Battery cell and power battery

Abstract

The utility model relates to new energy battery technical field and provide a kind of battery cell and power battery.The utility model discloses battery cell including pole group in battery cell shell, cover is located the battery cell cover plate of battery cell shell top, and is located between the isolating protective piece of battery cell cover plate and pole group.Isolated protective piece includes isolating sheet attached in the inside of battery cell cover plate, and protective sheet can be buckled on isolating sheet, and hot melt structure is equipped between isolating sheet and protective sheet;Isolating sheet is equipped with the pole post via hole of the pole post on battery cell cover plate, and corresponding pole post via hole, protective cavity is equipped on protective sheet;In the case where protective sheet is buckled on isolating sheet, protective sheet is fixedly connected on isolating sheet by hot melt structure, protective cavity is received in the position below the bottom of pole post for the welding of tab, and the bottom of protective cavity is protruding towards pole group and abuts on pole group.The utility model discloses battery cell, it is favorable to improve the isolation protection effect between battery cell cover plate and its pole post and pole group.

Description

Technical Field

[0001] This utility model relates to the field of new energy battery technology, and in particular to a battery cell and a power battery. Background Technology

[0002] With the development of new energy technologies, lithium-ion batteries, as a typical example, are widely used in new energy vehicles due to their excellent energy storage and safety.

[0003] During battery manufacturing, the electrode assembly located inside the battery casing needs to have tabs extended from it. These tabs, of the same polarity, are then welded to terminals on the cover plate to establish electrical connection between the battery and external electrical components. The welding of the tabs to the terminals is one of the key processes in battery production, and its quality directly affects the battery's safety and reliability.

[0004] In an electrode assembly, the separator is a crucial component for isolating the positive and negative electrodes. If there are protrusions or fallen weld slag at the welding points of the tabs and terminals, these could puncture the electrode assembly, posing a significant risk to the safe operation of the separator and electrodes. For example, if the separator is punctured by weld slag, the positive and negative electrodes will be directly connected, creating a short circuit. The high temperatures generated by this short circuit can trigger a chain reaction inside the battery, leading to electrolyte decomposition, electrode material decomposition, and ultimately thermal runaway. Thermal runaway can not only damage the battery but also threaten the safety of the vehicle, personnel, and the surrounding environment. Utility Model Content

[0005] In view of this, the present invention aims to provide a battery cell to improve the isolation and protection effect between the battery cell cover plate and its terminals and electrode groups.

[0006] To achieve the above objectives, the technical solution of this utility model is implemented as follows: A battery cell includes an electrode assembly located within a battery cell housing, a battery cell cover plate covering the top of the battery cell housing, and an isolation and protective member disposed between the battery cell cover plate and the electrode assembly. The isolation and protective member includes an isolation sheet attached to the inner side of the battery cell cover plate and a protective sheet that can be fastened to the side of the isolation sheet facing away from the battery cell cover plate, and a heat-fusion structure is provided between the isolation sheet and the protective sheet. The isolation sheet has an electrode post through hole for an electrode post on the battery cell cover plate to pass through, and a protective cavity is provided on the protective sheet corresponding to the electrode post through hole. When the protective sheet is fastened to the isolation sheet, the protective sheet is fixed to the isolation sheet by the heat-fusion structure, and the protective cavity is located below the part of the electrode post bottom used for welding electrode tabs, and the bottom of the protective cavity protrudes towards the electrode assembly and abuts against the electrode assembly.

[0007] Furthermore, along the length of the battery cell, two pole posts are spaced apart on the battery cell cover plate, and an explosion-proof valve mounting hole is provided between the two pole posts; corresponding to the pole posts, two pole post through holes are provided on the isolation plate; corresponding to the explosion-proof valve mounting hole, an explosion-proof valve clearance groove is provided on the isolation plate, and a vent hole is opened on the wall plate of the explosion-proof valve clearance groove.

[0008] Furthermore, the protective sheet is a single-unit structure. In the length direction of the battery cell, the protective sheet is connected to one end of the insulating sheet through a bending portion. By bending the bending portion, the protective sheet can be fastened onto the insulating sheet. The protective sheet includes a central connecting section corresponding to the explosion-proof valve clearance groove and electrode tab protective sections corresponding to the two electrode post through holes respectively. The protective cavity is provided on the electrode tab protective sections. A set of the heat-fused structure is provided at the position corresponding to the central connecting section and the electrode tab protective section, and at the end position corresponding to the end of the protective sheet away from the bending portion.

[0009] Furthermore, the width between the protective cavity and the side edge of the protective sheet is between 0.5mm and 12mm.

[0010] Furthermore, along the length of the battery cell, the protective sheet consists of two pieces connected to both ends of the insulating sheet via bending portions; a set of the hot-melt structure is provided between each protective sheet and the insulating sheet, and the hot-melt structure is located at the end of the protective sheet away from the bending portion.

[0011] Furthermore, the hot-melt structure includes a hot-melt column integrally formed on the insulating sheet and a hot-melt hole correspondingly disposed on the protective sheet; the hot-melt column is inserted into and hot-melted fixed in the hot-melt hole.

[0012] Furthermore, the protective sheet has a boss on the side facing the isolation sheet, and the hot-melt hole is opened on the boss. As the hot-melt column is hot-melted and fixed to the hot-melt hole, the boss abuts against the isolation sheet. The hot-melt hole includes a through section and a hot-melt section connected in sequence, and the radial dimension of the hot-melt section is larger than the radial dimension of the through section. The hot-melt column passes through the through section, and the head of the hot-melt column is hot-melted and compacted in the hot-melt section.

[0013] Furthermore, holes are formed on the side wall of the protective cavity, and a gap is left between the holes and the bottom of the protective cavity.

[0014] Furthermore, the width and length directions of the protective cavity are consistent with those of the battery cell, and the hole is provided on the two side walls in the length direction of the protective cavity; deformation grooves that penetrate the entire length of the protective cavity are provided on the two side walls in the width direction of the protective cavity, and the deformation grooves penetrate the side walls of the protective cavity.

[0015] Compared with the prior art, this utility model has the following advantages: (1) The battery cell of this utility model, by setting an isolation and protective component on the inner side of the battery cell cover, and setting the isolation and protective component as two parts, an isolation sheet and a protective sheet that can be bent and folded together, when assembling the electrode group, the isolation sheet can be first attached to the inner side of the battery cell cover, then the electrode tabs led out from the electrode group can be welded to the corresponding electrode post, and then the protective sheet can be fastened to the isolation sheet; in this way, the isolation sheet can form a reliable insulation isolation between the battery cell cover and the electrode tab, and the protective sheet can cover the welding part between the electrode post and the electrode tab, and isolate the electrode group from the electrode tab welded to the bottom of the electrode post, ensuring the isolation and protection effect between the welding part of the electrode post and the electrode group, and preventing The system prevents weld slag from falling into the electrode assembly or weld protrusions from puncturing it. Furthermore, the heat-fusion bonding between the separator and the protective sheet ensures reliable connection of the protective sheet to the separator. A protective cavity is provided on the protective sheet, with its bottom abutting against the electrode assembly. This effectively restricts and constrains the electrode assembly along the cell height, ensuring the stability of the cell's internal structure. The protective cavity also provides ample space below the electrode post to accommodate weld protrusions from the tabs and post, while also absorbing weld slag and other foreign matter, preventing them from entering the electrode assembly. This enhances the isolation and protection effect between the cell cover, the electrode post, and the electrode assembly.

[0016] (2) Two pole through holes are set at intervals on the isolation plate, which is compatible with the case where most battery cells have two poles on the cell cover plate; then, an explosion-proof valve installation hole is set in the middle of the cell cover plate for the installation of the explosion-proof valve, and an explosion-proof valve clearance groove is set on the isolation plate accordingly. Ventilation holes are set on the side wall of the explosion-proof valve clearance groove, etc. When the pole group in the battery cell has a short circuit or other abnormality, which causes the gas pressure in the battery cell to increase sharply, the gas can be discharged to the outside through the ventilation hole and the explosion-proof valve in sequence, reducing the risk of battery cell explosion.

[0017] (3) By setting the bending part, the isolation and protection parts can be processed into an integral structure, which is convenient for storage and retrieval. When performing the fastening operation of the protective plate on the isolation plate, the operation can be completed conveniently by bending the bending part, so as to achieve accurate fastening and positioning of the protective plate on the isolation plate. The protective plate is designed as three parts: the middle connecting section and the electrode tab protection sections located on both sides of the middle connecting section. The two electrode tab protection sections can respectively cover and protect the bottom of the two pole posts. The protective cavity is set on the electrode tab protection section, which can well realize the accommodation of the bottom of the pole post and the welding part of the electrode tab.

[0018] (4) A certain width dimension is reserved between the protective cavity and the side edge of the protective sheet. When the electrode tab is inserted between the protective sheet and the isolation sheet, the side edge of the protective sheet can press the electrode tab that has passed through onto the isolation sheet, ensuring sufficient contact area between the protective sheet and the electrode tab, ensuring that the electrode tab can have good fixing and shaping effect, and preventing the electrode tab from shifting or deforming.

[0019] (5) The protective plate adopts a split design, which is set and connected to both ends of the isolation plate respectively, so that the isolation and protection components are symmetrical as a whole, which is convenient for storage and fastening operation; at the same time, since the setting of the corresponding part of the explosion-proof valve clearance groove is reduced, the amount of consumable material used for the protective plate can be reduced.

[0020] (6) The hot-melt structure is set as an insert hot-melt form of hot-melt column and hot-melt hole. When the hot-melt column on the isolation plate is inserted into the hot-melt hole on the protective plate, the hot-melt column can be heated and hot-melted to be fixed to the hot-melt hole, which has a good positioning effect and a strong connection performance.

[0021] (7) A boss is provided on the protective sheet, and a hot-melt hole is opened on the boss. When the protective sheet is fastened to the isolation sheet and the hot-melt column is hot-melted and fixed into the hot-melt hole, the boss can form a supporting effect between the isolation sheet and the protective sheet, thereby defining an isolation space for the electrode tab to pass through between the isolation sheet and the protective sheet, providing good accommodation conditions for the electrode tab to be inserted. (8) Making holes in the side wall of the protective cavity not only helps to reduce the weight of the isolation and protection components, but also allows the electrolyte to enter the electrode assembly inside the cell housing through the holes in the protective cavity and its side wall when the electrolyte is injected into the electrode assembly through the electrode post through the hole. In addition, since there is a gap between the hole and the bottom of the protective cavity, the risk of welding slag, foreign objects, etc. in the protective cavity falling into the electrode assembly through the hole is reduced.

[0022] (9) By opening long strip holes in the sidewalls on both sides of the width direction of the protective cavity, the plate at the bottom of the protective cavity can be more easily deformed and displaced in the height direction of the cell, so as to elastically abut against the top of the electrode group; at the same time, when multiple holes are evenly distributed on the sidewalls on both sides of the length direction of the protective cavity, a connecting rib will be formed between two adjacent holes. With the help of the elastic deformation performance of the connecting rib and the setting of the deformation groove, a good elastic support is formed between the bottom of the protective cavity and the electrode group, and a good elastic buffering effect can be generated between the electrode group and the protective plate when the cell vibrates.

[0023] This utility model also proposes a power battery, which uses the battery cell described in this utility model. The power battery of this utility model has the technical advantages of the aforementioned battery cell. Attached Figure Description

[0024] The accompanying drawings, which form part of this utility model, are used to provide a further understanding of this utility model. The illustrative embodiments and descriptions of this utility model are used to explain this utility model. The directional terms such as front / back, up / down, etc., used therein are only used to indicate relative positional relationships and do not constitute an improper limitation of this utility model. In the drawings: Figure 1 This is a schematic diagram of the structure of the isolation and protection component described in an embodiment of the present utility model; Figure 2 for Figure 1 The diagram shows the structure of the other side of the isolation and protective component. Figure 3 for Figure 2 A magnified view of part A in the diagram; Figure 4 for Figure 3 A schematic diagram of the cross-sectional structure at the location shown in BB; Figure 5 This is a structural schematic diagram of another type of isolation and protective component described in an embodiment of the present utility model; Figure 6 for Figure 5 The diagram shows the structure of the other side of the isolation and protective component. Figure 7 This utility model embodiment shows a schematic diagram of the battery cell during the welding of the tabs and terminals; Figure 8 for Figure 7 The diagram shows the structure of the other side of the battery cell; Figure 9 for Figure 7 The diagram shows the structure of the battery cell after the protective pad is fastened to the main pad. Figure 10 for Figure 7 The diagram shown is a structural schematic of a battery cell after the assembly of the cell cover, insulating protective components, and electrode assembly is completed. Figure 11 for Figure 10 A schematic diagram of the cross-sectional structure at the location shown in CC; Figure 12 for Figure 10 A schematic diagram of a partial cross-sectional structure at the location shown in DD.

[0025] Explanation of reference numerals in the attached figures: 1. Cell cover plate; 10. Terminal post; 11. Insulating sleeve; 12. Explosion-proof valve mounting hole; 2. Electrode group; 20. Electrode ear; 3. Bending section; 32. Connecting platform; 33. Bending plate; 34. Thinning groove; 4. Isolating plate; 40. Pole post through hole; 41. Protrusion; 42. Hot melt column; 420. Head; 43. Explosion-proof valve clearance groove; 430. Vent hole; 5. Protective plate; 50. Middle connecting section; 500. Through hole; 51. Electrode protection section; 510. Protective cavity; 511. Hole; 512. Deformation groove; 52. Hot melt hole; 521. Insertion section; 522. Hot melt section; 53. Boss. Detailed Implementation

[0026] To make the technical solution and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0027] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0028] Furthermore, it should be stated in the description of this utility model that if terms indicating orientation or positional relationship, such as "up," "down," "left," "right," "front," "back," "inner," and "outer," appear, they are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and for clarity and conciseness of expression. They do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed or operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Taking the battery cell described in this utility model as an example, the directional terms such as "up," "down," "left," "right," "front," and "back" used in the embodiments are defined based on the vertical direction (also known as the height direction), horizontal direction (also known as the width direction), and front-back direction (also known as the length direction) of the battery cell. At the same time, the length, width, and height directions of the battery cell cover, the insulating sheet of the insulating protective component, etc., are also consistent with the battery. Specifically, as shown in the accompanying drawings, the X direction is the front-back direction (length direction) of the battery cell, the Y direction is the horizontal direction (width direction) of the battery cell, and the Z direction is the vertical direction (height direction) of the battery cell.

[0029] Furthermore, in the description of this utility model, unless otherwise explicitly defined, the terms "installation," "connection," "joining," and "connector" should be interpreted broadly. For example, a connection can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model in light of the specific circumstances.

[0030] In this utility model, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this utility model. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0031] The present invention will now be described in detail through exemplary embodiments. However, it should be understood that, without further description, elements, structures, and features in one embodiment may be advantageously incorporated into other embodiments.

[0032] The first aspect of this utility model provides a battery cell that can be assembled into a power battery. The battery cell of this embodiment, with its innovative structural design, can improve the isolation and protection effect between the battery cell cover plate 1 and its terminal post 10 and the electrode group 2.

[0033] Currently, the plastic insulating protective components under the cell cover are mostly located between the aluminum plate and the tab to ensure its insulation performance. However, there is no shaping and fixing structure between the tab 20 and the electrode group 2, resulting in poor consistency of the tab 20 after bending, which poses a safety hazard to the product. In particular, due to the welding of the tab 20 and the pole post 10, the protruding structure or welding slag formed by welding, if it punctures the electrode group 2 or falls into the electrode group 2, could pose a huge risk to the safe operation of the diaphragm and electrode plates in the electrode group 2; once the diaphragm is punctured by welding slag, the positive and negative electrodes will be directly connected, forming a short circuit.

[0034] In view of this, in order to overcome the above-mentioned shortcomings of the prior art, the present invention proposes a battery cell equipped with a novel isolation and protection component, an exemplary structure of which is as follows: Figure 1 , Figure 2 and Figure 3 As shown.

[0035] Overall, the battery cell includes an electrode assembly 2 located inside the battery cell housing, a battery cell cover plate 1 covering the top of the battery cell housing, and an isolation and protective component disposed between the battery cell cover plate 1 and the electrode assembly 2. The isolation and protective component includes an isolation sheet 4 attached to the inner side of the battery cell cover plate 1, and a protective sheet 5 that can be fastened to the side of the isolation sheet 4 facing away from the battery cell cover plate 1. A heat-fusion structure is provided between the isolation sheet 4 and the protective sheet 5. The isolation sheet 4 has an electrode post through-hole 40 through which the electrode post 10 on the battery cell cover plate 1 passes. Corresponding to the electrode post through-hole 40, a protective cavity 510 is provided on the protective sheet 5. When the protective sheet 5 is fastened to the isolation sheet 4, the protective sheet 5 is fixed to the isolation sheet 4 by the heat-fusion structure. The protective cavity 510 is located below the part of the electrode post 10 used for welding the electrode tab 20, and the bottom of the protective cavity 510 protrudes towards the electrode assembly 2 and abuts against the electrode assembly 2.

[0036] It should be noted that, based on the above overall design concept, the technical solution of this utility model can adopt a variety of different specific implementation structures, forms, or configuration sequences. For example, the aforementioned isolation sheet 4 and protective sheet 5 can be integrally injection molded from materials with insulating properties such as rubber and plastic; the bending part 3 can be made easy to bend by thinning, opening holes, and other methods. The specific arrangement sequence and assembly method of the isolation and protective components on the cell cover plate 1, and the fastening and fixing of the protective sheet 5 on the isolation sheet 4, can also be flexibly adjusted. For parts required for the overall implementation but not covered in the above overall setup, reasonable and flexible designs can be made by referring to mature setup methods in the field and the actual situation during implementation, which will not be elaborated here. The specific implementation schemes described below in this embodiment are only one of the many solutions that can be formed by the various combinations and variations mentioned above. In actual implementation, those skilled in the art can make flexible adjustments and improvements based on the actual situation. Obviously, the various solutions that can be formed by the combinations and variations of the above specific forms, as well as the specific implementation schemes of this embodiment, are all within the protection scope of this utility model.

[0037] Of course, the aforementioned isolation sheet 4 and protective sheet 5 can be of a separate structure; however, preferably, in this embodiment, such as Figures 1 to 3 As shown, in some preferred exemplary embodiments, the protective sheet 5 is connected to one end of the isolation sheet 4 along its length via a bendable bending portion 3. As the bending portion 3 bends, the protective sheet 5 is fastened onto the isolation sheet 4. By providing the bending portion 3, the isolation protective component can be processed into an integral structure, facilitating storage and retrieval. Furthermore, the operation of fastening the protective sheet 5 onto the isolation sheet 4 can be conveniently completed by bending the bending portion 3, achieving accurate fastening and positioning of the protective sheet 5 onto the isolation sheet 4.

[0038] Regarding the specific design of the bending portion 3, there are naturally many different structural options available; for example, an elongated hole arranged along the width direction of the isolation piece 4 can be made in the bending portion 3. This way, when bending the bending portion 3, the position of the elongated hole can be easily bent, allowing the protective piece 5 to smoothly engage with the isolation piece 4. However, in this embodiment, as... Figure 3 and Figure 4 As shown, the bending portion 3 includes a connecting platform 32 protruding from the end of the isolation piece 4 toward the side that engages with the protective piece 5, and a bending plate 33 connecting the top of the connecting platform 32 and the protective piece 5; the bending plate 33 is provided with a thinning groove 34 extending through the width direction of the isolation piece 4. The thinning groove 34 can be provided on only one side of the bending plate 33, or it can be provided on both sides of the bending plate 33, with the two thinning grooves 34 facing back to back and their bottoms facing each other. The position where the bottom of the thinning groove 34 is located is the thinnest position on the bending plate 33, and the bending part of the bending portion 3 will naturally appear at this position.

[0039] Based on the above configuration, in the width direction of the isolation plate 4, the width dimension W3 of the bent plate 33 can be set to 0.25-0.5 times the width dimension W2 of the protective plate 5. Designing the bent plate 33 as a sheet and setting its width dimension W3 to 0.25-0.5 times the width dimension W2 makes the bent plate 33 easier to bend, thereby improving the convenience and yield of the protective component assembly. Furthermore, designing the bending part 3 as two parts—a connecting platform 32 and the bent plate 33—and providing a thinning groove 34 on the bent plate 33, can reduce the difficulty of bending the bending part 3, thus smoothly completing the fastening operation of the protective plate 5 on the isolation plate 4. Moreover, the connecting platform 32, together with the aforementioned boss 53, can define the height dimension H of the isolation space between the isolation plate 4 and the protective plate 5, thereby effectively accommodating the inserted tab 20.

[0040] Continue as Figure 4As shown, in this embodiment, in some preferred exemplary embodiments, the depth of the thinning groove 34 is about one-third of the thickness T2 of the bent plate 33, and the bending portion 3 is formed at the bottom of the thinning groove 34. By setting the depth of the thinning groove 34 to about one-third of the thickness T2 of the bent plate 33, since there is a thinning groove 34 on each side of the bent plate 33, the thickness of the plate at the bottom of the thinning groove 34 is one-third of the thickness T2 of the bent plate 33. After this portion is significantly thinned, it is easier to bend the bending portion 3 at this location, thus forming the bending portion 3 at a predetermined position at the bottom of the thinning groove 34. Preferably, the thickness T2 of the bent plate 33 can be set to 0.45mm-1.2mm, then the thickness of the plate at the bottom of the thinning groove 34 is limited to the range of 0.15mm-0.4mm. This makes it easier to fold the bent part 3 from this position. After folding, the bent plate 33 on both sides of the folded part 3 can fit together well. With the help of the connecting platform 32, it is easier and more accurate to define the height dimension H of the isolation space between the snap-fit ​​protective plate 5 and the isolation plate 4.

[0041] For other specific dimensions of the bent plate 33 and its surrounding structure, the following settings can be adopted. (Still as...) Figure 4 As shown, to facilitate the processing and forming of the thinning groove 34, its cross-section can be designed as a triangle, and the side walls on both sides of the thinning groove 34 are constructed as slopes. The width D1 of the first transition area with slopes on both sides of the bending part can be set to 0.3mm-4.5mm, and the width D2 of the second transition area can be set to 0.35mm-4.8mm. This ensures a smooth overall transition after the bent plate 33 is bent, ensuring the stability of the product and preventing defects such as shrinkage that could reduce the reliability of the product. By designing the thinning groove 34 as a groove with a triangular cross-section, a slope-shaped transition will be formed on both sides of the bending part at the bottom of the thinning groove 34 by the side walls of the thinning groove 34. This not only reduces the risk of breakage that may occur when the bending part 3 is bent, but also results in a relatively smooth and regular shape on the outer side of the bending part 3 after bending.

[0042] In addition, the thickness T1 of the aforementioned connecting platform 32 can be set to 0.6mm-2.8mm to ensure the connection strength of the product and prevent the electrode tab 20 from collapsing due to deformation of the protective component during and after bending. The thickness T2 of the bent plate 33 located between the thinning groove 34 and the protective plate 5 can be set to 0.4mm-1.2mm, or it can be the same thickness as the protective plate 5, to ensure sufficient connection strength between the isolation plate 4 and the protective plate 5, so that the electrode tab 20 can be firmly fixed in the welding design position located between the isolation plate 4 and the protective plate 5.

[0043] There is no limitation on the number of pole posts 10 configured on the cell cover plate 1; the pole post through holes 40 on the insulating plate 4 and the protective cavity 510 on the protective plate 5 can be configured accordingly for the pole posts 10. In this embodiment, two pole posts 10 are spaced apart on the cell cover plate 1 along the length of the cell, and an explosion-proof valve mounting hole 12 is provided between the two pole posts 10; corresponding to the pole posts 10, two pole post through holes 40 are provided on the insulating plate 4; corresponding to the explosion-proof valve mounting hole 12, an explosion-proof valve clearance groove 43 is provided on the insulating plate 4, and a vent hole 430 is opened on the wall of the explosion-proof valve clearance groove 43. Two pole post through holes 40 are provided at intervals on the isolation plate 4, which is compatible with the case where the cell cover plate 1 of most cells has two pole posts 10, one positive and one negative. Furthermore, an explosion-proof valve mounting hole 12 for installing an explosion-proof valve is provided in the middle of the cell cover plate 1, and an explosion-proof valve clearance groove 43 is provided on the isolation plate 4 accordingly. Ventilation holes 430 are provided on the side wall of the explosion-proof valve clearance groove 43. When a short circuit or other abnormality occurs in the pole group 2 inside the cell, causing a sharp increase in the gas pressure inside the cell, the gas can be discharged to the outside through the ventilation holes 430 and the explosion-proof valve in sequence, reducing the risk of cell explosion.

[0044] Regarding the specific number of protective plates 5, there are of course several different structural options to choose from; for example, it can be as follows: Figure 1 and Figure 2 As shown, the protective sheet 5 adopts a single-piece structure and is connected to one end of the isolation sheet 4 along its length direction via a bending portion 3. That is, the protective sheet 5 is also located at the end of the isolation sheet 4 along the length direction of the battery cell. The bending portion 3 allows the protective sheet 5 to be fastened onto the isolation sheet 4. In this embodiment, the protective sheet 5 includes a central connecting section 50 corresponding to the explosion-proof valve clearance groove 43, and electrode tab protection sections 51 corresponding to the two electrode post through holes 40 respectively. A protective cavity 510 is provided on the electrode tab protection section 51. A set of heat-fused structures is provided at the positions corresponding to the central connecting section 50 and the electrode tab protection section 51, and at the end of the protective sheet 5 furthest from the bending portion 3. By providing the bending portion 3, the isolation and protective component can be processed into a single-piece structure, facilitating storage and retrieval. When performing the fastening operation of the protective sheet 5 on the isolation sheet 4, the operation can be conveniently completed through the bending portion 3, achieving accurate fastening and positioning of the protective sheet 5 on the isolation sheet 4. The protective plate 5 is designed as three parts: a central connecting section 50 and two tab protection sections 51 located on both sides of the central connecting section 50. The two tab protection sections 51 can respectively cover and protect the bottom of the two pole posts 10. The protective cavity 510 is set on the tab protection section 51, which can effectively accommodate the welding part between the bottom of the pole post 10 and the tab 20.

[0045] Of course, it can also be like Figure 5 and Figure 6As shown, the protective plates 5 are two in number, connected to both ends of the isolation plate 4 along its length via bending portions 3. A set of heat-fusion structures is provided between each protective plate 5 and the isolation plate 4, with the heat-fusion structures located at the end of the protective plate 5 furthest from the bending portion 3. The protective plates 5 adopt a split design, each connected to both ends of the isolation plate 4, making the overall protective components symmetrical and facilitating storage and fastening operations. Simultaneously, by reducing the corresponding portion of the explosion-proof valve clearance groove 43, the material consumption of the protective plates 5 can be reduced.

[0046] Based on the above configuration, a certain width of plate will be left between the protective cavity 510 and the side edge of the protective sheet 5. Preferably, such as... Figure 3 As shown, the width W of the plate body at the side edge of the remaining protective sheet 5 can be set between 0.5mm and 12mm. A certain width is maintained between the protective cavity 510 and the side edge of the protective sheet 5. When the electrode tab 20 is inserted between the protective sheet 5 and the insulating sheet 4, the side edge of the protective sheet 5 can press the passing electrode tab 20 firmly onto the insulating sheet 4, ensuring sufficient contact area between the protective sheet 5 and the electrode tab 20. This ensures that the electrode tab 20 has good fixing and shaping effects, preventing displacement or deformation of the electrode tab 20.

[0047] For the specific structure of the heat-fusion structure, there are naturally many different structural solutions to choose from; for example, a mating structure of insert plate and slot can be used, where heating and heat fusion occur simultaneously with insertion. In this embodiment, such as... Figure 1 , Figure 2 and combined Figures 7 to 12 As shown, with Figure 1 and Figure 2 Taking the illustrated isolation and protective component as an example, in some preferred exemplary embodiments, the hot-melt structure includes a hot-melt column 42 integrally formed on the isolation plate 4, and a corresponding hot-melt hole 52 disposed on the protective plate 5; the hot-melt column 42 is inserted and hot-melted fixedly connected to the hot-melt hole 52. By configuring the hot-melt structure as an inserted hot-melt form of the hot-melt column 42 and the hot-melt hole 52, after the hot-melt column 42 on the isolation plate 4 is inserted into the hot-melt hole 52 on the protective plate 5, the hot-melt column 42 can be heated and hot-melted to be fixedly connected to the hot-melt hole 52, providing good positioning and strong connection performance.

[0048] Based on the above configuration of the hot-melt structure, such as Figure 2 As shown, each set of hot melt structures may include three hot melt pillars 42 evenly distributed along the width direction of the protective sheet 5, and three hot melt holes 52 correspondingly disposed on the protective sheet 5.

[0049] Based on the above configuration, the arrangement of the heat-fusion structure in this embodiment preferably adopts the following scheme. A set of heat-fusion structures is provided at the position between the corresponding middle connecting section 50 and the tab protection section 51, and at the end position of the corresponding protective sheet 5 away from the bending portion 3. Each set of heat-fusion structures may include one or more heat-fusion structures.

[0050] Based on the layout of the protective sheet 5 and the isolation sheet 4, three sets of heat-fused structures are provided at the end furthest from the bending part 3 and between the middle connecting section 50 and the tab protection section 51. Together with the connection of the bending part 3, four sets of connection structures are formed between the isolation sheet 4 and the protective sheet 5. Moreover, these four sets of connection structures are arranged in pairs, with each set corresponding to a pole through hole 40. There is a set of connection structures on each side of each pole through hole 40. The two sets of connection structures in the same group form a channel for the tab 20 to pass through the side of the protective sheet 5 into the isolation space. This connection layout not only ensures the reliability of the connection between the protective sheet 5 and the isolation sheet 4, but also provides good separation and restriction for the tab 20 passing through the isolation space, greatly improving the isolation and protection effect of the isolation and protection component.

[0051] Furthermore, in some preferred exemplary embodiments, the protective sheet 5 has a boss 53 on the side facing the isolation sheet 4, and a hot-melt hole 52 is formed on the boss 53. As the hot-melt column 42 is hot-melted and fixed to the hot-melt hole 52, the boss 53 abuts against the isolation sheet 4 to define the height dimension H of the isolation space. By providing the boss 53 on the protective sheet 5 and forming the hot-melt hole 52 on the boss 53, when the protective sheet 5 is fastened to the isolation sheet 4 and the hot-melt column 42 is hot-melted and fixed to the hot-melt hole 52, the boss 53 can form a supporting effect between the isolation sheet 4 and the protective sheet 5, thereby defining an isolation space for the tab 20 to pass through between the isolation sheet 4 and the protective sheet 5, providing good accommodation conditions for the insertion of the tab 20. The height of the boss 53 itself can define the height dimension H of the isolation space. By reasonably setting the height dimension of the boss 53, the required height dimension H of the isolation space can be obtained. Preferably, the height dimension H (i.e. the height dimension of the boss 53) can be set between 1mm and 5mm. At the same time, the height of the connecting platform 32 at the bending part 3 should be consistent with the height of the boss 53, so that the isolation space formed between the protective plate 5 and the isolation plate 4 is more regular.

[0052] like Figure 12In some preferred exemplary embodiments, the heat-fusion hole 52 includes a through section 521 and a heat-fusion section 522 connected in sequence, and the radial dimension D of the heat-fusion section 522 is larger than the radial dimension d of the through section 521. When the protective sheet 5 is fastened to the insulating sheet 4, the heat-fusion column 42 passes through the through section 521, and the head 420 of the heat-fusion column 42 is heat-fused and compacted in the heat-fusion section 522. The hot melt hole 52 is designed with two sections: an insertion section 521 and a hot melt section 522. The radial dimension D of the hot melt section 522 is larger. After the hot melt column 42 is inserted into the hot melt hole 52, the head 420 of the hot melt column 42 can protrude outside the hot melt section 522. Then, the head 420 of the hot melt column 42 is hot melted and pressed into the hot melt section 522. The head 420, which is deformed by hot pressing, will fill the entire hot melt section 522. After the head 420 solidifies, the hot melt column 42 is securely fixed in the hot melt hole 52, which can avoid the risk of the hot melt column 42 coming out of the hot melt hole 52.

[0053] In practical applications, the cell cover plate 1 typically has two pole posts 10 spaced apart. An insulating sleeve 11 is fitted over the pole post 10, forming an insulating barrier between the pole post 10 and the cell cover plate 1. An explosion-proof valve is installed between the two pole posts 10. Therefore, in this embodiment, an explosion-proof valve mounting hole 12 is provided in the middle of the cell cover plate 1. Corresponding to the explosion-proof valve mounting hole 12, the isolation plate 4 in this embodiment has an explosion-proof valve clearance groove 43, and a vent hole 430 is provided at the bottom of the explosion-proof valve clearance groove 43. A corresponding through hole 500 is provided on the protective plate 5. When a short circuit or other abnormality occurs in the electrode group 2 inside the cell, the exhaust channels formed by the aforementioned holes can release the high-pressure gas inside the cell casing. Simultaneously, a protrusion 41 can be provided around the perimeter of the pole post through hole 40. This protrusion 41 can have a slot or other structure, and a corresponding locking protrusion is provided on the cell cover plate 1 to better position and install the isolation plate 4 when it is attached to the cell cover plate 1.

[0054] As mentioned above, a protective cavity 510 is formed on the protective plate 5 corresponding to the through hole 40 of the pole post. The protective cavity 510 is positioned directly opposite the welding area of ​​the pole post 10 and the tab 20. The protective cavity 510 on the protective plate 5 creates a relatively spacious area below the pole post 10 to accommodate the welding protrusion of the tab 20 and the pole post 10. It can also catch foreign objects such as weld slag formed during welding, preventing them from entering the pole assembly 2.

[0055] Furthermore, holes 511 can be made in the side wall of the protective cavity 510, with a gap between the holes 511 and the bottom of the protective cavity 510. Making holes 511 in the side wall of the protective cavity 510 not only helps reduce the weight of the isolation and protection components, but also allows the electrolyte to enter the electrode group 2 of the battery cell through the protective cavity 510 and the holes 511 on its side wall when electrolyte is injected into the electrode group 2 through the electrode post through-hole 40. Moreover, the gap between the holes 511 and the bottom of the protective cavity 510 reduces the risk of welding slag, foreign objects, etc., inside the protective cavity 510 falling into the electrode group 2 through the holes 511. In practical implementation, multiple holes 511 can be evenly distributed along the edge of the protective cavity 510. A connecting rib will be formed between two adjacent holes 511. With the help of the elastic deformation performance of the connecting rib, when the bottom of the protective cavity 510 abuts against the electrode group 2, the protective cavity 510 forms a good elastic support between the cell cover plate 1 and the protective sheet 5.

[0056] Continue as Figure 5 and Figure 6 As shown, in this embodiment, in the width direction of the protective sheet 5, both sides of the protective sheet 5 are located inside the side edge of the insulating sheet 4; at the same time, corresponding to each electrode through hole 40, two protective cavities 510 are provided at intervals in the width direction of the protective sheet 5. By reasonably setting the width dimension W1 of the insulating sheet 4 and the width dimension W2 of the protective sheet 5, and simultaneously centering the protective sheet 5 relative to the insulating sheet 4, space can be reserved on the side of the protective sheet 5 for the bending part of the electrode tab 20 to pass through; in specific settings, the width dimension W2 can be 1.0mm-6.0mm smaller than the width dimension W1, so that the spacing space on the side of the protective sheet 5 is maintained between 0.5mm-3.0mm, forming a suitable space to avoid the bending part of the electrode tab 20 from passing through, preventing the electrode tab 20 from contacting the cell housing or cell cover plate 1 and causing a short circuit. Space is reserved on both sides of the protective sheet 5 for the tabs 20 to pass through. The electrode group 2 inside the cell housing can lead out two sets of tabs 20 from both sides of the protective sheet 5 and pass into the isolation space between the protective sheet 5 and the isolation sheet 4, and be welded to the same pole post 10. Since two protective cavities 510 are provided for each pole post through hole 40 (i.e. each pole post 10), there is a protective cavity 510 below the welding part of each set of tabs 20, which well meets the needs of accommodating the welding part between each pole post 10 and tab 20 and receiving welding slag.

[0057] In addition, in some preferred exemplary embodiments, such as Figure 3As shown, the width and length directions of the protective cavity 510 in this embodiment are consistent with the battery cell and the insulating sheet 4. The holes 511 are provided on the two side walls in the length direction of the protective cavity 510. The two side walls in the width direction of the protective cavity 510 are provided with deformation grooves 512 that penetrate the entire length of the protective cavity 510, and the deformation grooves 512 penetrate the side walls of the protective cavity 510. By creating elongated deformation grooves 512 on the sidewalls of the protective cavity 510 in the width direction, the bottom plate of the protective cavity 510 can more easily deform and shift in the height direction of the battery cell, thus elastically abutting against the top of the electrode group 2. Simultaneously, with multiple evenly spaced holes 511 on the sidewalls of the protective cavity 510 in the length direction, connecting ribs are formed between adjacent holes 511. Utilizing the elastic deformation properties of the connecting ribs and the deformation grooves 512, a good elastic support is formed between the bottom of the protective cavity 510 and the electrode group 2, providing a good elastic buffering effect between the electrode group 2 and the protective sheet 5 when the battery cell vibrates. Of course, similar to the hole 511 arrangement, a gap should also be left between the deformation grooves 512 and the bottom of the protective cavity 510 to reduce the risk of welding slag, foreign objects, etc., inside the protective cavity 510 falling into the electrode group 2 through the deformation grooves 512.

[0058] In summary, the battery cell of this embodiment, by providing an insulating protective component on the inner side of the battery cell cover plate 1, and configuring the insulating protective component into two parts, an insulating sheet 4 and a protective sheet 5, which can be bent and folded together, allows for the following assembly when assembling the electrode group 2: first, the insulating sheet 4 is attached to the inner side of the battery cell cover plate 1; then, the tabs 20 led out from the electrode group 2 are welded to the corresponding terminals 10; and finally, the protective sheet 5 is fastened to the insulating sheet 4. In this way, the insulating sheet 4 forms a reliable insulating barrier between the battery cell cover plate 1 and the tabs 20, while the protective sheet 5 covers the welding area between the terminals 10 and the tabs 20, separating the electrode group 2 from the tabs 20 welded to the bottom of the terminals 10. This ensures effective isolation and protection between the welding area of ​​the terminals 10 and the electrode group 2. To prevent welding slag from falling into electrode group 2 or welding protrusions from puncturing electrode group 2; and to ensure the reliability of the fastening connection between the isolation plate 4 and the protective plate 5 by heat fusion bonding, the protective plate 5 is provided on the isolation plate 4; a protective cavity 510 is provided on the protective plate 5, and the bottom of the protective cavity 510 abuts against the electrode group 2, which can effectively restrict and constrain the electrode group 2 in the height direction of the cell, so as to ensure the stability of the internal structure of the cell. Moreover, the protective cavity 510 forms a relatively spacious space below the pole post 10 to accommodate the welding protrusion of the electrode tab 20 and the pole post 10, and can also bear foreign objects such as welding slag formed by welding, preventing foreign objects from entering the electrode group 2, which is conducive to improving the isolation and protection effect between the cell cover plate 1 and its pole post 10 and the electrode group 2.

[0059] The second aspect of this utility model provides a power battery, which uses the battery cell provided in the first embodiment.

[0060] When using the battery cell of Example 1, such as Figures 7 to 12 As shown, during the assembly of the insulating protective components for the battery cell, after the welding of the tab 20 and the fastening and fixing of the protective plate 5 onto the insulating plate 4 are completed, the overall cross-sectional structure of the battery cell is as follows. Figure 11 and Figure 12 As shown, due to the thinning groove 34, the bending portion 3 is folded at the bottom of the thinning groove 34. After folding, the bent plates 33 on both sides of the bending portion fit together. Due to the presence of the connecting platform 32 and the boss 53 at the hot-melt structure, the isolation space for accommodating the tab 20 between the insulating sheet 4 and the protective sheet 5 is well defined, and the height H of the isolation space is consistent with the height of the connecting platform 32 and the boss 53. In the specific dimensional settings of the hot-melt structure in this embodiment, the net height of the boss 53 is 0.8mm-3.2mm, and the height of the connecting platform 32 at the bending portion 3 is also set to 0.8mm-3.2mm. After the protective sheet 5 is fastened to the insulating sheet 4, it can be ensured that the protective sheet 5 presses the tab 20 tightly. The height H of the isolation space between the protective sheet 5 and the insulating sheet 4 is also 0.8mm-3.2mm.

[0061] like Figure 11 As shown, the protective plate 5 has a protective cavity 510 located directly below the electrode tab 20. Multiple holes 511 and deformation grooves 512 are spaced apart on the top of the sidewall of the protective cavity 510. The spacing between the holes 511, deformation grooves 512, and the bottom of the protective cavity 510 can be the same, i.e., the net depth t of the protective cavity 510. This net depth t can be flexibly set within a reasonable range. Preferably, the total depth T of the protective cavity 510 can be set between 1.5mm and 5.5mm, such as 1.5mm, 4mm, or 5mm. A suitable depth of the protective cavity 510 can better accommodate protrusions or weld slag at the welding points of the electrode tab 20 and the electrode post 10, thus reducing the risk of weld slag piercing the diaphragm of the electrode assembly 2. In a further preferred embodiment, the net depth t of the protective cavity 510 can be set between 0.3mm and 5mm, such as 0.3mm, 4mm, 5mm, etc., where T>t, ensuring sufficient wetting effect of the electrolyte and the capacity of the protective cavity 510 to accommodate welding slag.

[0062] like Figure 12As shown, after the protective plate 5 is fastened, the hot-melt column 42 is inserted into the hot-melt hole 52. The hot-melt hole 52 includes a through section 521 and a hot-melt section 522 connected in sequence. The radial dimension D of the hot-melt section 522 is larger than the radial dimension d of the through section 521. The diameter of the hot-melt column 42 can also be set to the radial dimension d. After the hot-melt column 42 is inserted into place, the head 420 of the hot-melt column 42 will protrude outside the hot-melt hole 52. The head 420 is melted by heating, and then the melted head 420 is pressed into the hot-melt section 522. Due to the deformation caused by heat and pressure, the radial dimension of the head 420 increases, completely filling the entire hot-melt section 522. This effectively prevents the hot-melt column 42 from coming out of the hot-melt hole 52, making the hot-melt connection firm and reliable.

[0063] In terms of specific dimensions, preferably, the total depth of the hot-melt hole 52 is 1.8mm-5.0mm, which can be reasonably adjusted according to the thickness of the tab 20 to ensure that the insulation features after bending are completely compacted onto the tab 20, so that the tab 20 is in a fixed state; the depth h of the hot-melt section 522 can be set to 0.4mm-1.5mm, and the radial dimension D of the hot-melt section 522 is set to 2.05mm-6.5mm; the radial dimension d of the insertion section 521 and the diameter of the hot-melt column 42 are both set to 1.5mm-6mm, and the difference between D and d is ensured to be between 0.5mm-3mm to ensure the strength of the hot-melt connection, ensure the structural reliability of the protective sheet 5 fastened to the isolation sheet 4, and ensure the safety of the product.

[0064] This solution incorporates a novel tab protection structure, adding a protective plate 5. The protective plate 5 is securely fastened to the insulating plate 4, serving to fix and shape the tab 20. The rational design of the bending part 3 ensures its bending effect. In this way, the bent tab 20 can be well confined between the protective plate 5 and the insulating plate 4, ensuring the consistency of the bent tab 20 and preventing the risk of the tab 20 and the electrode post 10 being inserted backwards into the electrode group 2 at the welding point, thus improving the safety of the product.

[0065] The above description is merely a preferred embodiment of this utility model. Detailed explanations of configurations, examples of specific structural arrangements, and descriptions of assembly and connection methods are provided to ensure sufficient disclosure so that those skilled in the art can better implement this utility model, and are not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A battery cell, characterized in that: It includes an electrode assembly (2) located inside the cell housing, a cell cover plate (1) covering the top of the cell housing, and an isolation and protective component disposed between the cell cover plate (1) and the electrode assembly (2); The isolation and protective component includes an isolation sheet (4) attached to the inner side of the cell cover plate (1) and a protective sheet (5) that can be fastened to the side of the isolation sheet (4) facing away from the cell cover plate (1), and a heat-fusion structure is provided between the isolation sheet (4) and the protective sheet (5); The isolation plate (4) is provided with a pole post through hole (40) for the pole post (10) on the cell cover plate (1) to pass through. Corresponding to the pole post through hole (40), the protective plate (5) is provided with a protective cavity (510). When the protective plate (5) is fastened to the isolation plate (4), the protective plate (5) is fixed to the isolation plate (4) through the hot melt structure. The protective cavity (510) is located below the part of the pole post (10) used for welding the electrode tab (20), and the bottom of the protective cavity (510) protrudes towards the electrode group (2) and abuts against the electrode group (2).

2. The battery cell according to claim 1, characterized in that: Along the length of the battery cell, two pole posts (10) are spaced apart on the battery cell cover plate (1), and an explosion-proof valve mounting hole (12) is provided between the two pole posts (10). Corresponding to the pole (10), two pole through holes (40) are provided on the isolation plate (4); corresponding to the explosion-proof valve mounting hole (12), an explosion-proof valve clearance groove (43) is provided on the isolation plate (4), and a vent hole (430) is opened on the wall plate of the explosion-proof valve clearance groove (43).

3. The battery cell according to claim 2, characterized in that: The protective sheet (5) is a single unit structure. In the length direction of the battery cell, the protective sheet (5) is connected to one end of the isolation sheet (4) through a bending part (3). By bending the bending part (3), the protective sheet (5) can be fastened to the isolation sheet (4). The protective plate (5) includes a middle connecting section (50) corresponding to the explosion-proof valve relief groove (43) and a tab protection section (51) corresponding to the two pole through holes (40) respectively. The protective cavity (510) is provided on the tab protection section (51). A set of the hot melt structure is provided at the position between the middle connecting section (50) and the tab protection section (51) and at the end position of the protective plate (5) away from the bending part (3).

4. The battery cell according to claim 3, characterized in that: The width W between the protective cavity (510) and the side edge of the protective sheet (5) is between 0.5mm and 12mm.

5. The battery cell according to claim 2, characterized in that: Along the length of the battery cell, the protective sheet (5) consists of two pieces connected to both ends of the insulating sheet (4) via a bend (3); a set of hot-melt structures is provided between each of the protective sheet (5) and the insulating sheet (4), and the hot-melt structures are located at one end of the protective sheet (5) away from the bend (3).

6. The battery cell according to claim 1, characterized in that: The hot-melt structure includes a hot-melt column (42) integrally formed on the isolation sheet (4) and a hot-melt hole (52) correspondingly disposed on the protective sheet (5); the hot-melt column (42) is inserted and hot-melted fixed in the hot-melt hole (52).

7. The battery cell according to claim 6, characterized in that: The protective plate (5) has a boss (53) on the side facing the isolation plate (4), and the hot melt hole (52) is opened on the boss (53). As the hot melt column (42) is hot melted and fixed to the hot melt hole (52), the boss (53) abuts against the isolation plate (4). The hot-melt hole (52) includes a through section (521) and a hot-melt section (522) connected in sequence, and the radial dimension D of the hot-melt section (522) is greater than the radial dimension d of the through section (521); the hot-melt column (42) passes through the through section (521), and the head (420) of the hot-melt column (42) is hot-melted and compacted in the hot-melt section (522).

8. The battery cell according to any one of claims 1 to 7, characterized in that: The protective cavity (510) has a hole (511) on its side wall, and there is a gap between the hole (511) and the bottom of the protective cavity (510).

9. The battery cell according to claim 8, characterized in that: The width and length directions of the protective cavity (510) are consistent with the battery cell, and the holes (511) are provided on the two side walls of the protective cavity (510) in the length direction. The protective cavity (510) has deformation grooves (512) that extend through the entire length of the protective cavity (510) on both side walls in the width direction, and the deformation grooves (512) penetrate the side walls of the protective cavity (510).

10. A power battery, characterized in that: The power battery uses the battery cell described in any one of claims 1 to 9.

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