aluminum alloys, titanium alloys, and stainless steel;

e. the cathode current collector (118 a) is comprised of the at least one metal;

f. the cathode current collector (118 a) is a metal foil, a metal foam, a woven fabric, or a metal mesh.

3. The electrochemical cell of claim 1 or 2, having the following additional features:

a. the anode current collector (115 a) has two flat sides (115 d, 115 e) separated from each other by at least one edge (115 f, 115 g);

b. said anode current collector (115 a) being loaded with at least one layer of negative electrode active material on said two flat sides (115 d, 115 e);

c. the at least one idle area comprises two sub-areas on two flat sides (115 d, 115 e) of the anode current collector (115 a);

d. the two sub-areas of the anode current collector (115 a) are coated with the support material (119).

4. An electrochemical cell according to any preceding claim, having the additional features of:

a. the cathode current collector (118 a) having two flat sides (118 d, 118 e) separated from each other by at least one edge (118 f, 118 g);

b. the cathode current collector (118 a) is loaded with at least one layer of positive electrode active material on the two flat sides (118 d, 118 e);

c. the at least one free area (115 c, 118 c) comprises two sub-areas on two flat sides (118 d, 118 e) of the cathode current collector (118 a);

d. the two sub-areas of the cathode current collector (118 a) are coated with the support material (119).

5. An electrochemical cell according to any preceding claim, having the additional features of:

a. the support material (119) is a non-metallic material;

b. the non-metallic material is a ceramic material, a glass-ceramic material or glass;

c. the ceramic material is alumina (Al)₂O₃) Or titanium oxide (TiO)₂）。

6. An electrochemical cell according to any preceding claim, having the additional features of:

a. the electrode-membrane complex (101) is in the form of a coil having two end sides (103, 109);

b. the electrode-separator composite (101) and at least one separator (116, 117) comprised by the electrode-separator composite, an electrode (115, 118) comprised by the electrode-separator composite, and thereby also the anode current collector (115 a) and the cathode current collector (118 a) are configured in the form of a strip and each have two longitudinal edges;

c. the two end sides (103, 109) of the electrode-membrane complex are formed by the longitudinal edges of the at least one membrane (116, 117);

d. -the surface of the anode current collector (115 a) and the surface of the cathode current collector (118 a) comprise idle areas (115 c, 118 c), respectively, not loaded with electrode active material;

e. the free area (115 c) on the surface of the anode current collector (115 a) is a strip-like edge area along one (115 g) of its two longitudinal edges;

f. the free area (118 c) on the surface of the cathode current collector (118 a) is a strip-like edge area along one (118 f) of its two longitudinal edges;

g. the strip-shaped anode (115) and the strip-shaped cathode (118) are arranged offset to each other within the electrode-separator composite (100) in such a way that

A longitudinal edge (115 g) of the anode current collector (115 a) protrudes from one (109) of the two end sides together with a free area (115 c) of the anode current collector (115 a), and

the longitudinal edge (118 f) of the cathode current collector (118 a) protrudes from the other (103) of the two end sides together with the free area (118 c) of the cathode current collector (118 a).

7. An electrochemical cell according to any preceding claim, having the additional features of:

a. the electrode-separator composite together with at least one other identical electrode-separator composite is a constituent of a stack in which at least two electrode-separator composites are stacked on top of one another;

b. the at least two electrode-separator composites and the anodes, cathodes and separators thereof and thereby also the anode and cathode current collectors thereof each have at least one longitudinal edge;

c. the anode current collector has a vacant area along its longitudinal edge or one of its longitudinal edges, respectively;

d. the cathode current collector has a vacant area along its longitudinal edge or one of its longitudinal edges, respectively;

e. the anodes and cathodes of the at least two electrode-separator combinations are arranged offset to one another within the stack in such a way that

On one side of the stack, the free areas of the anode current collectors overlap, and

on the other side of the stack, the vacant areas of the cathode current collectors overlap.

8. An electrochemical cell according to any preceding claim, having the additional features of:

a. -the coating of said at least one free area (115 c, 118 c) with said support material (119) has a thickness in the range of 0.015 to 1.0 mm, preferably 0.05 to 0.2 mm;

b. at least one layer (115 b) of negative electrode material on the anode current collector (115 a) has a thickness in the range of 0.03 to 1.0 mm, preferably 0.1 to 0.2 mm;

c. at least one layer (118 b) of positive electrode material on the cathode current collector (118 a) having a thickness in the range of 0.03 to 1.0 mm, preferably 0.1 to 0.2 mm;

d. the thickness of the coating of said support material (119) on the anode or cathode current collector is between 50% and 100% of the thickness of the layer of electrode material located thereon.

9. An electrochemical cell according to any one of the preceding claims 2 to 8, having at least one of the following additional features:

a. the anode current collector (115 a) and the cathode current collector (118 a) are constructed in accordance with claims 3 and 4;

b. the battery (100) comprises a first electrical conductor (104) welded to an edge (115 g) of the anode current collector (115 a);

c. the battery (100) includes a second electrical conductor (104) welded to an edge (118 f) of the cathode current collector (118 a).

10. The electrochemical cell of claim 9, having the additional features of:

a. the battery (100) is constructed in accordance with claim 6;

b. -said first electrical conductor (104) is welded to a longitudinal edge (115 g) of an anodic current collector (115 a) configured in the form of a band, along which a free area (115 c) of said anodic current collector (115 a) extends;

c. the second electrical conductor (104) is welded to a longitudinal edge (118 f) of a cathode current collector (118 a) configured in the form of a strip, along which a free area (118 c) of the cathode current collector (118) extends.

11. The electrochemical cell of claim 10 having the additional features of:

a. the first electrical conductor (104) is a metallic contact plate;

b. the second electrical conductor (104) is a metallic contact plate;

c. the first metal contact plate (104) is placed flat on an end face (109) of the coil, from which end face a longitudinal edge (115 g) projects to which the contact plate is welded;

d. the second metal contact plate (104) is placed flat on an end face (103) of the coil, from which end face a longitudinal edge (118 f) projects to which the contact plate is welded.

12. An electrochemical cell according to any preceding claim, characterized by the following additional features:

a. the battery is a component of a battery pack together with at least one other identical battery.

13. A method for manufacturing an electrochemical cell (100) according to any of claims 1 to 11, the method comprising the steps of:

a. providing an anode (115) comprising an anode current collector (115 a) having a surface comprised of at least one metal, said surface being loaded with at least one layer (115 b) of a negative electrode active material;

b. providing a cathode (118) comprising a cathode current collector (118 a) having a surface consisting of at least one metal, said surface being loaded with at least one layer (118 b) of a positive electrode active material; and also

c. Producing an electrode-separator composite (101) using a provided anode (115) and a provided cathode (118), said electrode-separator composite having an anode, at least one separator and a cathode,

wherein before or after the electrode-separator composite is manufactured,

d. the vacant areas (115 c) on the surface of the anode current collector (115 a) that are not loaded with negative electrode active material and/or the vacant areas (118 c) on the surface of the cathode current collector (118 a) that are not loaded with positive electrode active material are coated with a support material (119) that is more heat resistant than the surface coated with it.

14. The method according to claim 13, characterized by the following additional features:

a. the support material (119) is vapor deposited on one or more free areas (115 c, 118 c);

b. the support material (119) is applied as a constituent of a suspension or paste onto the one or more free areas (115 c, 118 c).

Technical Field

The invention described subsequently relates to an electrochemical cell having an electrode-separator composite with an anode, at least one separator and a cathode.

Background

Such batteries are known in principle, for example from DE 102009060800 a 1. In this german patent application, cylindrical coils are described which are composed of electrode-diaphragm composites and which are inserted into a cylindrical metal housing. For the electrical contacting of the electrodes, current collectors are used, which are loaded with electrode active material. The current collectors are respectively welded with a metal foil which acts as a separate electrical conductor and which is electrically connected with the housing.

The method described in DE 102009060800 a1 for electrically contacting the electrodes is efficient and cost-effective. However, this method has disadvantages in some application cases. For example, electrical connection of the electrodes through the metal foil is problematic. If the electrodes connected in this way should store or release a high current for a short time, the metal foil heats up very strongly.

Electrochemical cells of this type are known from WO 2017/215900 a1, in which the electrode-separator combination and its electrodes are designed in the form of strips and are present in the form of coils or stacks. The electrodes each have a current collector loaded with an electrode material. The electrodes of opposite polarity are arranged offset from one another within the electrode-separator composite such that the longitudinal edge of the current collector of the positive electrode protrudes from the coil or stack on one side and the longitudinal edge of the current collector of the negative electrode protrudes from the coil or stack on the other side. For the electrical contacting of the current collectors, the battery has at least one contact plate, which is placed on one of the longitudinal edges in such a way that a linear contact area is obtained. The contact plate and the longitudinal edge are connected by welding along the line-shaped contact area. It is thereby possible to: the current collector and thus also the associated electrode are electrically contacted over their entire length. This reduces the internal resistance within the described battery very significantly. The occurrence of high currents can thus be prevented much better than for example the batteries known from DE 102009060800 a 1.

However, a problem in the battery described in WO 2017/215900 a1 is that: it is very difficult to weld the longitudinal edges and the contact plates to each other. The current collector of the electrode has a very thin thickness compared to the contact plate. Thus, the edge regions of the current collector are mechanically very sensitive and may be inadvertently sagged or melted during the welding process. In addition, when the contact plate is welded, melting of the separator of the electrode-separator composite may occur. In extreme cases, short circuits may thereby result.

The invention is based on the task of: an electrochemical cell of this type is provided which is distinguished over the cited prior art not only by an improved current-carrying capacity but also by an improved manufacturability.

Disclosure of Invention

In order to solve this object, the invention proposes an electrochemical cell having the features of claim 1 and a method having the features of claim 13. Further developments of the invention are the subject matter of the dependent claims. The entire contents of all claims are hereby incorporated by reference into the specification.

The electrochemical cell according to the invention is always characterized by the following features a-d:

a. the battery includes an electrode-separator composite having an anode, at least one separator, and a cathode; and also

b. The anode comprises an anode current collector having a surface comprised of at least one metal loaded with at least one layer comprised of a negative electrode active material; and also

c. The cathode comprises a cathodic current collector having a surface consisting of at least one metal loaded with at least one layer consisting of a positive electrode active material; and also

d. The surface of the anode current collector and/or the surface of the cathode current collector comprise at least one free area, which is not loaded with the respective electrode active material.

The battery is characterized in particular by the following features:

e. in the at least one vacant area, the surface of the anode current collector and/or the surface of the cathode current collector is coated with a support material that is more heat-resistant than the surface coated therewith.

In this case, "more heat resistant" shall mean: the support material remains solid at the temperature at which the surface melts. That is, either the support material has a higher melting point than the surface or the support material sublimes or decomposes at a temperature at which the surface has melted.

Preferably, not only the surface of the anode current collector but also the surface of the cathode current collector respectively have vacant regions not loaded with the respective electrode active materials. In one embodiment, it is preferred that: the free areas on the surface of the anode current collector as well as the free areas on the surface of the cathode current collector are coated with the support material. It is particularly preferred to use the same support material for each of these regions.

The battery according to the invention is preferably a secondary battery, i.e. a rechargeable battery. Thus, materials that can be used in secondary electrochemical cells are preferably considered for the battery according to the present invention as electrode active materials.

Particularly preferably, the electrochemical cell is a lithium ion cell. In this case, all materials that can absorb lithium ions and re-release lithium ions can be considered as the electrode active material. The negative electrode active material may be, for example, a carbon-based material such as graphitic carbon or other material capable of intercalating lithium ions. Metals and semimetals which can form intermetallic phases with lithium, such as silicon, can be used as negative electrode materials, in particular also in a mixture with carbon-based materials which are capable of intercalating lithium ions. For example, lithium-metal oxide compounds and lithium-metal phosphate compounds, such as LiCoO, can be considered₂And LiFePO₄As a positive electrode active material. Also suitable are materials based on NMC (lithium nickel cobalt manganese), LTO (lithium titanate) and on NCA (lithium nickel cobalt aluminate).

In a further preferred embodiment, the battery according to the invention can be a nickel-metal hydride battery which has a hydrogen storage alloy as electrode active material on the side of the negative electrode and nickel hydroxide/nickel oxyhydroxide as electrode active material on the side of the positive electrode.

Furthermore, the electrodes of the battery according to the invention can be constructed like the electrodes of the systems described in WO 2016/005529 a1 and in WO 2016/005528 a 2. In these documents systems are described in which the positive electrode has an electrode active material based on nickel oxyhydroxide/nickel hydroxide, while the negative electrode contains, as electrode active material, a mixture of activated carbon and a hydrogen storage alloy or a mixture of activated carbon and iron in metallic and/or oxidized form.

In all the cases mentioned, the electrode active material is preferably present in the form of particles not only on the side of the positive electrode but also on the side of the negative electrode.

The electrode of the battery according to the present invention may have other constituent parts in addition to the electrode active material and the current collector. Electrode binders and conductive agents are common among others. The electrode binder ensures the mechanical stability of the electrode and causes electrical and mechanical contact of the electrode active material particles with each other and with the current collector. Conductive agents such as carbon black are used to improve the conductivity of the electrode.

Generally, the electrode-separator composite includes an electrolyte, with which the electrodes are impregnated, and which ensures an ion flow occurring between the electrodes of the battery upon charging or discharging of the battery. In the case of lithium ion batteries, a mixture composed of an organic carbonate containing a conductive lithium salt is often used as an electrolyte. In the case of nickel-metal hydride batteries and the batteries described in WO 2016/005529 a1 and in WO 2016/005528 a2, it is preferred to use an aqueous alkaline solution as the electrolyte.

At least one membrane for: preventing direct contact of the electrodes of opposite polarity. At the same time, the separator must be permeable to ions that migrate back and forth between the electrodes during charging and discharging. In particular, separators made of porous plastic films, for example made of polyolefins or of polyetherketones, can be considered as separators for the electrode-separator composite of the battery according to the invention. Webs and textiles constructed from these materials may also be used.

Generally, the electrode-separator complex includes the electrodes and the at least one separator in the order of positive electrode/separator/negative electrode. In a preferred embodiment, there is a composite with two separators, for example with the possible order negative electrode/first separator/positive electrode/second separator or positive electrode/first separator/negative electrode/second separator.

In some embodiments, the electrode-separator composite may also have more than one positive electrode or more than one negative electrode. Thus, for example, it is possible to: the composite has: a sequential negative electrode/first separator/positive electrode/second separator/negative electrode; or a sequential positive electrode/first separator/negative electrode/second separator/positive electrode.

Within the composite, the electrodes and the separators are preferably connected to one another by lamination and/or gluing.

The current collectors in these electrodes serve to electrically contact the electrode active material over as large an area as possible.

Particularly preferably, the current collector of the battery according to the invention and thus also the battery itself according to the invention are characterized by at least one of the following additional features a.

a. The at least one metal constituting the surface of the anode current collector includes at least one member from the group consisting of copper, copper alloy, titanium alloy, nickel alloy, and stainless steel;

b. the anode current collector is composed of the at least one metal;

c. the anode current collector is metal foil, metal foam, woven fabric or metal mesh;

d. the at least one metal constituting the surface of the cathode current collector includes at least one member from the group consisting of aluminum, aluminum alloys, titanium alloys, and stainless steel;

e. the cathode current collector is composed of the at least one metal;

f. the cathode current collector is a metal foil, metal foam, woven fabric or metal mesh.

In a preferred embodiment, the above features a.to c.are all realized simultaneously in combination with each other. In other preferred embodiments, the above features d.to f.are all realized simultaneously in combination with each other. In a particularly preferred embodiment, the above features a.to f.are all realized simultaneously in combination with one another.

Particularly preferably, the anode current collector consists of copper or a copper alloy, while the cathode current collector consists of aluminum or an aluminum alloy.

However, in addition to a current collector which is composed entirely of the at least one metal, it is also possible to use a current collector in which the surface composed of the at least one metal surrounds a non-metallic structure, for example a woven fabric composed of filaments made of glass or plastic. In this case, the term "woven fabric" refers in particular to fibrous webs, woven fabrics, nets and knits.

In a particularly preferred embodiment, the cathode current collector consists of aluminum foil, preferably aluminum foil having a thickness in the range of 5 to 30 μm. Particularly preferably, the anode current collector consists of a copper foil, preferably a copper foil with a thickness in the range of 5 to 15 μm, or of a nickel foil, preferably a nickel foil with a thickness in the range of 3 to 10 μm.

In a particularly preferred embodiment, the current collector of the battery according to the invention and thus also the battery itself according to the invention are characterized by at least one of the following additional features a.

a. The anode current collector has two flat sides separated from each other by at least one edge;

d. the anode current collector is loaded with at least one layer of negative electrode active material on both flat sides;

c. the surface of the anode current collector comprises an idle area coated with a support material, which is divided into two sub-areas on its two flat sides;

d. the two sub-regions of the anode current collector are coated with a support material.

Particularly preferably, all of the above features a.to d.are realized simultaneously in combination with one another.

In a particularly preferred embodiment, the current collector of the battery according to the invention and thus also the battery itself according to the invention are characterized by at least one of the following additional features a.

a. The cathode current collector has two flat sides separated from each other by at least one edge;

b. the cathode current collector is loaded with at least one layer of positive electrode active material on both flat sides;

c. the surface of the cathode current collector comprises an idle area coated with a support material, which is divided into two sub-areas on its two flat sides;

d. the two sub-regions of the cathode current collector are coated with a support material.

Particularly preferably, all of the above features a.to d.are realized simultaneously in combination with one another.

The free area or the sub-areas may be completely or partially coated with a support material. In contrast, the flat side and thereby also the at least one edge separating the two partial regions from one another are preferably not coated with a support material.

In one embodiment, both the cathode current collector and the anode current collector have the flat side mentioned and a free region, which is coated with a support material and is divided into two partial regions. This applies in particular when foil or another mentioned substrate, such as the mentioned textile fabric, can be used as cathode and anode current collector, respectively. In the case of such a substrate, the surfaces of the current collectors substantially correspond to the surfaces of the two flat sides. The at least one edge may be ignored during quantitative detection of the surface. Due to the mentioned small thickness of the substrate, the at least one edge is usually not a significant part of the surface of the current collectors.

It is particularly preferred that both sub-areas on the cathode current collector and on the anode current collector are coated with a support material.

It is particularly preferred that at least one free area on the surface of the anode current collector and/or at least one free area on the surface of the cathode current collector is coated with a support material. More precisely, it may be preferred that: the layer consisting of the positive electrode material and the negative electrode material is also coated with a support material. For process reasons, it is simpler to: when applying the support material to the at least one free area, the support material is also applied to the layers of electrode material, since otherwise masking of these layers may be required.

In principle, the support material that can be used within the scope of the invention may be a metal or a metal alloy, as long as the metal or the metal alloy has a higher melting point than the metal that constitutes the surface, which surface is coated with the support material. However, in many embodiments, the battery according to the invention is preferably characterized by at least one of the following additional features a.

a. The support material is a non-metallic material;

b. the non-metallic material is a ceramic material, a glass-ceramic material or glass;

c. the ceramic material is alumina (Al)₂O₃) Titanium oxide (TiO)₂) Titanium nitride (TiN), titanium aluminum nitride (TiAlN), or titanium carbonitride (TiCN).

In the present case, the term "ceramic material" is to be interpreted broadly. Ceramic materials are to be understood as meaning, in particular, carbides, nitrides, oxides, silicides or mixtures and derivatives of these compounds. According to the invention, the support material is particularly preferably constructed according to the above feature c.

The term "glass-ceramic material" especially refers to a material comprising crystalline particles embedded in an amorphous glass phase.

In principle, the term "glass" refers to any inorganic glass that meets the thermal stability criteria defined above and is chemically stable with respect to the electrolyte that may be present in the battery.

It is particularly preferred that the anode current collector consists of copper or a copper alloy, while the cathode current collector consists of aluminum or an aluminum alloy, and the support material is aluminum oxide or titanium oxide.

In a particularly preferred first variant of the battery according to the invention, the battery is characterized by at least one of the following additional features a.

a. The electrode-separator complex is in the form of a coil having two distal end sides;

b. the electrode-separator composite and at least one separator comprised by the electrode-separator composite, the electrode comprised by the electrode-separator composite and thereby also the anode current collector and the cathode current collector are configured in the form of a strip and each have two longitudinal edges;

c. both distal end side of the electrode-separator complex are formed by the longitudinal edges of the at least one separator;

d. the surface of the anode current collector and the surface of the cathode current collector respectively include vacant regions not loaded with the electrode active material;

e. the free area on the surface of the anode current collector is a strip-like edge area along one of its two longitudinal edges;

f. the free area on the surface of the cathode current collector is a strip-like edge area along one of its two longitudinal edges;

g. the strip-shaped anode and the strip-shaped cathode are arranged in the electrode-separator composite in a staggered manner such that

The longitudinal edge of the anode current collector protrudes from one of the two end sides together with the free area of the anode current collector, and

the longitudinal edge of the cathode current collector protrudes from the other of the two end side together with the free area of the cathode current collector.

Preferably, the above features a.to g. are all realized simultaneously in combination with each other.

In the case of such a coil-shaped embodiment of the electrode/separator composite, the current collectors preferably also have two flat sides and are preferably each coated on both sides with a layer of the respective electrode material. Particularly preferably, both the edge region on the surface of the anode current collector and the edge region on the surface of the cathode current collector are divided by the respective edge region along which these surfaces extend into two partial regions each configured in the form of a strip, which are both coated with the support material. Particularly preferably, the partial regions are each coated with a strip of support material. These current collectors are therefore not only loaded on both sides with the respective electrode material but also coated on both sides with a support material. The longitudinal edges are preferably not coated with a support material.

In the manufacture of electrode-separator composites, it is common to note that: the electrode and the current collector are combined with each other so that one side of the current collector, which is opposite in polarity, does not protrude, because this may increase the risk of short circuit. However, in the described staggered arrangement, the risk of short circuits is minimized, since the current collectors of opposite polarity protrude from opposite end sides of the coil.

Preferably, the maximum height of the coil is in the range of 30 mm to 100 mm and the maximum diameter of the coil is in the range of 10 mm to 45 mm.

Preferably, the anode and cathode current collectors configured in a band shape have a length in a range of 50 mm to 300 mm, a width in a range of 30 mm to 100 mm, and a thickness in a range of 30 μm to 200 μm.

The strip-shaped edge regions and the strip-shaped sub-regions preferably have a width in the range from 0.5 mm to 5 mm.

In a preferred embodiment, the coil is a cylindrical coil. However, in other embodiments, the coil may also be a prismatic pancake coil. It is well known that the construction of prismatic flat coils is similar to that of cylindrical coils. However, the electrode-membrane composite is not wound helically around the shaft but flat in order to produce the flat coil, so that the composite processed to form the flat coil comprises flat, non-warped sections which are stacked on top of one another in the flat coil.

In a second, particularly preferred variant of the battery according to the invention, the battery is characterized by at least one of the following additional features a.

a. The electrode-separator composite together with at least one other identical electrode-separator composite is part of a stack in which at least two electrode-separator composites are stacked on top of one another;

b. the at least two electrode-separator composites and the anodes, cathodes and separators thereof and thereby also the anode and cathode current collectors thereof each have at least one longitudinal edge;

c. the anode current collector has a free area, in particular in the form of a strip-shaped edge area, along its longitudinal edge or one of its longitudinal edges, respectively;

d. the cathode current collector has a free area, in particular in the form of a strip-shaped edge area, along its longitudinal edge or one of its longitudinal edges, respectively;

e. the anodes and cathodes of the at least two electrode-separator composites are arranged offset to one another within the stack and thus also within the composites, so that

On one side of the stack, the vacant areas of the anode current collectors overlap, and

on the other side of the stack, the vacant areas of the cathode current collectors overlap.

Preferably, the above features a.to e.are all implemented simultaneously in combination with each other.

In the case of such a stack-shaped embodiment, the current collectors also preferably have two flat sides and are preferably each loaded on both sides with a layer of the respective electrode material. Particularly preferably, both the edge region on the surface of the anode current collector and the edge region on the surface of the cathode current collector are divided by the respective edge region along which these surfaces extend into two partial regions each configured in the form of a strip, which are both coated with the support material. Particularly preferably, the partial regions are each coated with a strip of support material. These current collectors are therefore not only loaded on both sides with the respective electrode material but also coated on both sides with a support material. The longitudinal edges are preferably not coated with a support material.

Preferably, the maximum height of the stack is in the range 5 mm to 20 mm.

The anode and cathode current collectors, like these electrodes, are preferably rectangular in shape. Particularly preferably, the anode and cathode current collectors have a length in the range of 100 mm to 300 mm, a width in the range of 50 mm to 150 mm, and a thickness in the range of 50 μm to 250 μm.

The strip-shaped edge regions and the strip-shaped sub-regions preferably have a width in the range from 0.5 mm to 5 mm.

It is preferable that: the battery according to the invention is characterized by at least one of the following additional features a.

a. The coating of the at least one free area with the support material has a thickness in the range of 0.015 to 1.0 mm, preferably 0.05 to 0.2 mm;

b. at least one layer of negative electrode material on the anode current collector has a thickness in the range of 0.03 to 1.0 mm, preferably 0.1 to 0.2 mm;

c. at least one layer of positive electrode material on the cathode current collector has a thickness in the range of 0.03 to 1.0 mm, preferably 0.1 to 0.2 mm;

d. the thickness of the coating of support material on the anode or cathode current collector is between 1% and 100% of the thickness of the layer of electrode material located thereon.

Preferably, the above features a.to d.are all implemented simultaneously in combination with each other.

In one embodiment, the thickness of the coating of the support material on the anode or cathode current collector is between 5% and 50%, particularly preferably between 2% and 25%, of the thickness of the layer of electrode material lying thereon.

Particularly preferably, the battery according to the invention is characterized by at least one of the following additional features a.

a. The anode current collector and the cathode current collector are constructed according to claims 3 and 4, i.e. with the mentioned two flat sides and an empty area, divided into two sub-areas, coated with a support material, respectively;

b. the cell includes a first electrical conductor welded to an edge of an anode current collector;

c. the cell includes a second electrical conductor welded to the edge of the cathode current collector.

Preferably, the above features a.to d.are all implemented simultaneously in combination with each other.

The welding of these electrical conductors can be carried out in particular by means of laser welding or by means of WIG welding (tungsten inert gas welding).

In a preferred embodiment, the battery according to the invention is additionally characterized by at least one of the following features a.

a. The cell is constructed according to claim 6, i.e. has an electrode-separator composite in the form of a coil with two end faces and an anode current collector constructed in the form of a strip and a cathode current collector constructed in the form of a strip, each of which has two longitudinal edges;

b. the first electrical conductor is welded to a longitudinal edge of the anode current collector configured in the form of a strip, along which longitudinal edge the free area of the anode current collector extends;

c. the second electrical conductor is welded to a longitudinal edge of the cathode current collector configured in the form of a band, along which the free area of the cathode current collector extends.

Preferably, the above features a.to c.are all implemented simultaneously in combination with each other.

In a further development of the preferred embodiment according to the above features a.to c., the battery according to the invention is additionally characterized by at least one of the following features a.to d.:

a. the first electrical conductor is a metal contact plate;

b. the second electrical conductor is a metal contact plate;

c. a first metal contact plate is laid flat on the end side of the coil, from which the longitudinal edge to which the contact plate is welded protrudes;

d. a second metal contact plate is laid flat on the end side of the coil, from which the longitudinal edge, to which the contact plate is welded, protrudes.

Preferably, the above features a.to d.are all implemented simultaneously in combination with each other.

In this embodiment of the battery according to the invention, the projections of the current collectors caused by the offset arrangement are used in that they are contacted over a large area by means of contact plates. With these contact plates, it is possible to: the current collectors and thus also the associated electrodes are electrically contacted over their entire length. That is, by being flatly placed on the end side of the coil, a linear contact area is obtained. If the electrode-separator composite according to this embodiment is in the form of a spiral coil, for example, the longitudinal edges of the anode and cathode current collectors which project from the end faces of the coil likewise have a spiral geometry. A similar situation then applies to the line-shaped contact areas along which the contact plates are welded to the longitudinal edges.

Preferably, the contact plates are connected to the longitudinal edges along line-shaped contact areas by welding. This shaping is excellent in preventing the occurrence of high currents, as described in WO 2017/215900 a 1.

These contact plates can in turn be connected to the poles of the battery according to the invention, for example the positive and negative housing poles.

The contact plates can be connected to the longitudinal edges along line-shaped contact regions by at least one weld seam or by a plurality of weld spots. Particularly preferably, the longitudinal edges comprise one or more sections which are each connected to the contact plates continuously over their entire length by a weld seam. If necessary, these longitudinal edges are welded to the contact plate continuously over their entire length.

In the case of welding of the contact plates to the longitudinal edges, the problem mentioned at the outset, namely the unintentional sagging or melting of the edge regions of the current collectors, can occur. The support material solves these problems. The support material mechanically supports the edges of the current collectors and prevents melting of the edges, particularly when the current collectors are coated on both sides with the support material. Furthermore, the support material also prevents short circuits which are caused by the melting mentioned at the outset of the separator of the electrode-separator composite. The support material electrically insulates the vacant areas that it covers. That is, in a preferred embodiment, the support material is configured to be electrically insulating.

The contact plates are preferably metal plates having a thickness in the range of 200 to 1000 μm, preferably 400 and 500 μm. These contact plates are preferably composed of aluminum, aluminum alloys, titanium alloys, nickel alloys, stainless steel or nickel-plated steel. These contact plates are preferably composed of the same material as the current collector to which they are welded.

The contact plates preferably each have at least one slot and/or at least one perforation. By means of the slits and/or perforations it is ensured that the contact plate does not warp during the welding process. It also ensures that: the contact plate does not impede the penetration of electrolyte into the coil or stack of electrode-separator composites.

In a preferred embodiment, the contact plates have the shape of a disk, in particular a circular disk or at least approximately the shape of a circular disk. These contact plates therefore have an outer disc edge or at least an approximate disc edge. In this case, a near circular disk is to be understood to mean, in particular, a disk having a circular shape with at least one separate circular arc segment, preferably with two to four separate circular arc segments.

In other preferred embodiments, the contact plates can also have the shape of a polygon, preferably a regular polygon, in particular a regular polygon having 4 to 10 corners and sides.

In particular in the embodiment as a lithium ion battery, the battery according to the invention is preferably designed as a cylindrical round battery. The battery then comprises a cylindrical housing in which the electrode-separator complex of the coil comprised by the battery is present. The height of the cylindrical round cell is greater than its diameter. These cylindrical round cells are particularly suitable for applications in the automotive sector, for electric bicycles or also for other applications where energy requirements are high.

The free area or the sub-areas may be completely or partially coated with a support material. In contrast, the flat side and thereby also the at least one edge separating the two partial regions from one another are preferably not coated with a support material.

The height of the lithium ion battery configured as a circular battery is preferably in the range of 15 mm to 150 mm. The diameter of the cylindrical circular cell is preferably in the range of 10 mm to 50 mm. Within these ranges, a shape factor of, for example, 18 x 65 (diameter by height in mm) or 21 x 70 (diameter by height in mm) is particularly preferred. Cylindrical round batteries with these form factors are particularly suitable for the power supply of electric drives of motor vehicles.

The nominal capacity of the lithium ion battery according to the invention, which is constructed as a cylindrical round battery, is preferably up to 6000 mAh. In the case of a form factor of 21 x 70, the battery in the embodiment as a lithium ion battery preferably has a nominal capacity in the range from 2000 mAh to 5000 mAh, particularly preferably in the range from 3000 to 4500 mAh.

In some embodiments, the battery according to the invention can also be a button cell, in particular a lithium-ion button cell, which has a metal housing consisting of two housing parts which are electrically insulated from one another by an electrically insulating seal, as shown, for example, in fig. 1 of DE 102009060800 a 1. In this case, the contact plate can be connected, for example, to a half-housing part with positive polarity. Button cells are cylindrical in shape and have a height that is smaller than their diameter. Preferably, the height is in the range of 4 mm to 15 mm. It is also preferred that: the diameter of the button cell is in the range of 5 mm to 25 mm. Button cells are suitable for supplying small electronic devices, such as watches, hearing aids and wireless headsets, with electrical energy.

The nominal capacity of the lithium ion battery according to the invention, which is designed as a button cell, is typically up to 1500 mAh. Preferably, the nominal capacity is in the range of 100 mAh to 1000 mAh, particularly preferably in the range of 100 to 800 mAh.

In the european union, manufacturer specifications of data on the nominal capacity of a secondary battery pack are strictly regulated. Thus, for example, data on the nominal capacity of a secondary nickel-cadmium battery is based on measurements according to the IEC/EN 61951-1 and IEC/EN 60622 standards, data on the nominal capacity of a secondary nickel-metal hydride battery is based on measurements according to the IEC/EN 61951-2 standard, data on the nominal capacity of a secondary lithium battery is based on measurements according to the IEC/EN 61960 standard, and data on the nominal capacity of a secondary lead acid battery is based on measurements according to the IEC/EN 61056-1 standard. Any data in this application regarding nominal capacity is preferably based on these criteria as well.

However, the battery according to the invention can also be part of a battery pack together with at least one other identical battery, wherein the battery is preferably connected in parallel or in series with the at least one other identical battery and the two batteries further preferably have a common housing and, if appropriate, also a common electrolyte.

The method according to the invention for producing the described electrochemical cell always comprises the following steps:

a. providing an anode comprising an anode current collector having a surface comprised of at least one metal loaded with at least one layer comprised of a negative electrode active material;

b. providing a cathode comprising a cathode current collector having a surface comprised of at least one metal loaded with at least one layer comprised of a positive electrode active material; and also

c. An electrode-separator composite is produced using the provided anode and the provided cathode, said electrode-separator composite having an anode, at least one separator and a cathode.

According to the present invention, before or after the electrode-separator composite is manufactured,

d. the vacant areas on the surface of the anode current collector that are not loaded with the negative electrode active material and/or the vacant areas on the surface of the cathode current collector that are not loaded with the positive electrode active material are coated with a support material that is more heat resistant than the surface coated with it.

The materials and cell components used in the method have already been described in the description of the cell according to the invention. Reference is made herein to these embodiments.

In a preferred embodiment, the method is characterized by one of the following additional features:

a. a support material is vapor deposited on the one or more vacant areas;

b. the support material is applied to the one or more vacant areas as a component of a suspension or paste;

c. the support material is obtained from a sol-gel process.

The best method for coating the current collector with the support material depends on the type of support material. Vapor deposition can be carried out, for example, by means of CVD or PVD methods (CVD = chemical vapor deposition), PVD = physical vapor deposition) or variants of these methods (for example by means of atomic layer deposition, ALD method). In PVD methods, the material to be deposited usually already exists as a vapor in the gas phase (the material is brought into the gas phase by physical methods), whereas in CVD methods compounds of the elements to be deposited (so-called precursors) are evaporated. These compounds decompose to the desired thin film material on the surface of the substrate. In PVD methods, the coating can be formed by evaporation, sputtering, ion plating and variants of these processes.

For example, alumina coatings can be produced based on organometallic aluminum compounds, such as trimethylaluminum, as precursors. In particular, coatings of the titanium carbonitride (TiCN) mentioned can also be produced by means of CVD methods. TiN coatings and Ti-AlN coatings can be produced by means of PVD. Corresponding methods are known from the literature.

Application of the suspension or paste can be effected by means of customary coating methods, such as spraying, dipping, printing and extrusion.

Furthermore, oxidic coatings such as alumina coatings can also be produced by sol-gel processes known from the literature. The alumina can be produced, for example, based on an aluminum alkyl such as aluminum tri-sec-butoxide or based on aluminum tri-isopropoxide.

In principle it is possible to: a support material is coated onto the current collectors, which are then loaded with electrode material. In this case, it is appropriate that: the areas of these current collectors that should be loaded with electrode active material in a subsequent step are masked. However, preferably, the support material is coated on the current collector that has been loaded with the electrode active material. In this case, only the mentioned free areas can be coated with a corresponding masking. However, for process reasons, it may be preferred that: not only the free areas but also the entire electrodes, i.e. also the layers consisting of electrode active material, are coated with the support material. In this case, no masking is required.

In some preferred embodiments, the support material is applied next to the wide first strips of the respective electrode material in the free areas, but does not completely cover these free areas here. Instead, the support material is coated in the form of a second strip or line along the longitudinal edges of the anode and/or cathode current collector, while at the same time the third strip or line of the respective free area is uncovered along the longitudinal edges. Particularly preferably, the second strip or the second thread separates the first strip of electrode material from the second strip or the second thread.

Drawings

Further features of the invention and advantages derived therefrom emerge from the figures and from the subsequent description of these figures. The embodiments described below are only for explanation and better understanding of the present invention and should not be construed as limiting in any way.

In fig. 1 and 5, an embodiment of an electrode-separator composite 101, which is designed as a spiral coil and can be processed to form a battery 100 according to the invention, is schematically illustrated in a top view obliquely above and in cross section. The coil has two end sides 103 and 109, of which only one, namely the end side 103, can be seen in fig. 1. The electrode-separator complex 101 includes a strip-shaped anode 115 and a strip-shaped cathode 118, which are separated from each other by strip-shaped separators 116 and 117.

Detailed Description

The two end sides 103 and 109 are formed by the longitudinal edges of the band-shaped diaphragms 116 and 117. Within the electrode-separator composite 100, the electrodes 115 and 118 are arranged offset from one another, so that the longitudinal edge of the anode 115 projects from one of the end sides and forms the projection 110, while the longitudinal edge of the cathode 118 projects from the opposite end side and forms the projection 102.

Fig. 6 is used to clarify the configuration of the coil shown in fig. 1 and 5. Here, a cross section through the anode 115 and the cathode 118 and one precursor each of the two electrodes 115 and 118 is shown. The precursors differ from the electrodes 115 and 118 only in that: the latter each have a coating of support material 119. Like the electrodes 115 and 118, these precursors include an anode current collector 115a and a cathode current collector 118 a. The anode current collector 115a is a copper foil. The cathode current collector 118a is an aluminum foil. These foils have two flat sides 115d, 115e and 118d, 118e, respectively, which are separated from one another by longitudinal edges 115f, 115g and 118f, 118g and are each loaded on both sides with a layer 115b of electrode active material; 118 b.

The surface of the anode current collector 115a and the surface of the cathode current collector 118a respectively include strip-shaped free areas 115 c; 118c, said free areas being not loaded with the respective electrode active material. These idle areas comprise two strip-like sub-areas on the two flat sides 115d, 115e of the anode current collector 115a and the two flat sides 118d, 118e of the cathode current collector 118a, respectively. In the case of the electrodes of the coil 101, these subregions are each coated with a layer of aluminum oxide as support material 119. The longitudinal edges 118f and 115g themselves are free of support material 119.

The free areas 115c and 118c are more stable with respect to mechanical and thermal loads due to the support material 119 coated on both sides. In addition, support material 119 electrically insulates regions 115c and 118 c.

Fig. 8 shows a top view of anode 115 shown in cross section in fig. 6.

In the case of the electrode-diaphragm composite 101 shown in fig. 1 and 5, which is designed as a coil, the longitudinal edges 115g of the anode current collector 115a project from the end face 109 together with the free region 115c coated with the support material 119. The longitudinal edge 118f of the cathode current collector 118a protrudes from the tip end side 103 together with the vacant region 118 c. Due to the helical winding of the electrode-membrane complex 101, the protruding longitudinal edges 115g and 118f likewise have a helical geometry.

In order to produce the battery 100 according to the invention, two contact plates 104 are placed flat on the end sides 103 and 109 of the coil. In fig. 3, the contact plate 104 is shown on the end side 103. Between the contact plate and the longitudinal edges 115g and 118f projecting from the end sides 103 and 109, a line-shaped contact area is obtained. These contact plates are connected to the longitudinal edges 115g and 118f along linear contact areas by welding. It is thereby possible to: the current collectors 115a and 118a are electrically contacted throughout their length.

Contact plate 104 is shown in fig. 2. These contact plates are configured to approximate a circular disk. Only approximately, since the disk edge 113 deviates from a perfect circular geometry in four points 113a to 113d, in each of which a flat circular segment is separated. The contact plate 104 has slits 105a, 105b, 105c, and 105 d. The four slots are oriented in the radial direction from the outer disk edge 113 toward the center of the contact plate. In the center of the contact plate, the contact plate 104 has a passage 114 in the form of a circular hole. Two other channels 120 and 121 are found on the right and left sides of the central bore 114. These channels may serve as a positioning aid when installing contact plate 104.

The results of the welding are shown in fig. 4 (top view obliquely above) and 7 (cross section). Contact plate 104 and longitudinal edge 118f are joined by weld 122. In this case, the contact plate has the same spiral course as the longitudinal edge 118 f. The weld seam 122 follows exactly the spiral course of the longitudinal edge 118 f. However, due to the slits 105a to 105d, the longitudinal edge 118f cannot be welded consistently with the contact plate 104 over its entire length. Instead, the longitudinal edge 118f, interrupted by the slits 105a to 105d, comprises a plurality of sections which are each continuously connected over their entire length to the contact plate 104 along the contact region by a weld seam 122.