Electricity storage device and electric equipment

Abstract

The utility model provides an electricity storage device and electric equipment. The electricity storage device comprises a battery cell group and a bottom shell, wherein the battery cell group consists of a plurality of soft package battery cells which are stacked and arranged along a first direction; the bottom shell consists of a first metal shell and a second metal shell; the first metal shell comprises a first abutting wall, a plurality of side walls and a first connecting wall. The multiple side walls and the first abutting wall jointly define a mounting groove position, and the first connecting wall is located on the side, away from the abutting wall, of the side walls. The second metal shell comprises a second abutting wall and a second connecting wall arranged on the outer side of the second abutting wall. The first connecting wall is fixedly connected with the second connecting wall, the second abutting wall covers at least part of the mounting groove position and forms a first accommodating cavity, at least part of the battery cell group is located in the first accommodating cavity, and the first abutting wall and the second abutting wall are located on the two opposite sides of the battery cell group in the first direction respectively and abut against the battery cell group respectively. And the bottom shell applies pressing force to the soft package battery cells along the stacking direction of the plurality of soft package battery cells, so that the cycle performance of the soft package battery cells can be improved.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the field of new energy, in particular, to a power storage device and an electric device with the same. BACKGROUND

[0002] The power storage device can store and release electric energy, and is widely used in various electric devices and systems. The electric core is the part of the power storage device that performs electrochemical reactions, and is the core of the power storage device. Some power storage devices use soft package electric cores. Because the soft package electric core has the advantages of light weight, low cost, and high safety, the application scenarios of the power storage device using the soft package electric core are gradually expanding. The durability of such power storage devices mainly depends on the cycle performance of the soft package electric core. Therefore, there is a continuous demand in the art to improve the cycle performance of the soft package electric core. SUMMARY

[0003] Therefore, the present disclosure provides a power storage device using a soft package electric core and an electric device with the same, to improve the cycle performance of the soft package electric core and thus improve the durability of the power storage device.

[0004] In one aspect, the present disclosure provides a power storage device.

[0005] The power storage device includes an electric core group and a bottom shell. The electric core group includes a plurality of soft package electric cores stacked in a first direction. The bottom shell includes a first metal shell and a second metal shell. The first metal shell includes a first abutment wall, a plurality of side walls, and a first connecting wall. The plurality of side walls are arranged on the side of the first abutment wall, and the plurality of side walls and the first abutment wall together form a mounting slot. The first connecting wall is located on the side of the side wall away from the first abutment wall. The second metal shell includes a second abutment wall and a second connecting wall arranged on the outer side of the second abutment wall. The first connecting wall is fixedly connected with the second connecting wall, and the second abutment wall covers at least part of the mounting slot and forms a first accommodating cavity. At least part of the electric core group is located in the first accommodating cavity, and the first abutment wall and the second abutment wall are respectively located on the opposite sides of the electric core group in the first direction and abut with the electric core group.

[0006] Additionally or alternatively, the plurality of side walls includes two vertical side walls and a bottom side wall. The two vertical side walls are arranged on the opposite sides of the first abutment wall in a second direction perpendicular to the first direction, and the bottom side wall is located between the two vertical side walls. The bottom shell is provided with an opening on the side away from the bottom side wall, and the bottom side wall is provided with a glue injection port communicating with the first accommodating cavity.

[0007] Additionally or alternatively, each side wall is provided with a rounded corner at the connection with the first abutment wall. In a projection plane perpendicular to the first direction, the projection of the rounded corner and the projection of the electric core group do not overlap.

[0008] Supplementarily or alternatively, the bottom side wall is arranged to be inclined towards the opening, and an included angle between the bottom side wall and the first abutting wall is B, 90°≤B≤150°.

[0009] Supplementarily or alternatively, the second abutting wall is coplanar with the second connecting wall.

[0010] Supplementarily or alternatively, the power storage device further comprises an upper shell and a circuit board, the upper shell is sealingly connected with the bottom shell, the upper shell is internally provided with a second accommodating cavity in communication with the first accommodating cavity, the first accommodating cavity and the second accommodating cavity jointly form an inner cavity, and the circuit board is electrically connected with the battery cell group and located in the inner cavity; the first abutting wall comprises a first protruding portion facing away from the protrusion of the first metal shell, the first protruding portion is formed with a protruding cavity in the inner cavity, and at least part of the circuit board is located in the protruding cavity.

[0011] Supplementarily or alternatively, a sealing groove is arranged on one side surface of the first connecting wall facing the second connecting wall, and the sealing groove is filled with sealing glue abutting against the second connecting wall.

[0012] Supplementively or alternatively, a sealing groove is arranged on one side surface of the second connecting wall facing the first connecting wall, and the sealing groove is filled with sealing glue abutting against the first connecting wall.

[0013] Supplementively or alternatively, a sealing groove is arranged on one side surface of the first connecting wall facing the second connecting wall, and a sealing groove is arranged on one side surface of the second connecting wall facing the first connecting wall, and the two sealing grooves are filled with sealing glue in a cavity formed by the two sealing grooves.

[0014] Supplementively or alternatively, a support plate is arranged between the first abutting wall and the battery cell group.

[0015] Supplementively or alternatively, a support plate is arranged between the second abutting wall and the battery cell group.

[0016] Supplementively or alternatively, a support plate is arranged between the first abutting wall and the battery cell group, and a support plate is arranged between the second abutting wall and the battery cell group.

[0017] Supplementively or alternatively, the support plate is an epoxy resin plate or a polypropylene plate.

[0018] In another aspect, the present disclosure further provides a power utilization device. The power utilization device comprises the power storage device described above.

[0019] According to the energy storage device provided in this disclosure, the cell assembly includes multiple pouch cells stacked in a first direction. A first abutting wall of a first metal shell and a second abutting wall of a second metal shell are located on opposite sides of the cell assembly in the first direction, and a first connecting wall of the first metal shell is fixedly connected to a second connecting wall of the second metal shell. Accordingly, the first and second metal shells apply a suitable clamping force to the multiple pouch cells in the stacking direction. This suitable clamping force helps to slow down battery capacity decay, improve battery discharge capacity, and shorten the distance between the positive and negative electrodes, thereby improving the cycle performance of the pouch cells and extending the durability of the energy storage device. Furthermore, since metal has a high elastic modulus, it possesses good elasticity and resistance to deformation. Therefore, on the one hand, compared to a plastic bottom shell, a metal bottom shell composed of a first and second metal shell can provide a higher clamping force to the pouch cells; on the other hand, considering the volume changes during the charging and discharging process of the pouch cells, and the irreversible expansion in the later stages of the pouch cells' lifespan, the metal bottom shell can also utilize its good elasticity and resistance to deformation to stably provide a higher clamping force to the pouch cells. Combining these two aspects, using this bottom shell composed of two metal shells can more effectively improve the cycle performance of pouch cells and extend the durability of energy storage devices. Attached Figure Description

[0020] It should be understood that the following figures only illustrate certain embodiments of this disclosure and should not be construed as limiting the scope.

[0021] It should be understood that the same or similar reference numerals are used in the accompanying drawings to denote the same or similar elements.

[0022] It should be understood that the accompanying drawings are only schematic, and the dimensions and scales of the elements in the drawings are not necessarily precise.

[0023] Figure 1 This is a schematic diagram of the structure of an energy storage device according to an embodiment of the present disclosure.

[0024] Figure 2 It shows Figure 1 An exploded view of the energy storage device.

[0025] Figure 3 for Figure 1 A schematic front view of a portion of the energy storage device.

[0026] Figure 4 for Figure 1 A schematic diagram of the structure of the first metal casing of the energy storage device.

[0027] Figure 5 for Figure 1 A schematic diagram of the structure of the second metal shell of the energy storage device.

[0028] Figure 6 is a schematic cross-sectional view taken along Figure 3 is a schematic cross-sectional view taken along

[0029] Figure 7 is a schematic cross-sectional view taken along Figure 3 is a schematic cross-sectional view taken along

[0030] Figure 8 is a schematic structural view of an electrical device according to an embodiment of the present disclosure.

[0031] Legend: 100, bottom shell; 10, first metal shell; 11, first abutting wall; 12, side wall; 121, vertical side wall; 122, bottom side wall; 1221, glue injection port; 13, first connecting wall; 14, mounting slot; 15, first protruding part; 151, protruding cavity; 20, second metal shell; 21, second abutting wall; 22, second connecting wall; 221, sealing groove; 222, sealing glue; 30, first accommodating cavity; 40, opening; 50, rounded corner; 60, cavity; 70, support plate; 200, battery cell group; 201, soft-pack battery cell; 300, upper shell; 301, second accommodating cavity; 302, hole; 400, circuit board; 401, port; 500, electrical device; 600, power storage device. DETAILED DESCRIPTION

[0032] Power storage devices are used to store electrical energy and are widely used in various electrical devices and systems. Some power storage devices use a battery cell group composed of a plurality of stacked soft-pack battery cells. Research has found that applying appropriate compression force along the stacking direction of the plurality of soft-pack battery cells helps to improve the cycle performance of the soft-pack battery cells. However, the inventors have found that the power storage devices of the prior art use an integrally formed plastic bottom shell, and it is difficult to apply appropriate compression force to the soft-pack battery cells along the stacking direction with such a bottom shell. This results in poor cycle performance of the soft-pack battery cells of the power storage devices of the prior art, which reduces the durability of the power storage devices.

[0033] To solve this problem, the present disclosure provides a power storage device and an electrical device having the same. The power storage device and the electrical device having the same according to the present disclosure will be described below with reference to the accompanying drawings.

[0034] It can be appreciated that many specific details will be listed below to provide an understanding of the structure, function, and use of the embodiments described in the specification and shown in the drawings. It can be appreciated that the embodiments described and shown herein are non-limiting examples, so that it can be recognized that the specific structural and functional details disclosed herein are representative and exemplary. Variations and changes can be made to these embodiments without departing from the scope of the claims.

[0035] <Example Power Storage Device>

[0036] The present disclosure provides a power storage device. For ease of understanding, the overall configuration of the power storage device according to the present disclosure is first described below. It should be understood that the configuration of the power storage device is not limited to the description below. For example, one or more elements introduced below can be omitted or replaced, and the layout relationship therebetween can be replaced.

[0037] Reference Figures 1-5 The power storage device 600 can include a bottom case 100 and a cell group 200.

[0038] The cell group 200 can include a plurality of soft package cells 201 stacked in a first direction. The soft package cell 201 can be understood as a device in which an electrochemical reaction occurs. The soft package cell 201 can be a flat plate structure. The soft package cell 201 can include an aluminum-plastic film supported film shell, and a roll core or a stack core located in the film shell.

[0039] The roll core can be a structure including a positive electrode sheet, a negative electrode sheet, and a separator sandwiched therebetween, which can be stacked together by winding to form an electrochemically active material region of the battery. The positive electrode sheet can be any combination of lithium cobaltate, lithium manganate, lithium iron phosphate, and lithium nickel manganate. The negative electrode sheet can be any combination of natural graphite, graphene, silicon, or lithium titanate. The separator can be located between the positive and negative electrode sheets to prevent physical contact between the two electrodes from causing a short circuit, while allowing lithium ions to pass through during charging and discharging. In the current embodiment, the separator can be a water-based separator. The raw material cost of the water-based separator is low, the preparation process is simple, and it has a high porosity, which can improve the permeability of ions. However, compared to other types of separators, the water-based separator requires a suitable compression force to delay performance degradation after multiple cycles. It should be noted that in other embodiments of the present disclosure, the separator can also be a ceramic-coated separator and an aramid-coated separator, etc.

[0040] The plurality of soft package cells 201 can be stacked in the first direction, which can be any direction, for example, the width direction, the height direction, and the thickness direction of the soft package cell 201.

[0041] Specifically, the first direction is the thickness direction of the soft package cell 201. The plurality of soft package cells 201 can be stacked in the thickness direction of the soft package cell 201, wherein the size of the soft package cell 201 in the thickness direction is smaller than that in the height direction and the width direction.

[0042] When the plurality of soft package cells 201 are stacked in the thickness direction of the soft package cell 201, the space utilization rate is high, the structural stability is good, and the energy density, stability, safety, and service life of the battery can be improved.

[0043] Each soft package battery cell 201 can include one positive electrode tab and one negative electrode tab, and the electrode tabs of the plurality of soft package battery cells 201 can be connected together by welding or riveting, thereby forming a total positive electrode and a total negative electrode of the battery cell group 200.

[0044] For ease of understanding, the thickness direction of the soft package battery cell 201 is indicated by an arrow x in the drawings of the present disclosure. In addition, the width direction and the height direction of the soft package battery cell 201 are also indicated by arrows y and z, respectively, in the drawings.

[0045] The bottom shell 100 includes a first metal shell 10 and a second metal shell 20. The first metal shell 10 includes a first abutting wall 11, a plurality of side walls 12, and a first connecting wall 13. The plurality of side walls 12 are arranged on the circumferential side of the first abutting wall 11, and the plurality of side walls 12 and the first abutting wall 11 together enclose a mounting slot 14, and the first connecting wall 13 is located on the side of the side wall 12 away from the first abutting wall 11. The second metal shell 20 includes a second abutting wall 21 and a second connecting wall 22 arranged outside the second abutting wall 21. The first connecting wall 13 is fixedly connected with the second connecting wall 22, and the second abutting wall 21 covers at least part of the mounting slot 14 and forms a first accommodating cavity 30, at least part of the battery cell group 200 is located in the first accommodating cavity 30, and the first abutting wall 11 and the second abutting wall 21 are respectively located on the opposite sides of the battery cell group in the first direction and abut against the battery cell group 200.

[0046] In the above embodiment, the battery cell group 200 includes a plurality of soft package battery cells 201 stacked in the first direction, the first abutting wall 11 of the first metal shell 10 and the second abutting wall 21 of the second metal shell 20 are respectively located on the opposite sides of the battery cell group 200 in the first direction, and the first connecting wall 13 of the first metal shell 10 and the second connecting wall 22 of the second metal shell 20 are fixedly connected. Accordingly, the first metal shell 10 and the second metal shell 20 will apply appropriate compression force to the plurality of soft package battery cells 201 in the stacking direction of the plurality of soft package battery cells 201, and the appropriate compression force is beneficial to slow down the capacity decay of the battery (especially the silicon-doped battery), improve the discharge capacity of the battery, and shorten the distance between the positive electrode and the negative electrode, thereby improving the cycle performance of the soft package battery cell 201 and prolonging the durability of the power storage device 600.

[0047] In addition, since the metal has a high elastic modulus, it has good elasticity and deformation resistance. Therefore, on the one hand, compared with the plastic bottom shell, the metal bottom shell 100 composed of the first metal shell 10 and the second metal shell 20 can provide higher compression force to the soft-pack battery cell 201. On the other hand, for the volume change of the soft-pack battery cell 201 during the charging and discharging process, and for the irreversible expansion of the soft-pack battery cell 201 in the later life, the metal bottom shell 100 can also use its good elasticity and deformation resistance to stably provide higher compression force to the soft-pack battery cell 201. Especially for the adverse effects caused by the expansion of the silicon-doped battery cell in the later cycle, it not only avoids the problem of small deformation space of the cast shell, but also avoids the problem of easy pressure rupture of the injection molded shell, thereby effectively improving the phenomenon of low cycle life of the battery cell group 200 made of silicon-doped battery cells. In summary, using such a bottom shell 100 composed of two metal shells can more effectively improve the cycle performance of the soft-pack battery cell 201 and prolong the durability of the power storage device 600.

[0048] In other embodiments, the second metal shell 20 can have the same structure as the first metal shell 10, i.e., the same mounting groove 14 is formed on the second metal shell 20. In this way, the same mold can be used when manufacturing the first metal shell 10 and the second metal shell 20. At the same time, if both metal shells are provided with mounting grooves 14, the size of the mounting groove 14 in the thickness direction of the soft-pack battery cell 201, which can also be referred to as the protrusion height, can be smaller than the protrusion height when only one metal shell is provided with a mounting groove 14. After reducing the protrusion height, the requirement for the strength of the metal shell is reduced, which can save costs.

[0049] In the above embodiments, the shape of the first accommodating cavity 30 can match the shape of the battery cell group 200, for example, the shape of the battery cell group 200 is a rectangular cuboid, and the shape of the first accommodating cavity 30 can be a rectangular cuboid. The shape of the first accommodating cavity 30 can not match the shape of the battery cell group 200, for example, the shape of the battery cell group 200 is a rectangular cuboid, and the shape of the first accommodating cavity 30 can be a cylinder. As long as the first accommodating cavity 30 can accommodate at least part of the battery cell group 200, and the first abutting wall 11 and the second abutting wall 21 respectively abut the battery cell group 200 and apply compression force, it is acceptable. The first accommodating cavity 30 can accommodate the battery cell group 200 and play a protective role. For example, the first accommodating cavity 30 can avoid direct exposure of the battery cell group 200 to the external environment and pollution by pollutants in the external environment. At the same time, the first accommodating cavity 30 can also avoid direct contact of the battery cell group 200 with external structures and damage.

[0050] In the above embodiment, the plurality of side walls 12 are arranged on the circumferential side of the first abutting wall 11, which not only cooperates with the first abutting wall 11 to form the mounting groove 14 and the first accommodating cavity 30 with the second abutting wall 21 to protect the battery cell group 200, but also makes the shell less likely to deform and can maintain the predetermined compression force.

[0051] The reason is that the plurality of side walls 12 can be perpendicular to the first abutting wall 11 and the first connecting wall 13. After the first abutting wall 11 and the second abutting wall 21 compress the battery cell group 200, the first abutting wall 11 will be subjected to the reaction force of the soft-pack battery cell 201. If the first metal shell 10 is a flat plate structure, the reaction force acting on the first abutting wall 11 will generate bending stress on the first metal shell 10, causing the first metal shell 10 to deform, for example, to bulge, so that the first abutting wall 11 and the second abutting wall 21 do not maintain the predetermined spacing, resulting in a decrease in compression force and affecting the service life of the soft-pack battery cell 201. Therefore, the plurality of side walls 12 are arranged on the circumferential side of the first abutting wall 11, so that the bending stress on the first metal shell 10 becomes the tensile stress of the plurality of side walls 12. The tensile strength of the first metal shell 10 is higher than the bending strength, so the shell is less likely to deform and can maintain the predetermined compression force, thereby improving the service life of the soft-pack battery cell 201.

[0052] Further, as shown in Figure 6 and Figure 7 The plurality of side walls 12 include two vertical side walls 121 and a bottom side wall 122. The two vertical side walls 121 are arranged opposite each other on the two sides of the first abutting wall 11 in the second direction, and the bottom side wall 122 is located between the two vertical side walls 121. The bottom shell 100 is provided with an opening 40 on the side away from the bottom side wall 122. The opening 40 can serve as a mounting port of the battery cell group 200, and the battery cell group 200 can be placed into the first accommodating cavity 30 through the opening 40. The opening 40 can also serve as an electrical connection port of the battery cell group 200, and the total positive electrode and the total negative electrode of the battery cell group 200 can be connected to the circuit board, the electrical device, and the charging device through the opening 40.

[0053] It should be noted that the second direction is perpendicular to the first direction. For example, when the first direction is the thickness direction of the soft-pack battery cell 201, the second direction can be the width direction of the soft-pack battery cell 201.

[0054] The bottom side wall 122 is provided with a glue injection port 1221 communicating with the first accommodating cavity 30.

[0055] The glue injection port 1221 allows the technical personnel to inject glue into the power storage device 600, which can improve the sealing performance of the power storage device 600 and enhance the stability of the power storage device 600.

[0056] Another particular advantage of providing a glue injection port 1221 on the bottom sidewall 122 is that the energy storage device 600 can be inverted during glue injection. The glue can flow under gravity and fill the entire first receiving cavity 30.

[0057] Furthermore, such as Figure 4 As shown, a rounded corner 50 is provided at the connection between any sidewall 12 and the first abutting wall 11. The first metal shell 10 can be manufactured by a stamping process. The rounded corner 50 at the connection between each sidewall 12 and the first abutting wall 11 can effectively alleviate the stress concentration problem at the connection between the sidewall 12 and the first abutting wall 11 during the stamping process, prevent the first metal shell 10 from breaking, and improve the strength and durability of the first metal shell 10.

[0058] In the above embodiment, if some of the pouch cells 201 are attached to the rounded corner portion 50, it will cause the pouch cells 201 to deform. Moreover, the pouch cells 201 attached to the rounded corner portion 50 will be subjected to uneven force, which will affect the service life of the pouch battery.

[0059] Therefore, as Figure 3 As shown, in this disclosure, on a projection plane perpendicular to the first direction, the orthographic projection of the rounded corner portion 50 does not overlap with the orthographic projection of the cell assembly 200. That is, on the projection plane perpendicular to the first direction, the orthographic projection of the edge of the rounded corner portion 50 that contacts the first abutting wall 11 is located outside the orthographic projection of the cell assembly 200. The orthographic projection of the cell assembly 200 falls within the orthographic projection of the first abutting wall 11.

[0060] Thus, the surface of the cell assembly 200 only contacts the surface of the first abutment wall 11. The surface shape of the first abutment wall 11 can match the surface shape of the pouch cell 201. For example, if the surface of the pouch cell 201 is flat, the first abutment wall 11 can be a flat plate-like structure. The advantage of this arrangement is that the clamping force applied by the first abutment wall 11 to the cell assembly 200 can be evenly distributed on the surface of the cell assembly 200, making the force on the cell assembly 200 more uniform and improving the service life of the pouch battery.

[0061] like Figure 7 As shown, the bottom sidewall 122 can be inclined toward the opening 40, and the angle between the bottom sidewall 122 and the first abutting wall 11 is B, 90°≤B≤150°.

[0062] The inclined bottom sidewall 122 forms a cavity 60 between the bottom sidewall 122 and the soft-pack battery cell 201, which can serve as a flow channel for the colloid.

[0063] In particular, the angle B between the bottom side wall 122 and the first abutting wall 11 should not be too large or too small. If the angle B is too large, the cavity 60 occupies a large space, increasing the volume of the power storage device 600. If the angle B is too small, the gel is difficult to flow in the cavity 60. For example, the angle B can be 100°, 110°, 120° or 130°.

[0064] Further, as shown in Figure 6 The vertical side wall 121 can be inclined away from the battery cell group 200, so that the vertical side wall 121 and the soft-pack battery cell 201 form a cavity 60, which can serve as a flow channel for the gel. When injecting the gel, the power storage device 600 can be inverted, i.e. the bottom side wall 122 faces upward. After the gel is injected into the cavity 60 between the bottom side wall 122 and the battery cell group 200, it can flow along the cavity 60 into the space between the vertical side wall 121 and the battery cell group 200. Thus, the gel can fill the entire power storage device 600.

[0065] As shown in Figure 5 The second abutting wall 21 and the second connecting wall 22 are coplanar to form a flat plate structure.

[0066] In this way, the flat second abutting wall 21 can uniformly distribute the pressing force on the surface of the battery cell group 200, and the flat plate structure is easy to process, which can reduce the cost.

[0067] As shown in Figure 1 and Figure 2 The power storage device 600 further includes an upper shell 300 and a circuit board 400. The upper shell 300 is sealingly connected to the bottom shell 100. The upper shell 300 is provided with a second accommodating cavity 301 communicating with the first accommodating cavity 30, and the first accommodating cavity 30 and the second accommodating cavity 301 together form an inner cavity. The circuit board 400 is electrically connected to the battery cell group 200 and located in the inner cavity.

[0068] The circuit board 400 can be a BMS protection board. The BMS protection board can include a total positive terminal and a total negative terminal, and can further include a control chip, a voltage detection circuit, a current detection circuit, a temperature detection circuit, etc. The BMS protection board can be used to improve battery utilization, prevent overcharging and overdischarging of the battery, prolong the service life of the battery, and monitor the state of the battery to ensure safe, stable and efficient operation of the battery. The total positive terminal and the total negative terminal of the BMS protection board can be electrically connected to the total positive electrode and the total negative electrode of the soft-pack battery cell 201, and the electrical connection can be achieved by plug-in, welding or riveting. The tab of each soft-pack battery cell 201 can also be connected to the circuit board 400. A port 401 can be provided on the BMS protection board, which can pass through a hole 302 on the upper shell 300 to be electrically connected to an external power consumption device or a charging device.

[0069] Since the size of the circuit board 400 in the first direction can be greater than the size of the battery cell group 200 in the first direction. Therefore, the first abutting wall 11 can include a first protruding portion 15 protruding away from the first metal shell 10, and the first protruding portion 15 is formed with a protruding cavity 151 in the inner cavity, and at least part of the circuit board 400 is located in the protruding cavity 151. The protruding cavity 151 can accommodate part of the circuit board 400 to place the circuit board 400 in the inner cavity.

[0070] The circuit board 400 and the battery cell group 200 are arranged in the inner cavity, and the upper shell 300 and the bottom shell 100 can protect the circuit board 400 and the battery cell group 200 from being polluted by the external environment. And the first protruding portion 15 forms an angle step structure on the surface of the first abutting wall 11, which can improve the structural strength of the bottom shell 100. As shown in Figure 6 The second connecting wall 22 is provided with a sealing groove 221 on one side surface facing the first connecting wall 13. In another embodiment, the first connecting wall 13 is provided with a sealing groove 221 on one side surface facing the second connecting wall 22. In another embodiment, the first connecting wall 13 is provided with a sealing groove 221 on one side surface facing the second connecting wall 22, and the second connecting wall 22 is provided with a sealing groove 221 on one side surface facing the first connecting wall 13.

[0071] Optionally, the sealing groove 221 can be a curved portion protruding away from the first connecting wall 13. That is, the sealing groove 221 is arranged on the second connecting wall 22, and the sealing groove 221 protrudes from the surface of the second connecting wall 22.

[0072] Optionally, the sealing groove 221 can extend through the entire second connecting wall 22, or can be arranged at a partial position of the second connecting wall 22.

[0073] The first connecting wall 13 and the second connecting wall 22 are connected by sealing.

[0074] Optionally, the sealing groove 221 can be filled with sealing glue or a sealing glue ring.

[0075] During the use of the soft package battery cell 201, the volume will expand. The expanded soft package battery cell 201 will exert a pressure on the first metal shell 10 and the second metal shell 20. Under the action of the pressure, the sealing groove 221 protruding on the first connecting wall 13 or the second connecting wall 22 can be deformed, for example, one edge of the sealing groove 221 is warped.

[0076] Therefore, at the position where the edge of the sealing groove 221 is warped, the first connecting wall 13 and the second connecting wall 22 can be spaced apart from each other by a distance to release the pressure. The sealing groove 221 can reduce the risk of damage to the metal shell under the pressure. At the same time, the pressure can be prevented from gradually increasing with the expansion of the soft-pack battery cell 201, so that the pressure is ensured within a predetermined range, and the service life of the soft-pack battery cell 201 is improved.

[0077] As shown in Figure 6 When the sealing groove 221 is arranged on the second connecting wall 22, the sealing groove 221 is filled with the sealing glue 222 abutting against the first connecting wall 13. When the sealing groove 221 is arranged on the first connecting wall 13, the sealing groove 221 is filled with the sealing glue 222 abutting against the second connecting wall 22. When the first connecting wall 13 is provided with the sealing groove 221 on the side surface facing the second connecting wall 22, and the second connecting wall 22 is provided with the sealing groove 221 on the side surface facing the first connecting wall 13, the two sealing grooves 221 as a whole form a cavity filled with the sealing glue.

[0078] The sealing groove 221 can extend through the entire first connecting wall 13 or the second connecting wall 22, and the sealing glue 222 can comprehensively seal the gap between the first metal shell 10 and the second metal shell 20 in the circumferential direction of the battery cell group 200. The present disclosure does not limit the material of the sealing glue 222, as long as the sealing glue 222 can be filled in the sealing groove 221 after curing.

[0079] The sealing glue 222 can further improve the sealing between the first metal shell 10 and the second metal shell 20, reduce the risk of a leakage channel between the first connecting wall 13 and the second connecting wall 22, avoid pollution of the soft-pack battery cell 201 by external pollutants, and improve the service life of the soft-pack battery cell 201.

[0080] In some embodiments, the first connecting wall 13 and the second connecting wall 22 can be connected together by a rivet.

[0081] The rivet can provide high-strength fastening, has strong load-bearing capacity and shock resistance, and does not require processing links such as welding and polishing when the rivet is installed, thereby avoiding deformation problems caused by high temperature. Riveting can connect the first connecting wall 13 and the second connecting wall 22 into a whole, has good sealing performance, and is not prone to problems such as loosening and air leakage.

[0082] In some embodiments, the first connecting wall 13 and the second connecting wall 22 can also be welded together.

[0083] Welding does not require additional connecting pieces such as bolts or rivets, thereby saving materials and costs.

[0084] In some embodiments, the first connecting wall 13 and the second connecting wall 22 are easily deformed during welding, which causes the pressing force on the soft-pack battery cell 201 to be different at different positions, and uneven pressing force affects the service life of the soft-pack battery cell 201.

[0085] Therefore, as shown in FIG. 1, a support plate 70 can be arranged between the first abutting wall 11 and the battery cell group 200. In another embodiment, a support plate 70 can be arranged between the second abutting wall 21 and the battery cell group 200. In another embodiment, support plates 70 can be arranged between the first abutting wall 11 and the battery cell group 200 and between the second abutting wall 21 and the battery cell group 200. Figure 2

[0086] In this way, the pressing force on the first connecting wall 13 and / or the second connecting wall 22 can be evenly applied to the soft-pack battery cell 201 through the support plate 70.

[0087] In some embodiments, the present disclosure does not limit the material of the support plate 70, as long as it has a certain rigidity and is not easily deformed, and can evenly apply the pressing force to the soft-pack battery cell 201.

[0088] For example, the support plate 70 can be an epoxy plate or a polypropylene plate.

[0089] The epoxy plate has sufficient rigidity and strength, and has a certain elasticity, and its surface is smooth and flat, which can evenly apply the pressing force to the soft-pack battery cell 201, thereby improving the service life of the soft-pack battery cell 201. The polypropylene plate is low in price and can reduce costs; and has high toughness and good impact resistance and is not easily broken.

[0090] The present disclosure does not limit the material of the first metal shell 10 and the second metal shell 20, which can be, for example, a steel thin-walled member. The steel thin-walled member has good ductility and can absorb energy when subjected to external force, thereby improving the anti-seismic performance of the soft-pack battery cell 201, and can provide good stability and rigidity and reduce structural deformation.

[0091] <Example power utilization equipment>

[0092] The present disclosure also provides a power utilization equipment 500. As shown in FIG. 2, the power utilization equipment 500 includes the battery module 100. Figure 8 ​As shown, the electrical equipment 500 can comprise the above-mentioned power storage device 600. By way of example only, the electrical equipment 500 can be, but is not limited to, a vehicle, a household appliance, a power tool, a power storage station, an industrial equipment, etc. By way of example only, the vehicle can be, but is not limited to, a car, a sports utility vehicle (SUV), a multi-purpose vehicle (MPV), a freight vehicle, an engineering vehicle, etc. In particular, when the electrical equipment 500 is a vehicle, the power storage device 600 can be a start-stop battery pack. In this context, the start-stop battery pack can refer to a storage battery designed for a start-stop system of a vehicle. By way of example only, the start-stop battery pack is capable of shutting down the engine when the vehicle is idling, and quickly starting the engine when needed, thereby effectively reducing the fuel consumption and emission of the vehicle in the idling state.

[0093] Alternatively, the power storage device 600 can also be a low-voltage battery pack, a power battery pack, a power storage module, etc.

[0094] It should be noted that the various elements described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the disclosure will not describe various possible combinations again.

[0095] It should be understood that multiple components and / or parts can be provided by a single integrated component or part. Alternatively, a single integrated component or part can be divided into separate multiple components and / or parts. The disclosure using “one” or “a” to describe a component or part is not intended to exclude other components or parts.

[0096] It should be understood that although the terms “first” or “second” and the like can be used in this disclosure to describe various elements (such as a first metal shell and a second metal shell), these elements are not intended to be established by these terms, and these terms are only used to distinguish one element from another.

[0097] The above describes the basic principles of the disclosure in combination with specific embodiments, but it should be noted that the advantages, advantages, effects, etc. mentioned in the disclosure are only examples and are not limited. These advantages, advantages, effects, etc. cannot be considered as the various embodiments of the disclosure must have. In addition, the above specific details are only for the purpose of example and for the purpose of understanding, and are not limited to the above specific details. The above specific details do not limit the disclosure to be necessarily implemented with the above specific details.

[0098] The above merely describes specific embodiments of the present disclosure, but the protection scope of the present disclosure is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical scope disclosed by the present disclosure, which should be covered within the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be subject to the protection scope of the claims.

Claims

1. An electrical energy storage device, characterized by, The application relates to a power storage device. The power storage device comprises a cell group, a bottom shell and an upper shell. The cell group comprises a plurality of soft package cells arranged in a first direction. The bottom shell comprises a first metal shell and a second metal shell. The first metal shell comprises a first abutting wall, a plurality of side walls and a first connecting wall. The plurality of side walls are arranged on the periphery of the first abutting wall.

2. The power storage device according to claim 1, wherein The first connecting wall is located on the side of the side wall away from the first abutting wall. The second metal shell comprises a second abutting wall and a second connecting wall arranged on the outer side of the second abutting wall.

3. The power storage device according to claim 2, wherein The first connecting wall is fixedly connected with the second connecting wall. The second abutting wall covers at least part of the installation groove and forms a first accommodating cavity.

4. The power storage device according to claim 2, wherein At least part of the cell group is located in the first accommodating cavity.

5. The power storage device according to claim 1, wherein The first abutting wall and the second abutting wall are located at the opposite ends of the cell group in the first direction and abut against the cell group.

6. The power storage device according to claim 1, wherein The plurality of side walls comprise two vertical side walls and a bottom side wall. The two vertical side walls are oppositely arranged on the two sides of the first abutting wall in a second direction.

7. The power storage device according to claim 1, wherein The bottom side wall is located between the two vertical side walls. The bottom shell is provided with an opening on the side away from the bottom side wall.

8. The power storage device according to claim 1, wherein The bottom side wall is inclinedly arranged towards the opening.

9. The power storage device according to claim 8, wherein The included angle between the bottom side wall and the first abutting wall is B.

10. The power storage device according to claim 1, wherein 90 DEG <= B <= 150 DEG. The second abutting wall is coplanar with the second connecting wall. The power storage device further comprises an upper shell and a circuit board.

11. An electrical device, characterized by The upper shell is sealingly connected with the bottom shell. The upper shell is provided with a second accommodating cavity communicating with the first accommodating cavity. The first accommodating cavity and the second accommodating cavity jointly form an inner cavity. The circuit board is electrically connected with the cell group and is located in the inner cavity. The first abutting wall comprises a first protruding part protruding away from the first metal shell. The first protruding part forms a protruding cavity in the inner cavity. At least part of the circuit board is located in the protruding cavity. The first connecting wall is provided with a sealing groove on the side surface thereof facing the second connecting wall. The sealing groove is filled with sealing glue abutting against the second connecting wall. The second connecting wall is provided with a sealing groove on the side surface thereof facing the first connecting wall. The sealing groove is filled with sealing glue abutting against the first connecting wall. The first abutting wall and the cell group and / or the second abutting wall and the cell group are provided with a support plate. The support plate is an epoxy resin plate or a polypropylene plate. The first connecting wall and the second connecting wall are riveted. The first connecting wall and the second connecting wall are welded. The first connecting wall and the second connecting wall are sealingly connected. The application further relates to a power storage device. The power storage device comprises a cell group, a bottom shell and an upper shell. The cell group comprises a plurality of soft package cells arranged in a first direction. The bottom shell comprises a first metal shell and a second metal shell. The first metal shell comprises a first abutting wall, a plurality of side walls and a first connecting wall. The plurality of side walls are arranged on the periphery of the first abutting wall. The first connecting wall is located on the side of the side wall away from the first abutting wall. The second metal shell comprises a second abutting wall and a second connecting wall arranged on the outer side of the second abutting wall. The first connecting wall is fixedly connected with the second connecting wall. The second abutting wall covers at least part of the installation groove and forms a first accommodating cavity. At least part of the cell group is located in the first accommodating cavity. The first abutting wall and the second abutting wall are located at the opposite ends of the cell group in the first direction and abut against the cell group. The plurality of side walls comprise two vertical side walls and a bottom side wall. The two vertical side walls are oppositely arranged on the two sides of the first abutting wall in a second direction. The bottom side wall is located between the two vertical side walls. The bottom shell is provided with an opening on the side away from the bottom side wall. The bottom side wall is inclinedly arranged towards the opening. The included angle between the bottom side wall and the first abutting wall is B. 90 DEG <= B <= 150 DEG. The second abutting wall is coplanar with the second connecting wall. The power storage device further comprises an upper shell and a circuit board. The upper shell is sealingly connected with the bottom shell. The upper shell is provided with a second accommodating cavity communicating with the first accommodating cavity. The first accommodating cavity and the second accommodating cavity jointly form an inner cavity. The circuit board is electrically connected with the cell group and is located in the inner cavity. The first abutting wall comprises a first protruding part protruding away from the first metal shell. The first protruding part forms a protruding cavity in the inner cavity. At least part of the circuit board is located in the protruding cavity. The first connecting wall is provided with a sealing groove on the side surface thereof facing the second connecting wall. The sealing groove is filled with sealing glue abutting against the second connecting wall. The second connecting wall is provided with a sealing groove on the side surface thereof facing the first connecting wall. The sealing groove is filled with sealing glue abutting against the first connecting wall. The first abutting wall and the cell group and / or the second abutting wall and the cell group are provided with a support plate. The support plate is an epoxy resin plate or a polypropylene plate. The first connecting wall and the second connecting wall are riveted. The first connecting wall and the second connecting wall are welded. The first connecting wall and the second connecting wall are sealingly connected. The application further relates to a power storage device.

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