Battery pack and electric device

Abstract

The utility model provides a battery pack and a power utilization device, the battery pack comprises a box body, a plurality of single batteries and a buffer piece, and the buffer piece is arranged between two adjacent single batteries and is arranged on a first surface of each single battery. The first face comprises a first area in the middle and a second area on the edge. The buffer piece is arranged in the second area and surrounds the first area. The buffering pieces comprise the first buffering piece and the second buffering piece, one buffering piece is arranged below the second buffering piece in the first direction, and the first buffering piece and the second buffering piece are arranged in a spaced mode. In the charging and discharging process, when the battery monomer expands, the characteristic that the middle expansion is large and the edge expansion is small is followed, so that expansion of the middle part of the battery monomer is facilitated only by arranging the buffer piece in the second area of the edge of the first surface. The first buffer part and the second buffer part are arranged at intervals, so that gas can be smoothly discharged from the second gap between the first buffer part and the second buffer part after being extruded during expansion, and the situation that the buffer parts are impacted by the extruded gas, and consequently bonding is not firm is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and specifically provides a battery pack and an electric device. Background Art

[0002] Due to the environmental protection advantages of new energy, it has developed rapidly in all walks of life, especially in electric devices (such as electric vehicles). The battery system is one of the key systems of electric vehicles, and the power battery pack (hereinafter referred to as the battery pack) is the core component of the battery system. The technical development of the power battery pack seriously affects the development of the electric vehicle industry.

[0003] Safety is one of the most important performances of the power battery pack, which has a great impact on consumers' acceptance of electric vehicles. The power battery pack specifically includes a box body and a plurality of battery cells in the box body. The main reason for the safety accidents of the power battery pack is the failure of the battery cells in the box body. Therefore, how to improve the safety of the battery cells is an urgent problem to be solved in the field. Summary of the Utility Model

[0004] In order to improve the safety of the battery cells in the battery pack, the utility model provides a battery pack. The battery pack includes a box body and a plurality of battery cells, and the plurality of battery cells are arranged in the box body. The battery pack further includes a buffer member, and the buffer member is arranged between two adjacent battery cells. The surface of the battery cell where the buffer member is arranged is the first surface, and the first surface includes a first area in the middle and a second area at the edge, and the buffer member is arranged in the second area. The buffer member includes a first buffer member and a second buffer member. Along a first direction, the first buffer member is arranged below the second buffer member, and the first buffer member and the second buffer member are arranged at intervals.

[0005] When the battery pack is charging and discharging, the battery cells will expand. By arranging a buffer member between adjacent battery cells, when the battery cells expand, they will squeeze the buffer member to obtain extra space and thus expand safely. When expanding, it follows the characteristic that the middle expands more and the edge expands less. Therefore, by only arranging the buffer member in the second area at the edge of the first surface, the first gap between the first areas of the first surfaces of two adjacent battery cells is larger, which is more conducive to the expansion of the middle part of the battery cells. By arranging the first buffer member below and the second buffer member above at intervals, when expanding, the gas in the first gap can be smoothly discharged from the second gap between the first buffer member and the second buffer member, avoiding the gas being squeezed to impact the buffer member and causing the buffer member to be not firmly adhered to the battery cell.

[0006] In an alternative technical solution of the present utility model, the buffer member includes two of the second buffer members extending in the first direction, and the two second buffer members and the first buffer member enclose a U shape. In this way, the two second buffer members also form a notch at the top of the first surface, allowing the compressed gas to be discharged.

[0007] In an alternative technical solution of the present utility model, the buffer member further includes a third buffer member, and the first buffer member, the two second buffer members and the third buffer member enclose a square shape. The bonding force between the square-shaped buffer member and the first surface of the battery cell is more balanced.

[0008] In an alternative technical solution of the present utility model, the third buffer member and the two second buffer members are arranged at intervals. That is, the square-shaped structure of the buffer member is actually a structure with discontinuous four sides. In this way, it not only ensures that the bonding force between the square-shaped buffer member and the first surface of the battery cell is more balanced, but also allows the gas to be evenly discharged from the gaps at the four corners of the square-shaped structure.

[0009] In an alternative technical solution of the present utility model, the material of the first buffer member includes at least one of melamine or silica gel. The material of the second buffer member includes at least one of polyurethane foam material and silica gel. The second buffer member has good flexibility and elasticity and is mainly used for the expansion of the battery cell.

[0010] In an alternative technical solution of the present utility model, the thickness of the first buffer member is greater than the thickness of the second buffer member. In this way, the first buffer member can block the gap at the bottom of adjacent battery cells, preventing the glue at the bottom from entering between adjacent two battery cells.

[0011] In an alternative technical solution of the present utility model, the buffer member is bonded to the battery cell.

[0012] In an alternative technical solution of the present utility model, the thickness of the first buffer member is H1, and the thicknesses of the second buffer member and the third buffer member are H2. H1 and H2 satisfy: 1 mm ≤ H1 ≤ 2.5 mm, 0.6 mm ≤ H2 ≤ 1.4 mm. Setting H1 within the above numerical range can effectively block the gap at the bottom of adjacent two battery cells without occupying too much space inside the package. Setting H2 within the above numerical range can ensure the normal expansion of the battery cell without occupying too much space inside the package, ensuring the energy density of the battery pack.

[0013] In an alternative technical solution of the present utility model, any one of the second buffer member and the first buffer member includes a plurality of discontinuous elastic members. In this way, there are more notches for the compressed gas to be discharged.

[0014] In an alternative technical solution of the present utility model, the first surface is the surface with the largest area of the above-mentioned battery cell. Therefore, the first surface is the surface with the largest expansion deformation, which can better absorb the expansion of the battery cell.

[0015] The present utility model also provides an electrical device, including the above-mentioned battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic diagram of the battery pack;

[0017] Figure 2 is Figure 1 a partially enlarged view of the battery pack;

[0018] Figure 3 is a schematic diagram of the U-shaped buffer member disposed on the first surface of the battery cell;

[0019] Figure 4 is a schematic diagram of the square-shaped buffer member disposed on the first surface of the battery cell;

[0020] Figure 5 is a schematic diagram of an embodiment of the second buffer member;

[0021] Figure 6 is Figure 4 the right view of;

[0022] REFERENCE SIGNS

[0023] Cabinet 1;

[0024] End plate 11, intermediate beam 12;

[0025] Battery cell 2;

[0026] First surface 21;

[0027] First region 211;

[0028] Buffer member 3;

[0029] First buffer member 31, second buffer member 32, second gap 33, third buffer member 34. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] The following describes the alternative embodiments of the present utility model with reference to the drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principle of the present utility model and are not intended to limit the protection scope of the present utility model.

[0031] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by terms such as "distance", "width", "thickness", "upper", "lower", "left", "right", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present utility model.

[0032] In the description of the present utility model, the terms "first", "second", "third", "fourth" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. In the description of the present utility model, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0033] In addition, it should be noted that in the description of the present utility model, unless otherwise clearly specified and defined, the terms "arranged" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, and can also be the communication inside two elements. For those skilled in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0034] In this application, the battery cell may include a lithium-ion secondary battery cell, a lithium-ion primary battery cell, a lithium-sulfur battery cell, a sodium-lithium-ion battery cell, a sodium-ion battery cell, a magnesium-ion battery cell, etc., and the embodiments of this application do not limit this. The battery cell can be in a cylindrical shape, a flat shape, a cuboid shape or other shapes, etc., and the embodiments of this application also do not limit this.

[0035] The battery cell includes an electrode assembly and an electrolyte. The electrode assembly includes a positive electrode plate, a negative electrode plate, and a separator. The battery cell mainly operates by the movement of metal ions between the positive electrode plate and the negative electrode plate. The positive electrode plate includes a positive current collector and a positive active material layer, and the positive active material layer is coated on the surface of the positive current collector; the positive current collector includes a positive coating area and a positive tab connected to the positive coating area, the positive coating area is coated with the positive active material layer, and the positive tab is not coated with the positive active material layer. Taking a lithium-ion battery as an example, the material of the positive current collector can be aluminum, and the positive active material layer includes a positive active material, and the positive active material can be lithium cobaltate, lithium iron phosphate, ternary lithium, lithium manganate, etc. The negative electrode plate includes a negative current collector and a negative active material layer, and the negative active material layer is coated on the surface of the negative current collector; the negative current collector includes a negative coating area and a negative tab connected to the negative coating area, the negative coating area is coated with the negative active material layer, and the negative tab is not coated with the negative active material layer. The material of the negative current collector can be copper, and the negative active material layer includes a negative active material, and the negative active material can be carbon or silicon, etc. The material of the separator can be PP (polypropylene) or PE (polyethylene), etc.

[0036] As Figure 1 shown, the present utility model provides a battery pack, which includes a box body 1 and a plurality of battery cells 2, and the plurality of battery cells 2 are arranged in the box body 1. The battery pack further includes a buffer member 3, and the buffer member 3 is arranged between two adjacent battery cells 2. The surface of the battery cell 2 where the buffer member 3 is arranged is the first surface 21, and the first surface 21 includes a first area 211 in the middle and a second area at the edge. The buffer member 3 is arranged in the second area, and the buffer member 3 surrounds the first area 211. The buffer member 3 includes a first buffer member 31 and a second buffer member 32. Along the first direction (i.e., the Z axis), the first buffer member 31 is arranged below the second buffer member 32, and the first buffer member 31 and the second buffer member 32 are arranged at intervals.

[0037] When the battery pack is in the process of charging and discharging, the battery cell 2 will expand. A buffer member 3 is provided between adjacent battery cells 2. When the battery cell 2 expands, it will squeeze the buffer member 3 to obtain extra space and thus expand safely. When expanding, it follows the characteristic that the middle expands more and the edge expands less. Therefore, the buffer member 3 is only provided in the second area 212 at the edge of the first surface 21. Then, the first gap between the first areas 211 of the first surfaces 21 of two adjacent battery cells 2 is larger, which is more conducive to the expansion of the middle part of the battery cell 2. The first buffer member 31 located below and the second buffer member 32 located above are arranged at intervals. Then, when expanding, the gas in the first gap can be smoothly discharged from the second gap 33 between the first buffer member 31 and the second buffer member 32, avoiding the gas being squeezed and impacting the buffer member 3, which may cause the buffer member 3 to be not firmly adhered to the battery cell 2. Compared with the integrally formed buffer member 3, the split buffer member 3 composed of the first buffer member 31 and the second buffer member 32 can determine its length according to actual needs, avoiding waste generation.

[0038] In an alternative embodiment of the present utility model, the first surface 21 is the surface with the largest area of the battery cell 2. Therefore, the first surface 21 is the surface with the largest expansion deformation, which can better absorb the expansion of the battery cell 2. Specifically, the electrode assembly inside the battery cell 2 can be a wound core or a stacked sheet. The largest surface of the motor assembly faces the first surface 21. During the charging and discharging process, the electrode assembly will expand in a direction perpendicular to the first surface 21, thereby squeezing the housing of the battery cell 2 to cause the first surface 21 to expand.

[0039] In an alternative embodiment of the present utility model, as Figure 1 shown, the box body 1 includes end plates 11 and intermediate beams 12 arranged along the X-axis. A plurality of battery cells 2 are arranged along the X-axis and the Y-axis and are clamped between the end plates 11 and the intermediate beams 12. The end plates 11 and the intermediate beams 12 jointly apply pressure to the plurality of battery cells 2 therebetween. The buffer member 3 is provided between two adjacent battery cells 2 arranged along the X-axis. The buffer member 3 and the plurality of battery cells 2 form a battery core group. Before being put into the box, first clamp both sides of the battery core group with a tooling fixture. The buffer member 3 is compressed to reduce the size of the battery core group, and then it is placed between the end plates 11 and the intermediate beams 12. The tooling fixture releases the pressure on the battery core group, and the buffer member 3 rebounds to increase the size of the battery core group so as to abut against the end plates 11 and the intermediate beams 12. As Figure 1 shown, along the Y-axis, a plurality of battery core groups are provided between the end plates 11 and the intermediate beams 12. In this embodiment, the box body 1 and the end plates 11 are integrally formed. Of course, the end plates can also be separately provided and fixed to the box body. In this embodiment, the battery core group is clamped between the end plates 11 and the intermediate beams 12. Of course, the intermediate beams can also be not provided in the box body, and the battery core group is directly clamped between the two end plates. The battery pack further includes a cold plate. The cold plate can be provided between adjacent battery cells or at the bottom of the battery cells. The cold plate and the battery cells can be adhered.

[0040] In an alternative embodiment of the present utility model, as Figure 3 shown, the buffer member 3 includes two second buffer members 32 extending along a first direction (Z-axis), the first buffer member 31 extends along a second direction, a second gap 33 is provided between the two second buffer members 32 and the first buffer member 31, and the two second buffer members 32 and the first buffer member 31 enclose a U-shape. In this way, the two second buffer members 32 also form a notch at the top of the first surface 21, and the compressed gas can be discharged from the notch and the second gap 33 simultaneously.

[0041] In an alternative embodiment of the present utility model, as Figure 4 shown, the buffer member further includes a third buffer member 34, and the third buffer member 34 and the first buffer member 31 also extend along the second direction (Y-axis). The first buffer member 31, the two second buffer members 32, and the third buffer member 34 enclose a square shape. The bonding force between the square-shaped buffer member 3 and the first surface 21 of the battery cell 2 is more balanced. Moreover, the third buffer member 34 and the two second buffer members 32 are arranged at intervals, and the two second buffer members 32 and the first buffer member 31 are arranged at intervals, that is, the square-shaped structure of the buffer member is actually a structure in which the four sides are not connected, so that the gas can be evenly discharged from the gaps at the four corners of the square-shaped structure.

[0042] In the above embodiment, each side of the three sides of the U-shaped structure and the four sides of the square-shaped structure is continuous. Of course, each side can also be provided with a discontinuous elastic member, so that a plurality of notches can be formed along the edge of the first surface 21 for the compressed gas to be discharged. As Figure 5 shown, the second buffer member 32 includes two discontinuous elastic members, and the gas can be discharged from the gap between the two discontinuous elastic members.

[0043] In an alternative embodiment of the present utility model, the material of the first buffer member 31 includes at least one of melamine or silica gel. The materials of the second buffer member 32 and the third buffer member 34 include at least one of polyurethane foam material and silica gel. The second buffer member and the third buffer member have good flexibility and elasticity, and are mainly used for the expansion of the battery cell.

[0044] In an alternative embodiment of the present utility model, as Figure 6As shown in the figure, along the third direction (Z-axis), the thickness of the first buffer member 31 is greater than the thicknesses of the second buffer member 32 and the third buffer member 34. In this way, the first buffer member 31 can block the gap at the bottom of the adjacent battery cells 2, preventing the glue at the bottom from entering between the two adjacent battery cells 2. The thickness of the first buffer member 31 is H1, and the thicknesses of the second buffer member 32 and the third buffer member 34 are H2. H1 and H2 satisfy: 1mm ≤ H1 ≤ 2.5mm, 0.6mm ≤ H2 ≤ 1.4mm. Setting H1 within the above numerical range can effectively block the gap at the bottom of the two adjacent battery cells 2 without occupying too much space inside the package. Setting H2 within the above numerical range can ensure the normal expansion of the battery cell 2 without occupying too much space inside the package, thus ensuring the energy density of the battery pack.

[0045] The present utility model also provides an electrical device. The electrical device of the present utility model includes the battery pack of the optional embodiment. The electrical device can be, but is not limited to, a mobile phone, a tablet computer, a laptop computer, an electric toy, an electric tool, a battery car, an electric vehicle, a ship, a spacecraft, etc. Among them, the electric toy can include a fixed or mobile electric toy, such as a game console, an electric vehicle toy, an electric ship toy, an electric aircraft toy, etc. The spacecraft can include an airplane, a rocket, a space shuttle, a spaceship, etc.

[0046] So far, the technical solution of the present utility model has been described in combination with the optional embodiments shown in the drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present utility model is obviously not limited to these specific embodiments. Without departing from the principle of the present utility model, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present utility model.

Claims

1. A battery pack, characterized in that: The battery pack includes Box; A plurality of battery cells are arranged in the box; A buffer is arranged between two adjacent battery cells, the surface of the battery cell on which the buffer is arranged is a first surface, the first surface includes a first area in the middle and a second area at the edge, and the buffer is arranged in the second area; The buffer member includes a first buffer member and a second buffer member. Along a first direction, the first buffer member is disposed below the second buffer member, and the first buffer member and the second buffer member are spaced apart from each other.

2. The battery pack according to claim 1, characterized in that: The buffer member includes two second buffer members extending along a first direction, and the two second buffer members and the first buffer member form a U shape.

3. The battery pack according to claim 2, characterized in that: The buffer member further includes a third buffer member, and the first buffer member, the two second buffer members and the third buffer member form a square shape.

4. The battery pack according to claim 3, characterized in that: The third buffer member and the two second buffer members are arranged at intervals.

5. The battery pack according to claim 1, wherein: The material of the first buffer member includes melamine, and the material of the second buffer member includes polyurethane foam material.

6. The battery pack according to claim 1, wherein: The thickness of the first buffer member is greater than the thickness of the second buffer member.

7. The battery pack according to claim 1, characterized in that: The buffer member is bonded to the battery cell.

8. The battery pack according to claim 3, characterized in that: The thickness of the first buffer member is H1, the thickness of the second buffer member and the third buffer member is H2, and H1 and H2 satisfy: 1mm≤H1≤2.5mm, 0.6mm≤H2≤1.4mm.

9. The battery pack according to claim 1, characterized in that: Either the second buffer component or the first buffer component includes a plurality of discontinuous elastic components.

10. The battery pack according to claim 1, wherein: The first surface is the surface of the battery cell with the largest area.

11. An electrical device, characterized in that: A battery pack comprising the battery pack as claimed in any one of claims 1 to 9.

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