阅读说明：本技术 一种电池及制备方法 (Battery and preparation method thereof ) 是由 王生旭 刘关心 陈杰 杨山 于子龙 于 2021-07-19 设计创作，主要内容包括：本发明属于电池的技术领域,具体涉及一种电池,包括第一极片(11)、第二极片(12)和用于隔离所述第一极片(11)和所述第二极片(12)的隔离膜(13),所述隔离膜(13)设置有袋状空间,所述第一极片(11)或所述第二极片(12)容纳于所述袋状空间。本发明通过隔离膜隔离第一极片和第二极片,避免极片因碰撞或跌落发生偏移,有助于提高电池的安全性。此外,本发明还公开了一种电池的制备方法。(The invention belongs to the technical field of batteries, and particularly relates to a battery which comprises a first pole piece (11), a second pole piece (12) and an isolating film (13) for isolating the first pole piece (11) from the second pole piece (12), wherein the isolating film (13) is provided with a bag-shaped space, and the first pole piece (11) or the second pole piece (12) is accommodated in the bag-shaped space. The first pole piece and the second pole piece are isolated by the isolating film, so that the pole pieces are prevented from deviating due to collision or falling, and the safety of the battery is improved. In addition, the invention also discloses a preparation method of the battery.)

1. A battery, comprising:

first pole piece (11), second pole piece (12) and be used for keeping apart first pole piece (11) with barrier film (13) of second pole piece (12), barrier film (13) are provided with pocket space, first pole piece (11) or second pole piece (12) hold in pocket space.

2. A battery as in claim 1, wherein: the size of the first pole piece (11) and the size of the second pole piece (12) are both smaller than the size of the isolation film (13), and the size of the second pole piece (12) is larger than the size of the first pole piece (11).

3. A battery as in claim 1, wherein: the isolation film (13) comprises a first sealing edge (131), a second sealing edge (132), a third sealing edge (133) and an opening edge (134), wherein the first sealing edge (131) and the second sealing edge (132) are arranged oppositely, and the third sealing edge (133) and the opening edge (134) are arranged oppositely.

4. A battery as in claim 3, wherein: the widths of the first sealing edge (131), the second sealing edge (132) and the third sealing edge (133) are 0.5-2 mm.

5. A battery as in claim 1, wherein: the isolation film (13) is located on the upper side and the lower side of the first pole piece (11), and the second pole piece (12) is located inside the isolation film (13).

6. A battery as in claim 1, wherein: the isolation film (13) is provided with an opening, and one side of the opening is bonded by hot pressing.

7. A battery as in claim 1, wherein: the distance between the second pole piece (12) and the first pole piece (11) in the length and width directions is 0.01-3 mm; the distance of the isolating film (13) exceeding the first pole piece (11) in the length and width directions is 0.6-3 mm.

8. A preparation method of a battery is characterized by comprising the following steps:

s1, preparing an isolating membrane (13);

s2, placing the second pole piece (12) in the isolation film (13), and carrying out hot pressing on the opening edge (134) to form a sealing edge;

s3, placing the first pole piece (11) on the outer side of the isolation film (13);

s4, placing an isolating film (13) on the outer side of the first pole piece (11);

and S5, repeating the steps S2 to S4 to finish the preparation of the battery.

9. The method of claim 8, wherein: in step S1, the separator (13) is formed by hot pressing.

10. The method of claim 8, wherein: in the step S2, the opening edge (134) is hot-pressed, including stripe hot-pressing or dot hot-pressing.

Technical Field

The invention belongs to the technical field of batteries, and particularly relates to a battery and a preparation method thereof.

Background

Nowadays, green, high-efficiency secondary batteries are vigorously developed in various countries. The lithium ion battery as a novel secondary battery has the advantages of large energy density and power density, high working voltage, light weight, small volume, long cycle life, good safety, environmental protection and the like, and has wide application prospect in the aspects of portable electric appliances, electric tools, large-scale energy storage, electric traffic power supplies and the like. The lithium ion battery has the advantages of large specific energy, high specific power, high voltage platform, small self-discharge, long cycle life, small environmental pollution, no memory effect and the like, so that the lithium ion battery is widely applied to the aspects of power, consumption and energy storage. Conventional lithium ion batteries are mostly in a wound structure or a laminated structure, and the laminated battery is more dominant in energy density than a wound cell.

At present, the conventional laminated battery usually adopts a mode that an anode sheet, a diaphragm and a cathode sheet are stacked in sequence, and Overhang is formed by utilizing the size difference between adjacent layers, so that the effect of design safety is achieved, however, under the condition, the electric core is easy to cause the deviation of the pole pieces due to the collision in the use process, so that the potential safety hazard is generated.

Disclosure of Invention

One of the objects of the present invention is: the battery is provided aiming at the defects of the prior art, the first pole piece and the second pole piece are isolated through the isolation film, the pole pieces are prevented from deviating due to collision or falling, and the safety of the battery is improved.

In order to achieve the purpose, the invention adopts the following technical scheme:

a battery comprises a first pole piece, a second pole piece and an isolation film for isolating the first pole piece and the second pole piece, wherein the isolation film is provided with a bag-shaped space, and the first pole piece or the second pole piece is accommodated in the bag-shaped space.

Preferably, the size of the first pole piece and the size of the second pole piece are both smaller than the size of the isolation film, and the size of the second pole piece is larger than the size of the first pole piece.

Preferably, the isolation film comprises a first sealing edge, a second sealing edge, a third sealing edge and an opening edge, wherein the first sealing edge and the second sealing edge are arranged oppositely, and the third sealing edge and the opening edge are arranged oppositely.

Preferably, the width of the first sealing edge, the width of the second sealing edge and the width of the third sealing edge are 0.5-2 mm.

Preferably, the isolation films are located on the upper side and the lower side of the first pole piece, and the second pole piece is located inside the isolation film.

Preferably, the separation film is provided with an opening, and one side of the opening is bonded by heat pressing.

Preferably, the distance between the second pole piece and the first pole piece in the length and width directions is 0.01-3 mm; the distance of the isolating film exceeding the first pole piece in the length and width directions is 0.6-3 mm.

The invention also aims to provide a preparation method of the battery, which comprises the following steps:

s1, preparing an isolating membrane;

s2, placing the second pole piece inside the isolation film, and carrying out hot pressing on the opening edge to form a sealing edge;

s3, placing the first pole piece on the outer side of the isolation film;

s4, placing an isolating film on the outer side of the first pole piece;

and S5, repeating the steps S2 to S4 to finish the preparation of the battery.

Preferably, in step S1, the isolation film is formed by hot pressing.

Preferably, in step S2, the open edge is hot-pressed, including a stripe hot-pressing or a dot hot-pressing.

The invention has the beneficial effects that the invention comprises a first pole piece, a second pole piece and an isolating film for isolating the first pole piece and the second pole piece, wherein the isolating film is provided with a bag-shaped space, and the first pole piece or the second pole piece is accommodated in the bag-shaped space. Because the cell is easy to cause the pole piece to shift due to the collision in the using process, thereby generating potential safety hazard, aiming at the laminated battery, the pole piece is easy to shift, the isolating film is internally provided with a bag-shaped space for accommodating the second pole piece or the first pole piece, the second pole piece or the first pole piece is ensured to be always fixed in the isolating film, the bag-shaped space of the second pole piece or the first pole piece is limited, the first pole piece and the second pole piece are not contacted due to the falling or collision and other mechanical factors, the safety performance of the battery is improved, when the second pole piece is arranged in the isolating film, namely in the bag-shaped space, the first pole piece is arranged at the outer side of the bag-shaped space in the isolating film, or when the first pole piece is arranged in the isolating film, the second pole piece is arranged at the outer side of the bag-shaped space in the isolating film, the first pole piece and the second pole piece are mutually insulated through the isolating film, reduce the probability that first pole piece and second pole piece take place the contact, help improving the security of battery, wherein, the barrier film seals the barrier film through the heat-seal after putting into the second pole piece, guarantees that the second pole piece can not be because of the collision, falls etc. mechanical action and takes place the skew to avoid second pole piece and first pole piece contact, help improving battery security performance has been guaranteed. The first pole piece and the second pole piece are isolated by the isolating film, so that the pole pieces are prevented from deviating due to collision or falling, and the safety of the battery is improved.

Drawings

Features, advantages and technical effects of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings.

Fig. 1 is a schematic structural diagram of a battery cell according to the present invention.

Fig. 2 is a schematic structural diagram of the isolation film of the present invention.

FIG. 3 is a schematic view of a hot-pressing process for a separator strip according to the present invention.

FIG. 4 is a schematic diagram of a dot-like hot pressing of the separator of the present invention.

Wherein the reference numerals are as follows:

1-electric core;

11-a first pole piece;

12-a second pole piece;

13-a barrier film; 131-a first sealing edge; 132-a second sealing edge; 133-a third sealing edge; 134-open edge; 135-fourth sealing edge.

Detailed Description

As used in the specification and in the claims, certain terms are used to refer to particular components. As one skilled in the art will appreciate, manufacturers may refer to a component by different names. This specification and claims do not intend to distinguish between components that differ in name but not function. In the following description and in the claims, the terms "include" and "comprise" are used in an open-ended fashion, and thus should be interpreted to mean "include, but not limited to. "substantially" means within an acceptable error range, and a person skilled in the art can solve the technical problem within a certain error range to substantially achieve the technical effect.

Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

The present invention will be described in further detail with reference to fig. 1 to 4, but the present invention is not limited thereto.

Implementation mode one

The battery comprises a first pole piece 11, a second pole piece 12 and a separation film 13 for separating the first pole piece 11 from the second pole piece 12, wherein the separation film 13 is provided with a bag-shaped space, and the first pole piece 11 or the second pole piece 12 is accommodated in the bag-shaped space.

Because the cell 1 is easy to cause pole piece deviation due to collision in the using process, thereby generating potential safety hazard, aiming at the laminated battery, the pole piece deviation is easy to generate, a bag-shaped space for accommodating the second pole piece 12 or the first pole piece 11 is arranged in the isolating membrane 13, the second pole piece 12 or the first pole piece 11 is ensured to be always fixed in the isolating membrane 13, the bag-shaped space limitation on the second pole piece 12 or the first pole piece 11 is realized, the first pole piece 11 and the second pole piece 12 are not contacted due to mechanical factors such as falling or collision, the safety performance of the battery is improved, when the second pole piece 12 is arranged in the isolating membrane 13, namely in the bag-shaped space, the first pole piece 11 is arranged at the outer side of the bag-shaped space in the isolating membrane 13, or when the first pole piece 11 is arranged in the isolating membrane 13, the second pole piece 12 is arranged at the outer side of the bag-shaped space in the isolating membrane 13, the first pole piece 11 and the second pole piece 12 are mutually insulated through the isolating membrane 13, reduce the probability that first pole piece 11 and second pole piece 12 take place the contact, help improving the security of battery, wherein, barrier film 13 seals barrier film 13 through the heat-seal after putting into second pole piece 12, guarantees that second pole piece 12 can not be because of the collision, falls mechanical action such as and takes place the skew to avoid second pole piece 12 and first pole piece 11 contact, help improving battery security performance.

Specifically, the first pole piece 11 is a cathode piece, and the second pole piece 12 is an anode piece, but the invention is not limited thereto, and the first pole piece 11 may also be an anode piece, and correspondingly, the second pole piece 12 is a cathode piece.

In the battery according to the present invention, the first and second pole pieces 11 and 12 each have a size smaller than that of the separator 13, and the second pole piece 12 has a size larger than that of the first pole piece 11. Specifically, Overhang is formed through the size difference between adjacent layers, which is beneficial to improving the safety of the battery, the width and the length of the second pole piece 12 are greater than those of the first pole piece 11, the probability of contact between the first pole piece 11 and the second pole piece 12 is reduced, the length and the width of the isolation film 13 are greater than those of the first pole piece 11 and the second pole piece 12, the first pole piece 11 or the second pole piece 12 is limited in the isolation film 13, the probability of contact between the first pole piece 11 and the second pole piece 12 is also beneficial to reducing, and the safety of the battery is improved.

In the battery according to the present invention, the separation film 13 includes a first sealing edge 131, a second sealing edge 132, a third sealing edge 133, and an opening edge 134, the first sealing edge 131 and the second sealing edge 132 being disposed opposite to each other, and the third sealing edge 133 and the opening edge 134 being disposed opposite to each other. In this embodiment, the first pole piece 11 or the second pole piece 12 is placed inside the isolation film 13 from the opening edge 134, and the first sealing edge 131, the second sealing edge 132, and the third sealing edge 133 function to block the first pole piece 11 or the second pole piece 12, that is, the first pole piece 11 or the second pole piece 12 is limited in the isolation film 13, specifically, the two diaphragms are overlapped together, and three sides thereof are hot-pressed to form the first sealing edge 131, the second sealing edge 132, and the third sealing edge 133, and the first sealing edge 131 and the second sealing edge 132 are oppositely arranged, and the third sealing edge 133 and the opening edge 134 are oppositely arranged to ensure that the first pole piece 11 or the second pole piece 12 can be placed in the isolation film 13, and after the pole pieces are placed, the opening edge 134 is hot-pressed to form the fourth sealing edge 135, thereby isolating the first pole piece 11 from the second pole piece 12.

In the battery according to the present invention, the first sealing edge 131, the second sealing edge 132, and the third sealing edge 133 have a width of 0.5 to 2 mm. The width of the sealing edge is limited, so that the influence on the normal placement of the first pole piece 11 or the second pole piece 12 into the isolation film 13 due to the overlarge width of the sealing edge is prevented, and the situation that the bag-shaped space inside the isolation film 13 is small and the utilization rate of the bag-shaped space inside the isolation film 13 is not improved is avoided; meanwhile, the edge sealing cost of the isolation film 13 is also prevented from increasing.

The working principle of the invention is as follows:

aiming at the laminated battery, pole piece deviation is easy to occur, a bag-shaped space for accommodating the second pole piece 12 or the first pole piece 11 is arranged in the isolating membrane 13, so that the second pole piece 12 or the first pole piece 11 is always fixed in the isolating membrane 13, the bag-shaped space of the second pole piece 12 or the first pole piece 11 is limited, the first pole piece 11 and the second pole piece 12 are not contacted due to falling or collision and other mechanical factors, the safety performance of the battery is improved, when the second pole piece 12 is arranged in the isolating membrane 13, namely in the bag-shaped space, the first pole piece 11 is arranged on the outer side of the bag-shaped space in the isolating membrane 13, or when the first pole piece 11 is arranged in the isolating membrane 13, the second pole piece 12 is arranged on the outer side of the bag-shaped space in the isolating membrane 13, the first pole piece 11 and the second pole piece 12 are mutually insulated through the isolating membrane 13, and the probability of contact between the first pole piece 11 and the second pole piece 12 is reduced, the safety of the battery is improved, wherein the isolation film 13 is sealed through heat sealing after the second pole piece 12 is placed in the isolation film 13, and the second pole piece 12 is prevented from being deviated due to collision, falling and other mechanical actions, so that the second pole piece 12 is prevented from contacting with the first pole piece 11, and the safety performance of the battery is improved.

Second embodiment

The difference from the first embodiment is that: the separators 13 of the present embodiment are located at both upper and lower sides of the first pole piece 11, the second pole piece 12 is located inside the separator 13, the separator 13 is provided with an opening, and one side of the opening is bonded by hot pressing. The isolation film 13 plays an insulating role, so that insulation between the second pole piece 12 and the first pole piece 11 is ensured, and the probability of short circuit caused by contact between the second pole piece 12 and the first pole piece 11 is reduced. The opening is added, so that the second pole piece 12 or the first pole piece 11 can be conveniently placed in the isolating membrane 13, one side of the opening is bonded by hot pressing, the process is simple, and the production cost of the battery is reduced.

Other structures are the same as those of the first embodiment, and are not described herein again.

Third embodiment

The difference from the first embodiment is that: the distance between the second pole piece 12 and the first pole piece 11 in the length and width directions is 0.01-3 mm; the distance of the isolation film 13 exceeding the first pole piece 11 in the length and width directions is 0.6-3 mm. In this embodiment, according to actual production requirements, the distance that the second pole piece 12 exceeds the first pole piece 11 in the length and width directions can be limited, that is, Overhang is formed, which is beneficial to improving the safety of the battery, and the distance that the isolation film 13 exceeds the first pole piece 11 in the length and width directions is limited, so that the probability that the second pole piece 12 and the first pole piece 11 are in contact is reduced, which is beneficial to improving the safety of the battery.

Other structures are the same as those of the first embodiment, and are not described herein again.

Comparative embodiment

The difference from the first embodiment is that: the separator of the present embodiment does not have the separator 13, and adopts a manner in which the second pole piece 12, the separator, and the first pole piece 11 are stacked in this order.

Other structures are the same as those of the first embodiment, and are not described herein again.

The obtained 3 kinds of batteries of the example mode were subjected to safety tests of roller and drop, 5 batteries were tested for each test, and if no smoke, fire and explosion phenomena occurred, the test was passed, and the structure is shown in table 1;

TABLE 1

Serial number	Example mode one	Example mode two	Comparative embodiment
				Passing rate of the roller	5/5	5/5	1/5
Rate of passage of fall	5/5	5/5	0/5

It can be seen that, by using the method of the present invention, the safety of the battery is improved, the roller and the drop safety test can both pass, and the pass rates of the embodiment 1 and the example embodiment are both higher than those of the comparative embodiment, and it can be seen that, by adding the isolation film 13, the second pole piece 12 or the first pole piece 11 is limited in the bag-shaped space inside the isolation film 13, so that the first pole piece 11 or the second pole piece 12 is ensured to be always fixed in the isolation film 13, and the first pole piece 11 and the second pole piece 12 are not contacted due to mechanical factors such as drop or collision, which is helpful for improving the safety performance of the battery.

Method for preparing battery

The preparation method of the battery comprises the following steps:

s1, preparing an isolating membrane 13;

s2, placing the second pole piece 12 in the isolation film 13, and carrying out hot pressing on the opening edge 134 to form a sealing edge;

s3, placing the first pole piece 11 on the outer side of the isolation film 13;

s4, placing the isolation film 13 on the outer side of the first pole piece 11;

and S5, repeating the steps S2 to S4 to finish the preparation of the battery.

It should be noted that: in step S6, a plurality of stacked cores of one embodiment are stacked to form a laminated battery

Preferably, in step S1, the separation film 13 is formed by hot pressing. Specifically, two planar diaphragms are overlapped together, three sides of the two planar diaphragms are hot-pressed to form a first sealing edge 131, a second sealing edge 132 and a third sealing edge 133, the first sealing edge 131 and the second sealing edge 132 are oppositely arranged, the third sealing edge 133 and an opening edge 134 are oppositely arranged, it is ensured that the first pole piece 11 or the second pole piece 12 can be placed into the isolation film 13, after the pole pieces are placed into the isolation film, the opening edge 134 is hot-pressed to form a fourth sealing edge 135, and isolation of the first pole piece 11 and the second pole piece 12 is realized.

Preferably, as shown in fig. 3 and 4, in step S2, the opening edge 134 is hot pressed, including stripe hot pressing or dot hot pressing. According to actual production and cost requirements, the opening edge 134 can be hot pressed by using a strip hot press or a spot hot press.

Variations and modifications to the above-described embodiments may also occur to those skilled in the art, which fall within the scope of the invention as disclosed and taught herein. Therefore, the present invention is not limited to the above-mentioned embodiments, and any obvious improvement, replacement or modification made by those skilled in the art based on the present invention is within the protection scope of the present invention. Furthermore, although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.