Laminated lithium battery

Abstract

The utility model provides a laminated lithium battery, which relates to the technical field of batteries and comprises a naked battery cell and a coating body, a positive tab and a negative tab are respectively arranged on two sides of the naked battery cell, the positive tab and the negative tab are different in structure, the coating body comprises a shell and a cover plate, the top surface of the shell is provided with an accommodating space for accommodating the naked battery cell, the cover plate is fixedly arranged at the opening end of the shell, and a first positioning piece and a second positioning piece are respectively arranged at two ends of the shell. A first positioning groove matched with the positive lug is formed in the first positioning piece, and a second positioning groove matched with the negative lug is formed in the second positioning piece. According to the laminated lithium battery disclosed by the utility model, the positioning pieces are respectively arranged at the two ends of the shell, the structures of the positive and negative tabs of the naked battery cell are differentiated, and meanwhile, the positioning grooves in the positioning pieces are matched with the structures of the positive and negative tabs, so that the tabs are prevented from being displaced or misplaced in the assembly process; therefore, the problem of aliasing caused by wrong positions of the positive and negative pole pieces is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a laminated lithium battery. Background Art

[0002] The bare battery cell is an important component of a lithium-ion battery. The bare battery cells are divided into wound type and laminated type. Among them, the laminated bare battery cell is composed of a positive electrode sheet, a separator and a negative electrode sheet, and one or more bare battery cells are encapsulated by a wrapping member to form a final lithium-ion battery product.

[0003] At present, the positive electrode tab and the negative electrode tab of the common laminated bare battery cell are generally rectangular structures, and are located on the same side but at different positions, and are distinguished by different colors. However, in the actual assembly process, there are some defects. For example, when the positive electrode sheet and the negative electrode sheet of the laminated bare battery cell are misaligned, it is difficult to detect the misalignment problem without damaging the structure of the bare battery cell. If this misalignment or the phenomenon that the positive and negative electrode sheets are in contact with each other is not discovered in time, it may cause serious consequences to the lithium-ion battery, such as short circuit or even spontaneous combustion. Summary of the Utility Model

[0004] In view of this, the utility model provides a laminated lithium battery, aiming to solve the problem of mixing or misalignment of the positive electrode sheet and the negative electrode sheet during the assembly process of the lithium battery.

[0005] The technical solution of the utility model is realized as follows:

[0006] The utility model discloses a laminated lithium battery, which comprises a bare battery cell and a wrapping body;

[0007] The bare battery cell includes a positive electrode sheet, a separator and a negative electrode sheet which are stacked, the separator is arranged between the positive electrode sheet and the negative electrode sheet, the same ends of a plurality of the positive electrode sheets are all provided with positive electrode tabs, the same ends of a plurality of the negative electrode sheets are all provided with negative electrode tabs, the positive electrode tabs and the negative electrode tabs are respectively located on both sides of the separator, and the structures of the positive electrode tabs and the negative electrode tabs are different;

[0008] The wrapping body includes a shell and a cover plate. The top surface of the shell has a receiving space, the bare battery cell is arranged in the receiving space, the cover plate is fixedly arranged at the opening end of the receiving space, the two ends of the shell are respectively provided with a first positioning member and a second positioning member, the first positioning member is provided with a first positioning groove adapted to the positive electrode tab, and the second positioning member is provided with a second positioning groove adapted to the negative electrode tab.

[0009] On the basis of the above technical solution, preferably, the first positioning groove is arranged on the top surface of the first positioning member and is communicated with the receiving space, and a first notch communicated with the first positioning groove is arranged on the top surface of the side of the first positioning member away from the shell;

[0010] The positive electrode tab includes a positive electrode positioning portion and a positive electrode connecting portion. The positive electrode positioning portion is received in the first positioning groove, and the outer contour of the positive electrode positioning portion is adapted to the inner contour of the first positioning groove. The positive electrode connecting portion horizontally extends outside the first notch.

[0011] Based on the above technical solution, preferably, the second positioning groove is provided on the top surface of the second positioning member and communicates with the accommodating space. A second notch communicating with the second positioning groove is formed on the top surface of the side of the second positioning member away from the housing.

[0012] The negative electrode tab includes a negative electrode positioning portion and a negative electrode connecting portion. The negative electrode positioning portion is received in the second positioning groove, and the outer contour of the negative electrode positioning portion is adapted to the inner contour of the second positioning groove. The negative electrode connecting portion horizontally extends outside the second notch. The structure of the negative electrode positioning portion is different from that of the positive electrode positioning portion.

[0013] Furthermore, preferably, the structure of the negative electrode connecting portion is the same as or different from that of the positive electrode connecting portion.

[0014] Furthermore, preferably, the length of the positive electrode connecting portion extending outside the first notch is the same as the length of the negative electrode connecting portion extending outside the second notch.

[0015] Based on the above technical solution, preferably, a plurality of limiting rods are vertically provided on the inner side wall of the accommodating space, and first limiting grooves adapted to the limiting rods are formed on the positive electrode plate, the separator, and the negative electrode plate.

[0016] Based on the above technical solution, preferably, a backing plate is further provided in the accommodating space. The backing plate is located between the cover plate and the bare battery cell, and a plurality of heat dissipation holes are formed on the backing plate.

[0017] Furthermore, preferably, second limiting grooves adapted to the limiting rods are formed on the backing plate.

[0018] Based on the above technical solution, preferably, a first sealing plate and a second sealing plate are respectively provided on the bottom surfaces of both ends of the cover plate. The first sealing plate is adapted to the first positioning groove, and the second sealing plate is adapted to the second positioning groove.

[0019] The utility model has the following beneficial effects compared with the prior art:

[0020] (1) By respectively arranging positioning members at both ends of the housing and differentiating the structures of the positive and negative electrode tabs of the bare battery cell, and at the same time making the positioning grooves on the positioning members adapt to the structures of the positive and negative electrode tabs, it is ensured that during the assembly process of the lithium battery, the positive electrode tab and the negative electrode tab are accurately embedded into the corresponding positioning grooves respectively. This structural arrangement not only prevents the displacement or misalignment of the electrode tabs that may occur during the assembly process, but also ensures that each electrode plate can be accurately positioned, thereby avoiding the problem of overlapping caused by the wrong position of the positive and negative electrode plates.

[0021] (2) By vertically arranging limiting rods in the accommodating space and correspondingly arranging first limiting grooves on the positive electrode plate, the separator and the negative electrode plate, and making the limiting rods cooperate with the first limiting grooves opened on the positive electrode plate, the separator and the negative electrode plate, even when impacted, can still avoid offset and misalignment, and the overall service life of the battery is improved.

[0022] (3) By respectively arranging sealing plates on the bottom surfaces at both ends of the cover plate, the positioning parts on the electrode tabs can be pressed in the vertical direction, ensuring that the positioning parts of all the electrode tabs can be stacked together in close contact, avoiding the increase in resistance caused by poor contact of the electrode tabs during the use of the battery, and ensuring the stability and reliability of the electrical connection. Description of the Drawings

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0024] Figure 1 It is a schematic perspective view of the first perspective of the stacked battery disclosed by the present invention;

[0025] Figure 2 It is a schematic perspective view of the second perspective of the stacked battery disclosed by the present invention;

[0026] Figure 3 It is a schematic perspective view of the bare battery cell disclosed by the present invention;

[0027] Figure 4 It is a schematic exploded view of the first perspective of the stacked battery disclosed by the present invention;

[0028] Figure 5 It is a schematic exploded view of the second perspective of the stacked battery disclosed by the present invention;

[0029] Reference Signs:

[0030] 1. Bare battery cell; 2. Coating body; 11. Positive electrode plate; 12. Separator; 13. Negative electrode plate; 14. Positive electrode tab; 15. Negative electrode tab; 21. Housing; 22. Cover plate; 210. Accommodating space; 23. First positioning member; 24. Second positioning member; 231. First positioning groove; 241. Second positioning groove; 232. First notch; 242. Second notch; 141. Positive electrode positioning portion; 142. Positive electrode connecting portion; 151. Negative electrode positioning portion; 152. Negative electrode connecting portion; 25. Limiting rod; 10. First limiting groove; 3. Pad; 31. Heat dissipation hole; 32. Second limiting groove; 221. First sealing plate; 222. Second sealing plate. Detailed implementation mode

[0031] Next, in combination with the implementation mode of the present utility model, the technical solutions in the implementation mode of the present utility model will be clearly and completely described. Obviously, the described implementation mode is only a part of the implementation modes of the present utility model, rather than all the implementation modes. Based on the implementation modes in the present utility model, all other implementation modes obtained by those of ordinary skill in the art without making creative efforts belong to the protection scope of the present utility model.

[0032] As Figure 1 shown, in combination with Figures 2 - 5 , an embodiment of the present utility model discloses a stacked lithium battery, including a bare battery cell 1 and a coating body 2.

[0033] Among them, the bare battery cell 1 includes a positive electrode plate 11, a separator 12 and a negative electrode plate 13 which are stacked. The separator 12 is arranged between the positive electrode plate 11 and the negative electrode plate 13. Positive electrode tabs 14 are arranged at the same end of multiple positive electrode plates 11, and negative electrode tabs 15 are arranged at the same end of multiple negative electrode plates 13. The positive electrode tab 14 and the negative electrode tab 15 are respectively located on both sides of the separator 12. Thus, the entire bare battery cell 1 is in the form of two-sided output of electrode tabs.

[0034] In this embodiment, the structures of the positive electrode tab 14 and the negative electrode tab 15 are different, so that during the stacking process of the bare battery cell 1, even if misalignment or mixed stacking occurs, operators or automated equipment can quickly identify and correct it through the structural differences. This structural setting fundamentally reduces the possibility of misalignment of the electrode plates, ensuring that each electrode plate can be correctly aligned and positioned.

[0035] The encapsulation body 2 is used to wrap the bare battery cell 1, and it includes a housing 21 and a cover plate 22. The top surface of the housing 21 has a receiving space 210, and the bare battery cell 1 is disposed in the receiving space 210. The cover plate 22 is fixedly disposed at the opening end of the receiving space 210, thereby encapsulating the bare battery cell 1 in the encapsulation body 2. First positioning members 23 and second positioning members 24 are respectively disposed at two ends of the housing 21. A first positioning groove 231 adapted to the positive electrode tab 14 is formed on the first positioning member 23, and a second positioning groove 241 adapted to the negative electrode tab 15 is formed on the second positioning member 24.

[0036] With the above technical solution, by respectively disposing positioning members at two ends of the housing 21, and making the positive and negative electrode tab structures of the bare battery cell 1 be differentially arranged, and at the same time, by making the positioning grooves on the positioning members be adapted to the structures of the positive and negative electrode tabs, it is ensured that during the assembly process of the lithium battery, the positive electrode tab 14 and the negative electrode tab 15 are respectively accurately inserted into the corresponding positioning grooves. This structural setting not only prevents the displacement or misalignment of the electrode tabs that may occur during the assembly process, but also ensures that each electrode plate can be accurately positioned, thereby avoiding the problem of overlapping caused by the incorrect position of the positive and negative electrode plates 13.

[0037] In addition, through the above structural setting, the automated equipment can more reliably identify and position the positive and negative electrode plates 13, reducing the risk of assembly errors caused by misalignment or overlapping. The combination of the positioning members and the differential design of the electrode tab structures enables effective avoidance of misalignment problems even in a high-speed production environment, ensuring that each electrode plate can be accurately assembled. Secondly, through the above structural setting, the problem of battery short circuit caused by the misalignment or overlapping of the positive and negative electrode plates 13 can be effectively avoided during the assembly process, thereby greatly improving the safety of the lithium battery.

[0038] As some preferred embodiments, the first positioning groove 231 is disposed on the top surface of the first positioning member 23 and is communicated with the receiving space 210. A first notch 232 communicated with the first positioning groove 231 is formed on the top surface of the side of the first positioning member 23 away from the housing 21. The positive electrode tab 14 includes a positive electrode positioning portion 141 and a positive electrode connecting portion 142. The positive electrode positioning portion 141 is received in the first positioning groove 231, and the outer contour of the positive electrode positioning portion 141 is adapted to the inner contour of the first positioning groove 231. The positive electrode connecting portion 142 horizontally extends out of the outside of the first notch 232.

[0039] With the above technical solution, by making the outer contour of the positive electrode positioning portion 141 be adapted to the inner contour of the first positioning groove 231, the accurate fixation of the positive electrode positioning portion 141 in the first positioning groove 231 is ensured, thereby avoiding problems such as loosening or position deviation during the assembly or use process. The horizontal extension of the positive electrode connecting portion 142 out of the outside of the first notch 232 ensures that the positive electrode tab 14 can be smoothly connected to the external circuit, guaranteeing the electrical performance of the battery.

[0040] As some preferred embodiments, the second positioning groove 241 is provided on the top surface of the second positioning member 24 and communicates with the accommodating space 210. A second notch 242 communicating with the second positioning groove 241 is formed on the top surface of the side of the second positioning member 24 away from the housing 21.

[0041] The negative electrode tab 15 includes a negative electrode positioning portion 151 and a negative electrode connecting portion 152. The negative electrode positioning portion 151 is received in the second positioning groove 241, and the outer contour of the negative electrode positioning portion 151 is adapted to the inner contour of the second positioning groove 241. The negative electrode connecting portion 152 horizontally extends outside the second notch 242.

[0042] With the above technical solution, by making the outer contour of the negative electrode positioning portion 151 adapted to the inner contour of the second positioning groove 241, the accurate fixation of the negative electrode positioning portion 151 in the second positioning groove 241 is ensured, thus avoiding problems such as loosening or position deviation during assembly or use. The horizontal extension of the negative electrode connecting portion 152 outside the second notch 242 ensures that the negative electrode tab 15 can be smoothly connected to the external circuit, guaranteeing the electrical performance of the battery.

[0043] In this embodiment, the structure of the negative electrode positioning portion 151 is different from that of the positive electrode positioning portion 141. This differential design not only helps to quickly identify and distinguish the positive and negative electrode tabs during assembly to avoid assembly errors, but also can further enhance the distinguishability and functionality of the positive and negative electrode tabs through different material or shape designs.

[0044] As some preferred embodiments, the structure of the negative electrode connecting portion 152 is the same as or different from that of the positive electrode connecting portion 142. When the structure of the negative electrode connecting portion 152 is the same as that of the positive electrode connecting portion 142, the same molds and materials can be used in the production process, reducing the complexity of the production line and the switching cost, improving the production efficiency, and reducing the production cost. When the structure of the negative electrode connecting portion 152 is different from that of the positive electrode connecting portion 142, this allows for customized design of the positive and negative electrode connecting portions 152 according to different application scenarios. For example, when higher current-carrying capacity or different environmental adaptability is required, different structural designs can be adopted to optimize the overall performance of the battery.

[0045] As some preferred embodiments, the length of the positive electrode connecting portion 142 extending outside the first notch 232 is the same as the length of the negative electrode connecting portion 152 extending outside the second notch 242. With the above technical solution, the same length of the positive and negative electrode connecting portions 152 can ensure that when connecting to the external circuit, the resistance and current distribution received by both are the same. This reduces the problem of inconsistent electrical performance that may be caused by the length difference of the connecting portions, thus ensuring the stability and uniformity of the battery during charge and discharge processes, and improving the overall performance and safety of the battery.

[0046] As some preferred embodiments, a plurality of limiting rods 25 are vertically arranged on the inner side wall of the accommodating space 210, and first limiting grooves 10 matching with the limiting rods 25 are formed on the positive electrode sheet 11, the separator 12 and the negative electrode sheet 13. Specifically, in this embodiment, the limiting rods 25 are respectively arranged on both sides in the width direction of the accommodating space 210. By the cooperation of the limiting rods 25 and the first limiting grooves 10 formed on the positive electrode sheet 11, the separator 12 and the negative electrode sheet 13, even when impacted, the offset and dislocation can be avoided, and the service life of the battery is improved as a whole.

[0047] As some alternative embodiments, it further includes a backing plate 3 arranged in the accommodating space 210. The backing plate 3 is located between the cover plate 22 and the bare battery cell 1, and a plurality of heat dissipation holes 31 are formed on the backing plate 3. By adopting the above technical solution, the buffering effect of the backing plate 3 in the battery structure can effectively reduce the direct impact of external force on the bare battery cell 1, and reduce the damage of the battery cell caused by mechanical stress, thereby improving the safety and durability of the battery. After the cover plate 22 is installed on the opening end of the housing 21, the heat dissipation holes 31 formed on the backing plate 3 prevent complete fitting, so that there is a certain heat dissipation gap. The arrangement of the heat dissipation holes 31 enables the heat inside the battery to be conducted to the outside faster, reducing the temperature accumulation inside the battery.

[0048] On the basis of the above technical solution, by designing second limiting grooves 32 on the backing plate 3 that match with the limiting rods 25, the backing plate 3 can be more firmly fixed inside the battery, reducing the possible displacement or loosening of the backing plate 3 during the assembly and use processes, thereby improving the overall structural stability of the battery.

[0049] Since the first positioning member 23 and the second positioning member 24 are arranged outside the housing 21, and the area of the cover plate 22 is adapted to the area of the opening end of the housing 21, the positive electrode positioning portion 141 in the first positioning groove 231 cannot be tightly pressed in the height direction of the housing 21. Correspondingly, the negative electrode positioning portion 151 in the second positioning groove 241 cannot be tightly pressed in the height direction of the housing 21.

[0050] Therefore, in this embodiment, a first sealing plate 221 and a second sealing plate 222 are respectively arranged on the bottom surfaces at both ends of the cover plate 22. The first sealing plate 221 is adapted to the first positioning groove 231, and the second sealing plate 222 is adapted to the second positioning groove 241.

[0051] By adopting the above technical solution, the first sealing plate 221 can press the positive electrode positioning portion 141 in the vertical direction to ensure that all the positive electrode positioning portions 141 can be stacked together in close contact. Correspondingly, the second sealing plate 222 can press the negative electrode positioning portion 151 in the vertical direction to ensure that all the negative electrode positioning portions 151 can be stacked together in close contact, avoiding the increase in resistance caused by poor contact of the electrode tabs during the use of the battery, and ensuring the stability and reliability of the electrical connection.

[0052] It should be noted that for the stacked lithium battery disclosed in this embodiment, after assembly, glue can be applied for sealing at the connection between the above-mentioned sealing plate and the positioning groove. At the same time, glue is applied for sealing at the connection between the tab and the notch, so as to ensure the sealing performance of the entire lithium battery.

[0053] The above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A laminated lithium battery, comprising a bare cell (1) and a coating (2), characterized in that: The bare battery cell (1) comprises a positive electrode sheet (11), a separator (12) and a negative electrode sheet (13) which are stacked, the separator (12) being arranged between the positive electrode sheet (11) and the negative electrode sheet (13), a positive electrode ear (14) being arranged at the same end of a plurality of the positive electrode sheets (11), a negative electrode ear (15) being arranged at the same end of a plurality of the negative electrode sheets (13), the positive electrode ear (14) and the negative electrode ear (15) being respectively located on two sides of the separator (12), and the structure of the positive electrode ear (14) is different from that of the negative electrode ear (15); The encapsulation body (2) comprises a shell (21) and a cover plate (22); the top surface of the shell (21) has a containing space (210); the bare battery cell (1) is arranged in the containing space (210); the cover plate (22) is fixedly arranged at the open end of the containing space (210); a first positioning member (23) and a second positioning member (24) are respectively arranged at both ends of the shell (21); a first positioning groove (231) adapted to the positive electrode ear (14) is provided on the first positioning member (23); and a second positioning groove (241) adapted to the negative electrode ear (15) is provided on the second positioning member (24).

2. The laminated lithium battery according to claim 1, characterized in that: The first positioning groove (231) is arranged on the top surface of the first positioning member (23) and is connected to the accommodating space (210); a first notch (232) connected to the first positioning groove (231) is provided on the top surface of the first positioning member (23) away from the housing (21); The positive electrode ear (14) comprises a positive electrode positioning portion (141) and a positive electrode connecting portion (142), wherein the positive electrode positioning portion (141) is received in the first positioning groove (231), and the outer contour of the positive electrode positioning portion (141) is matched with the inner contour of the first positioning groove (231), and the positive electrode connecting portion (142) extends horizontally out of the outside of the first notch (232).

3. The laminated lithium battery according to claim 2, characterized in that: The second positioning groove (241) is arranged on the top surface of the second positioning member (24) and is connected to the accommodating space (210); a second notch (242) connected to the second positioning groove (241) is provided on the top surface of the second positioning member (24) away from the housing (21); The negative electrode ear (15) comprises a negative electrode positioning portion (151) and a negative electrode connecting portion (152); the negative electrode positioning portion (151) is received in the second positioning groove (241), and the outer contour of the negative electrode positioning portion (151) is matched with the inner contour of the second positioning groove (241); the negative electrode connecting portion (152) extends horizontally out of the outside of the second notch (242); and the structure of the negative electrode positioning portion (151) is different from that of the positive electrode positioning portion (141).

4. The laminated lithium battery according to claim 3, characterized in that: The structure of the negative electrode connecting portion (152) is the same as or different from the structure of the positive electrode connecting portion (142).

5. The laminated lithium battery according to claim 3, characterized in that: The length of the positive electrode connecting portion (142) extending out of the outside of the first notch (232) is the same as the length of the negative electrode connecting portion (152) extending out of the outside of the second notch (242).

6. The laminated lithium battery according to claim 1, characterized in that: A plurality of limiting rods (25) are vertically arranged on the inner side wall of the accommodating space (210), and first limiting grooves (10) matching with the limiting rods (25) are provided on the positive electrode sheet (11), the diaphragm (12) and the negative electrode sheet (13).

7. The laminated lithium battery according to claim 1, characterized in that: It also includes a pad (3) arranged in the accommodating space (210), the pad (3) being located between the cover plate (22) and the bare battery cell (1), and having a plurality of heat dissipation holes (31) formed on the pad (3).

8. The laminated lithium battery according to claim 7, characterized in that: The backing plate (3) is provided with a second limiting groove (32) which matches the limiting rod (25).

9. The laminated lithium battery according to claim 3, characterized in that: The bottom surfaces at both ends of the cover plate (22) are respectively provided with a first sealing plate (221) and a second sealing plate (222); the first sealing plate (221) is matched with the first positioning groove (231), and the second sealing plate (222) is matched with the second positioning groove (241).

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