阅读说明：本技术 一种极柱密封模块及包含其的电池顶盖 (Utmost point post seals module and contains its battery top cap ) 是由 谭勇刚 郭铁男 郭铁龙 徐广林 于 2021-02-07 设计创作，主要内容包括：本发明提供一种极柱密封模块及包含其的电池顶盖。本发明采用具有凹凸结构的金属塑料粘结剂/纳米氧化物复合膜层作为密封结合层,密封结合层协同纳米注塑件将极柱和扣环紧密配合得到极柱密封模块,气密性测试氦气泄漏率小于10～(-8)(Pa·m～3)/s。本发明提供的极柱密封模块将难以解决的极柱与电池顶盖的密封问题集中于模块化处理,提高了电池顶盖的生产效率和成品率。(The invention provides a pole sealing module and a battery top cover comprising the same. The invention adopts the metal plastic binder/nano oxide composite film layer with the concave-convex structure as the sealing combination layer, the sealing combination layer cooperates with the nano injection molding piece to tightly match the pole with the retaining ring to obtain the pole sealing module, and the helium leakage rate is less than 10 in the air tightness test ‑8 (Pa·m 3 ) And s. The pole sealing module provided by the invention concentrates the sealing problem of the pole and the battery top cover which is difficult to solve on modularization treatment, and improves the production efficiency and the yield of the battery top cover.)

1. A pole seal module, comprising: the composite electrode comprises a pole, a retaining ring and a nano injection molding piece, wherein sealing bonding layers are arranged on the surfaces of the pole and the retaining ring, and the sealing bonding layers are organic binder/nano oxide composite film layers; the nano injection molded part at least comprises a first injection molded part molded between the buckle ring sealing combination layer and the pole post sealing combination layer.

2. The pole sealing module according to claim 1, wherein the organic adhesive is a metal plastic adhesive, the sealing bonding layer has a concave-convex structure, and the sealing bonding layer hermetically connects the pole, the snap ring and the nano injection molded part through a bonding effect of a chemical bond and an anchoring effect of the concave-convex structure.

3. A pole sealing module according to claim 1, wherein the organic binder/nano-oxide composite film layer is a stacked structure or a hybrid cross-linked structure.

4. The pole-sealing module of claim 1, wherein the pole-sealing module has a leak rate of less than 10 for air tightness test^-8(Pa·m³)/s。

5. A pole sealing module according to claim 2, wherein the pits in the relief structure have an average pore size of 5-50 nm and a depth of 10-500 nm.

6. A pole sealing module according to claim 2, wherein the ratio of the diameter to the depth of the pit structure in the relief structure is 1:1 to 1: 10.

7. A pole sealing module as claimed in claim 1, wherein the pole comprises a waist provided with one or more projections, indentations or holes.

8. The pole seal module of claim 1, wherein the snap ring is a hollow structure with an upper edge and a lower edge both converging inwardly, the upper edge being provided with one or more protrusions, indentations or holes.

9. The pole sealing module according to claim 7 or 8, wherein the waist of the pole is provided with a protrusion, the upper edge of the snap ring is provided with a notch or a hole, and the protrusions and the notches or holes are arranged in a one-to-one correspondence; or the waist of the pole is provided with a notch or a hole, the upper edge of the retaining ring is provided with a protruding part, and the notch or the hole is in one-to-one correspondence with the protruding part.

10. A battery top cap comprising a top cover sheet and a post sealing module according to any one of claims 1 to 9, wherein the top cover sheet is provided with an assembling portion for mounting the post sealing module.

Technical Field

The invention relates to the field of batteries, in particular to a pole sealing module and a battery top cover comprising the same.

Background

With the increasing popularization of new energy electric vehicles, the safety and durability of lithium ion batteries become the concern of the public. The lithium ion battery needs to complete the charging and discharging process in an anhydrous and oxygen-free environment, so the sealing and packaging requirements of the top cover of the lithium ion battery are high.

Even if only a small amount of moisture permeates into the power battery through the sealing parts of the electrodes and the top cover, water vapor is formed inside the battery unit, and further, the water vapor and lithium ions undergo violent chemical reaction, so that the performance of the battery is influenced. At the same time, the entry of moisture may change the chemical composition of the battery (e.g., the generation of hydrofluoric acid, etc.), resulting in capacity loss, increased impedance and ultimately a shortened life span of the battery, and reduced safety. The existing widely used sealing packaging technology is sealed by a rubber sealing ring, but the sealing ring has the thermal expansion coefficient far larger than that of a battery shell made of an aluminum alloy material, so that the battery shell cannot ensure effective sealing performance along with long-term cold and hot change of external temperature, and further has the defects of electrolyte leakage, battery performance reduction and the like.

Secondly, a process of integrally packaging by adopting a nano injection molding process is adopted, a sealing ring is omitted, but the air tightness is generally 10 DEG^-5～10^-7The magnitude order, and all adopt top cap and utmost point post to carry out nanometer simultaneously and handle, not only cause the very big waste of nanometer processing liquid medicine, unnecessary nanometer handles still can make the local weatherability that the top cap need not sealed worsen and the yield is not high.

Therefore, a battery top cover with good air tightness, high production efficiency and high yield is urgently needed.

Disclosure of Invention

The present invention provides a pole sealing module, comprising: the composite electrode comprises a pole, a retaining ring and a nano injection molding piece, wherein sealing bonding layers are arranged on the surfaces of the pole and the retaining ring, and the sealing bonding layers are organic binder/nano oxide composite film layers; the nano injection molded part at least comprises a first injection molded part molded between the buckle ring sealing combination layer and the pole post sealing combination layer.

Preferably, the organic binder is a metal plastic binder.

Preferably, the metal plastic binder is an acidic or a meta-acidic organic binder having covalent bonds of at least one of-O-, -S-, -N-.

More preferably, the metal plastic binder further has a basic group such as an amino group or an amine group.

Preferably, the metal plastic binder comprises trithiocyanuric acid and derivatives thereof.

Preferably, the sealing and bonding layer has a concave-convex structure, and the pole, the snap ring and the nano injection molding part are hermetically connected through the bonding effect of a chemical bond and the anchoring effect of the concave-convex structure.

Preferably, the pole and the retaining ring are made of metal.

Preferably, the material of the retaining ring is pure aluminum or aluminum alloy.

Preferably, the pole comprises a positive pole and a negative pole.

Preferably, the positive pole is made of pure aluminum or aluminum alloy.

More preferably, the aluminum alloy is a 1-series aluminum alloy or a 3-series aluminum alloy. Wherein, the 1 series aluminum alloy is high-purity aluminum alloy containing more than 99.00 percent of aluminum, and has good conductivity, corrosion resistance and welding performance; the 3-series aluminum alloy is an aluminum alloy taking manganese as a main alloy element, has excellent corrosion resistance and welding performance, and has good plasticity. The linear expansion coefficient alpha of the aluminum is 23.8 multiplied by 10 within the range of 0-100 DEG C^-6/℃。

Preferably, the material of the negative pole column is pure copper or a copper-aluminum composite plate. The linear expansion coefficient alpha of pure copper and copper-aluminum alloy is 17-18 multiplied by 10 within the range of 20-100 DEG C^-6/℃。

The copper-aluminum composite board is a composite material with a layer of copper coated on the surface of an aluminum plate. The production method of copper-aluminium composite plate mainly includes rolling composite method, explosion composite method, die-casting composite method and casting-pressing method.

The copper-aluminum composite board has the advantages of small thermal resistance, good heat dissipation, easy machining, good electromagnetic shielding property, flat board, stable size, good rigidity and the like; the copper-aluminum composite plate is used as the pole material, and has the advantages of stable conductivity, low electric energy loss, long service life and low price.

Preferably, the leakage rate of the pole sealing module in the air tightness test is less than 10^-8(Pa·m³)/s。

More preferably, the leakage rate of the pole sealing module in the air tightness test is less than 10^-9(Pa·m³)/s。

Preferably, the seal bonding layer is formed in situ on the surface of the pole or the snap ring.

Preferably, the metal plastic adhesive/nano oxide composite film layer is a metal plastic adhesive layer/nano oxide layer laminated structure. The metal plastic adhesive layer/nano oxide layer laminated structure is called 'laminated structure' for short.

Preferably, the metal plastic binder/nano-oxide composite film layer is a nano-oxide hybrid cross-linked structure doped with the metal plastic binder. The nanometer oxide hybrid cross-linked structure mixed with the metal plastic binder is called hybrid cross-linked structure for short.

In the hybrid cross-linked structure, the metal plastic binder and the nano oxide are subjected to staggered cross-linking in the deposition film-forming process, are mutually embedded into film layer structures, form a compact organic/inorganic hybrid film layer structure through covalent bonds or metal salts, have complementary advantages, have hardness and toughness, and form a uniform and compact hybrid cross-linked film layer with small linear expansion coefficient. The nanometer oxide in the sealing combination layer has plastic resin compatibility, and the raw material of the nanometer injection molding piece is induced to be evenly injected to the surface of the sealing combination layer, so that good air seal is formed.

The metal plastic binder layer and the nano oxide layer in the laminated structure are respectively formed by deposition, and the best deposition process parameters can be set according to the material types, so that the compactness, uniformity and concave-convex degree of a single film layer are best controlled, but the interface of the metal plastic binder layer and the nano oxide layer can be generated, the interface adhesive force is slightly poor compared with that of a hybrid cross-linked structure, but the influence on the air tightness is small.

Preferably, a first sealing combination layer is arranged between the positive pole and the nano injection molding piece, a second sealing combination layer is arranged between the negative pole and the nano injection molding piece, a third sealing combination layer is arranged between the retaining ring and the nano injection molding piece, and the first sealing combination layer, the second sealing combination layer and the third sealing combination layer are all in a hybrid cross-linked structure or a laminated structure.

Preferably, at least one of the first, second, and third sealing and bonding layers is a hybrid cross-linked structure.

Preferably, the first sealing bonding layer and the third sealing bonding layer are of a metal plastic adhesive/nano-alumina hybrid cross-linked structure, and the second sealing bonding layer is of a metal plastic adhesive layer/nano-alumina layer laminated structure.

Preferably, the hybrid cross-linked structure is formed by a chemical passivation process or an anodic oxidation/electrolytic polymerization process.

More preferably, the sealing and bonding layer of the hybrid cross-linked structure on the surfaces of the positive post and the retaining ring is prepared by an anodic oxidation/electrolytic polymerization process.

Preferably, the sealing bonding layer of the hybrid cross-linked structure on the surface of the negative pole column is formed by a chemical passivation process or an anodic oxidation/electrolytic polymerization process.

The chemical passivation is to soak the metal to be treated in a passivation liquid medicine to generate a compact sealing bonding layer with good coverage and firmly adsorbed on the metal surface on the surface. The anodic oxidation/electrolytic polymerization process refers to a treatment process for synchronously carrying out anodic oxidation and electrolytic polymerization, and is characterized in that a metal to be treated is used as an anode, a metal plastic binder is added into electrolyte, and an electric field is applied to generate a uniform and compact sealing bonding layer on the surface of the metal.

In other preferred embodiments, the sealing and bonding layer between the positive post and the surface of the retaining ring is a laminated structure.

Preferably, the laminated structure is formed by depositing a metal plastic adhesive layer and a nano oxide layer respectively.

Preferably, the deposition process is one of impregnation, passivation, anodic oxidation or electrolytic polymerization.

Preferably, the metal plastic adhesive layer in the laminated structure is formed by a dipping process or an electrolytic polymerization process.

Preferably, the nano-oxide layer in the stacked structure is formed by a chemical passivation process or an anodic oxidation process.

Preferably, the nano oxide on the surfaces of the positive pole and the retaining ring is aluminum oxide (Al)₂O₃)。

Preferably, the nano-oxide components in the sealing and bonding layer of the copper plate part in the pure copper negative pole column or the copper-aluminum composite plate negative pole column are copper oxide (CuO) and cuprous oxide (Cu)₂O)。

Preferably, the cuprous oxide (Cu)₂O) accounts for 20 to 80 percent of the molar ratio of the nano copper oxide component.

The sealing and bonding layer of the copper pole is mainly formed by cuprous oxide (Cu)₂O) and the nano injection plastic form chemical bond or acid-base bond, so that cuprous oxide (Cu)₂O) is beneficial to improving the adhesive force of the metal-plastic interface; but cuprous oxide (Cu)₂Too high O) content may result in insufficient formation of a uniform uneven structure.

The sealing and bonding layer is formed on the surface of the pole or the snap ring in situ, so that the bonding strength between the sealing and bonding layer and the metal of the pole or the snap ring body is very strong. The sealing bonding layer with a specific concave-convex structure can be formed on the surface of the pole or the retaining ring by controlling the pretreatment process of the sealing bonding layer formation and the process parameters in the passivation or anodic oxidation/electrolytic polymerization process. The metal plastic adhesive in the invention belongs to an adhesive for promoting the combination of metal and resin, but the metal plastic adhesive is used for connecting metal and resin, so that the high standard requirement of power battery sealing cannot be met, and the metal plastic adhesive/nano oxide hybrid film layer can enhance the combination sealing property between metal and nano injection molding. Because the metal can form a metal salt or metal complex with the metal plastic binder in the seal bond layer; in addition, covalent bonds or acid-base bonds can be formed between the metal plastic adhesive and the terminal functional groups of the thermoplastic resin forming the nano injection molding; the existence of the metal plastic binder can promote the raw materials of the nano injection molding piece to fully enter the concave-convex structure of the sealing and combining layer for polymerization, so that the anchoring and combining of the nano injection molding piece and the metal surface of the pole or the retaining ring are formed, the interface porosity is reduced, the interface is not only simple physical combination, but also more covalent bond combination, so the interface stability is high, and the encapsulation air tightness can reach higher level.

Preferably, the average pore diameter of the pits in the concave-convex structure is 5-50 nanometers, and the depth of the pits is 10-500 nanometers.

Preferably, the ratio of the diameter to the depth of the pit structure in the concave-convex structure is 2: 1-1: 10.

More preferably, the ratio of the diameter to the depth of the pit structure in the concave-convex structure is 1:1 to 1: 6.

The "diameter" in the diameter-depth ratio refers to the diameter of the inscribed circle of the pit structure, and the "depth" refers to the depth of the pit structure. The concave-convex structure is favorable for forming anchoring connection between the nano injection molding piece and the pole or the retaining ring, and the connection strength is enhanced. For pits that are not regular in shape, the "diameter" in the diameter-depth ratio refers to the average inscribed circle diameter.

If the diameter-depth ratio of the concave-convex structure of the sealing and bonding layer is too small, raw materials of the nano injection molding piece are difficult to permeate into the bottom of the concave pit, so that a gap exists in the sealing and bonding layer, a compact structure cannot be formed, and the air tightness is reduced; if the diameter-depth ratio of the concave-convex structure is too large, the anchoring connection effect is poor. Because the pit forms a capillary structure under the condition of small diameter-depth ratio, injection molding glue of the nano injection molding piece is difficult to enter the bottom of the capillary due to surface tension and wetting capacity, so that the gap cannot be completely filled, and a compact structure cannot be formed.

More preferably, the average pore diameter of the concave pits in the concave-convex structure of the sealing and bonding layer on the surface of the retaining ring is 10-50 nanometers, and the depth of the concave pits is 10-500 nanometers.

Preferably, the thickness of the sealing and bonding layer is 5-600 nanometers.

More preferably, the thickness of the sealing and bonding layer on the surface of the retaining ring is 80-500 nm.

More preferably, the thickness of the sealing and bonding layer on the surface of the positive pole is 80-500 nanometers.

More preferably, the thickness of the sealing bonding layer on the surface of the negative pole column is 5-100 nanometers.

The thickness of the sealing bonding layer is set within a reasonable range, so that the bonding strength of a metal-plastic interface can be ensured; the pit diameter depth ratio of the concave-convex structure in the sealing combination layer is set in a reasonable range, so that the full embedding of nano injection molding raw materials is facilitated, the embedding molding of the nano injection molding part is more comprehensive and compact due to the existence of the metal plastic binder, and the leakage rate of the air tightness test of the packaging module of the pole and the retaining ring is smaller than 10^-9A rank.

Preferably, the raw material of the nano injection molding part is a material with a linear expansion coefficient of 20-100 multiplied by 10^-6Resin at/° c.

Preferably, the material of the nano injection molding is an electric insulating material. The on-resistance of the pole and the snap ring in the anode sealing module after nano injection molding is required to be 100-10000 ohms, and the pole and the snap ring in the cathode sealing module are insulated under the conditions of 800V voltage and 20mA current.

Preferably, the material of the nano injection molding is one of polyphenylene sulfide (PPS) and polybutylene terephthalate (PBT).

Wherein the structural formula of the polyphenylene sulfide (PPS) is as follows:

PPS is a high polymer with a thiophenyl group on a molecular main chain, and because the structure of the PPS is that benzene rings and sulfur are alternately connected, molecular chains have high rigidity and regularity, the PPS is a crystalline polymer, has small molding shrinkage and has a plurality of excellent properties such as heat resistance, rigidity, flame retardance and electrical insulation. The lone pair electrons on the sulfur atom ensure that the PPS and the metal have good affinity, and the PPS and the metal can be easily prepared into various reinforced compounds and alloy materials. The linear expansion coefficient alpha of the polyphenylene sulfide PPS is 50 multiplied by 10 within the range of 23-100 DEG C^-6/℃。

The polybutylene terephthalate (PBT) has the structural formula:

the PBT has extremely low water absorption, can maintain excellent electrical property when used for a long time in a wide temperature and humidity range, has very small dimensional change in the using process, and has excellent performance in the aspects of molding stability and dimensional precision; linear expansion coefficient alpha of 60 x 10^-6/℃。

The metal and the plastic belong to different material types, and the air tightness of the connection interface of the metal and the plastic is related to the physical combination or the chemical bond combination of the interface and the thermal stress of the interface; the linear expansion coefficients of general plastics and metals are greatly different, so that the interfaces of the general plastics and the metals can generate large thermal stress after being heated, the interfaces are delaminated and failed, and finally gas leaks along the delamination gaps; the linear expansion coefficients of PPS resin and PBT resin used by the nano injection molding part are basically in an order of magnitude with the linear expansion coefficient of metal, the difference is not large, the dimensional stability of the nano injection molding part is excellent, so that the thermal stress of the interface between the pole or the retaining ring and the nano injection molding part is relatively small, the possibility of thermal stress delamination failure is reduced, and the airtight stability of the sealing part is good.

Preferably, the nano-injection molded part further comprises a second injection molded part overmolded on the upper edge of the retaining ring.

Preferably, the first injection-molded part and the second injection-molded part are integrally injection-molded.

Preferably, the nano injection molding piece between the positive pole and the retaining ring and the nano injection molding piece between the negative pole and the retaining ring are made of resin raw materials added with different pigments. The plastic package of the positive pole column and the negative pole column adopts different colors, which is beneficial to sorting and identification.

The metal plastic binder has an acid group, some metal plastic binders contain basic groups such as amino or amino, polyphenylene sulfide (PPS) is basic, and polybutylene terephthalate (PBT) contains carboxyl and hydroxyl, so that the metal plastic binders, PPS resin and PBT resin can be subjected to polymerization reaction to form a covalent bond or acid-base combination; on the other hand, the PPS resin and the PBT resin both contain benzene rings, and the benzene rings are in a planar hexagonal structure, so that polymers generated by polymerization reactions among the PPS resins, between the metal plastic binder and the PPS resin, and between the metal plastic binder and the PBT resin can form a uniform and compact network structure more easily, and have low porosity and good air tightness.

The air tightness of the combination of the snap ring or the pole and the nano injection molding is not only related to the combination of materials and interfaces, but also the structural design of the joint is important for the stability of the air tightness.

Preferably, the pole comprises an upper part, a waist part and a lower part, wherein the waist part protrudes out of the upper part and the lower part to form a skirt.

Preferably, the negative pole column is made of a copper-aluminum composite plate in an integrated molding mode, wherein the upper portion is an aluminum plate, and the waist portion and the lower portion are copper plates.

Preferably, the negative pole column is made of copper-aluminum composite plates in an integrated molding mode, wherein an aluminum plate is arranged above the waist center line, and a copper plate is arranged below the waist center line.

Preferably, the upper part of the negative pole is made of pure aluminum or aluminum alloy, and the lower part of the negative pole is made of pure copper; the waist is made of pure copper or copper-aluminum composite plates.

More preferably, the copper plate and the aluminum plate in the copper-aluminum composite plate material of the waist portion respectively account for 1/2 of the total thickness of the waist portion, wherein the copper plate is partially adjacent to the lower portion.

Preferably, a notch or a hole is formed in the skirt edge of the waist of the pole.

Preferably, the waist skirt is provided with a protrusion.

Preferably, the protrusions, the notches or the holes are uniformly arranged at intervals. Thereby the area of contact that sets up that bellying, breach or hole can increase utmost point post and nanometer injection molding improves the cohesion, increases the torsion of utmost point post after moulding plastics simultaneously.

Preferably, the number of the protrusions, the notches or the holes is at least one.

More preferably, the number of the protrusions, indentations or holes is at least two.

More preferably, the number of the protrusions, the notches or the holes is even.

Preferably, the bottom surface of the lower part of the pole is provided with a positioning hole. The positioning holes can reduce the weight of a product and play a positioning role in the injection molding process.

Preferably, the retaining ring is a hollow structure with an upper edge and a lower edge both shrinking inwards.

The upper edge and the lower edge of the retaining ring both contract inwards, so that the pole sealing module is not easy to fall off under the action of forward and reverse thrust, the rigidity of the sealing module is improved, and the stability of the sealing structure is ensured.

Preferably, one or more protruding parts are arranged on the waist skirt of the pole; correspondingly, the upper edge of the retaining ring is provided with one or more notches, and the protruding parts correspond to the notches one to one.

More preferably, the notch and the protrusion are complementary in shape to form a snap-fit structure.

Since the protrusion and the notch are complementary, in other embodiments, the notch may be provided on the waist skirt of the pole, and the upper edge of the retaining ring is correspondingly provided with the protrusion.

Preferably, the hollow structure of the retaining ring comprises an upper opening and a lower opening, and the size of the upper opening is larger than that of the lower opening.

Preferably, the size of the outer edge of the waist part of the pole is larger than the size of the inner edge of the upper opening of the retaining ring and the size of the lower opening of the retaining ring. The structure can ensure that the pole does not fall off from the retaining ring under the action of forward thrust and reverse thrust of the pole sealing module.

More preferably, the upper edge of the retaining ring is provided with a notch or a hole.

In other preferred embodiments, the retaining ring has a raised portion on an upper edge thereof.

Preferably, a notch or a hole is formed in the side wall of the retaining ring.

The arrangement of the notch, the hole and the protruding part can increase the contact area of the retaining ring and the nano injection molding part, so that the binding force is improved, and meanwhile, the torsion of the retaining ring after injection molding is increased.

Preferably, the circumference of the pole sealing module is circular, rectangular, parallelogram or any other geometric shape.

Preferably, a clearance groove is formed between the lower part of the pole and the lower opening of the retaining ring in the pole sealing module.

Preferably, the lower part of the pole in the pole sealing module protrudes out of the lower edge of the retaining ring.

The invention also provides a preparation method of the pole sealing module, which comprises the following steps:

(1) carrying out surface treatment on the snap ring and the pole;

(2) passivating or anodizing/electropolymerizing the surface-treated snap ring or polar column to form a sealing bonding layer with a concave-convex structure;

(3) and (3) respectively fixing the snap ring and the pole obtained in the step (2) by using a mold, and directly injecting resin between the snap ring and the pole and on the upper surface of the snap ring to form a nano injection molding part, so that the pole sealing module with an integrated structure is obtained.

Preferably, the positive post and the retaining ring in step (2) are treated by anodic oxidation/electrolytic polymerization.

Preferably, the negative pole column in the step (2) adopts chemical passivation treatment or anodic oxidation/electrolytic polymerization treatment.

Preferably, the retaining ring is a hollow structure with an upper edge and a lower edge both shrinking inwards.

Preferably, the pole comprises an upper part, a waist part and a lower part, wherein the waist part protrudes out of the upper part and the lower part to form a skirt.

Preferably, one or more protruding parts are arranged on the waist skirt of the pole; correspondingly, the upper edge of the retaining ring is provided with one or more notches, and the protruding parts correspond to the notches one to one.

Preferably, the step (3) further comprises:

(3i) aligning the protruding part of the pole to the position of the notch of the retaining ring, so that the pole smoothly enters the hollow structure of the retaining ring;

(3ii) rotating the pole such that the projection and the notch are in a misaligned overlapping or fully overlapping position, and holding the grommet and the pole in that position by a mold.

The invention also provides a battery top cover comprising the pole sealing module, which comprises a top cover plate and the pole sealing module, wherein the top cover plate is provided with an assembling part for installing the pole sealing module.

Preferably, the mounting portion includes a positive electrode mounting portion and a negative electrode mounting portion. The positive assembling part is used for installing a positive sealing module, and the negative assembling part is used for installing a negative sealing module.

Preferably, the assembling portion is an assembling hole, and the shape of an inner hole of the assembling hole is consistent with the peripheral shape of the lower edge of the retaining ring.

Preferably, the size of the inner hole of the assembly hole is consistent with the peripheral size of the lower edge of the retaining ring.

Preferably, the size of the inner hole of the assembling hole is slightly smaller than the peripheral size of the lower edge of the retaining ring. The term slightly smaller means that the size difference is within 10%.

In other preferred embodiments, the fitting portion is a groove having a central through hole.

Preferably, the central through hole is matched and connected with the lower part of the pole in the pole sealing module.

Preferably, the side wall of the groove of the positive and negative electrode assembly part is matched and connected with the side wall of the retaining ring of the pole sealing module.

Preferably, the periphery of the central through hole is provided with a circle of bosses. The lug boss is matched and connected with the clearance groove of the pole sealing module.

The assembly part of the top cover plate is connected with the snap ring and the lug boss is connected with the clearance groove in a double mode, so that the top cover plate and the pole sealing module are connected stably in the structure.

Preferably, the top cover plate is connected with the pole sealing module in a sealing mode through the assembling portion.

Preferably, the pole sealing module is installed at the assembling portion of the top cover plate through a welding process.

The beneficial effects of the invention comprise the following aspects:

1. the metal plastic binder/nano oxide composite film layer is combined with the nano injection molding part to realize high-grade air-tight sealing of the snap ring and the pole;

2. the concave-convex structure design of the metal plastic binder/nano oxide composite film layer and the selection of the nano injection molding material are beneficial to improving the air tightness grade and the air tightness stability;

3. the polar column sealing module provided by the invention concentrates the difficult sealing problem of the polar column and the battery top cover on modularization treatment, thereby improving the production efficiency and the yield of the battery top cover;

4. the pole sealing module is particularly suitable for large-size battery top covers, injection molding sealing and welding sealing are separately processed, and the cost and difficulty of chemical treatment are reduced;

5. the structure design is carried out on the matching parts of the top cover plate and the pole sealing module, and the airtight joint of the top cover plate and the pole sealing module is realized by adopting physical matching and welding processes, so that the battery top cover with high airtight grade is obtained.

Drawings

FIG. 1 is an exploded view of one embodiment of the positive seal module of the present invention;

fig. 2 is a perspective view of an assembled structure of the positive electrode sealing module shown in fig. 1, wherein fig. 2a is a front view of the assembled structure; FIG. 2b is a schematic reverse side view of the assembled structure;

fig. 3 is a schematic view of an assembled structure of the positive sealing module shown in fig. 1, wherein fig. 3a is a top view of the assembled structure; FIG. 3b is a cross-sectional view taken along the line A-A in a plan view;

fig. 4 is a schematic view of a connection structure of a sealing bonding layer in the positive electrode sealing module of fig. 1;

FIG. 5 is a scanning electron microscope photograph of the sealing and bonding layer between the positive post and the nanoplastic member;

fig. 6 is a sem photograph of a sealing bonding layer between a snap ring and a nanopastomer in the positive sealing module of fig. 1;

fig. 7 is a schematic structural view of a positive post in the positive sealing module shown in fig. 1, wherein fig. 7a is a top view of the positive post, and fig. 7b is a left side view of the positive post;

FIG. 8 is a schematic structural diagram of a retaining ring in the positive sealing module shown in FIG. 1, wherein FIG. 8a is a top view of the retaining ring and FIG. 8b is a left side view of the retaining ring;

fig. 9 is a sectional view of an assembly structure of a positive post and a grommet, wherein fig. 9a and 9b are sectional views of the assembly structure at different positions;

fig. 10 is a scanning electron microscope photograph of the sealing bonding layer between the negative electrode pillar and the nanopaste;

fig. 11 is an exploded view of a battery top cover structure;

fig. 12 is an exploded view of another embodiment of a battery top cover structure.

Detailed Description

The invention is further described below with reference to the figures and examples.

Example 1

As shown in fig. 1 to 8, a positive sealing module C includes an aluminum alloy positive post 1, a PPS nano injection molding 2, and an aluminum alloy retaining ring 3. As shown in fig. 2 and 3, the nano injection molding member 2 is embedded between the positive pole 1 and the retaining ring 3, covers and is injection molded on the surface of the upper edge of the retaining ring 3 and part of the side wall of the retaining ring 3 to tightly connect the positive pole 1 and the retaining ring 3 together, and a clearance groove 4 is reserved on the reverse side of the positive pole sealing module C; as can be seen from fig. 7 and 8, the gap groove 4 is located between the lower portion 12 of the positive post 1 and the lower opening of the snap ring 3.

As shown in fig. 4, a sealing bonding layer 5 is arranged between the positive post 1 and the nano injection molding member 2, and the sealing bonding layer 5 is a metal plastic adhesive/nano Al with a concave-convex structure₂O₃A hybrid cross-linked structure. Fig. 5 and 6 are SEM photographs obtained by scanning electron microscopy using SU8100 field emission at 50000 magnification. Wherein, as shown in FIG. 5, the sealing and bonding layer on the surface of the positive pole column 15 had an average thickness of 210 nm. As can be seen from fig. 4 and 5, the concave-convex structure of the sealing and bonding layer 5 is crater-shaped protrusions and pits, wherein the depth h of the pits is 15nm to 35nm, the average pore diameter D of the pits is about 20nm to 35nm (not shown in the figure), and the ratio of the diameter to the depth of the pit structure is 4:3 to 1: 2; because the pits are irregular in shape, the pit depth and the average pore diameter are within a certain data range, not fixed values. In other embodiments, the shape of the pits and the bulges can be any other geometric shape, and the diameter-depth ratio of the pits can be freely set within the range of 2: 1-1: 10. Also be provided with sealed bonding layer BC between nanometer injection molding 2 and buckle 3, it is basically unanimous with sealed bonding layer 4's formation technology and structure, the difference is: as shown in FIG. 6, the sealing bonding layer BC on the surface of the grommet 3 has an average thickness of 425nm and the ratio of the diameter to the depth of the dimples is in the range of 1:1 to 1:3 (not shown). In the embodiment, the color of the nano injection molding piece is black, the peripheral shapes of the positive pole and the retaining ring are circular, and in other embodiments, the peripheral shapes of the pole and the retaining ring can be any other geometric figures as long as the sealing assembly of the pole and the retaining ring can be completed.

Fig. 7 is a schematic structural diagram of the positive post 1, and as shown in the drawing, the positive post 1 includes an upper portion 11, a lower portion 12 and a waist portion 13, the waist portion 13 protrudes from the upper portion 11 and the lower portion 12 to form a skirt, and 4 protruding portions 131 are uniformly arranged on the skirt at intervals, and the 4 protruding portions 131 can increase the contact area between the positive post 1 and the nano injection molded part 2, so as to improve the binding force, and increase the torsion of the positive post after injection molding. As can be seen from fig. 2 and 3, the positioning holes 141 and 142 are respectively formed in the central positions of the upper portion 11 and the lower portion 12, and the positioning holes 141 and 142 not only can reduce the weight of the product, but also can play a role in positioning during the injection molding process.

FIG. 8 is a schematic structural view of buckle 3, showing buckle 3 as a hollow structure with upper edge 31 and lower edge 32 both converging radially inward, and as can be seen in connection with FIG. 3, the hollow structure of buckle 3 has an upper opening and a lower opening, wherein dimension L1 of the upper opening is greater than dimension L2 of the lower opening; the upper edge 31 and the lower edge 32 of the retaining ring 3 contract inwards in the radial direction, so that the pole sealing module is not easy to fall off under the action of forward and reverse thrust, and the stability of the sealing structure is ensured.

The upper edge 31 of the retaining ring 3 is provided with 4 notches 311 at even intervals along the circumference; the notches 311 are arranged in one-to-one correspondence with the protrusions 131, and have complementary shapes to form a snap structure. The arrangement of the notch 311 and the bulge 131 ensures that the contact areas of the positive post 1 and the snap ring 2 in the positive sealing module and the nano injection molding piece 3 are large, the binding force is strong, and the torsion resistance is excellent after injection molding.

On the other hand, the provision of the notch 311 and the boss 131 facilitates the assembly of the positive post 1 and the grommet 3. When the pole is assembled, the convex part 131 of the pole 1 is aligned with the notch 311 of the retaining ring 3, then the positive pole 1 can smoothly enter the hollow structure of the retaining ring 3, the sectional view of the assembled structure of the positive pole 1 and the retaining ring 3 is shown in fig. 9, wherein fig. 9a is the sectional view of the position where the convex part 131 is aligned with the notch 311, and fig. 9b is the sectional view of the non-convex position of the skirt edge of the pole which is aligned with the non-notch position of the upper edge of the retaining ring. Then the positive post 1 is rotated to make the protrusion 131 and the notch 311 in a staggered overlapping or fully overlapping state, and at this position, the nano injection molding piece 2 is obtained by mold clamping and injection molding, as can be seen from fig. 3b, the protrusion 131 is aligned with the non-notch position of the upper edge of the retaining ring. Therefore, the polar column sealing module is not easy to fall off under the action of forward and reverse thrust, and the stability of the sealing structure is ensured.

Of course, in other embodiments, the size of the raised portion may be smaller than the size of the notch in the upper edge of the retaining ring for ease of assembly; the shape of the protruding part can be different from that of the notch, so long as the protruding part can smoothly enter the hollow structure of the retaining ring through the notch.

The on-resistance of the terminal post and the snap ring in the positive electrode sealing module obtained in this embodiment was measured with a digital multimeter, and the measurement result was 186 ohms.

The positive pole sealing module in the embodiment is subjected to airtightness test by using a Keke instrument AQJ-2000 helium mass spectrometer leak detector according to the helium detection standard of an industrial valve, and the leak rate of He gas is measured to be 3.4 multiplied by 10^-10(Pa·m³)/s。

Example 2

A negative electrode sealing module An, which is in accordance with the basic structure of the positive electrode post sealing module C of example 1, except that: (1) the cathode column materials are different; (2) the nanometer injection molding has different colors.

The cathode pole is made of copper-aluminum composite board integrally, wherein the upper part is an aluminum plate, and the lower part and the waist part are copper plates. The sealing bonding layer on the surface of the negative electrode post is formed by a chemical passivation process in this embodiment, but may be formed by an anodic oxidation/electrolytic polymerization process in other embodiments.

Fig. 10 is a SEM photograph of the sealing and bonding layer between the negative electrode pillar and the nano plastic member in this example, which is obtained by enlarging the SU8100 field emission scanning electron microscope at 50000 times. As can be seen from fig. 10, the sealing bonding layer on the surface of the negative electrode post had a concavo-convex structure having projections and recesses similar to craters, and the average thickness of the sealing bonding layer was 32.7 nm.

The nano injection molded part of this example uses a pigment different from the pigment in the injection molding material of example 1, and the color of the nano injection molded part in this example is off-white. Therefore, the anode sealing module and the cathode sealing module can be distinguished only by the color of the nano injection molding piece, and subsequent flow sorting and packaging finished products are facilitated.

The current conduction rate of a pole and a retaining ring in the negative electrode sealing module is measured by using a Rake RK2672 type voltage-withstanding tester, and the negative electrode sealing module is insulated under the conditions of 800V voltage and 20mA current.

The cathode column sealing module in the embodiment is subjected to airtightness test by using a Kyoco instrument AQJ-2000 helium mass spectrometer leak detector according to the helium detection standard of an industrial valve, and the leak rate of He gas is measured to be 2.8 multiplied by 10^-10(Pa·m³)/s。

Example 3

A battery top cover G1, as shown in FIG. 11, comprises a top cover plate P1, a positive electrode sealing module C of example 1, a negative electrode sealing module An of example 2, An explosion-proof hole P13 and a liquid injection hole P14. The top cover sheet P1 is provided with a positive electrode mounting part P11 and a negative electrode mounting part P12. The positive and negative electrode assembling parts P11 and P12 are grooves O1 and O2 which are respectively provided with central through holes K01 and K02, and the central through holes K01 and K02 are respectively matched and connected with the lower parts of the poles of the positive electrode sealing module C and the negative electrode sealing module An; the side walls of the grooves O1 and O2 are respectively matched and connected with the side walls of the retaining rings of the positive and negative sealing modules. The peripheries of the central through holes K01 and K02 are also respectively provided with a circle of bosses T1 and T2. The bosses T1 and T2 are respectively matched with the clearance grooves in the positive and negative sealing modules. And welding and sealing the positive and negative electrode sealing modules C, An and the assembling parts P11 and P12 by adopting a laser welding process to obtain the battery top cover G1.

The positive and negative electrode assembling parts P11 and P12 are in double physical connection with the positive and negative electrode sealing module through grooves O1 and O2 and retaining rings, bosses T1 and T2 and clearance grooves, and the top cover plate P1 and the pole sealing module C, An are in welded sealing, so that stable sealing connection is achieved structurally.

The hermetically assembled battery top cap G1 was subjected to an airtightness test, and the leak rate of He gas was found to be 5.5X 10^-9(Pa·m³)/s。

Example 4

A battery top cover G2, as shown in fig. 12, differs from embodiment 3 in that: in this embodiment, the top cover sheet P2 is provided with a positive electrode assembly hole K1 and a negative electrode assembly hole K2 as assembly portions for mounting the positive electrode sealing module C and the negative electrode sealing module An, respectively.

The inner hole shapes of the positive and negative electrode assembly holes K1 and K2 and the peripheral shape of the lower edge of the retaining ring in the positive and negative electrode sealing module are both circular; and the inner diameters of the positive and negative pole assembling holes K1 and K2 are consistent with the outer diameter of the lower edge of the retaining ring. During assembly, one side of the lower portion of the pole in the positive and negative sealing modules is respectively embedded into the positive and negative assembling holes K1 and K2, and the bottom edge of the retaining ring and the inner peripheries of the inner holes of the assembling holes K1 and K2 are welded and sealed by a laser welding process.

The hermetically assembled battery top cap G2 was subjected to an airtightness test, and the leak rate of He gas was found to be 6.7X 10^-9(Pa·m³)/s。

While the invention has been described in connection with specific preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.