Battery and electric equipment

Abstract

The utility model discloses a battery and electric equipment. The battery comprises a shell and a battery cell assembly accommodated in the shell, the shell is provided with a top opening, and the shell comprises a plurality of side walls which define the top opening; the battery cell assembly comprises a plurality of battery cell surfaces which are opposite to and parallel to the plurality of side walls one by one; in a cross section parallel to the top opening, first chamfers are formed at corner parts of adjacent side walls in the plurality of side walls; and second chamfers matched with the first chamfers are formed at the corner parts of the adjacent battery cell surfaces in the plurality of battery cell surfaces. Therefore, the planarization arrangement of the battery cell surface of the battery cell assembly is realized, the occupied space of the semicircular arc section (please see the figure 1) is reduced, the shell with the same volume can accommodate more positive and negative electrode materials, and the energy density of the battery is increased.

Description

Technical Field

[0001] The present application relates to the technical field of lithium-ion batteries, and more specifically to a battery, and also to an electrical device including the battery. Background Art

[0002] When the existing battery cell is placed in the shell, since the wound battery cell often has a semicircular arc segment, there will be a large gap between it and the shell, resulting in a waste of shell space and leaving a large window for improving energy density. Utility Model Content

[0003] In view of this, the present application provides a battery and also provides an electrical device including the battery, which solves the problem of a large gap between the battery cell and the shell.

[0004] In order to achieve the above objectives, this application provides the following technical solutions:

[0005] A battery, comprising a shell and a cell assembly contained in the shell; the shell has a top opening, and the shell comprises a plurality of side walls surrounding the top opening; the cell assembly comprises a plurality of cell surfaces which are opposite to and parallel to the plurality of side walls; in a cross section parallel to the top opening:

[0006] A first chamfer is formed at a corner portion of adjacent side walls among the plurality of side walls;

[0007] Corners of adjacent battery cell surfaces among the plurality of battery cell surfaces are formed with second chamfers that match the first chamfers.

[0008] Optionally, in the above battery, the shell is a rectangular shell with a top opening; the first direction is parallel to the long side of the top opening, and the second direction is parallel to the short side of the top opening;

[0009] Along the second direction, the battery cell assembly includes a plurality of bare battery cells arranged in sequence; in a cross section parallel to the top opening, a corner portion of the bare battery cell forms a second chamfer, and the bare battery cell includes a second straight section parallel to the second direction;

[0010] The number of the bare cells is N; in a cross section parallel to the top opening, along the second direction, the width of the bare cells is W6, the width of the inner surface of the shell is W7, and W6 and W7 satisfy:

[0011] 1 <W7:(N×W6)≤1.2。

[0012] Optionally, in the above battery, the top opening is covered with a top cover; the outer surface of the bare cell is covered with a Mylar film, and the top cover and the area of ​​the cell assembly where no tabs are provided are provided with insulating supports; in a cross section parallel to the top opening:

[0013] The radius of the second chamfer is R, and R has a maximum value Rma x 、Minimum value Rmi n ,

[0014] The radius of the first chamfer is R1,

[0015] On the side of the long side close to the top opening, the spacing distance between the inner surface of the shell and the Mylar film is G1,

[0016] The thickness of the Mylar film is H1,

[0017] Along the second direction, the width of the bare cell is W6, and the length of the second straight section is W8.

[0018] in:

[0019] W8=W6-2R;

[0020] Rma x =W6 / 2;

[0021]

[0022] Rmin≤R≤R 1aX .

[0023] Optionally, in the above-mentioned battery, the bare cell includes a first pole piece, the first pole piece includes a first current collector and a first pole ear; the first pole ear includes a first sub-pole ear and a second sub-pole ear, the first sub-pole ear and the second sub-pole ear are respectively connected to the two side surfaces of the first current collector, and the second sub-pole ear is connected to the first sub-pole ear.

[0024] Optionally, in the above battery, there are multiple first pole tabs, and the multiple first pole tabs are divided into wide-width pole tabs and narrow-width pole tabs, and along the first direction, the width of the wide-width pole tab is greater than the width of the narrow-width pole tab;

[0025] Along the second direction, the bare cell is divided into a first half cell and a second half cell, the narrow-width tabs are all located in the first half cell, and the wide-width tabs are located in the second half cell.

[0026] Optionally, in the above battery, the bare cell includes a second pole piece, and the second pole piece includes a plurality of second pole tabs;

[0027] The second pole tab is located on the first half cell, and along the first direction, the second pole tab is spaced apart from the narrow-width pole tab.

[0028] Optionally, in the above battery,

[0029] The number of the first pole lugs is N1, and the number of the second pole lugs is N2; N1 and N2 satisfy: 1≤N1:N2≤3;

[0030] and / or,

[0031] Along the first direction, the length of the wide tab is L2, the length of the bare cell is L1, and L2 and L1 satisfy: 0.5 <L2:L1≤0.9;

[0032] and / or,

[0033] Along the first direction, the length of the narrow width tab is L3, the length of the bare cell is L1, and L3 and L1 satisfy: 0.2 <L3:L1≤0.5;

[0034] and / or

[0035] Along the first direction, the length of the second pole ear is L5, the length of the bare battery cell is L1, and L5 and L1 satisfy: 0.2 <L5:L1≤0.5;

[0036] and / or,

[0037] Along the first direction, the distance between the narrow-width pole ear and the second pole ear is L4, the length of the bare cell is L1, and L4 and L1 satisfy: 0.05 <L4:L1≤0.3;

[0038] and / or,

[0039] The first pole tab includes a first portion and a second portion, the first portion is electrically connected to the first current collector, along the first direction, the center of the second portion and the center of the second pole tab are spaced apart by W4, the length of the bare cell is L1, and W4 and L1 satisfy: 0.3 <W4:L1≤0.5。

[0040] Optionally, in the above battery, in a cross section perpendicular to the second direction, along the first direction:

[0041] On the first side close to the narrow width pole ear, the spacing distance between the inner surface of the shell and the Mylar film at the edge of the bare battery cell is G1;

[0042] On the first side close to the narrow width electrode ear, the distance between the edge of the second portion of the first electrode ear and the Mylar film at the edge of the bare cell is W1.

[0043] On the first side close to the narrow width electrode ear, the distance between the center of the second portion of the first electrode ear and the edge of the first electrode ear is W2.

[0044] The distance between the center of the first pole hole and the center of the second pole hole of the top cover is W3.

[0045] The distance between the center of the second portion of the first electrode tab and the center of the second electrode tab is W4.

[0046] On the first side close to the narrow width pole ear, the distance between the center of the first pole hole of the top cover and the edge of the top cover is W5.

[0047] The distance between the center of the first pole hole of the top cover and the edge of the first pole hole is A; wherein,

[0048]

[0049] Optionally, in the above battery, the bare cell includes a diaphragm located between the first pole piece and the second pole piece; the diaphragm includes an outer covering layer coated on the outer periphery of the bare cell; the number of coating layers of the outer covering layer is S, 0.1≤S≤10.

[0050] Optionally, in the above battery, the outer surface of the battery cell assembly is covered with a Mylar film, the shell includes a bottom plate opposite to the top cover, and the inner surface of the bottom plate is provided with a bottom support plate; the bottom support plate is provided with a through first through hole, and the side surface of the Mylar film opposite to the bottom support plate is provided with a through second through hole, and the first through hole is connected to the second through hole, wherein:

[0051] In a cross section perpendicular to the third direction, the projection area of ​​the bottom support plate is S1, the sum of the areas of all the first through holes is S2, S1 and S2 satisfy: 0≤S1:S2≤0.5; the third direction is perpendicular to the top opening of the housing 1;

[0052] and / or,

[0053] The bottom support plate is provided with a plurality of first positioning holes, and the surface of the Mylar film opposite to the bottom support plate is provided with a plurality of second positioning holes opposite to the first positioning holes; at least one group of the first positioning holes and the second positioning holes has an extended length.

[0054] An electrical device comprises the battery described above.

[0055] In the battery and electrical equipment provided by the present application, multiple cell surfaces of the cell assembly are arranged in parallel one to one with multiple side walls of the shell that surround the top opening, and a second chamfer that matches the shape of the first chamfer is formed at a position opposite to the first chamfer of the shell. As above, a planar arrangement of the cell surfaces of the cell assembly is achieved, avoiding the presence of semicircular arc segments in the multiple cell surfaces (see the attached diagram for the semicircular arc segments).Figure 1 ), thereby avoiding the space occupied by the semicircular arc segment, and the shell of the same volume can accommodate more positive and negative electrode materials, thereby increasing the energy density of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0057] Figure 1 It is a cross-sectional view of a bare battery cell in the prior art;

[0058] Figure 2 This is a schematic diagram of the structure of a bare battery cell in this application;

[0059] Figure 3 This is a front view of the bare battery cell in this application;

[0060] Figure 4 This is a schematic diagram of the structure of the first pole piece in this application;

[0061] Figure 5 A cross-sectional view of a battery in this application;

[0062] Figure 6 A cross-sectional view of the battery in the present application from another angle;

[0063] Figure 7 for Figure 6 An enlarged view of part B;

[0064] Figure 8 This is a schematic diagram of the structure of the bottom support plate in this application;

[0065] Fig. 9 It is a schematic diagram of the structure of the four-sided hot pressing flattening device.

[0066] Figure 1-Figure 9 middle:

[0067] 1. Shell; 2. Cell assembly; 3. Top cover; 4. Mylar film; 5. Insulating support; 6. First electrode adapter; 7. First pole; 8. Second electrode adapter; 9. Second pole; 10. Bottom support plate; 11. Through hole; 12. Four-sided hot pressing flattening device;

[0068] 101. first side wall; 102. second side wall;

[0069] 201, bare battery cell;

[0070] 1001, first positioning hole;

[0071] 1201, power device; 1202, guide rod; 1203, mobile platform; 1204, upper fixture; 1205, lower fixture;

[0072] 2011, composite current collector; 2012, first pole ear; 2013, second pole ear;

[0073] 20111, middle supporting layer; 20112, first conductive layer; 20113, second conductive layer;

[0074] 20121, first partial tab; 20122, second partial tab; 20123, wide tab; 20124, narrow tab; 20125, first part; 20126, second part. DETAILED DESCRIPTION

[0075] The present application provides a battery and also provides an electrical device including the battery.

[0076] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0077] like Figure 2-8 As shown, a battery comprises a shell 1 and a cell assembly 2 contained in the shell 1. The shell 1 has a top opening, and the shell 1 comprises a plurality of side walls surrounding the top opening. The cell assembly 2 comprises a plurality of cell faces that are opposite to and parallel to the plurality of side walls. In a cross section parallel to the top opening: the corners of adjacent side walls among the plurality of side walls of the shell 1 form a first chamfer; the corners of adjacent cell faces among the plurality of cell faces of the cell assembly 2 form a second chamfer that matches the first chamfer.

[0078] It should be noted that the housing 1 is a three-dimensional structure with a top opening, and the housing 1 includes a plurality of side walls and a housing bottom wall surrounded by the plurality of side walls, and the housing bottom wall is parallel to the top opening. The battery includes a top cover 3 covering the top opening of the housing 1; the battery cell assembly 2 is accommodated in a closed space surrounded by the housing 1 and the top cover 3.

[0079] The second chamfer that matches the first chamfer means that the battery cell assembly 2 is placed in the internal space of the shell 1, and a second chamfer is formed at the position of the battery cell assembly 2 opposite to the first chamfer of the shell 1, the shape of the second chamfer is matched with the shape of the first chamfer, and the radius of the second chamfer is not greater than the radius of the first chamfer.

[0080] The cell assembly 2 may include only one bare cell 201, or may be composed of multiple bare cells 201. When the cell assembly 2 includes multiple bare cells 201, the cell assembly 2 includes a spliced ​​cell surface formed by splicing the side surfaces of multiple bare cells 201; the spliced ​​cell surface is parallel to the side wall opposite to it, but the parallelism here should ignore the chamfers of adjacent bare cells 201 at the splicing point.

[0081] Each side wall of the housing 1 is a planar structure. The housing 1 of the present application forms a second chamfer at the corner of the adjacent side wall to avoid the formation of sharp edges that may pierce foreign objects.

[0082] The multiple cell surfaces of the cell assembly 2 are arranged one by one opposite to the multiple side walls of the shell 1 and are arranged in parallel. The cell assembly 2 is formed with a second chamfer that matches the shape of the first chamfer at a position opposite to the first chamfer of the shell 1. As described above, the planarization of the cell surface is achieved, and the semicircular arc segment is reduced (for the semicircular arc segment, please refer to the attached Figure 1 ) occupies less space, and the shell of the same volume can accommodate more positive and negative electrode materials, increasing the energy density of the battery.

[0083] Please refer to the attached Figure 6 In some embodiments of the present application, the housing 1 is a rectangular housing with a top opening. The first direction is parallel to the long side of the top opening, and the second direction is parallel to the short side of the top opening; along the second direction, the battery cell assembly 2 includes a plurality of bare batteries 201 arranged in sequence. In a cross section parallel to the top opening, the corner of the bare battery 201 forms a second chamfer, and the bare battery 201 includes a second straight section parallel to the second direction.

[0084] It should be noted that the housing 1 includes four side walls, including two first side walls 101 that are parallel to the first direction and opposite to each other, and two second side walls 102 that are parallel to the second direction and opposite to each other. The corners where each first side wall 101 is connected to the two second side walls 102 form a first chamfer.

[0085] Please refer to the attached Figure 6 It should be further explained that the bare cell 201 is in the shape of a cuboid, and in a cross section parallel to the top opening: the bare cell 201 includes two first straight sections opposite to each other and parallel to the first direction, and two second straight sections opposite to each other and parallel to the second direction; each first straight section forms a second chamfer at a corner portion connected to the two second straight sections.

[0086] Please refer to the attached Figure 6 , attached Figure 6 The cross section of the battery parallel to the top opening, wherein the first direction is the Figure 6 The second direction is the direction indicated by the arrow in the middle. Figure 6The direction is indicated by another arrow.

[0087] It should be noted that the battery cell assembly 2 in the present application may include only one bare battery cell 201, or may include two or more bare batteries 201 arranged in parallel, and the bare batteries 201 are arranged in a square parallel to the second direction. The bare battery cell 201 is a winding core.

[0088] When the battery cell assembly 2 includes multiple bare battery cells 201, since the multiple bare battery cells 201 are arranged in sequence along the second direction, the battery cell assembly includes a spliced ​​cell surface parallel to the second direction; the spliced ​​cell surface is formed by splicing all the second straight sections of all the bare battery cells 201 (the spliced ​​cell surface is regarded as a plane, so the two adjacent second chamfers of two adjacent second straight sections can be ignored).

[0089] Please refer to the attached Figure 1 The winding core in the prior art has a semicircular arc segment. When the winding core in the prior art is placed in the shell 1, the arc segment is opposite to the second side wall 102 of the shell 1.

[0090] The bare battery cell 201 after the winding process in the present application changes its shape through a hot pressing process, and finally realizes the flattening (flattening is planarization) processing of the bare battery cell 201. Compared with the semicircular arc segment of the winding core in the prior art, the bare battery cell 201 in the present application realizes a planar setting, and there is no semicircular arc segment occupying a large spatial volume, so that the spliced ​​battery cell assembly 2 also does not include a semicircular arc segment; at this time, when the battery cell assembly 2 is placed in the shell 1, the battery cell surface of the battery cell assembly 2 opposite to the second side wall 102 is also flat, and the shell 1 of the same volume can accommodate more positive and negative electrode materials, thereby increasing the energy density of the battery.

[0091] When the size of the shell 1 is the same, the width of the bare battery cell 201 produced in the winding process of the present application is slightly larger than the length of the second side wall 102 of the shell 1. After the hot pressing process (hot pressing on four sides of the mold, the four sides of the mold undergoing hot pressing include two sides parallel to the first side wall 101 of the shell 1, and two sides parallel to the second side wall 102 of the shell 1), the arc segment of the bare battery cell 201 becomes smaller / flatter, and compared with the winding core in the prior art, the positive and negative electrode materials are increased, thereby increasing the battery energy density.

[0092] Furthermore, a second chamfer is formed at a position matching the first chamfer. As described above, it is explained that the radius R of the second chamfer of the battery cell assembly 2 is not greater than the radius R1 of the first chamfer of the shell 1, so that the full space utilization of the battery cell assembly 2 in the shell 1 can be further ensured, and the shell 1 of the same volume can accommodate more positive and negative electrode materials, further increasing the energy density of the battery.

[0093] Please refer to the attached Figure 6 In some embodiments, the number of bare cells 201 is N. In a cross section parallel to the top opening, along the second direction, the width of the bare cell 201 is W6, and the width of the inner surface of the housing 1 is W7, and W6 and W7 satisfy: 1 <W7:(N×W6)≤1.2。

[0094] Along the second direction, the width of the inner surface of the shell 1 is greater than the width of a single bare battery cell 201 multiplied by the total number of bare battery cells 201, and the ratio of the two is limited within the above-mentioned value range. As above, flexible assembly of multiple bare battery cells 201 in the shell 1 is ensured, and there is no excessive waste of internal space in the shell 1, thereby ensuring the energy density of the battery.

[0095] Please refer to the attached Fig. 9 , which is a four-sided hot pressing and flattening device 12 for a bare cell 201, and the four-sided hot pressing and flattening device 12 includes a power device 1201, a guide rod 1202, a mobile platform 1203, an upper fixture 1204, and a lower fixture 1205. The mobile platform 1203 is fixed to the telescopic rod of the power device 1201, and the upper fixture 1204 is fixed to the mobile platform 1203; the telescopic rod of the power device 1201 is telescopically moved to drive the mobile platform 1203 and the upper fixture 1204 to approach or move away from the lower fixture 1205; the mobile platform 1203 is guided and connected to the guide rod 1202 to ensure the guided movement of the mobile platform 1203, thereby ensuring the stability and reliability of the movement of the upper fixture 1204 approaching or moving away from the lower fixture 1205. The lower jig 1205 has a U-shaped groove, which includes a bottom surface parallel to the first direction and two side surfaces parallel to the second direction, providing a total of three hot pressing surfaces for hot pressing the bare battery cell 201. The upper jig 1204 has a hot pressing surface parallel to the first direction, and can move downward along the second direction to close the opening of the U-shaped groove of the lower jig 1205, providing one hot pressing surface for hot pressing the bare battery cell 201.

[0096] The bare cell 201 is wound by a diamond or round winding needle. When the bare cell 201 is flattened by hot pressing on four sides:

[0097] ① Place the bare cell 201 in the lower fixture 1205. Before hot pressing, the length of the bare cell 201 along the first direction is smaller than the length of the lower fixture 1205 along the first direction, and the width of the bare cell 201 along the second direction is larger than the width of the lower fixture 1205 along the second direction.

[0098] ② The power device 1201 pushes the upper jig 1204 to move downward along the second direction. Under the hot pressure of the upper jig 1204, the width dimension of the bare battery cell 201 along the second direction is reduced, while the length dimension along the first direction is increased, until the length dimension of the bare battery cell 201 along the first direction after hot pressing is consistent with the length dimension of the lower jig 1205 along the first direction; at this time, the width dimension of the bare battery cell 201 is the distance from the upper jig 1204 to the bottom surface of the U-shaped groove of the lower jig 1205; the U-shaped grooves of the upper jig 1204 and the lower jig 1205 form a hot pressing mold cavity with four hot pressing surfaces. Under the hot pressing action of the hot pressing mold cavity, the four sides of the bare battery cell 201 are finally flattened, and a circular second chamfer is formed at the connection between adjacent flattened side surfaces.

[0099] It should be noted that a circular third chamfer is formed at the connection between adjacent hot pressing surfaces of the hot pressing mold cavity, and the radius of the third chamfer is less than or equal to the radius of the second chamfer.

[0100] Please refer to the attached Figure 6 , 7 In some embodiments of the present application, the top opening of the housing 1 is covered with a top cover 3. The outer surface of the bare battery cell 201 is covered with a Mylar film 4. An insulating support 5 is provided between the top cover 3 and the area where the battery cell assembly 2 is not provided with a tab. In a cross section parallel to the top opening:

[0101] The radius of the second chamfer is R, and R has a maximum value R max , minimum value R min ,

[0102] The radius of the first chamfer is R1,

[0103] On the side of the long side close to the top opening, the spacing distance between the inner surface of the housing 1 and the Mylar film 4 is G1.

[0104] The thickness of the Mylar film 4 is H1,

[0105] Along the second direction, the width of the bare cell 201 is W6, and the width of the second straight section is W8.

[0106] in:

[0107] W8=W6-2R;

[0108] R max =W6 / 2;

[0109]

[0110] R min ≤R≤R max .

[0111] It should be noted that the insulating support 5 is provided between the top cover 3 and the area of ​​the battery cell assembly 2 where no tabs are provided, and is used to provide the required space for the tabs and the electrode adapter to be welded and folded. The insulating support 5 can be made of plastic.

[0112] The smaller the radius of the second chamfer is, the greater the utilization of the internal space of the housing 1 by the battery cell assembly 2 is, and the greater the energy density of the battery is.

[0113] As mentioned above, the value range of the radius of the second chamfer of the bare battery cell 201 is limited, and the second chamfer of the bare battery cell 201 can be flexibly adjusted according to the different sizes of R1, G1, H1, and W6, ultimately ensuring that the manufactured battery cell assembly 2 can adapt to various types of shells 1.

[0114] Please refer to the attached Figure 4 In certain embodiments of the present application, the bare cell 201 includes a first pole piece, the first pole piece includes a first current collector and a first pole ear 2012; the first pole ear 2012 includes a first sub-pole ear 20121 and a second sub-pole ear 20122, the first sub-pole ear 20121 and the second sub-pole ear 20122 are respectively connected to the two side surfaces of the first current collector, and the second sub-pole ear 20122 is connected to the first sub-pole ear 20121.

[0115] Specifically: the first current collector is a composite current collector 2011; the composite current collector 2011 includes an intermediate support layer 20111 and two conductive layers arranged on both sides of the intermediate support layer 20111, the two conductive layers are a first conductive layer 20112 and a second conductive layer 20113. The first sub-electrode ear 20121 is electrically connected to a side surface of the first conductive layer 20112 away from the intermediate support layer 20111, and the second sub-electrode ear 20122 is electrically connected to a side surface of the second conductive layer 20113 away from the intermediate support layer 20111. Along the third direction, the first sub-pole ear 20121 is located at one side end of the first conductive layer 20112, and the second sub-pole ear 20122 is located at one side end of the second conductive layer 20113, and along the third direction, the length of the first sub-pole ear 20121 is greater than the length of the second sub-pole ear 20122, and the second sub-pole ear 20122 is electrically connected to the first sub-pole ear 20121, thereby realizing the electrical connection between the two conductive layers of the composite current collector 2011, and conducting electrical energy to the outside of the bare battery cell 201 through the first sub-pole ear 20121.

[0116] It should be noted that the third direction is the direction from the bottom plate of the housing 1 to the top cover 3, and the third direction is perpendicular to the top opening of the housing 1; Figure 2 , 4 , the third direction is attached Figure 2 , and attached Figure 4 Direction indicated by the arrow.

[0117] The first electrode sheet is a positive electrode sheet. After the composite current collector 2011, the first sub-electrode tab 20121, and the second sub-electrode tab 20122 are stacked, they are electrically welded together by roller welding. The positive electrode sheet is a composite positive electrode sheet with a composite current collector 2011, which has higher safety, energy density, and lower manufacturing cost.

[0118] Please refer to the attached Figure 2 In some embodiments of the present application, the first pole tabs 2012 have a plurality of first pole tabs 2012, and the plurality of first pole tabs 2012 are divided into wide pole tabs 20123 and narrow pole tabs 20124. Along the first direction, the width of the wide pole tabs 20123 is greater than the width of the narrow pole tabs 20124. Along the second direction, the bare cell 201 is divided into a first half cell a and a second half cell b. All narrow pole tabs 20124 are located in the first half cell a, and all wide pole tabs are located in the second half cell b.

[0119] Furthermore, the bare cell 201 includes a second pole piece, and the second pole piece includes a plurality of second pole tabs 2013. The second pole tabs 2013 are located in the first half cell a, and along the first direction, the second pole tabs 2013 and the narrow width pole tabs 20124 are spaced apart.

[0120] It should be noted that the first pole piece is a positive pole piece, the second pole piece is a negative pole piece, the first pole ear 2012 is a positive pole ear, and the second pole ear 2013 is a negative pole ear.

[0121] In order to ensure the current capacity of the positive electrode sheet, a part of the positive electrode ears roll-welded to the composite current collector 2011 is set as a wide electrode ear 20123 with a larger width, and all the wide electrode ears 20123 are set in the second half of the battery cell b. The second half of the battery cell b is not provided with a negative electrode ear, so the width of the wide electrode ear 20123 can be set as much as possible, without considering that the width of the battery cell in the second direction is too large due to the superposition of the wide electrode ear 20123 and the negative electrode ear along the second direction, thereby affecting the energy density of the battery. Since the negative electrode ear is set in the first half of the battery cell a, the positive electrode ear in the first half of the battery cell a should avoid superposition with the negative electrode ear in the second direction. Therefore, the positive electrode ear in the first half of the battery cell a needs to be set in the form of a narrow electrode ear 20124, and it is ensured that the negative electrode ear and the narrow electrode ear 20124 are respectively set on both sides of the first half of the battery cell a, thereby effectively ensuring the energy density of the battery.

[0122] In some embodiments of the present application, the number of the first pole tabs 2012 is N1, and the number of the second pole tabs 2013 is N2; N1 and N2 satisfy: 1≤N1:N2≤3, for example, N1:N2 can be any one of 1, 1.5, 2, 2.5, and 3.

[0123] The first tab 2012 is a positive tab, and the second tab 2013 is a negative tab. Since the first electrode sheet of this application selects a composite positive electrode sheet with a composite current collector 2011, limiting the ratio of the number of positive tabs to negative tabs within the above range can ensure that the overcurrent capabilities of the positive and negative electrodes match.

[0124] Please refer to the attached Figure 3 , in some embodiments, along the first direction, the length of the wide tab 20123 is L2, and the length of the bare battery cell 201 is L1, and L2 and L1 satisfy: 0.5 < L2:L1 ≤ 0.9. For example, L2:L1 can be any one of 0.5, 0.6, 0.7, 0.8, 0.9.

[0125] As described above, it can ensure the maximum setting of the length of the wide tab 20123 in the first direction, which can occupy more than half of the length of the bare battery cell 201, thereby ensuring the overcurrent capability of the positive electrode sheet.

[0126] Please refer to the attached Figure 3 , in some embodiments, along the first direction, the length of the narrow tab 20124 is L3, and the length of the bare battery cell 201 is L1, and L3 and L1 satisfy: 0.2 < L3:L1 ≤ 0.5. For example, L3:L1 can be any one of 0.2, 0.3, 0.4, 0.5.

[0127] Furthermore, along the first direction, the length of the second tab 2013 is L5, and the length of the bare battery cell 201 is L1, and L5 and L1 satisfy: 0.2 < L5:L1 ≤ 0.5. For example, L5:L1 can be any one of 0.2, 0.3, 0.4, 0.5.

[0128] Still further, along the first direction, the distance between the narrow tab 20124 and the second tab 2013 is L4, and the length of the bare battery cell is L1, and L4 and L1 satisfy: 0.05 < L4:L1 ≤ 0.3.

[0129] As described above, it ensures that the narrow tab 20124 and the second tab 2013 are respectively located on both sides of the bare battery cell 201 along the first direction, avoiding the superposition thickness of the two in the second direction and ensuring the energy density of the battery.

[0130] Please refer to the attached Figure 3 , in some embodiments, along the third direction, the first tab 2012 includes a first part 20125 and a second part 20126. The first part 20125 is electrically connected to the composite current collector 2011, and the second part 20126 is electrically connected to the first electrode adapter 6.

[0131] Please refer to the attached Figure 5 , the attached Figure 5It is a cross-section perpendicular to the second direction of the battery. Along the first direction, the distance between the center of the second part 20126 of the first tab 2012 and the center of the second tab 2013 is W4, and the length of the bare battery cell is L1. W4 and L1 satisfy: 0.3 < W4:L1 ≤ 0.5. For example, W4:L1 can be any one of 0.3, 0.4, and 0.5.

[0132] It should be noted that both the wide tab 20123 and the narrow tab 20124 include a first part 20125 and a second part 20126. Along the first direction, the length of the first part 20125 of the wide tab 20123 is greater than the length of the first part 20125 of the narrow tab 20124. In the cross-section perpendicular to the second direction, the projection of the second part 20126 of the wide tab 20123 overlaps with the projection of the second part 20126 of the narrow tab 20124.

[0133] Please refer to the appendix Figure 5 , the first part 20125 of the first tab 2012 is used for roll welding to the composite current collector 2011. After all the second parts 20126 of the stacked first tabs 2012 are overlapped, they are welded to the first electrode adapter 6, and the first electrode adapter 6 is welded to the first pole 7. After all the second tabs 2013 of the stack are overlapped, they are welded to the second electrode adapter 8, and the second electrode adapter 8 is welded to the second pole 9. The first electrode adapter 6 is a positive electrode adapter, and the second electrode adapter 8 is a negative electrode adapter; the second pole 9 is a positive pole, and the second pole 9 is a negative pole.

[0134] As above, it is ensured that there is a spacing distance between the second part 20126 welded to the first electrode adapter 6 and the second tab 2013 welded to the second electrode adapter 8, avoiding the superposition thickness of the two in the second direction and ensuring the energy density of the battery.

[0135] In some embodiments of the present application, in the cross-section perpendicular to the second direction, along the first direction:

[0136] On the first side close to the narrow tab, the spacing distance between the inner surface of the housing 1 and the Mylar film 4 at the edge of the bare battery cell 201 is G1;

[0137] On the first side close to the narrow tab 20124, the distance between the edge of the first tab 2012 and the edge of the bare battery cell 201 is W1,

[0138] On the first side close to the narrow tab 20124, the distance between the center of the second part 20126 of the first tab 2012 and the edge of the first tab 2012 is W2,

[0139] The distance between the center of the first pole hole and the center of the second pole hole of the top cover 3 is W3,

[0140] The distance between the center of the second portion 20126 of the first electrode tab 2012 and the center of the second electrode tab 2013 is W4.

[0141] On the first side close to the narrow width pole ear 20124, the distance between the edge of the first pole hole of the top cover 3 and the edge of the top cover 3 is W5.

[0142] The distance between the center of the first pole hole of the top cover 3 and the edge of the first pole hole is A; wherein,

[0143] It should be noted that the first pole 7 is disposed in the first pole hole of the top cover 3 , and the second pole 9 is disposed in the second pole hole of the top cover 3 .

[0144] The battery cell assembly 2 is assembled into the shell 1 after being flattened by hot pressing. At this time, the size of the pole ear and the position size satisfy the above formula relationship; among them, considering the energy density and manufacturing assembly process, 0≤G1≤3mm (preferably, G1=1.5mm); W1 is determined by the winding and hot pressing flattening process, 0≤W1≤20mm; W5 is determined by the battery cell size or the top cover stamping capability.

[0145] In some embodiments of the present application, the bare cell 201 includes a diaphragm between the first pole piece and the second pole piece. The diaphragm includes an outer layer covering the outer periphery of the bare cell 201; the number of covering layers of the outer layer is S, 0.1≤S≤10, for example, S can be any one of 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10. Preferably, 0.5 <S<3。

[0146] The positive electrode sheet, separator and negative electrode sheet are stacked in sequence and wound by a winding needle; the negative electrode sheet is the last one among the positive and negative electrode sheets, and the last negative electrode sheet is cut to be detached from the negative electrode sheet roll, and is rolled into the bare battery cell to complete the negative electrode sheet finishing; after the negative electrode sheet is finished, the separator continues to be fed, and the part of the separator that exceeds the last negative electrode sheet (that is, the outer layer of the separator) is sequentially wrapped around the outer layer of the bare battery cell, which is connected from end to end as one layer, and the part that is not connected from end to end is calculated by the ratio of the length of this part to the length of the whole circle, and finally the final number of coating layers of the outer layer is obtained.

[0147] As mentioned above, the number of coating layers of the outer layer of the diaphragm is increased, thereby playing a protective effect on the bare battery cell, reducing the wrinkling of the pole piece and the diaphragm caused by the hot pressing process of the bare battery cell (hot pressing on four sides by the upper and lower jigs), and preventing the pole piece from being scratched.

[0148] In some embodiments of the present application, the outer surface of the battery cell assembly 2 is covered with a Mylar film 4, the housing 1 includes a bottom plate opposite to the top cover 3, and the inner surface of the bottom plate is provided with a bottom support plate 10. The bottom support plate 10 is provided with a through first through hole 11, and the side of the Mylar film 4 opposite to the bottom support plate 10 is provided with a through second through hole; the first through hole 11 is connected to the second through hole.

[0149] Further, a plurality of first through holes 11 are provided, a plurality of second through holes are provided, and each first through hole 11 has at least one second through hole connected thereto.

[0150] It should be noted that the bottom support plate 10 and the Mylar film 4 are connected together by heat melting.

[0151] A first through hole 11 and a second through hole are respectively provided on the Mylar film 4 and the bottom support plate 10 , so as to facilitate the electrolyte to flow in the housing 1 and better infiltrate the battery cell assembly 2 .

[0152] In certain embodiments of the present application, in a cross section perpendicular to the third direction, the projection area of ​​the bottom support plate 10 is S1, and the sum of the projection areas of all the first through holes 11 is S2, and S1 and S2 satisfy: 0≤S2:S1≤0.5, for example, S2:S1 can be any one of 0, 0.1, 0.2, 0.3, 0.4, and 0.5.

[0153] The ratio of the area of ​​the first through hole 11 to the area of ​​the bottom support plate 10 is limited to a range of 0-0.5, so as to ensure that the bottom support plate 10 has sufficient supporting strength and at the same time ensure that the opened first through hole 11 has a certain effect of improving the injection and infiltration efficiency.

[0154] In some embodiments, a plurality of first positioning holes 1001 are formed on the bottom support plate 10, and a plurality of second positioning holes opposite to the first positioning holes 1001 are formed on the surface of the Mylar film 4 opposite to the bottom support plate 10; at least one group of the first positioning holes 1001 and the second positioning holes have an extended length.

[0155] It should be noted that the first positioning hole 1001 and the second positioning hole in relative positions form a group. At least one group of the first positioning hole 1001 and the second positioning hole have an extension length, and the extension length of the first positioning hole 1001 and the extension length of the second positioning hole are parallel to the plane where the bottom support plate 10 is located; for example: at least one group of the first positioning hole 1001 and the second positioning hole are respectively runway-shaped positioning holes (i.e. waist-shaped positioning holes), or respectively elliptical positioning holes, or respectively slot-shaped positioning holes.

[0156] In some embodiments, the plurality of first through holes 11 are connected to the plurality of second through holes in a one-to-one manner, and the one-to-one first through holes 11 and the second through holes form a connecting channel.

[0157] The first positioning hole 1001 and the second positioning hole can be independently set from the connecting channel. Of course, two connecting channels greater than or equal to 2 can also be used as at least two groups of first positioning holes 1001 and second positioning holes respectively; in this case, the connecting channel used as the positioning hole should have an extended length, and the extended length of the connecting channel is parallel to the plane where the bottom support plate 10 is located; for example, the shape of the connecting channel can be a runway shape (i.e., waist shape), or an ellipse, or a groove shape.

[0158] The positioning pin passes through the first positioning hole 1001 and the second positioning hole in sequence, thereby realizing the assembly positioning of the bottom support plate 10 and the Mylar film 4. Since at least one set of the first positioning hole 1001 and the second positioning hole has an extended length, it provides a larger dimensional tolerance in the extended length direction, making it easier for the positioning pin to be inserted into the positioning hole to complete the positioning adjustment of the bottom support plate 10 and the Mylar film 4, thereby reducing the positioning difficulty and reducing the positioning time.

[0159] In summary, the present application also provides an electrical device, which includes the battery described above.

[0160] Since the electrical device has the battery as described above, the beneficial effects of the battery on the electrical device can be found above and will not be described in detail here.

[0161] The components and devices involved in this application are only illustrative examples and are not intended to require or imply that they must be connected, arranged, and configured in the manner shown in the drawings. As will be appreciated by those skilled in the art, these components and devices can be connected, arranged, and configured in any manner. Words such as "including", "comprising", "having", etc. are open words, meaning "including but not limited to", and can be used interchangeably with them. The words "or" and "and" used here refer to the words "and / or" and can be used interchangeably with them, unless the context clearly indicates otherwise. The word "such as" used here refers to the phrase "such as but not limited to", and can be used interchangeably with it.

[0162] It should also be noted that in the device of the present application, each component can be decomposed and / or reassembled, and these decompositions and / or reassemblies should be regarded as equivalent solutions of the present application.

[0163] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of the present application. Therefore, the present application is not intended to be limited to the aspects shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

[0164] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although multiple example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

[0165] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A battery, characterized in that: The invention comprises a shell and a battery cell assembly contained in the shell; the shell has a top opening, and the shell comprises a plurality of side walls surrounding the top opening; the battery cell assembly comprises a plurality of battery cell surfaces which are opposite to and parallel to the plurality of side walls; in a cross section parallel to the top opening: A first chamfer is formed at a corner portion of adjacent side walls among the plurality of side walls; Corners of adjacent battery cell surfaces among the plurality of battery cell surfaces are formed with second chamfers that match the first chamfers.

2. The battery according to claim 1, characterized in that The shell is a rectangular parallelepiped shell with a top opening; the first direction is parallel to the long side of the top opening, and the second direction is parallel to the short side of the top opening; Along the second direction, the battery cell assembly includes a plurality of bare battery cells arranged in sequence; in a cross section parallel to the top opening, a corner portion of the bare battery cell forms a second chamfer, and the bare battery cell includes a second straight section parallel to the second direction; The number of the bare cells is N; in a cross section parallel to the top opening, along the second direction, the width of the bare cells is W6, the width of the inner surface of the shell is W7, and W6 and W7 satisfy: 1<W7:(N×W6)≤1.

2.

3. The battery according to claim 2, characterized in that The top opening is sealed with a top cover; the outer surface of the bare battery cell is covered with a Mylar film, and the top cover and the area of ​​the battery cell assembly where the pole ear is not provided are provided with an insulating support; in a cross section parallel to the top opening: The radius of the second chamfer is R, and R has a maximum value R max , minimum value R min , The radius of the first chamfer is R1, On the side of the long side close to the top opening, the spacing distance between the inner surface of the shell and the Mylar film is G1, The thickness of the Mylar film is H1, Along the second direction, the width of the bare cell is W6, and the length of the second straight section is W8. in: W8=W6-2R; <h2 style=";text-align:left;direction:ltr">R<h2 style=";text-align:left;direction:ltr"> max <h2 style=";text-align:left;direction:ltr"> (W6 / 2) R min ≤R≤R max 。 4. The battery according to claim 2, characterized in that The bare cell includes a first pole piece, which includes a first current collector and a first pole ear; the first pole ear includes a first sub-pole ear and a second sub-pole ear, the first sub-pole ear and the second sub-pole ear are respectively connected to the two side surfaces of the first current collector, and the second sub-pole ear is connected to the first sub-pole ear.

5. The battery according to claim 4, characterized in that There are a plurality of first pole tabs, and the plurality of first pole tabs are divided into wide-width pole tabs and narrow-width pole tabs. Along a first direction, the width of the wide-width pole tab is greater than the width of the narrow-width pole tab; Along the second direction, the bare cell is divided into a first half cell and a second half cell, the narrow-width tabs are all located in the first half cell, and the wide-width tabs are located in the second half cell.

6. The battery according to claim 5, characterized in that The bare battery cell includes a second pole piece, and the second pole piece includes a plurality of second pole tabs; The second pole tab is located on the first half cell, and along the first direction, the second pole tab is spaced apart from the narrow-width pole tab.

7. The battery according to claim 6, characterized in that The number of the first pole lugs is N1, and the number of the second pole lugs is N2; N1 and N2 satisfy: 1≤N1:N2≤3; and / or, Along the first direction, the length of the wide-width tab is L2, the length of the bare cell is L1, and L2 and L1 satisfy: 0.5<L2:L1≤0.9; and / or, Along the first direction, the length of the narrow width tab is L3, the length of the bare cell is L1, and L3 and L1 satisfy: 0.2<L3:L1≤0.5; and / or Along the first direction, the length of the second electrode ear is L5, the length of the bare battery cell is L1, and L5 and L1 satisfy: 0.2<L5:L1≤0.5; and / or, Along the first direction, the distance between the narrow-width pole ear and the second pole ear is L4, the length of the bare cell is L1, and L4 and L1 satisfy: 0.05 <L4:L1≤0.3; and / or, The first pole tab includes a first portion and a second portion, the first portion is electrically connected to the first current collector, along the first direction, the center of the second portion and the center of the second pole tab are spaced apart by W4, the length of the bare cell is L1, and W4 and L1 satisfy: 0.3 <W4:L1≤0.5。 8. The battery according to claim 2, characterized in that In the cross section perpendicular to the second direction, along the first direction: On the first side close to the narrow width pole ear, the spacing distance between the inner surface of the shell and the Mylar film at the edge of the bare battery cell is G1; On the first side close to the narrow width electrode ear, the distance between the edge of the second portion of the first electrode ear and the Mylar film at the edge of the bare cell is W1. On the first side close to the narrow width electrode ear, the distance between the center of the second portion of the first electrode ear and the edge of the first electrode ear is W2. The distance between the center of the first pole hole and the center of the second pole hole of the top cover is W3. The distance between the center of the second portion of the first electrode tab and the center of the second electrode tab is W4. On the first side close to the narrow width pole ear, the distance between the center of the first pole hole of the top cover and the edge of the top cover is W5. The distance between the center of the first pole hole of the top cover and the edge of the first pole hole is A; wherein, 9. The battery according to claim 1, characterized in that The bare battery core comprises a diaphragm located between a first pole piece and a second pole piece; the diaphragm comprises an outer covering layer covering the outer periphery of the bare battery core; the number of covering layers of the outer covering layer is S, 0.1≤S≤10.

10. The battery according to claim 1, characterized in that The outer surface of the battery cell assembly is covered with a Mylar film, the shell includes a bottom plate opposite to the top cover, and the inner surface of the bottom plate is provided with a bottom support plate; the bottom support plate is provided with a first through hole, and the side of the Mylar film opposite to the bottom support plate is provided with a second through hole, and the first through hole is connected to the second through hole, wherein: In a cross section perpendicular to the third direction, the projection area of ​​the bottom support plate is S1, the sum of the areas of all the first through holes is S2, S1 and S2 satisfy: 0≤S1:S2≤0.5; the third direction is perpendicular to the top opening of the housing 1; and / or, The bottom support plate is provided with a plurality of first positioning holes, and the surface of the Mylar film opposite to the bottom support plate is provided with a plurality of second positioning holes opposite to the first positioning holes; at least one group of the first positioning holes and the second positioning holes has an extended length.

11. An electrical device, characterized in that: A battery comprising the battery according to any one of claims 1 to 10.

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