Battery module, battery pack and electrical device

Abstract

Provided in the present application are a battery module, a battery pack and an electrical device. The battery module comprises at least one battery group and a plurality of buffer members; and the battery group comprises a plurality of batteries arranged in a first direction. A plurality of positive electrode plates and a plurality of negative electrode plates which are alternately stacked in the first direction are provided in each battery. The positive electrode plate and part of the negative electrode plate overlap in the first direction to form an overlap area, and the positive electrode plate and the other part of the negative electrode plate are staggered in the first direction to form a non-overlap area.

Description

Battery module, battery pack and electric device

[0001] The present application claims priority to the Chinese patent application No. 202422418080.4, filed on September 30, 2024, to the Chinese Patent Office, the whole content of the above application being incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the technical field of battery, in particular to a battery module, a battery pack and an electric device. BACKGROUND

[0003] In the related art, during the cycle process of the battery, the battery will expand to different degrees due to the migration of lithium ions and the decomposition of electrolyte and other factors. SUMMARY

[0004] However, the battery is connected by structural adhesive in application, which cannot reserve a certain buffer space for the battery, so that the battery capacity is accelerated to decay in the cycle use, thereby affecting the cycle service life of the battery.

[0005] In a first aspect, the present application provides a battery module, comprising:

[0006] At least one battery pack comprising a plurality of batteries arranged along a first direction, the battery is provided with a plurality of positive plates and a plurality of negative plates alternately stacked in the first direction, a part of the positive plate and the negative plate overlaps in the first direction to form an overlapping area, and another part of the positive plate and the negative plate is staggered in the first direction to form a non-overlapping area;

[0007] A plurality of buffer members, at least one buffer member is arranged between two adjacent batteries.

[0008] The normal projection of the buffer member in the first direction is located in the overlapping area and outside the non-overlapping area.

[0009] In a second aspect, the present application provides a battery pack, the battery pack comprising the battery module.

[0010] In a third aspect, the present application provides an electric device, comprising the battery pack. ADVANTAGEOUS EFFECTS

[0011] The battery module provided in the embodiments of the present application comprises at least one battery pack and a plurality of buffer members, the battery pack comprises a plurality of batteries arranged in a first direction, the battery is provided with a plurality of positive plates and a plurality of negative plates alternately and stacked in the first direction, a part of the positive plate and the negative plate overlap in the first direction to form an overlapping area, and another part of the positive plate and the negative plate are staggered in the first direction to form a non-overlapping area, at least one buffer member is arranged between the two adjacent batteries, and the orthographic projection of the buffer member in the first direction is located in the overlapping area and outside the non-overlapping area; in the embodiments of the present application, the buffer member is arranged between the two adjacent batteries, so that the two batteries are spaced apart from each other, thereby providing a certain buffer space for the expansion of the battery in the cyclic use process, meanwhile, the buffer member does not abut against the non-overlapping area of the positive plate and the negative plate in the battery in the first direction, thereby avoiding uneven distribution of the expansion force of the battery, and further slowing down the capacity attenuation of the battery, so as to improve the cyclic use life of the battery. BRIEF DESCRIPTION OF DRAWINGS

[0012] Fig. 1 is an exploded schematic view of the battery module provided in the embodiments of the present application;

[0013] Fig. 2 is a schematic view of the size relationship comparison between the buffer member and the positive plate and the negative plate in the battery in the first direction provided in the embodiments of the present application;

[0014] Fig. 3 is a schematic view of the structure of the negative plate provided in the embodiments of the present application;

[0015] Fig. 4 is a schematic view of the size relationship comparison between the positive plate and the negative plate provided in the embodiments of the present application;

[0016] Fig. 5 is a schematic view of part of the structure of the battery module provided in the present application;

[0017] Fig. 6 is an assembly schematic view of the clamp clamping the battery provided in the present application;

[0018] Fig. 7 is a data graph showing the influence of reserving different expansion spaces for the battery on the cyclic life and the expansion force of the battery provided in the present application.

[0019] Explanation of reference signs:

[0020] 100, battery module; 1, battery pack; 11, battery; 110, positive plate; 111, negative plate; 112, separator; 2, buffer member; 3, overlapping area; 4, non-overlapping area; 5, thinning part; 6, end plate; 7, clamp; 71, clamping part. Embodiments of the present application

[0021] The application provides a battery module, and Figs. 1-7 are some embodiments of the application. As shown in the drawings, the X direction in the drawings is a first direction, the Y direction is a second direction, and the Z direction is a third direction. Hereinafter, the first direction X, the second direction Y, and the third direction Z are described. The first direction X and the second direction Y intersect, and both the first direction X and the second direction Y are perpendicular to the third direction Z.

[0022] Please refer to Figs. 1-3. In some embodiments of the application, the battery module 100 includes a battery pack 1, and the battery pack 1 includes a plurality of batteries 11 arranged along the first direction X. The battery 11 is provided with positive electrode sheets 110 and negative electrode sheets 111 alternately stacked in the first direction X, that is, the positive electrode sheets 110 and the negative electrode sheets 111 are arranged in the battery 11 so that the battery 11 can realize an electrochemical reaction to store and output electric energy.

[0023] The positive electrode sheets 110 and the negative electrode sheets 111 in the battery 11 do not completely overlap in the first direction X, that is, a part of the positive electrode sheets 110 and the negative electrode sheets 111 overlap in the first direction X to form an overlapping area 3, and another part of the positive electrode sheets 110 and the negative electrode sheets 111 are staggered in the first direction X to form a non-overlapping area 4.

[0024] The way in which the overlapping area 3 and the non-overlapping area 4 are formed between the positive electrode sheets 110 and the negative electrode sheets 111 is not limited. In an embodiment of the application, the positive electrode sheets 110 and the negative electrode sheets 111 can have different sizes in the plane of the second direction Y and the third direction Z, so that the overlapping area 3 and the non-overlapping area 4 are formed between the positive electrode sheets 110 and the negative electrode sheets 111.

[0025] In another embodiment of the application, the positive electrode sheets 110 and the negative electrode sheets 111 can be staggered in the second direction Y and the third direction Z, so that the overlapping area 3 and the non-overlapping area 4 are formed.

[0026] In yet another embodiment of the application, the positive electrode sheets 110 and the negative electrode sheets 111 can be staggered in the third direction Z, so that the overlapping area 3 and the non-overlapping area 4 are formed.

[0027] In yet another embodiment of the application, the positive electrode sheets 110 and the negative electrode sheets 111 can be staggered in both the second direction Y and the third direction Z, so that the overlapping area 3 and the non-overlapping area 4 are formed.

[0028] In yet another embodiment of the application, the positive electrode sheets 110 and the negative electrode sheets 111 have different sizes in the plane of the second direction Y and the third direction Z, and the positive electrode sheets 110 and the negative electrode sheets 111 are staggered in at least one of the second direction Y and the third direction Z, so that the overlapping area 3 and the non-overlapping area 4 are formed between the positive electrode sheets 110 and the negative electrode sheets 111.

[0029] The type of the battery 11 is not limited, and can be a stacked battery or a wound battery.

[0030] In some embodiments of the present application, the battery module 100 further comprises a plurality of buffer members 2, at least one buffer member 2 being arranged between two adjacent batteries 11; that is, the two adjacent batteries 11 are spaced apart by the buffer member 2, so that a certain buffer space is provided for the expansion of the battery 11 during use.

[0031] The buffer member 2 between the two adjacent batteries 11 can be one or more, which is not limited herein.

[0032] In some embodiments of the present application, the orthographic projection of the buffer member 2 in the first direction X is located in the overlapping region 3 and outside the non-overlapping region 4; in this way, the buffer member 2 does not press the non-overlapping region 4 of the positive electrode plate 110 and the negative electrode plate 111 in the battery 11, avoiding uneven distribution of the expansion force of the battery 11.

[0033] It should be noted that the battery 11 comprises an electrode assembly, and the electrode assembly comprises a plurality of positive electrode plates 110 and a plurality of negative electrode plates 111 arranged alternately and stacked in the first direction X. In the first direction X, the thickness of the overlapping region 3 between the positive electrode plate 110 and the negative electrode plate 111 is greater than the thickness of the non-overlapping region 4 between the positive electrode plate 110 and the negative electrode plate 111, and the area of the overlapping region 3 of the positive electrode plate 110 and the negative electrode plate 111 is greater than the area of the non-overlapping region 4 between the positive electrode plate 110 and the negative electrode plate 111. By arranging the orthographic projection of the buffer member 2 in the first direction X not to be located in the non-overlapping region 4, the buffer member 2 is prevented from pressing the non-overlapping region 4 of the positive electrode plate 110 and the negative electrode plate 111, so that the expansion force of the battery 11 is evenly distributed; at the same time, since the buffer member 2 in the first direction X is opposite to the larger area overlapping region 3 in the battery 11, the expansion stress of the battery 11 can be better absorbed, and the cycle life of the battery 11 is improved.

[0034] In the technical solution of the present application, the buffer member 2 is arranged between the two adjacent batteries 11, so that the two batteries 11 are spaced apart from each other, thereby providing a certain buffer space for the expansion of the battery 11 during the cycle use, and the buffer member 2 in the first direction X does not abut against the non-overlapping region 4 of the positive electrode plate 110 and the negative electrode plate 111 in the battery 11, avoiding uneven distribution of the expansion force of the battery 11, thereby slowing down the capacity decay of the battery 11, and improving the cycle life of the battery 11.

[0035] In some embodiments of the present application, the battery 11 is a lithium ion battery; that is, the positive electrode sheet 110 performs a reduction reaction or cathode process when the battery 11 is working, and the negative electrode sheet 111 performs an oxidation reaction or anode process when the battery 11 is working; wherein, during the charging process, lithium ions are deintercalated from the positive electrode sheet 110 and embedded into the negative electrode sheet 111 through the electrolyte, so that the negative electrode sheet 111 is in a lithium-rich state; and during the discharging process, lithium ions are deintercalated from the negative electrode sheet 111 and returned to the positive electrode sheet 110, so that the positive electrode sheet 110 returns to the lithium-rich state.

[0036] In addition, in order to ensure the safety and stability of the battery, the positive electrode sheet 110 and the negative electrode sheet 111 are isolated by the separator 112 to prevent direct contact between the positive electrode sheet 110 and the negative electrode sheet 111 causing internal short circuit of the battery, and the separator 112 allows lithium ions in the battery 11 to migrate through the separator 112.

[0037] In some embodiments of the present application, the size of the negative electrode sheet 111 is greater than the size of the positive electrode sheet 110 in the plane of the second direction Y and the third direction Z; in this embodiment, the size of the negative electrode sheet 111 is greater than the size of the positive electrode sheet 110 in the plane of the second direction Y and the third direction Z, which can avoid the occurrence of lithium precipitation in the battery 11 during the charging process, thereby avoiding the performance degradation and the significant reduction of the cycle life of the lithium ion battery.

[0038] It should be noted that lithium precipitation refers to the phenomenon that lithium ions are deintercalated from the positive electrode sheet 110 and embedded into the negative electrode sheet 111 during the charging process of the battery 11, and if there is not enough space in the negative electrode sheet 111, the resistance of lithium ions embedded into the negative electrode sheet 111 will increase, causing lithium ions that cannot be embedded into the negative electrode sheet 111 to obtain electrons on the surface of the negative electrode sheet 111, forming a silver-white lithium metal.

[0039] In some embodiments of the present application, the positive projection of the positive electrode sheet 110 in the first direction X is completely located on the negative electrode sheet 111 to form an overlapping area 3; that is, in this embodiment, the peripheral portion of the positive electrode sheet 110 does not protrude from the peripheral portion of the negative electrode sheet 111, and such arrangement can facilitate the separator 112 located between the positive electrode sheet 110 and the negative electrode sheet 111 to completely separate the positive electrode sheet 110 and the negative electrode sheet 111, avoiding direct contact between the positive electrode sheet 110 and the negative electrode sheet 111, and forming an internal short circuit in the battery 11.

[0040] In addition, the arrangement that the positive projection of the positive electrode sheet 110 in the first direction X is completely located on the negative electrode sheet 111 can also improve the space utilization in the battery 11, thereby improving the energy density of the battery 11.

[0041] Please refer to FIG. 3, since the orthographic projection of the positive electrode sheet 110 in the first direction X is entirely located on the negative electrode sheet 111, that is, the overlapping area 3 and the non-overlapping area 4 are both located on the negative electrode sheet 111, the area framed by the dashed line on the negative electrode sheet 111 in FIG. 3 is the overlapping area 3, and the area outside the frame of the dashed line on the negative electrode sheet 111 is the non-overlapping area 4.

[0042] In some embodiments of the present application, since the orthographic projection of the positive electrode sheet 110 in the first direction X is entirely located on the negative electrode sheet 111, the area of the overlapping area 3 between the positive electrode sheet 110 and the negative electrode sheet 111 in the plane of the second direction Y and the third direction Z is equal to the area of the positive electrode sheet 110, and the orthographic projection of the buffer 2 in the first direction X is entirely located on the positive electrode sheet 110, thereby reducing the uneven distribution of the expansion force of the battery 11, and further slowing down the capacity attenuation of the battery 11, so as to improve the cycle life of the battery 11.

[0043] In some embodiments of the present application, the size of the buffer 2 in the plane of the second direction Y and the third direction Z is not limited in relation to the size of the positive electrode sheet 110.

[0044] In an embodiment of the present application, the size of the buffer 2 in the plane of the second direction Y and the third direction Z is smaller than the size of the positive electrode sheet 110.

[0045] In another embodiment of the present application, the size of the buffer 2 in the plane of the second direction Y and the third direction Z is equal to the size of the positive electrode sheet 110.

[0046] In some embodiments of the present application, the size of the buffer 2 in the plane of the second direction Y and the third direction Z is the same as the size of the positive electrode sheet 110, that is, the buffer 2 is designed in such a way that the orthographic projection of the entire part of the buffer 2 in the first direction X coincides with the overlapping area 3 of the positive electrode sheet 110 and the negative electrode sheet 111, so as to reduce the uneven distribution of the expansion force of the battery 11, and further slow down the capacity attenuation of the battery 11, so as to improve the cycle life of the battery 11.

[0047] Please refer to FIG. 4, in some embodiments of the present application, the negative electrode sheet 111 comprises a thinned portion 5, and the thinned portion 5 is located in the non-overlapping area 4, that is, the thinned portion 5 of the negative electrode sheet 111 does not face the positive electrode sheet 110 in the first direction X, thereby avoiding the accelerated deposition of lithium ions in the thinned portion 5 of the negative electrode sheet 111.

[0048] It needs to be supplemented that, since the capacity of the thinned portion 5 of the negative electrode sheet 111 is too small relative to the positive electrode sheet 110, the lithium ions released from the positive electrode sheet 110 cannot be completely embedded into the thinned portion 5 of the negative electrode sheet 111 during the charging process of the battery, thereby causing the accelerated deposition of lithium ions in the thinned portion 5 of the negative electrode sheet 111.

[0049] Please refer to FIG. 4, the thinning portion 5 of the negative plate 111 is shown in the dashed box of FIG. 4; of course, the size and the setting position of the thinning portion 5 are not limited to the position of the dashed box shown in FIG. 4, and can be designed according to actual production.

[0050] In some embodiments of the present application, the positive plate 110 also includes a thinning portion 5; of course, due to the different sizes of the positive plate 110 and the negative plate 111, the size and the design position of the thinning portion 5 on the positive plate 110 and the thinning portion 5 on the negative plate 111 can be the same or different.

[0051] It should be noted that the formation of the thinning portion 5 on at least one of the positive plate 110 and the negative plate 111 is that, in the coating process, due to the fluidity of the coating slurry, the slurry on the negative plate 111 is not uniformly covered, and the formation of the thinning portion 5 by thinning processing can ensure the uniformity of the slurry coating, thereby improving the capacity of the battery 11, reducing the internal resistance, prolonging the cycle life and improving the safety.

[0052] Among them, the thickness of the part provided with the thinning portion 5 on the positive plate 110 in the first direction X is less than the thickness of the part without the thinning portion 5 on the positive plate 110 in the first direction X; the thickness of the part provided with the thinning portion 5 on the negative plate 111 in the first direction X is less than the thickness of the part without the thinning portion 5 on the negative plate 111 in the first direction X.

[0053] Please refer to FIG. 5, in some embodiments of the present application, the size of the battery 11 in the first direction X is L, and the interval size of the two adjacent batteries 11 in the first direction X is L1; wherein, L and L1 satisfy: 0.02L≤L1≤0.05L; setting L1 and L to satisfy the interval range of 0.02L≤L1≤0.05L can improve the capacity retention rate of the battery 11 during the cycle use, so as to improve the cycle life of the battery 11.

[0054] The ratio of L1 and L can be L1=0.02L, L1=0.021L, L1=0.022L, L1=0.023L, L1=0.024L, L1=0.025L, L1=0.026L, L1=0.027L, L1=0.028L, L1=0.029L, L1=0.03L, L1=0.031L, L1=0.032L, L1=0.033L, L1=0.034L, L1=0.035L, L1=0.036L, L1=0.037L, L1=0.038L, L1=0.039L, L1=0.04L, L1=0.041L, L1=0.042L, L1=0.043L, L1=0.044L, L1=0.045L, L1=0.046L, L1=0.047L, L1=0.048L, L1=0.049L, L1=0.05L. The ratio of L1 and L is not limited to the listed values, and other values within the range are also applicable.

[0055] In some embodiments of the present application, L and L1 satisfy the ratio L:L1=1:0.03. That is, in this embodiment, L and L1 satisfy the ratio L:L1=1:0.03, which can improve the capacity retention rate of the battery 11 during the cycle use, thereby improving the cycle life of the battery 11.

[0056] In some embodiments of the present application, the buffer 2 has elasticity, and the buffer 2 has a compressed state and a non-compressed state. In the first direction X, the size of the buffer 2 in the compressed state is smaller than that in the non-compressed state. That is, in this embodiment, the buffer 2 can elastically deform in the first direction X.

[0057] In some embodiments of the present application, the buffer 2 between the adjacent two batteries 11 is in the compressed state. That is, in this way, the buffer 2 can apply a certain pre-tightening force to the battery 11, so as to reduce the capacity attenuation of the battery 11 during the cycle use and improve the cycle life of the battery 11.

[0058] It can be understood that the multiple batteries 11 in the battery module 100 need to be applied with a certain pre-tightening force and reserved with a certain expansion space by the buffer 2 during assembly. In this way, the capacity and power attenuation of the battery 11 in the initial stage of the service life can be slowed down, and the expansion of the battery during the service life can be slowed down.

[0059] In addition, since the battery 11 will shrink in the initial cycle, the buffer 2 which can elastically deform in the first direction X can still provide a certain pre-tightening force to the battery 11 after the battery 11 shrinks, and can also avoid the change of the position of the battery 11 in the battery module 100 after the battery 11 shrinks.

[0060] In some embodiments of the present application, the size of the buffer 2 in the first direction X in the non-compressed state is D1, and the size of the buffer 2 in the first direction X in the compressed state is D2; wherein the D1 and the D2 satisfy: 0.41D1≤D2≤0.45D1. The ratio of D1 and D2 is the compression ratio of the buffer 2 in the first direction X. The buffer 2 with a compression ratio in this range can apply a certain pre-tightening force to the battery 11 to reduce the capacity attenuation of the battery 11 during cyclic use and improve the cyclic use life of the battery 11.

[0061] In some embodiments of the present application, the buffer 2 is an irradiation cross-linked polypropylene foam.

[0062] In some embodiments of the present application, the buffer 2 is arranged on both sides of the battery 11 in the first direction X, and the two buffers 2 on both sides of the battery 11 in the first direction X are symmetrical and have the same size in the first direction X.

[0063] In some embodiments of the present application, the battery module 100 further comprises two end plates 6, and the two end plates 6 are respectively arranged on both sides of the battery group 1 in the first direction X; wherein the two end plates 6 are arranged to fix the plurality of batteries 11 in the battery module 100 and provide a certain pre-tightening force to the plurality of batteries 11.

[0064] In some embodiments of the present application, the buffer 2 is arranged between the end plate 6 and the adjacent battery 11. In this way, a certain expansion space is reserved between the end plate 6 and the adjacent battery 11, and the buffer 2 can absorb the expansion stress of the battery 11 to improve the cyclic use life of the battery 11 adjacent to the end plate 6.

[0065] Please refer to FIG. 6, the buffer 2 is arranged on both sides of the battery 11 in the first direction X, and the clamp 7 is used to apply a certain pre-tightening force to the battery 11 and the buffers 2 on both sides of the battery 11 for experimental testing; wherein the two clamping parts 71 of the clamp 7 are arranged opposite to each other in the first direction X to clamp the battery 11; in the first direction X, the spacing between the two clamping parts 71 and the battery 11 is the same and is L2.

[0066] In addition, the positive plate 110 in the battery 11 is completely projected on the negative plate 111 in the battery 11 in the first direction X; the buffer 2 is completely projected on the positive plate 110 in the battery 11 in the first direction X, and the size of the buffer 2 in the plane of the second direction Y and the third direction Z is equal to the size of the positive plate 110 in the plane of the second direction Y and the third direction Z.

[0067] In the following examples 1 to 5 and comparative example 1, the battery 11 is discharged at a maximum discharge depth under a pre-tightening force in the range of 2800N to 3200N and at a temperature of 35°C.

[0068] Example 1: The spacing dimension between the clamping portion 71 of the clamp 7 and the battery 11 in the first direction X is L2, where L2 is equal to 0.02L. The arrow mark C in Figure 7 is the experimental data result in example 1.

[0069] Example 2: The spacing dimension between the clamping portion 71 of the clamp 7 and the battery 11 in the first direction X is L2, where L2 is equal to 0.03L. The arrow mark B in Figure 7 is the experimental data result in example 2.

[0070] Example 3: The spacing dimension between the clamping portion 71 of the clamp 7 and the battery 11 in the first direction X is L2, where L2 is equal to 0.04L. The arrow mark E in Figure 7 is the experimental data result in example 2.

[0071] Example 4: The spacing dimension between the clamping portion 71 of the clamp 7 and the battery 11 in the first direction X is L2, where L2 is equal to 0.05L. The arrow mark D in Figure 7 is the experimental data result in example 2.

[0072] Comparative example 1: The spacing dimension between the clamping portion 71 of the clamp 7 and the battery 11 in the first direction X is zero. The arrow mark F in Figure 7 is the experimental data result in comparative example 1.

[0073] As shown in Figure 7, compared with comparative example 1, in examples 1 to 4, the battery 11 gradually decreases in the initial stage of the cycle, i.e. is less than 3000N, which can be explained as the battery shrinking during the charging and discharging process, and the expansion force decreases. When the battery is cycled for about 400 cycles, the battery expands, the expansion force gradually increases, and then gradually increases.

[0074] In addition, when the capacity of the battery 11 is maximum, i.e. the battery 11 is fully charged by applying a pre-tightening force in the range of 2800N to 3200N, the expansion force of the battery 11 is greater than the pre-tightening force applied to the battery 11.

[0075] In examples 1 to 4, the capacity retention rate of the battery 11 after multiple cycles is greater than that of the battery 11 in comparative example 1. When the spacing dimension between the clamping portion 71 of the clamp 7 and the battery 11 in the first direction X is 0.03L, the capacity retention rate of the battery 11 is best, thereby improving the cycle life of the battery.

[0076] The application further provides a battery pack comprising the battery module 100, and the specific structure of the battery module 100 is referred to the above embodiments. Since all the technical solutions of the above embodiments are adopted in the battery pack, all the beneficial effects brought by the technical solutions of the above embodiments are at least achieved, and thus will not be repeated here.

[0077] In the battery pack provided by the embodiments of the application, the buffer 2 is arranged between the two adjacent batteries 11 in the battery pack, so that the two batteries 11 are spaced apart, thereby providing a certain buffer space for the expansion of the batteries 11 during use. Meanwhile, the buffer 2 does not abut against the non-overlapping area 4 of the positive plate 110 and the negative plate 111 of the battery 11 in the first direction X, so as to reduce the uneven distribution of the expansion force of the battery 11, thereby slowing down the capacity attenuation of the battery 11, and improving the cycle life of the battery 11.

[0078] In addition, the application further provides a power consumption device comprising the battery pack. The specific structure of the battery pack is referred to the above embodiments. Since all the technical solutions of the above embodiments are adopted in the power consumption device, all the beneficial effects brought by the technical solutions of the above embodiments are at least achieved, and thus will not be repeated here.

[0079] It can be understood that the power consumption device includes but is not limited to electric toys, electric tools, electric vehicles, automobiles, ships, spacecraft, etc. The electric toys can include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, electric plane toys, etc. The spacecraft can include airplanes, rockets, space shuttles, and spaceships, etc. The automobile can be a fuel automobile, a gas automobile, and a new energy automobile.

Claims

1. A battery module (100) comprising: at least one battery pack (1) comprising a plurality of batteries (11) arranged in a first direction, each battery (11) comprising a plurality of positive electrode sheets (110) and negative electrode sheets (111) alternately stacked in the first direction, a portion of the positive electrode sheets (110) and the negative electrode sheets (111) overlapping in the first direction to form an overlapping region (3), and another portion of the positive electrode sheets (110) and the negative electrode sheets (111) staggered in the first direction to form a non-overlapping region (4); a plurality of buffer members (2), at least one buffer member (2) being arranged between two adjacent batteries (11); wherein a projection of the buffer member (2) in the first direction is located in the overlapping region (3) and outside the non-overlapping region (4).

2. The battery module (100) according to claim 1, wherein In a plane defined by a second direction and a third direction, a size of the negative electrode sheet (111) is greater than a size of the positive electrode sheet (110); wherein the first direction intersects the second direction, and both the first direction and the second direction are perpendicular to the third direction.

3. The battery module (100) according to claim 2, wherein A projection of the positive electrode sheet (110) in the first direction completely falls on the negative electrode sheet (111) to form the overlapping region (3); A projection of the buffer member (2) in the first direction completely falls on the positive electrode sheet (110).

4. The battery module (100) according to claim 3, wherein In the plane defined by the second direction and the third direction, a size of the buffer member (2) is the same as a size of the positive electrode sheet (110).

5. The battery module (100) of claim 1, wherein, At least one of the negative electrode sheet (111) and the positive electrode sheet (110) comprises a thinned portion (5) having a thickness smaller than a thickness of other portions.

6. The battery module (100) according to any one of claims 1 to 5, wherein A size of the battery in the first direction is defined as L, and a spacing size of two adjacent batteries in the first direction is defined as L1; wherein the L and the L1 satisfy: 0.02L≤L1≤0.05L.

7. The battery module (100) of claim 6, wherein The L and the L1 satisfy: L:L1=1:0.

03.

8. The battery module (100) according to any one of claims 1 to 5, wherein The buffer member (2) has elasticity, and the buffer member (2) has a compressed state and a non-compressed state; In the first direction, a size of the buffer member (2) in the compressed state is smaller than a size of the buffer member (2) in the non-compressed state; The buffer member (2) between two adjacent batteries is in the compressed state.

9. The battery module (100) of claim 8, wherein, A size of the buffer member (2) in the first direction in the non-compressed state is defined as D1, and a size of the buffer member (2) in the first direction in the compressed state is defined as D2; wherein the D1 and the D2 satisfy: 0.41D1≤D2≤0.45D1.

10. The battery module (100) according to any one of claims 1 to 5, wherein The battery module (100) further comprises two end plates (6), and the two end plates (6) are respectively located on opposite sides of the battery pack (1) in the first direction; wherein the buffer member (2) is arranged between the end plate (6) and the adjacent battery (11). 11.A battery pack comprising the battery module (100) according to any one of claims 1 to 10.

12. An electrical device comprising the battery pack of claim 11.

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