Soft package battery

Abstract

The utility model provides a soft package battery which comprises a packaging film, the packaging film comprises a first part, a second part and a third part, the first part comprises a first wall surface and a second wall surface which are opposite to each other, and a through hole is formed in the first part; the first battery cell is arranged on the first wall surface; the second battery cell is arranged on the second wall surface, and the projection of the first battery cell on the first part is not intersected with the projection of the second battery cell on the first part; the connecting mechanism penetrates through the through hole and enables the first battery cell and the second battery cell to be connected in series or in parallel; the positive tab and the negative tab are exposed out of the packaging film; the second part is attached to the first wall surface and seals the first battery cell in the packaging film; and the third part is attached to the second wall surface and seals the second battery cell in the packaging film. The problem that when a battery with a plurality of battery cells drops, electrolyte of different battery cells may be mixed together after leakage can be effectively solved.

Description

Technical Field

[0001] The utility model relates to the technical field of new energy, in particular to a soft-pack battery. Background Art

[0002] In modern soft-pack battery technology, the design of wound battery cores often faces a series of challenges. Especially in the process of pursuing large battery core capacity, it is usually necessary to increase the number of winding layers, which directly leads to a significant increase in the thickness of the battery core. This increase in thickness not only increases the overall size of the soft-pack battery, but may also cause a series of potential problems, among which the most prominent is the risk of lithium deposition at the corners. Lithium deposition at the corners means that during the charge and discharge process of the soft-pack battery, lithium metal precipitates at the corners to form lithium dendrites, which may pierce the separator and cause the soft-pack battery to short-circuit, seriously affecting the safety and service life of the soft-pack battery.

[0003] For the special requirements of some customers for the length of the battery core, they may have no specific restrictions on the length and width of the small battery core, but have strict control over the thickness of the battery core. This requirement is particularly common in electronic products that pursue high energy density and thin and light designs. However, when customers have a large demand for the battery core capacity, it is particularly difficult to achieve the design of a high-capacity battery core while meeting the thickness limit. Therefore, there are batteries in which multiple battery cores are connected in series or in parallel inside the battery, and multiple battery cores are sealed and fixed on the same side of the packaging film. During the falling process, the sealing and fixing of the packaging film is likely to fail, resulting in problems such as the battery cores falling off and shifting, which may cause the electrolyte to leak out and mix together, and even cause the battery cores to contact each other and cause the battery to short-circuit.

[0004] To solve this problem, the present solution proposes a new soft-pack battery. Summary of the Utility Model

[0005] The utility model aims to solve at least one of the technical problems existing in the prior art. For this purpose, the utility model proposes a soft-pack battery, which can effectively solve the problem that the electrolytes of different battery cores in a battery with multiple battery cores may mix together when the battery drops.

[0006] A soft-pack battery according to an embodiment of the first aspect of the utility model includes: a packaging film, the packaging film includes a first part, a second part and a third part, the first part includes a first wall surface and a second wall surface facing away from each other; a first battery core, the first battery core is arranged on the first wall surface; a second battery core, the second battery core is arranged on the second wall surface, and the projection of the first battery core in the thickness direction of the first part and the projection of the second battery core on the first part do not intersect; the second part is attached to the first wall surface and seals the first battery core in the packaging film; the third part is attached to the second wall surface and seals the second battery core in the packaging film.

[0007] A soft-pack battery according to an embodiment of the first aspect of the present invention has at least the following beneficial effects: The first battery cell and the second battery cell are arranged on two opposite sides of the packaging film. When the battery drops, even if the sealing and fixing between the battery cell and the packaging film fails, the packaging film will separate the first battery cell and the second battery cell on both sides of the packaging film, which can not only prevent the mixing of their electrolytes, but also prevent the first battery cell and the second battery cell from contacting each other and causing an internal short circuit of the battery.

[0008] According to some embodiments of the present invention, it further includes a connecting mechanism, a positive electrode tab and a negative electrode tab. A through hole is formed in the first part, and the connecting mechanism passes through the through hole to connect the first battery cell and the second battery cell in series or in parallel.

[0009] According to some embodiments of the present invention, the first part includes a first area and a second area. A first groove is formed in the first area, and the opening direction of the first groove faces the first battery cell, and the first battery cell is arranged in the first groove. A second groove is formed in the second area, and the opening direction of the second groove faces the second battery cell, and the second battery cell is arranged in the second groove.

[0010] According to some embodiments of the present invention, the packaging film is an aluminum-plastic film, and the aluminum-plastic film includes a polypropylene layer. The side of the first area close to the first battery cell is the polypropylene layer, the side of the second part close to the first battery cell is the polypropylene layer, the side of the second area close to the second battery cell is the polypropylene layer, and the side of the third part close to the second battery cell is the polypropylene layer.

[0011] According to some embodiments of the present invention, the aluminum-plastic film further includes a nylon layer, and the side of the aluminum-plastic film opposite to the polypropylene layer is the nylon layer.

[0012] According to some embodiments of the present invention, the second part, the first part and the third part are arranged in sequence along the length direction of the packaging film. The second part is bent and covers the first wall surface, and the third part is bent and covers the second wall surface.

[0013] According to some embodiments of the present utility model, it further includes a positive electrode tab and a negative electrode tab. The first battery cell and the second battery cell are connected in series. The connecting mechanism includes a first connecting member. The first connecting member passes through the through hole and connects the positive electrode of the first battery cell and the negative electrode of the second battery cell. The positive electrode tab is connected to the second battery cell and is exposed outside the packaging film. The negative electrode tab is connected to the first battery cell and is exposed outside the packaging film; or, the first connecting member passes through the through hole and connects the negative electrode of the first battery cell and the positive electrode of the second battery cell. The positive electrode tab is connected to the first battery cell and is exposed outside the packaging film. The negative electrode tab is connected to the second battery cell and is exposed outside the packaging film.

[0014] According to some embodiments of the present utility model, one end of the first connecting member is connected to the surface of the first battery cell close to the second battery cell, and the other end of the first connecting member is connected to the surface of the second battery cell close to the first battery cell.

[0015] According to some embodiments of the present utility model, it further includes a positive electrode tab and a negative electrode tab. The first battery cell and the second battery cell are connected in parallel. The connecting mechanism includes a second connecting member and a third connecting member. The second connecting member passes through the through hole and connects the positive electrodes of the first battery cell and the second battery cell. The third connecting member passes through the through hole and connects the negative electrodes of the first battery cell and the second battery cell; the positive electrode tab is connected to the positive electrode of the first battery cell or the second battery cell and is exposed outside the packaging film. The negative electrode tab is connected to the negative electrode of the first battery cell or the second battery cell and is exposed outside the packaging film.

[0016] According to some embodiments of the present utility model, the second part and the third part cover both ends of the through hole and wrap the connecting mechanism inside the packaging film.

[0017] The additional aspects and advantages of the present utility model will be partially given in the following description, partially become apparent from the following description, or be understood through the practice of the present utility model. Description of the Drawings

[0018] Figure 1 It is a schematic structural diagram of the packaging film of the present utility model;

[0019] Figure 2 It is a schematic structural diagram of the present utility model with a groove provided;

[0020] Figure 3 It is a schematic structural diagram of the battery cell arranged in the groove in the present utility model;

[0021] Figure 4 It is a schematic structural diagram of the battery cell being wrapped and sealed by the packaging film in the present utility model.

[0022] Reference numerals in the drawings:

[0023] 1. Packaging film; 11. First part; 111. First region; 112. Second region; 12. Second part; 13. Third part; 14. First wall surface; 15. Second wall surface; 16. First groove; 17. Second groove; 18. Through hole; 2. First battery cell; 3. Second battery cell; 4. Connecting mechanism; 5. Positive tab; 6. Negative tab. Detailed implementation manners

[0024] The embodiments of the present utility model will be described in detail below. The examples of the embodiments are shown in the drawings, wherein the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present utility model, and should not be construed as a limitation to the present utility model.

[0025] In the description of the present utility model, it should be understood that for the orientation description, such as the upper and lower directions, the orientation or positional relationship indicated is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present utility model.

[0026] In the description of the present utility model, "a plurality of" means more than two. If the first and second are described only for the purpose of distinguishing technical features, they should not be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or the sequence of the indicated technical features.

[0027] In the description of the present utility model, unless otherwise clearly defined, terms such as "set", "installed", and "connected" should be understood in a broad sense. Those skilled in the art can reasonably determine the specific meanings of the above terms in the present utility model in combination with the specific content of the technical solution.

[0028] In the prior art, an overly thick battery cell may bring many disadvantages, such as: increased internal resistance, decreased charge-discharge performance, and safety issues. An overly thick battery cell may cause an increase in the resistance encountered by ions when moving between the positive and negative electrodes, thereby increasing the internal resistance of the soft-pack battery. This will reduce the charge-discharge efficiency of the soft-pack battery and lead to a decline in the performance of the soft-pack battery. An overly thick battery cell may cause a decline in the charge-discharge performance of the soft-pack battery. During the charging process, a thicker battery cell takes longer to be fully charged; during the discharging process, a thicker battery cell may not be able to provide enough current to meet the device's requirements. An overly thick battery cell may increase the safety risk of the soft-pack battery. During the use of the soft-pack battery, if the battery cell is overly thick, it may cause excessive heat accumulation inside the soft-pack battery, thereby triggering safety issues such as thermal runaway. In addition, a thicker battery cell may also be more easily damaged when the soft-pack battery is subjected to an external impact, further increasing the safety risk. In summary, an overly thick battery cell may have a negative impact on the performance, safety, and cost of the soft-pack battery. Therefore, multiple battery cells are arranged inside the battery, and the battery cells are separately arranged to increase the length and width of the battery in order to reduce the thickness of the battery. However, when multiple battery cells are arranged, they are prone to falling off and shifting during the process of the battery dropping, resulting in liquid leakage and even short circuit of the battery.

[0029] Referring to Figure 1 , Figure 2 , Figure 3 and Figure 4 , a soft-pack battery in the first embodiment of the present utility model includes: a packaging film 1, a first battery cell 2, a second battery cell 3, a connection mechanism 4, a positive electrode tab 5, and a negative electrode tab 6. The packaging film 1 includes a first part 11, a second part 12, and a third part 13. The first part 11 includes a first wall surface 14 and a second wall surface 15 facing each other, and a through hole 18 is formed on the first part 11; the first battery cell 2 is arranged on the first wall surface 14; the second battery cell 3 is arranged on the second wall surface 15, and the projections of the first battery cell 2 and the second battery cell 3 on the first part 11 of the packaging film 1 do not intersect. By arranging the two battery cells on both sides of the first part 11 of the packaging film 1, when the first battery cell 2 and the second battery cell 3 are sealed at this time, the first battery cell 2 and the second battery cell 3 will be directly separated by the first part 11 of the packaging film 1. At this time, only by puncturing the packaging film 1 can the separation effect between the first battery cell 2 and the second battery cell 3 be destroyed. Compared with sealing and laminating the upper and lower layers of the packaging film 1 through a packaging line, separating through the first part 11 of the packaging film 1 is more stable. When the battery drops, the laminated packaging film 1 is more easily damaged and separated, while the packaging film 1 itself has high strength and is not easily damaged. Thus, the first battery cell 2 and the second battery cell 3 in this solution are not prone to shifting during dropping.

[0030] The connecting mechanism 4 passes through the through-hole 18 to connect the first battery cell 2 and the second battery cell 3 in series or in parallel. Since the first battery cell 2 and the second battery cell 3 are respectively arranged on both sides of the first part 11, it is necessary to penetrate the packaging film 1 to connect the first battery cell 2 and the second battery cell 3. Therefore, a through-hole 18 is opened on the first part 11 so that the connecting structure connecting the first battery cell 2 and the second battery cell 3 can pass through the packaging film 1.

[0031] When the first battery cell 2 and the second battery cell 3 are connected in parallel, the positive electrode tab 5 is connected to the positive electrode of the first battery cell 2 or the second battery cell 3 and is exposed outside the packaging film 1, and the negative electrode tab 6 is connected to the negative electrode of the first battery cell 2 or the second battery cell 3 and is exposed outside the packaging film 1. The positive electrode of the first battery cell 2 is connected to the positive electrode of the second battery cell 3 through the connecting mechanism 4, and the negative electrode of the first battery cell 2 is connected to the negative electrode of the second battery cell 3 through the connecting mechanism 4. At this time, the positive electrode tab 5 and the negative electrode tab 6 can be arranged at any positions of the first battery cell 2 and the second battery cell 3, that is, the positive electrode tab 5 and the negative electrode tab 6 can be respectively arranged on the first battery cell 2 and the second battery cell 3, or can be simultaneously arranged on the first battery cell 2 or the second battery cell 3.

[0032] When the first battery cell 2 and the second battery cell 3 are connected in series, the positive electrode tab 5 is arranged on one of the first battery cell 2 and the second battery cell 3 and is exposed outside the packaging film 1, and the negative electrode tab 6 is arranged on the other of the first battery cell 2 and the second battery cell 3 and is exposed outside the packaging film 1; at this time, when the positive electrode of the first battery cell 2 is connected to the negative electrode of the second battery cell 3 through the connecting mechanism 4, the positive electrode tab 5 is arranged on the second battery cell 3, and the negative electrode tab 6 is arranged on the first battery cell 2. When the negative electrode of the first battery cell 2 is connected to the positive electrode of the second battery cell 3 through the connecting mechanism 4, the positive electrode tab 5 is arranged on the first battery cell 2, and the negative electrode tab 6 is arranged on the second battery cell 3.

[0033] The second part 12 is attached to the first wall surface 14 and seals the first battery cell 2 inside the packaging film 1; the third part 13 is attached to the second wall surface 15 and seals the second battery cell 3 inside the packaging film 1. The first battery cell 2 and the second battery cell 3 are respectively encapsulated on both sides of the first part 11 through the second part 12 and the third part 13. When the first battery cell 2 is sealed inside the packaging film 1, the first part 11 may be recessed to accommodate the first battery cell 2, or the second part 12 may be recessed to accommodate the first battery cell 2, or the first part 11 and the second part 12 may be recessed simultaneously to jointly accommodate the first battery cell 2. The second battery cell 3 is arranged in the same way as the first battery cell 2.

[0034] According to some embodiments of the present utility model, the first part 11 includes a first region 111 and a second region 112. A first groove 16 is formed in the first region 111, and the opening direction of the first groove 16 faces the first battery cell 2. The first battery cell 2 is disposed in the first groove 16. A second groove 17 is formed in the second region 112, and the opening direction of the second groove 17 faces the second battery cell 3. The second battery cell 3 is disposed in the second groove 17. In order to more firmly seal and fix the first battery cell 2 and the second battery cell 3 in the packaging film 1, two grooves are stamped on the first part 11 by stamping. Among them, the first groove 16 in the two grooves is a groove formed by the inward depression of the first wall surface 14 with an opening facing the first battery cell 2, and the second groove 17 is a groove formed by the inward depression of the second wall surface 15 with an opening facing the second battery cell 3. Placing the first battery cell 2 into the first groove 16 can not only better seal the first battery cell 2, but also play a positioning role for the first battery cell 2 through the first groove 16, so that the inside of the first groove 16 forms a fixing force on the first battery cell 2, thereby reducing the stress at the sealed connection between the first part 11 and the second part 12 and reducing the risk of damage to the sealed ring of the first battery cell 2. The second battery cell 3 and the second groove 17 are arranged on the side of the first part 11 opposite to the first battery cell 2 in the same way.

[0035] According to some embodiments of the present utility model, the packaging film 1 is an aluminum-plastic film, and the aluminum-plastic film includes a polypropylene layer. The side of the first region 111 and the second part 12 close to the first battery cell 2 is the polypropylene layer, and the side of the second region 112 and the third part 13 close to the second battery cell 3 is the polypropylene layer. Among them, polypropylene has good sealing performance, is easy to weld, and at the same time has strong stability and is not easy to react with the electrolyte. Therefore, the side of the packaging film 1 close to the battery cell is set as the polypropylene layer. This not only ensures that it will not be corroded by the internal electrolyte, but also has a good sealing effect when the packaging film 1 is hermetically connected. The first part 11 is divided into two regions, namely the first region 111 and the second region 112. On the side facing the first battery cell 2, the first region 111 is the polypropylene layer and the second region 112 is the nylon layer. On the side facing the second battery cell 3, the second region 112 is the polypropylene layer and the first region 111 is the nylon layer. At this time, the nylon layer is exposed on the outside and has good anti-wear performance.

[0036] According to some embodiments of the present utility model, a second part 12, a first part 11 and a third part 13 are sequentially arranged along the length direction of the packaging film 1. The second part 12 is bent and covers the first wall surface 14, and the third part 13 is bent and covers the second wall surface 15. A whole packaging film 1 is used to wrap the first battery cell 2 and the second battery cell 3. Specifically, the packaging film 1 is divided from the middle, which is the boundary line between the first area 111 and the second area 112 in the first part 11. The sides of the first area 111 and the second part 12 facing the first battery cell 2 are polypropylene layers, and the sides of the second area 112 and the third part 13 facing the second battery cell 3 are polypropylene layers. The first battery cell 2 is placed in the first area 111, and the second part 12 is bent to cover the first battery cell 2 and is hermetically connected to the first area 111. The second battery cell 3 is arranged in the second area 112 in the same way.

[0037] According to some embodiments of the present utility model, when the first battery cell 2 and the second battery cell 3 are connected in series, the connection mechanism 4 includes a first connecting piece. The first connecting piece passes through the through hole 18 and connects the positive electrode of the first battery cell 2 and the negative electrode of the second battery cell 3. The positive electrode tab 5 is connected to the second battery cell 3, and the negative electrode tab 6 is connected to the first battery cell 2; alternatively, the first connecting piece passes through the through hole 18 and connects the negative electrode of the first battery cell 2 and the positive electrode of the second battery cell 3. The positive electrode tab 5 is connected to the first battery cell 2, and the negative electrode tab 6 is connected to the second battery cell 3. The first battery cell 2 and the second battery cell 3 can be connected in series or the first battery cell 2 and the second battery cell 3 can be connected in parallel, which can adapt to various connection methods.

[0038] According to some embodiments of the present utility model, one end of the first connecting piece is connected to the surface of the first battery cell 2 close to the second battery cell 3, and the other end of the first connecting piece is connected to the surface of the second battery cell 3 close to the first battery cell 2. At this time, the first connecting piece can connect the first battery cell 2 and the second battery cell 3 within the smallest distance, thereby reducing the use length of the first connecting piece, reducing the weight of the battery, and increasing the energy density of the battery.

[0039] According to some embodiments of the present utility model, when the first battery cell 2 and the second battery cell 3 are connected in parallel, the connection mechanism 4 includes a second connecting piece and a third connecting piece. The second connecting piece passes through the through hole 18 and connects the positive electrodes of the first battery cell 2 and the second battery cell 3, and the third connecting piece passes through the through hole 18 and connects the negative electrodes of the first battery cell 2 and the second battery cell 3. Both the second connecting piece and the third connecting piece pass through the through hole 18. Two through holes 18 can be provided so that the second connecting piece and the third connecting piece pass through different through holes 18 respectively. Or only one through hole 18 can be provided, and an insulating layer is provided between the second connecting piece and the third connecting piece to insulate the second connecting piece from the third connecting piece and prevent the battery from short-circuiting.

[0040] According to some embodiments of the present utility model, a plurality of positive electrodes and a plurality of negative electrodes are provided on the first battery cell 2, and one positive electrode and one negative electrode of the first battery cell 2 are arranged on one side close to the second battery cell 3; a plurality of positive electrodes and a plurality of negative electrodes are provided on the second battery cell 3, and one positive electrode and one negative electrode of the second battery cell 3 are arranged on one side close to the first battery cell 2. One positive electrode and one negative electrode of the first battery cell 2 and one positive electrode and one negative electrode of the second battery cell 3 are arranged between the first battery cell 2 and the second battery cell 3 to facilitate the connection between the first battery cell 2 and the second battery cell 3 through the connection mechanism 4.

[0041] According to some embodiments of the present utility model, the second part 12 and the third part 13 cover both ends of the through hole 18 and wrap the connection mechanism 4 in the packaging film 1. When covering the first battery cell 2 and the second battery cell 3 through the second part 12 and the third part 13, a larger coverage range is set to cover and wrap the through hole 18 and the connection mechanism 4 on the packaging film 1 as well.

[0042] The embodiments of the present utility model have been described in detail above in conjunction with the accompanying drawings. However, the present utility model is not limited to the above embodiments, and various changes can be made without departing from the gist of the present utility model within the scope of knowledge possessed by those of ordinary skill in the art to which it pertains.

Claims

1. A soft pack battery, characterized in that: include: A packaging film, the packaging film comprising a first portion, a second portion and a third portion, the first portion comprising a first wall surface and a second wall surface opposite to each other; a first battery cell, wherein the first battery cell is disposed on the first wall surface; a second battery cell, wherein the second battery cell is disposed on the second wall surface, and a projection of the first battery cell in a thickness direction of the first portion and a projection of the second battery cell on the first portion do not intersect; The second part is attached to the first wall surface and seals the first battery cell in the packaging film; The third portion is attached to the second wall surface and seals the second battery cell in the packaging film.

2. A soft pack battery according to claim 1, characterized in that: It also includes a connecting mechanism, a positive electrode ear and a negative electrode ear. The first part is provided with a through hole. The connecting mechanism passes through the through hole and connects the first battery cell and the second battery cell in series or in parallel.

3. A soft pack battery according to claim 1, characterized in that: The first part includes a first area and a second area, the first area is provided with a first groove, the opening direction of the first groove is toward the first battery cell, and the first battery cell is arranged in the first groove, the second area is provided with a second groove, the opening direction of the second groove is toward the second battery cell, and the second battery cell is arranged in the second groove.

4. A soft pack battery according to claim 3, characterized in that: The packaging film is an aluminum-plastic film, which includes a polypropylene layer. The side of the first region close to the first battery cell is the polypropylene layer, the side of the second portion close to the first battery cell is the polypropylene layer, the side of the second region close to the second battery cell is the polypropylene layer, and the side of the third portion close to the second battery cell is the polypropylene layer.

5. A soft pack battery according to claim 4, characterized in that: The aluminum-plastic film further comprises a nylon layer, and the side of the aluminum-plastic film facing away from the polypropylene layer is the nylon layer.

6. The soft pack battery according to claim 1, characterized in that: The second part, the first part and the third part are sequentially arranged along the length direction of the packaging film, the second part is bent and covers the first wall surface, and the third part is bent and covers the second wall surface.

7. The soft pack battery according to claim 2, characterized in that: It also includes a positive electrode ear and a negative electrode ear, the first battery cell and the second battery cell are connected in series, the connecting mechanism includes a first connecting member, the first connecting member passes through the through hole and connects the positive electrode of the first battery cell and the negative electrode of the second battery cell, the positive electrode ear is connected to the second battery cell and exposed outside the packaging film, and the negative electrode ear is connected to the first battery cell and exposed outside the packaging film; or, the first connecting member passes through the through hole and connects the negative electrode of the first battery cell and the positive electrode of the second battery cell, the positive electrode ear is connected to the first battery cell and exposed outside the packaging film, and the negative electrode ear is connected to the second battery cell and exposed outside the packaging film.

8. The soft pack battery according to claim 7, characterized in that: One end of the first connecting member is connected to a side of the first battery cell close to the second battery cell, and the other end of the first connecting member is connected to a side of the second battery cell close to the first battery cell.

9. The soft pack battery according to claim 2, characterized in that: It also includes a positive electrode ear and a negative electrode ear, the first battery cell and the second battery cell are connected in parallel, the connecting mechanism includes a second connecting member and a third connecting member, the second connecting member passes through the through hole and connects the positive electrode of the first battery cell and the positive electrode of the second battery cell, the third connecting member passes through the through hole and connects the negative electrode of the first battery cell and the negative electrode of the second battery cell; the positive electrode ear is connected to the positive electrode of the first battery cell or the second battery cell and is exposed outside the packaging film, and the negative electrode ear is connected to the negative electrode of the first battery cell or the second battery cell and is exposed outside the packaging film.

10. The soft pack battery according to claim 2, characterized in that: The second part and the third part cover both ends of the through hole and wrap the connecting mechanism in the packaging film.

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