Single battery, battery pack and electric equipment

Abstract

The utility model relates to the battery field, discloses a single battery, battery pack and electric equipment, has first direction, second direction and third direction that intersect pairwise, single battery includes: casing and battery cell, casing has the accommodation cavity, battery cell is provided in the accommodation cavity, battery cell includes electrode subassembly and first tab, the first tab is provided with the first tab, the second tab is provided with the second tab, and the third tab is provided with the second tab. The plurality of first tabs are electrically connected with the electrode assembly, each first tab comprises a first root part and a first folding part, and the first root part is connected with the electrode assembly and the first folding part; the first root parts extend in the third direction, the multiple first root parts are arranged at intervals in the second direction, the first folding parts are bent relative to the first root parts, the first folding parts are arranged in a flat plate shape, and at least two adjacent first folding parts are stacked in the third direction; according to the utility model, the space occupied by the tabs in the third direction is reduced, and the space utilization rate of active matters in the shell is improved, so that the energy density of the whole single battery is higher, and the overall performance of the single battery is better.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a single cell battery, a battery pack and an electrical device. Background Technology

[0002] Lithium-ion power batteries have advantages such as small size, large capacity, high energy density, high charge and discharge rate, excellent low temperature performance, long service life and high safety. However, with the development of technology, the requirements for battery energy density are getting higher and higher, and the space utilization of battery cells is becoming more and more important.

[0003] In existing technologies, conventional wound power cells typically have tabs that are bent and covered with tab protection sheets. The tabs located above the protection sheets are welded to the busbars. In this structure, the space occupied by the tabs is relatively large in the Z direction, which affects the space utilization of the active material and makes the overall space utilization of the battery low, thus affecting the overall energy density. Utility Model Content

[0004] The technical problem this invention aims to solve is how to improve the space utilization and energy density of batteries. To address this problem, this invention provides a single battery cell, a battery pack, and an electrical device. The single battery cell has three intersecting directions: a first direction, a second direction, and a third direction, including:

[0005] The housing has a receiving cavity; and

[0006] A battery cell, wherein the battery cell is disposed within the receiving cavity, the battery cell includes an electrode assembly and a first tab, wherein the first tab is provided in multiple manner and is electrically connected to the electrode assembly;

[0007] The first electrode tab includes a first root and a first folded portion. The first root connects the electrode assembly and the first folded portion. The first root extends along the third direction, and a plurality of first roots are spaced apart along the second direction. The first folded portion is bent relative to the first root and is flat. At least two adjacent first folded portions are stacked in the third direction.

[0008] Preferably, the electrode assembly has a central hole extending through it in the third direction, and the central hole has a first side and a second side disposed opposite to each other in the second direction, and the first tab is provided on both the first side and the second side.

[0009] Preferably, the first folding portion of the first tab on the first side and the first folding portion of the first tab on the second side are both folded towards the same side along the second direction; or, the first folding portion of the first tab on the first side and the first folding portion of the first tab on the second side are folded towards different sides along the second direction respectively.

[0010] Preferably, the battery cell further comprises a second tab, the second tab is provided with a plurality of second tabs and is electrically connected with the electrode assembly, the polarity of the second tab is different from the polarity of the first tab, the second tab is arranged in the first direction with the first tab, and the first side and the second side are both provided with the second tab.

[0011] Preferably, the second tab comprises a second root portion and a second folding portion, the second root portion connects the electrode assembly and the second folding portion; the second root portion extends along the third direction, and a plurality of second root portions are arranged in the second direction; the second folding portion is arranged by being folded relative to the second root portion, and any two adjacent second folding portions are arranged in the third direction.

[0012] Preferably, the shell is provided with a first pole, and the single battery further comprises a first bus bar, the first bus bar is electrically connected with the first pole and the first tab, and along the third direction, the first bus bar is located between the first folding portion and the first pole.

[0013] Preferably, along the third direction, a side of the first pole away from the battery cell is provided with a first groove, and the first bus bar is welded with a side of the first pole facing the battery cell.

[0014] Preferably, the electrode assembly has a plurality of layers around the third direction, each layer has at least two first tabs, and the at least two first tabs are arranged in the circumferential direction around the third direction, and at least one first tab of each layer is electrically connected with the first bus bar.

[0015] The utility model further provides a battery pack which adopts the single battery described in the foregoing.

[0016] The utility model further provides a power consumption equipment which adopts the battery pack described in the foregoing.

[0017] Compared with the prior art, the single battery, the battery pack and the power consumption equipment provided in the utility model embodiment have the following beneficial effects:

[0018] In the embodiment, the first tab includes a first root portion and a first folded portion. The first folded portion is bent relative to the first root portion and is in a flat plate shape. The first folded portions of the plurality of first tabs are stacked in the third direction Z. The first tab occupies less space in the third direction Z, and the space utilization of the shell of the single battery is improved. The overall performance of the single battery is improved, and the energy density is improved. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a schematic view of the internal structure of the prior art;

[0020] Figure 2 is a schematic view of the overall structure of the present application;

[0021] Figure 3 is a schematic view of the internal structure of the first tab of the present application;

[0022] Figure 4 is a schematic view of the internal structure of the second tab of the present application;

[0023] Figure 5 is a schematic view of the unfolded first tab of the present application;

[0024] Figure 6 is a schematic view of the cross-sectional structure of the battery cell at the first tab of the present application;

[0025] Figure 7 is a schematic view of the cross-sectional structure of the battery cell at the second tab of the present application;

[0026] Figure 8 is a top view of the battery cell of the present application.

[0027] In the figure: 1, shell; 11, accommodating cavity; 12, first busbar; 13, second busbar; 14, first pole; 141, first groove; 15, second pole; 151, second groove; 16, first end;

[0028] 2, battery cell; 21, electrode assembly; 211, first tab; 212, second tab; 213, separator; 22, first tab; 221, first folded portion; 222, first root portion; 23, second tab; 231, second folded portion; 232, second root portion; 24, center hole. DETAILED DESCRIPTION

[0029] The specific embodiments of the present application will be further described in detail below in conjunction with the drawings and examples. The following examples are used to illustrate the present application, but are not used to limit the scope of the present application.

[0030] As Figures 2 to 8As shown, the utility model discloses a single battery, battery pack and electric equipment, wherein the single battery has the first direction X, the second direction Y and the third direction Z that intersect two by two, and the single battery comprises:

[0031] The shell 1 has the accommodating cavity 11.

[0032] The electric core 2 is arranged in the accommodating cavity 11, and the electric core 2 comprises an electrode assembly 21 and a first tab 22, the first tab 22 is provided with a plurality of first tabs 22 and is electrically connected with the electrode assembly 21.

[0033] The first tab 22 comprises a first root 222 and a first folding portion 221, the first root 222 is connected with the electrode assembly 21 and the first folding portion 221, the first root 222 extends along the third direction Z, and a plurality of first roots 222 are arranged at intervals along the second direction Y, the first folding portion 221 is arranged in a bent manner relative to the first root 222, and the first folding portion 221 is arranged in a flat plate shape, and at least two adjacent first folding portions 221 are arranged in a stacked manner in the third direction Z.

[0034] The first tab 22 comprises a first root 222 and a first folding portion 221, the first folding portion 221 is arranged in a flat plate shape relative to the first root 222, so that the first folding portions 221 of a plurality of first tabs 22 can be arranged in a stacked manner in the third direction Z, thereby reducing the occupied space of the first tab 22 in the third direction Z, improving the space utilization rate in the shell 1 of the single battery, and also improving the overall performance of the single battery.

[0035] It can be understood that: the two adjacent first folding portions 221 are arranged in a stacked manner, which can be that the two adjacent first folding portions 221 are in contact and electrically connected after being folded, so as to electrically connect the plurality of first folding portions 221 with each other, thereby improving the overcurrent capacity of the electric core 2.

[0036] In addition, the first folding portion 221 is arranged in a flat plate shape, and the flat plate shape refers to that the first folding portion 221 of the single battery extends in a manner of being substantially parallel to a plane in the plane, rather than being curved or extended, so that the plurality of first folding portions 221 can be arranged in a stacked manner. Figure 6 As shown, the first folding portion 221 is substantially parallel to the plane perpendicular to the third direction Z, so that at least two adjacent first folding portions 221 can be arranged in a stacked manner in the third direction Z.

[0037] As shown, Figure 3As shown, the electrode assembly 21 has a first end 16 in the third direction Z; the first tab 22 is located on the side of the first end 16 of the electrode assembly 21, and due to the stacking arrangement of the first folding portion 221 in the third direction Z, the Z-direction space between the first end 16 of the electrode assembly 21 and the shell 1 is reduced, thereby improving the space utilization in the shell 1.

[0038] Specifically, referring to Figures 2 to 4 In the conventional technical solutions, the tabs need to be bent and covered with tab protection sheets before being welded and fixed with the pole or other components. The entire tab bending is in an arc-shaped structure, which occupies a large space in the height direction, i.e., the third direction Z, and thus the overall energy density is low. Moreover, the bending state of each tab is different, and the tabs closer to the tab protection sheet are bent more severely, resulting in different strengths and conductive states of the tabs. In the present embodiment, the first tab 22 is divided into a first root portion 222 and a first folding portion 221, wherein the first folding portion 221 is bent relative to the first root portion 222, and any two adjacent first folding portions 221 in the third direction Z are stacked together. Compared with bending, the first folding portion 221 in the first tab 22 in the present embodiment adopts a folding and lapping scheme, the overall height of the first tab 22 is lower, the occupied space is smaller, the space utilization of the active material in the shell 1 is higher, and the overall energy density of the single battery is higher. In addition, since the folding and lapping scheme is adopted, the folding state of each first tab 22 is substantially equivalent, the structural consistency between the plurality of first tabs 22 is better, the strength and conductive state are closer, and the state between the plurality of first tabs 22 is closer and more stable. For example, in the present embodiment Figure 3 and Figure 4 As shown, the height H0 occupied by the part of the first tab 22 and the busbar is composed of the height H2 of the first tab 22 after the stacking arrangement and the height H1 of the busbar, which is obviously lower than Figure 1 the total height of the tab and the busbar in the prior art.

[0039] In some embodiments, the electrode assembly 21 is provided with a center hole 24 in the third direction Z, and the center hole 24 has a first side and a second side oppositely arranged in the second direction Y, and the first side and the second side are provided with the first tab 22.

[0040] Referring to Figure 3 、 Figure 6 and Figure 8It can be clearly known that the first tabs 22 of the same polarity in the embodiment are arranged on the first side and the second side of the center hole 24, that is, the first tabs 22 are arranged on the opposite sides of the center hole 24, the first tabs 22 on the first side are arranged in a stack, and the first tabs 22 on the second side are also arranged in a stack. In this structure, the height of the first tabs 22 is reduced, the space utilization in the shell 1 of the single battery is improved, the number of the first tabs 22 is greatly increased, and the overcurrent capacity of the single battery is improved. In addition, more first tabs 22 can contact the first bus bars 12 corresponding to the first tabs 22 in the single battery, the current transmission is more uniform and reasonable, and the current transmission state is better.

[0041] In some embodiments, the first folding portions 221 of the first tabs 22 on the first side and the first folding portions 221 of the first tabs 22 on the second side are all folded towards the same side along the second direction Y. In this way, all the first folding portions 221 are folded towards the same side and stacked in the third direction Z, as shown in FIG. 6. Figure 8 Figure 8 As shown in FIG. 6, all the first folding portions 221 are folded towards the lower side of the viewing angle, so that all the first folding portions 221 are overlapped and conductive, and the overcurrent capacity of the battery cell 2 is improved.

[0042] In other embodiments, the first folding portions 221 of the first tabs 22 on the first side and the first folding portions 221 of the first tabs 22 on the second side are folded towards different sides along the second direction Y. In this case, the first folding portions 221 on the first side are folded and all stacked together, and the first folding portions 221 on the second side are folded and all stacked together, and the folding directions are different, so that the current of the same tab flows in two paths. Without affecting the overall overcurrent capacity, the heat generated by the large current in a single path can be reduced.

[0043] In some embodiments, the battery cell 2 further includes second tabs 23, the second tabs 23 are provided in plurality and are all electrically connected with the electrode assembly 21, the polarity of the second tabs 23 is different from that of the first tabs 22, the second tabs 23 and the first tabs 22 are arranged in a spaced manner in the first direction X, and the second tabs 23 are arranged on the first side and the second side.

[0044] The first tabs 22 and the second tabs 23 are arranged in a spaced manner in the first direction X to prevent the first tabs 22 and the second tabs 23 from being conductive and to avoid short circuit.

[0045] ​Further, the second lug 23 comprises a second root 232 and a second folded portion 231, the second root 232 connecting the electrode assembly 21 and the second folded portion 231; the second root 232 extends along the third direction Z, and a plurality of second roots 232 are arranged at intervals along the second direction Y, the second folded portion 231 is arranged in a bent manner relative to the second root 232, and any two adjacent second folded portions 231 are arranged in a stacked manner in the third direction Z.

[0046] Specifically, in the embodiment, as shown in Figures 5 to 7 the electrode assembly 21 comprises a first tab 211, a second tab 212 and a separator 213, which are sequentially stacked and wound. One end of the first tab 211 along the third direction Z is electrically connected to the first root 222 on the first lug 22, and a plurality of first lugs 22 are provided on the first tab 211. One end of the second tab 212 along the third direction Z is fixedly connected to the second root 232 on the second lug 23, and a plurality of second lugs 23 are also provided on the second tab 212. The polarity of the second lug 23 is different from that of the first lug 22, one is positive and the other is negative, the first lug 22 and the second lug 23 are arranged at intervals in the first direction X, and the second lug 23 comprises a second folded portion 231 and a second root 232. The second folded portion 231 in the second lug 23 is also stacked and overlapped along the third direction Z, and the bending direction of the second folded portion 231 can be the same as or different from that of the first folded portion 221. The welding of the second lug 23 on both sides of the center hole 24 to the second bus bar 13 in the single battery can be partial welding, and the directions of the second folded portion 231 of the second lug 23 on both sides of the center hole 24 can be the same or different.

[0047] Optionally, the folding direction of the second folded portion 231 is the same as or different from that of the first folded portion 221.

[0048] In addition, in the embodiment, as shown in Figures 6 to 8 the length of the first folded portion 221 along the second direction Y is defined as L1; the length of the second folded portion 231 along the second direction Y is defined as L2; the length of the center hole 24 along the second direction Y is defined as D1; the length of the electrode assembly 21 along the second direction Y is defined as D3; the thickness of the first tab 211 along the second direction Y is defined as T1; the thickness of the second tab 212 along the second direction Y is defined as T2; the thickness of the separator 213 along the second direction Y is defined as T3; the number of empty winding turns of the separator 213 at the head of the battery cell 2 is defined as N0, and the length L1 of the first folded portion 221 and the length L2 of the second folded portion 231 satisfy the following relationship:

[0049] [D1+2*(N0+1)*T3+2*T2+T1]<L1<[D3 / 2-D1 / 2-(N0+1)*T3-T2-T1];

[0050] (D1+2*N0*T3+T2)<L2<(D3 / 2-D1 / 2-N0*T3-T2);

[0051] Meanwhile, the width of the first folding part 221 along the first direction X is W1, the width of the second folding part 231 along the first direction X is W2, and the width of the center hole along the first direction X is D2, and W1 and W2 satisfy the following relationship:

[0052] 6mm≤W1≤D2 / 3;

[0053] 6mm≤W2≤D2 / 3.

[0054] In some embodiments, the shell 1 is provided with a first pole column 14, and the single battery further includes a first bus bar 12, which is electrically connected to the first pole column 14 and the first tab 22, and is located between the first folding part 221 and the first pole column 14 along the third direction Z.

[0055] Since the first folding part 221 is arranged in a stacked manner in the third direction Z, the occupied space of the first tab 22 in the third direction Z is greatly reduced, not only improving the internal space utilization rate of the single battery, but also making the welding of the first pole column 14 and the second tab 23 more convenient, and also avoiding the problem of tab reverse insertion caused by welding and downward pressing after tab bending.

[0056] Optionally, the single battery further includes a second pole column 15 and a second bus bar 13, which is electrically connected to the second pole column 15 and the second tab 23, and is located between the second folding part 231 and the second pole column 15 along the third direction (Z).

[0057] It can be understood that one of the first pole column 14 and the second pole column 15 is electrically connected to the shell 1, and the other is insulatedly connected to the shell 1, which will not be described again.

[0058] Further, the side of the first pole column 14 away from the battery cell 2 is provided with a first groove 141 along the third direction Z, and the first bus bar 12 is welded to the side of the first pole column 14 facing the battery cell 2.

[0059] Due to the provision of the first groove 141, the thickness of the first pole column 14 in the third direction Z is reduced, thereby enabling the welding of the first bus bar 12 and the first pole column 14 to be performed outside the shell 1, greatly facilitating the welding operation and reducing the process difficulty.

[0060] Optionally, the side of the second pole column 15 away from the battery cell 2 is provided with a second groove 151, and the second bus bar 13 is welded to the side of the second pole column 15 facing the battery cell 2.

[0061] The second groove 151 is also convenient for welding of the second bus bar 13 and the second pole 15, so that the welding operation can be directly performed outside the shell 1, thereby reducing the process difficulty.

[0062] In some embodiments, as shown in Figure 8 The electrode assembly 21 has a plurality of layers around the third direction Z, each layer having at least two first tabs 22, and the at least two first tabs 22 are arranged at intervals in the circumferential direction of the third direction Z, and the at least one first tab 22 of each layer is electrically connected to the first bus bar 12.

[0063] As shown in Figure 8 The electrode assembly 21 is wound around the third direction Z to form a plurality of layers around the third direction Z, each layer being provided with at least two first tabs 22, and the at least two first tabs 22 on each layer are arranged at intervals in the circumferential direction of the third direction Z to make the current distribution more uniform; at the same time, the at least one first tab 22 of each layer is electrically connected to the first bus bar 12, so as to ensure that each layer of the pole where the first tab 22 is located can be electrically connected to the first pole 14, preventing the situation that although two first tabs 22 are folded, they are not actually overlapped and conducted, and ensuring the balance of the current. Specifically, the electrode assembly 21 includes two layers of opposite polarity, i.e., a first layer and a second layer formed by winding the first pole piece 211 and the second pole piece 212, respectively, and the diaphragm 213 is arranged between the first pole piece 211 and the second pole piece 212. The plurality of first pole pieces 211, the diaphragm 213 and the second pole piece 212 are stacked and then wound to form the electrode assembly 21 of the battery cell 2, each first pole piece 211 in the first layer has at least two first tabs 22, each second pole piece 212 has at least two second tabs 23, and at least one first tab 22 on each first pole piece 211 is electrically connected to the first bus bar 12, and at least one second tab 23 on each second pole piece 212 in the second layer is electrically connected to the second bus bar 13. In the preferred embodiment, each first pole piece 211 has two first tabs 22 connected to the first bus bar 12, and the second pole piece 212 is the same, which ensures stable current transmission and prevents the current transmission from being faulty due to the failure of part of the tabs.

[0064] The utility model also provides a kind of battery pack, at least one single battery described in the foregoing is used in the battery pack.

[0065] Further, the utility model also provides a kind of electric equipment, which uses the above-mentioned battery pack to supply energy.

[0066] The above are only preferred embodiments of the present application, and it should be pointed out that, for those skilled in the art, without departing from the technical principles of the present application, a number of improvements and substitutions can be made, and these improvements and substitutions should also be considered as the protection scope of the present application.

Claims

1. A single-cell battery having intersecting first direction (X), second direction (Y), and third direction (Z), characterized in that, include: The housing (1) has a receiving cavity (11); and The battery cell (2) is disposed in the receiving cavity (11). The battery cell (2) includes an electrode assembly (21) and a first tab (22). The first tab (22) has multiple tabs and is electrically connected to the electrode assembly (21). The first tab (22) includes a first root (222) and a first fold (221). The first root (222) connects the electrode assembly (21) and the first fold (221). The first root (222) extends along the third direction (Z), and a plurality of first roots (222) are spaced apart along the second direction (Y). The first fold (221) is bent relative to the first root (222) and is flat. At least two adjacent first folds (221) are stacked in the third direction (Z).

2. The single-cell battery according to claim 1, characterized in that, The electrode assembly (21) has a central hole (24) through it along the third direction (Z). The central hole (24) has a first side and a second side that are arranged opposite to each other in the second direction (Y). The first side and the second side are each provided with the first tab (22).

3. The single-cell battery according to claim 2, characterized in that, The first fold (221) of the first electrode tab (22) located on the first side and the first fold (221) of the first electrode tab (22) located on the second side are both bent toward the same side along the second direction (Y); or, the first fold (221) of the first electrode tab (22) located on the first side and the first fold (221) of the first electrode tab (22) located on the second side are bent toward different sides along the second direction (Y).

4. The single-cell battery according to claim 2, characterized in that, The battery cell (2) also includes a second tab (23). The second tab (23) is provided in multiple ways and is electrically connected to the electrode assembly (21). The polarity of the second tab (23) is different from that of the first tab (22). The second tab (23) and the first tab (22) are spaced apart in the first direction (X), and the second tab (23) is provided on both the first side and the second side.

5. The single-cell battery according to claim 4, characterized in that, The second electrode tab (23) includes a second root (232) and a second fold (231). The second root (232) connects the electrode assembly (21) and the second fold (231). The second root (232) extends along the third direction (Z), and a plurality of second roots (232) are spaced apart along the second direction (Y). The second fold (231) is bent relative to the second root (232), and any two adjacent second folds (231) are stacked in the third direction (Z).

6. The single-cell battery according to any one of claims 1-5, characterized in that, The housing (1) is provided with a first terminal post (14); the single cell also includes a first busbar (12), which is electrically connected to the first terminal post (14) and the first tab (22). Along the third direction (Z), the first busbar (12) is located between the first fold (221) and the first terminal post (14).

7. The single-cell battery according to claim 6, characterized in that, Along the third direction (Z), a first groove (141) is provided on the side of the first pole (14) away from the cell (2), and the first busbar is welded to the side of the first pole (14) facing the cell (2).

8. The single-cell battery according to claim 7, characterized in that, The electrode assembly (21) has a plurality of coils around the third direction (Z), each coil having at least two first tabs, the at least two first tabs being spaced apart in the circumferential direction around the third direction (Z), and at least one first tab of each coil being electrically connected to the first busbar.

9. A battery pack, characterized in that, Includes the single-cell battery as described in any one of claims 1-8.

10. An electrical appliance, characterized in that, Includes the battery pack as described in claim 9.

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