High-safety soft package battery cell with liquid packaging structure

Abstract

The utility model discloses a high-safety soft package battery cell with a liquid packaging structure, which comprises a shell with two open ends and a shock pad, and a gap is arranged between a battery cell body in the shell and the shell. The gap is divided into a first insulation area, a liquid packaging area and a second insulation area from left to right through a shock pad fixed on the battery cell body in a surrounding manner, the liquid packaging area is filled with insulation liquid, the first insulation area and the second insulation area are both filled with pouring sealant, and sealing edges between the positive and negative electrode lugs and the battery cell body are located in the insulation areas; furthermore, an end cover used for reinforcing sealed packaging is arranged at the opening of the shell, and the end cover on the same side as the tab end is integrally formed by injection molding, so that the tab and the end cover as well as the end cover and the shell can be stably fixed, the structural strength of the soft package battery cell is enhanced, and the sealing performance of liquid packaging is enhanced through a glue injection process. The soft package battery core has good sealing, pressure-bearing and insulating characteristics, the safety of the soft package battery core is improved, and the failure risk can be effectively reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of battery safety, and in particular relates to a high-safety soft-pack battery with a liquid packaging structure. Background Art

[0002] There are currently two commonly used battery cell packaging methods, one is hard-shell packaging and the other is soft-pack packaging, which are called hard-shell cells and soft-pack cells respectively. Hard-shell cells are more often used as power battery cells because of their relatively simple grouping structure, easier installation of explosion-proof valves, and better heat dissipation. However, in contrast, hard-shell cells have low space utilization when grouped, so the energy density of single cells is not as high as that of soft-pack cells and they are heavier. However, if you want to use soft-pack cells with a slimmer volume and higher cell energy density as power battery cells, you have to face the problems of poor mechanical strength of soft-pack cells, complex grouping structure, difficult heat dissipation design, difficulty in designing explosion-proof devices, and higher manufacturing process requirements than hard-shell cells.

[0003] After searching, for hard-shell batteries, the existing Chinese invention application document with publication number CN2021113927487 discloses a battery thermal safety prevention and control device and method. "The device includes a battery box, a pressure control valve, a one-way valve, a liquefaction device, a flame-retardant porous material, fins, coolant, gas delivery pipelines and liquid return pipelines." Since the hard-shell battery itself is simple and easy to design in grouping, it is also more convenient to set up an explosion-proof device. The above device is a battery box composed of multiple square hard-shell encapsulated batteries. However, soft-pack batteries have weaker mechanical strength and more difficult sealing processes, especially difficult grouping. The later group heat dissipation design is also complicated, so it is difficult to add explosion-proof devices related to hard-shell batteries to soft-pack batteries.

[0004] Traditional soft-pack batteries often use aluminum-plastic film as the outer insulating shell to seal the positive and negative pole ears. The size change is flexible and the cost is low. However, after long-term use, the soft-pack batteries have the problem of bulging. This is because when the soft-pack batteries have thermal runaway, the electrolyte generally partially vaporizes, causing the aluminum-plastic film to swell first. When the bulging reaches a certain degree, it will break the aluminum-plastic film package, causing the internal electrolyte to leak and take away a lot of heat. Although it is better than the hard-shell battery in terms of safety performance, if the electrolyte undergoes a violent oxidation or reduction decomposition reaction after the aluminum-plastic cracks, the flammable conductive particles will cause an internal short circuit, which may also cause spontaneous combustion and even more dangerous safety accidents. In other words, before applying soft-pack batteries to power batteries, it is necessary to note that the failure forms of soft-pack batteries usually include leakage, cracking, fire and explosion. Especially in the aviation field, battery cells are often in a state of high-load operation for a long time, so higher safety requirements are placed on the battery cells, requiring no open flames, toxic smoke, and violent runaway reactions. The safety of current soft-pack battery cells still has certain limitations.

[0005] In summary, the existing soft-pack battery cells have problems such as difficulty in adding explosion-proof devices, bulging leakage during thermal runaway, and electrolyte overheating and spontaneous combustion, which have become technical problems that need to be urgently solved by technical personnel in this field. Utility Model Content

[0006] In order to solve the problems existing in the prior art mentioned above, the purpose of the present utility model is to provide a high-safety soft-pack battery cell with a liquid packaging structure. The utility model has good sealing, pressure-bearing and insulation properties, improves the safety of the soft-pack battery cell, and can effectively reduce the failure risk of the soft-pack battery cell.

[0007] In order to achieve the above purpose and other related purposes, the utility model adopts the following technical solutions:

[0008] The utility model provides a high-safety soft-pack battery cell with a liquid packaging structure, comprising a battery cell body and positive and negative electrode tabs, characterized in that it also comprises a shell and a shock-absorbing pad, the left and right ends of the shell are open and hollow, the battery cell body is located in the shell, a gap is provided between the shell and the battery cell body, the shock-absorbing pads are all fixed around the battery cell body, the shock-absorbing pads comprise a first shock-absorbing pad and a second shock-absorbing pad, the first shock-absorbing pad and the second shock-absorbing pad separate the gap between the shell and the battery cell body from left to right into a first insulating area, a liquid packaging area and a second insulating area, the liquid packaging area is filled with insulating liquid, the first insulating area and the second insulating area are both filled with potting glue, and the edge sealing between the positive and negative electrode tabs and the battery cell body is located in the insulating area.

[0009] As a preferred technical solution, it also includes an end cover fixed to the open end of the shell, the end cover includes a pole ear end cover with a pole ear groove and a non-pole ear end cover for sealing the shell, and a positioning protrusion is provided on the inner side of the end cover, and the end cover is fixedly connected to the corresponding shell end face through the positioning protrusion.

[0010] As a preferred technical solution, the pole lug end cover includes an injection molded body and an embedded part, the embedded part and the injection molded body are integrally formed by injection molding, the embedded part includes a shell welding frame, the positioning protrusion is located on the shell welding frame, and the shell welding frame is embedded in the end face of the shell through the positioning protrusion and is fixedly connected to the shell.

[0011] As a further preferred technical solution, a tab groove for the tab to pass through is provided in the injection molded body, and the tab is fixedly connected to the injection molded body via the tab groove.

[0012] As a further preferred technical solution, the embedded part also includes an electrode welding skeleton, the number of the electrode welding skeleton is the same as the number of the same-side tabs, and the position of the electrode welding skeleton on the injection molding body corresponds to the position of the same-side tab, the tab groove is located in the electrode welding skeleton, and the end cover is fixedly connected to the tab through the electrode welding skeleton. Further, the electrode welding skeleton includes a direct buried part for fixing the tab, one end of the direct buried part is located in the injection molding body, the other end of the direct buried part extends outside the injection molding body, and a tab groove for penetrating the tab is provided in the middle of the direct buried part, and the tab groove is annularly covered around the tab. Further, the shape of the cross section of the tab groove includes a rectangular, elliptical or runway shape. Further, a bending portion is also provided at one end of the direct buried part located in the injection molding body. As a further preferred technical solution, the injection molding body is provided with a glue injection cavity from the end of the electrode welding skeleton to the inner end surface of the injection molding body.

[0013] As a preferred technical solution, each end cover is provided with a glue injection hole and a glue overflow hole.

[0014] As a further preferred technical solution, a liquid injection port and a safety valve are further provided on the end cover located at the pole ear. The liquid injection port and the safety valve penetrate the shock-absorbing pad through a connecting pipe and are connected to the liquid packaging area.

[0015] As described above, the utility model has the following beneficial effects:

[0016] (1) The utility model discloses a high-safety soft-pack battery cell with a liquid packaging structure. The shell serves as a liquid sealing container for the battery cell body and has a certain pressure bearing capacity. Since the liquid is sealed, the battery cell will not short-circuit and will not catch fire. Heat evaporates in the electrolyte to maintain the liquid vaporization temperature, which will not exceed the liquid vaporization temperature. For example, the vaporization temperature of water is 100°C. At the same time, it has the function of buffering and shock absorption when combined with a shock-absorbing pad, and since it is made of metal, it also has the function of heat conduction. After being preferably set to a rectangular shape, it is more convenient to stack and group the soft-pack batteries.

[0017] (2) The utility model provides a high-safety soft-pack battery cell with a liquid packaging structure, which has good sealing, pressure-bearing and insulation properties through the injection molding process, and the pole ear end cover formed by injection molding can better fix the shell and the pole ear while achieving sealing between the pole ear, the pole ear end cover and the shell, thereby improving the safety of the soft-pack lithium battery during use.

[0018] (3) The utility model provides a high-safety soft-pack battery cell with a liquid packaging structure, which improves the welding strength by welding the end cover and the shell. At the same time, the special structure of the pole ear end cover and the electrode welding skeleton improves the injection molding strength, thereby ensuring the safe use of the soft-pack battery cell and providing a mechanical strength foundation for stacking use. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a three-dimensional schematic diagram of a high-safety soft-pack battery cell with a liquid packaging structure in which the positive and negative electrode tabs are located on both sides in Example 1.

[0020] Figure 2 yes Figure 1 A three-dimensional cross-sectional view of .

[0021] Figure 3 yes Figure 2 Top view of the .

[0022] Figure 4 yes Figure 1 A three-dimensional longitudinal section of .

[0023] Figure 5 yes Figure 4 A front view of the local structure of the connection between the pole ear end cover and the pole ear.

[0024] Figure 6 yes Figure 4 Front view of .

[0025] Figure 7 yes Figure 6 A schematic diagram of the local structure of one end of a connecting pipe is provided.

[0026] Figure 8 yes Figure 1 Left view of .

[0027] Fig. 9 yes Figure 1 Right view of .

[0028] Fig.10 It is a schematic diagram of the three-dimensional structure of a high-safety soft-pack battery cell with a liquid packaging structure in which the positive and negative electrode tabs are located on one side in Example 2.

[0029] Fig.11 yes Fig.10 Front view with the shell removed.

[0030] Fig.12 yes Fig.11 A front view of the local structure of the connection between the pole ear end cover and the pole ear.

[0031] Fig.13 yes Fig.11 A top view of the local structure of the connection between the pole ear end cover and the pole ear.

[0032] Fig.14 yes Fig.10 Left view of .

[0033] Fig.15 yes Fig.14 Schematic diagram of the inner side of the middle ear end cover.

[0034] Fig.16 yes Fig.10 Right view of .

[0035] Fig.17 It is an exploded view of the outer side of the pole lug end cover provided with one end of the connecting pipe in Example 1.

[0036] Fig.18 It is an exploded view of the inner side of the pole lug end cover without a connecting pipe at one end in Example 1.

[0037] Fig.19 It is an exploded view of the outer side of the pole lug end cover in Example 2.

[0038] Fig. 20 It is a left view of a single electrode welding skeleton with a symmetrical L-shaped bending portion cross-section in Example 1 and Example 2.

[0039] Fig.21 It is a front view of a single electrode welding skeleton with a symmetrical L-shaped cross-section of the bending portion in Example 1 and Example 2.

[0040] Fig. 22 It is a front view of a single electrode welding skeleton when the longitudinal section of the bending portion is a symmetrical straight line.

[0041] Fig.23 It is a front view of a single electrode welding skeleton when there is no bend.

[0042] Fig.24 It is a schematic diagram of the three-dimensional structure of a high-safety soft-pack battery cell with a liquid packaging structure in Example 3, which has no end covers and has positive and negative electrode tabs on both sides before the tabs are filled with potting glue.

[0043] Fig.25 It is a schematic diagram of the three-dimensional structure of a high-safety soft-pack battery cell with a liquid packaging structure in Example 3, which has no end covers and has positive and negative electrode tabs located on one side, before the tabs are filled with potting glue.

[0044] Among them, the specific descriptions of the accompanying drawings are as follows: 1. battery cell body; 11. pole ear; 12. edge sealing; 2. shell; 21. first shock-absorbing pad; 22. second shock-absorbing pad; 31. first insulating area; 32. liquid packaging area; 33. second insulating area; 4. non-pole ear end cover; 5. pole ear end cover; 51. injection molding body; 511. glue injection cavity; 52. shell welding frame; 521. positioning protrusion; 53. electrode welding frame; 531. direct buried part; 532. bending part; 533. pole ear groove; 61. glue injection hole; 62. glue overflow hole; 71. liquid injection port; 72. safety valve port; 8. connecting pipe. DETAILED DESCRIPTION

[0045] In order to better understand the purpose, structure and function of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0046] In the description of the present invention, it should be noted that the positional relationships indicated by terms such as “longitudinal”, “lateral”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside” and “outside” cited in this specification are based on the positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0047] Example 1

[0048] like Figure 1-Figure 9 As shown, this embodiment provides a high-safety soft-pack battery cell with a liquid packaging structure in which positive and negative electrode tabs 11 are located on both sides, the soft-pack battery cell comprises a battery cell body 1 and positive and negative electrode tabs 11, wherein the positive electrode tab 11 is located on the left side of the battery cell body 1, and the negative electrode tab 11 is located on the right side of the battery cell body 1, and the tab 11 is fixed to the battery cell body 1 by an edge sealing 12, and the soft-pack battery cell also includes a hollow shell 2 with openings at left and right ends, a shock-absorbing pad, and an end cover 5 fixed to the open end of the shell 2.

[0049] The shape of the shell 2 can be adaptively changed according to the setting space or group stacking requirements to maximize the space utilization. The shape of the support pad matches the shape of the gap between the shell 2 and the battery body 1. In this embodiment, the shell 2 is rectangular, and the material of the shell 2 is metal. The packaging and sealing strength of the structure is strengthened by welding and fixing between metals. In another preferred embodiment, the shell 2 is made of super martensitic stainless steel, which has better toughness and corrosion resistance; the battery body 1 is located in the shell 2, and the two side ears 11 of the battery body 1 are respectively opened toward the two ends of the shell 2 and extend to the outside of the shell 2. A gap is provided between the inner wall of the shell 2 and the outer wall of the battery body 1. In another embodiment, in order to further promote heat dissipation, air cooling or a cold plate can also be provided outside the shell 2.

[0050] There are at least two shock-absorbing pads, which are fixed around the battery body 1 and divide the gap between the shell 2 and the battery body 1 from left to right into a first insulating area 31, a liquid packaging area 32 and a second insulating area 33. The edge seal 12 between the pole ear 11 on the left and the battery body 1 is located in the first insulating area 31, and the edge seal 12 between the pole ear 11 on the right and the battery body 1 is located in the second insulating area 33. The liquid packaging area 32 is filled with insulating liquid, and the first insulating area 31 and the second insulating area 33 are both filled with potting glue. The edge seal 12 between the positive and negative pole ears 11 and the battery body 1 is located in the insulating area.

[0051] The insulating liquid includes but is not limited to fluorinated liquid, ultrapure water or deionized water; the potting glue includes but is not limited to epoxy resin potting glue. In this embodiment, the insulating liquid is fluorinated liquid, and the potting glue is epoxy resin potting glue.

[0052] Since the surface of the edge seal 12 of the soft-pack battery cell is generally irregular, after fixing the shock-absorbing pad, in order to further ensure the sealing of the liquid packaging area 32 and the edge seal 12 structure, the first insulating area 31 and the second insulating area 33 are filled with glue to increase the structural strength between each shock-absorbing pad and the battery body 1 and the structural strength of the edge seal 12 of the soft-pack battery cell, thereby reducing the risk of liquid contacting the pole ear 11 when the soft-pack battery cell fails, and also reducing the risk of cracking and leakage when bulging.

[0053] In this embodiment, the shock absorbing pad includes a first shock absorbing pad 21 and a second shock absorbing pad 22, which provide support and positioning for the battery body 1 in the shell 2, and can avoid damage to the battery body 1 by shock absorption. The first shock absorbing pad 21 and the second shock absorbing pad 22 are both fixed around the battery body 1 along the short axis direction of the battery body 1, and the first shock absorbing pad 21 and the second shock absorbing pad 22 are respectively close to the left end and the right end of the battery body 1, and the inner side surfaces of the first shock absorbing pad 21 and the second shock absorbing pad 22 are both fitted with the outer side surface of the battery body 1, and the outer side surfaces of the first shock absorbing pad 21 and the second shock absorbing pad 22 are both fitted with the inner side surface of the shell 2, so that the gap between the left end surface of the shell 2 and the left end surface of the first shock absorbing pad 21 forms a first insulating area 31, the gap between the right end surface of the first shock absorbing pad 21 and the left end surface of the second shock absorbing pad 22 forms a liquid packaging area 32, and the gap between the right end surface of the second shock absorbing pad 22 and the right end surface of the shell 2 forms a second insulating area 33. The material of the shock-absorbing pad is but not limited to rubber or soft silicone.

[0054] In this embodiment, the end cover 5 includes two pole lug end covers 5 with pole lug grooves 533, which are respectively located at the left end opening of the shell 2 and the right end opening of the shell 2. The pole lug end cover 5 is fixedly connected to the end face of the shell 2. Each pole lug end cover 5 is provided with a glue injection hole 61 and a glue overflow hole 62, and an annular positioning protrusion 521 is provided on the inner side surface of the pole lug end cover 5, and the pole lug end cover 5 is fixedly connected to the corresponding shell 2 through the positioning protrusion 521, so that the shell 2 forms a seal.

[0055] The pole lug end cover 5 also includes an injection molded body 51 and an embedded part. The embedded part and the injection molded body 51 are integrally formed by injection molding. The embedded part includes a shell welding skeleton 52 and an electrode welding skeleton 53. The pole lug end cover 5 is fixedly connected to the pole lug 11 through the electrode welding skeleton 53. The pole lug end cover 5 is fixedly connected to the end face of the shell 2 through the shell welding skeleton 52.

[0056] The shell welding skeleton 52 is a rectangular metal plate that matches the opening shape and size of the shell 2. The inner side of the rectangular metal plate is provided with an annular positioning protrusion 521. The positioning protrusion 521 is close to the edge position of the shell welding skeleton 52, corresponding to the shape and position of the edge of the end face of the shell 2. An injection groove 533 for fixed connection with the injection body 51 is opened at the center position of the shell welding skeleton 52. The shell welding skeleton 52 is fixedly connected to the end face of the shell 2 through the positioning protrusion 521. The glue injection hole 61 and the glue overflow hole 62 are both located on the shell welding skeleton 52. The glue overflow hole 62 can be used to exhaust gas while injecting glue, which is conducive to sufficient filling. In addition, the glue overflow hole 62 can be used to observe in real time whether the insulating area is filled with glue.

[0057] like Figure 19-Figure 23 As shown, the number of the electrode welding skeletons 53 is the same as the number of the pole lugs 11 on the same side, and the position of the electrode welding skeleton 53 on the injection molding body 51 corresponds to the position of the pole lug 11. The electrode welding skeleton 53 includes a direct buried portion 531 for fixing the pole lug 11, the end of the direct buried portion 531 is located in the injection molding body 51, and the other end of the direct buried portion 531 extends to the outside of the outer end surface of the injection molding body 51. A pole lug groove 533 for penetrating the pole lug 11 is provided in the middle of the direct buried portion 531, and the pole lug groove 533 is annularly wrapped around the pole lug 11, and the shape of the cross section of the pole lug groove 533 includes but is not limited to a rectangular, elliptical or racetrack shape. In the actual manufacturing process, the pole lug 11 passes through the pole lug groove 533, and the buried portion 531 is pressed up and down to form the buried portion 531 and the pole lug 11, and then the pole lug 11 is welded and fixed to the buried portion 531. The welding method of the pole lug 11 and the buried portion 531 includes but is not limited to resistance welding, laser welding or ultrasonic welding. In order to prevent the electrode welding frame 53 from being separated from the injection molding body 51 due to deformation during the crimping process, thereby affecting the sealing, therefore, in this embodiment, as shown in FIG. Fig.17 and Fig.18 As shown, a bending portion 532 is also provided at the end of the direct buried portion 531, so that the cross-section of the electrode welding skeleton 53 is symmetrically L-shaped or symmetrically hook-shaped; and, a glue injection cavity 511 is provided at the end of the electrode welding skeleton 53 to the inner end surface of the injection molded body 51, and the pressure bearing capacity is further increased through the glue injection process, which can effectively prevent the battery body 1 from pulling the electrode inward when the battery cell is excessively expanded, thereby improving the insulation effect.

[0058] The tab end cover 5 is also provided with a liquid injection port 71 and a safety valve port 72. When the soft-pack battery core produces gas, the internal pressure of the housing 2 increases, and the spring in the safety valve is pressed open, thereby achieving pressure relief.

[0059] The liquid injection port 71 and the safety valve port 72 respectively penetrate the shock-absorbing pad through the connecting pipe 8 and are connected to the liquid packaging area 32, so that after the soft-pack battery cell is assembled, the packaging tightness can be tested through the liquid injection port 71 first, and the liquid injection can be carried out uniformly after ensuring the tightness of the packaging. After the liquid injection, the liquid injection port 71 is blocked by a plug, and a safety valve is installed at the outer end of the safety valve port 72, thereby improving the production efficiency and avoiding the production of defective products. The connecting pipe 8 can also play the role of supporting and fixing the shock-absorbing pad.

[0060] Specifically, in this embodiment, the liquid injection port 71 and the safety valve port 72 are located on one side of the shell welding frame 52, the safety valve is a one-way valve, and the number of the connecting pipes 8 is at least two, including a first connecting pipe 8 and a second connecting pipe 8, one end of the first connecting pipe 8 passes through the liquid injection port 71 on the shell welding frame 52, and the other end of the first connecting pipe 8 passes through the shock-absorbing pad, one end of the second connecting pipe 8 passes through the safety valve port 72 on the shell welding frame 52 and is fixedly installed with the safety valve, and the other end of the second connecting pipe 8 passes through the shock-absorbing pad, and the first connecting pipe 8 and the second connecting pipe 8 are fixedly connected to the liquid injection port 71 and the safety valve port 72, respectively.

[0061] Furthermore, in a more preferred embodiment, a connector is further provided on the safety valve, and the connector is connected to the waste liquid collection tank through a drain pipe. During operation, when the soft-pack battery in the present application bulges to generate gas and air pressure, the excess gas and liquid are automatically discharged after pressing the safety valve and recovered by the waste liquid collection tank, which can effectively prevent the leakage of the soft-pack battery from damaging the instrument or other nearby batteries, and the recovered liquid can be recycled again after separation, which saves costs while being more energy-saving and environmentally friendly. Furthermore, a liquid inlet is opened on the ear end cover 5 opposite to the safety valve, and is connected to the external circulation cooling system through the liquid inlet and the connector on the safety valve, so that the liquid flow path between the liquid inlet and the safety valve is the longest. The circulation cooling system has conductivity detection, pressure detection and exhaust functions. There are many mature cooling circulation systems in the prior art, so they will not be described here.

[0062] In another embodiment, a sensor may be directly packaged in the housing 2 to monitor the internal situation in real time and detect safety risks as early as possible. The sensor includes but is not limited to a pressure sensor and a temperature sensor.

[0063] In other embodiments, a conductive sensor is placed in the insulating liquid to perform a voltage test on the battery cell and the housing 2 to determine whether they are conductive, thereby controlling and reducing the conductivity.

[0064] In other embodiments, a diaphragm is provided in the safety valve, and the diaphragm undergoes plastic deformation when overpressure occurs, and automatically discharges liquid when the pressure reaches a certain value, thereby further improving the safety of the soft-pack battery cell.

[0065] Example 2

[0066] like Figure 10-Figure 16As shown, this embodiment provides a high-safety soft-pack battery cell with a liquid packaging structure in which the positive and negative electrode tabs 11 are located on a single side on the basis of Embodiment 1. The soft-pack battery cell includes a battery cell body 1 and positive and negative electrode tabs 11. The positive electrode tab 11 and the negative electrode tab 11 are both located on the left side of the battery cell body 1. The tab 11 is fixed to the battery cell body 1 by an edge sealing 12. The soft-pack battery cell also includes a shell 2, a shock-absorbing pad and an end cover 5.

[0067] The only difference from Example 1 is that the positive and negative pole tabs 11 of the soft-pack battery cell in Example 1 are located on both sides of the battery cell body 1, while the positive and negative pole tabs 11 of the soft-pack battery cell in this embodiment are located on the same side of the battery cell body 1. Therefore, in Example 1, the end cover 5 includes two pole tab end covers 5 provided with pole tab grooves 533, and only one electrode welding skeleton 53 is provided on each of the pole tab end covers 5, and the injection port 71 and the safety valve port 72 are located on one side of the shell welding skeleton 52; while in this embodiment, the end cover 5 includes a pole tab end cover 5 provided with a pole tab groove 533 and a non-pole tab end cover 4 for sealing the shell 2, and two electrode welding skeletons 53 are provided on the pole tab end cover 5 on the same side as the positive and negative pole tabs 11. Moreover, as a preferred solution, the injection port 71 and the safety valve port 72 are both located on the pole tab end cover 5, so the functional end of the soft-pack battery cell can be stacked in multiple layers facing the same side, thereby improving the space utilization rate, ensuring good heat dissipation and having the advantages of good concentration,

[0068] Example 3

[0069] like Fig.24 and Fig.25 As shown, this embodiment provides a high-safety soft-pack battery cell with a liquid packaging structure without an end cover 5, the soft-pack battery cell comprises a battery cell body 1 and positive and negative electrode tabs 11, and the positive and negative electrode tabs 11 are located on both sides of the battery cell body 1 or on one side of the battery cell body 1. The difference from Embodiment 1 and Embodiment 2 is that the soft-pack battery cell comprises a hollow shell 2 with openings at both ends and a shock-absorbing pad.

[0070] The shape of the shell 2 can be adaptively changed according to the setting space or group stacking requirements to maximize space utilization. The shape of the support pad matches the shape of the gap between the shell 2 and the battery cell body 1. In the present embodiment, the shell 2 is rectangular, and the material of the shell 2 is metal. The packaging sealing strength of the structure can be enhanced by welding and fixing between metals. The battery cell body 1 is located in the shell 2, and the two side ears 11 of the battery cell body 1 are respectively opened toward the two ends of the shell 2 and extend to the outside of the shell 2. A gap is provided between the inner wall of the shell 2 and the outer wall of the battery cell body 1.

[0071] There are two shock-absorbing pads, each of which is fixed around the battery body 1, and divides the gap between the shell 2 and the battery body 1 from left to right into a first insulating area 31, a liquid packaging area 32 and a second insulating area 33. The edge seal 12 between the pole ear 11 on the left and the battery body 1 is located in the first insulating area 31, and the edge seal 12 between the pole ear 11 on the right and the battery body 1 is located in the second insulating area 33. The liquid packaging area 32 is filled with insulating liquid, and the first insulating area 31 and the second insulating area 33 are both filled with potting glue. The edge seal 12 between the positive and negative pole ears 11 and the battery body 1 is located in the insulating area.

[0072] The insulating liquid includes but is not limited to fluorinated liquid, ultrapure water or deionized water; the potting glue includes but is not limited to epoxy resin potting glue. In this embodiment, the insulating liquid is fluorinated liquid, and the potting glue is epoxy resin potting glue.

[0073] In this embodiment, since the end cap 5 is not provided, the insulation seal of the first insulating area 31 and the second insulating area 33 is ensured only by the shock-absorbing pad and the glue injection process, the outer end face of the solidified potting glue is flush with the outer end face of the opening of the shell 2, and the positive pole tab 11 and the negative pole tab 11 are extended to the outer end face of the potting glue. That is, the insulating liquid in the liquid encapsulation area 32 is isolated from the pole tab 11 only by the shock-absorbing pad and the potting glue filling, so as to ensure the insulation at the pole tab 11; the soft-packed battery cell in this embodiment omits the end cap 5, and the manufacturing process is simple while saving the manufacturing cost of the end cap 5. When the soft-packed battery cell is installed, it can be installed area by area. For example, the first shock-absorbing pad 21 is fixed and the glue injection of the first insulating area 31 is completed on the battery body 1, and after being placed in the shell 2, the liquid encapsulation area 32 is injected with water, and then the second shock-absorbing pad 22 is fixed and the glue injection of the second insulating area 33 is completed on the battery body 1.

[0074] Example 4

[0075] This embodiment provides a safe working mechanism of a high-safety soft-pack battery cell with a liquid packaging structure in Embodiment 1 and Embodiment 2.

[0076] The working mechanism is specifically as follows: the positive and negative pole tabs 11 of the battery cell are isolated from the insulating liquid through the glue injection process and the special structure of the end cover 5, and the strength of the sealing edge 12 between the upper pole tab 11 of the soft-pack battery cell and the battery cell body 1 is strengthened, so that the soft-pack battery cell can be directly immersed in the insulating liquid, and the soft-pack battery cell is completely sealed by the shell 2, so that when the soft-pack battery cell fails, the reaction rate of electrolyte redox and gasification can be reduced by the insulating liquid; if the reaction intensifies and causes cracking, the electrolyte can be diluted by entering the insulating liquid from the crack of the aluminum-plastic film, which can also further reduce the reaction of the electrolyte; at the pole Under limited circumstances, the internal heat consumes all the liquid to generate gas, and the gas is discharged from the safety valve, so it can be guaranteed that there is no impact on the outside of the shell 2; if the reaction is violent and causes a fire in the soft-pack battery cell, the insulating liquid can also play a role in fire fighting, and the fire is directly controlled within the sealed packaging structure; during the whole process, when the internal pressure of the shell 2 increases due to the generation of gas by the electrolyte or the bulging of the battery, the pressure can be relieved through the safety valve, and the safety valve will automatically close after the pressure is reduced; if the safety valve is connected to a waste liquid collection tank, the gas or liquid discharged during the pressure relief can also be collected into the waste liquid collection tank.

[0077] The above description is only a preferred embodiment of the utility model, and is not intended to limit the utility model. It is known to those skilled in the art that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the utility model. In addition, under the guidance of the utility model, these features and embodiments can be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the utility model. Therefore, the utility model is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application belong to the scope protected by the utility model.

Claims

1. A high-safety soft-pack battery cell with a liquid packaging structure, comprising a battery cell body (1) and positive and negative electrode tabs (11), characterized in that: The invention also comprises a shell (2) and a shock absorbing pad, wherein the left and right ends of the shell (2) are open and hollow, the battery cell body (1) is located in the shell (2), a gap is provided between the shell (2) and the battery cell body (1), the shock absorbing pads are all fixed around the battery cell body (1), the shock absorbing pads comprise a first shock absorbing pad (21) and a second shock absorbing pad (22), the first shock absorbing pad (21) and the second shock absorbing pad (22) separate the gap between the shell (2) and the battery cell body (1) from left to right into a first insulating area (31), a liquid packaging area (32) and a second insulating area (33), the liquid packaging area (32) is filled with insulating liquid, the first insulating area (31) and the second insulating area (33) are both filled with potting glue, and the edge sealing (12) between the positive and negative electrode tabs (11) and the battery cell body (1) is located in the insulating area.

2. A high-safety soft-pack battery cell with a liquid packaging structure according to claim 1, characterized in that: The invention also comprises an end cover (5) fixed to the open end of the shell (2); when the positive and negative pole tabs (11) of the soft-pack battery cell are located on both sides, the end cover (5) comprises two pole tab end covers (5) provided with pole tab grooves (533); when the positive and negative pole tabs (11) of the soft-pack battery cell are located on one side, the end cover (5) comprises a pole tab end cover (5) provided with a pole tab groove (533) and a non-pole tab end cover (4) for sealing the shell (2); a positioning protrusion (521) is provided on the inner side of each end cover, and the end cover (5) is fixedly connected to the corresponding end face of the shell (2) through the positioning protrusion (521).

3. A high-safety soft-pack battery cell with a liquid packaging structure according to claim 2, characterized in that: The pole lug end cover (5) comprises an injection molded body (51) and an embedded part, wherein the embedded part and the injection molded body (51) are integrally formed by injection molding, and the embedded part comprises a shell welding frame (52), wherein the positioning protrusion (521) is located on the shell welding frame (52), and the shell welding frame (52) is embedded in the end face of the shell (2) through the positioning protrusion (521) and is fixedly connected to the shell (2).

4. A high-safety soft-pack battery cell with a liquid packaging structure according to claim 3, characterized in that: A pole lug groove (533) for the pole lug (11) to pass through is provided in the injection molded body (51), and the pole lug (11) is fixedly connected to the injection molded body (51) via the pole lug groove (533).

5. The high-safety soft-pack battery cell with a liquid packaging structure according to claim 3, characterized in that: The embedded part also includes an electrode welding skeleton (53), the number of the electrode welding skeletons (53) is the same as the number of the pole lugs (11) on the same side, and the position of the electrode welding skeleton (53) on the injection molded body (51) corresponds to the position of the pole lug (11) on the same side, the pole lug groove (533) is located in the electrode welding skeleton (53), and the pole lug end cover (5) is fixedly connected to the pole lug (11) through the electrode welding skeleton (53).

6. A high-safety soft-pack battery cell with a liquid packaging structure according to claim 5, characterized in that: The electrode welding skeleton (53) comprises a directly buried portion (531) for fixing the pole lug (11), one end of the directly buried portion (531) is located inside the injection molded body (51), and the other end of the directly buried portion (531) extends outside the injection molded body (51), a pole lug groove (533) for penetrating the pole lug (11) is provided in the middle of the directly buried portion (531), and the pole lug groove (533) is annularly wrapped around the pole lug (11).

7. A high-safety soft-pack battery cell with a liquid packaging structure according to claim 6, characterized in that: The shape of the cross section of the tab groove (533) includes a rectangle, an ellipse or a racetrack.

8. The high-safety soft-pack battery cell with a liquid packaging structure according to claim 7, characterized in that: A bent portion (532) is also provided at one end of the directly buried portion (531) located in the injection molded body (51).

9. A high-safety soft-pack battery cell with a liquid packaging structure according to claim 8, characterized in that: The injection molding body (51) is provided with a glue injection cavity (511) between the end of the electrode welding frame (53) and the inner end surface of the injection molding body (51).

10. A high-safety soft-pack battery cell with a liquid packaging structure according to any one of claims 2 to 9, characterized in that: Each end cover is provided with a glue injection hole (61) and a glue overflow hole (62).

11. A high-safety soft-pack battery cell with a liquid packaging structure according to claim 10, characterized in that: The end cover (5) located at the pole ear (11) is also provided with a liquid injection port (71) and a safety valve. The liquid injection port (71) and the safety valve respectively penetrate the shock-absorbing pad through a connecting pipe (8) and are connected to the liquid packaging area (32).

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