Battery and electric equipment

Abstract

The utility model relates to the technical field of lithium batteries, discloses a battery and electric equipment, and aims to reduce the occupied area of tabs and improve the energy density of the battery. The electric equipment comprises a pole piece and a diaphragm which are laminated in the thickness direction, wherein the pole piece comprises a positive pole piece and a negative pole piece; the pole piece is provided with a first side edge and a second side edge which are parallel to each other, and a third side edge and a fourth side edge which are connected to two ends of the second side edge; comprising a functional part provided with an active material layer, an empty foil part and a notch, and a boundary line is arranged between the functional part and the empty foil part; the empty foil part of the positive plate is positioned between the first side edge and the third side edge, and the notch is positioned between the first side edge and the fourth side edge; the empty foil part of the negative plate is positioned between the first side edge and the fourth side edge of the negative plate; the gap is positioned between the first side edge and the third side edge; the included angle between the first bevel edge and the third side edge of the positive plate, far away from the functional part, of the positive plate empty foil part is greater than 90 degrees, and / or the included angle between the first bevel edge and the fourth side edge of the negative plate, far away from the functional part, of the negative plate empty foil part is greater than 90 degrees.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery technology, specifically to a battery and electrical equipment. Background Technology

[0002] Battery tabs are typically led out separately from the side of the electrode plate, and then connected to an adapter plate to enable power transfer. However, these separately led-out tabs often occupy a large amount of internal space in the battery, thus reducing the overall energy density of the battery. Utility Model Content

[0003] In view of this, the present invention provides a battery and electrical device to solve the problem that a separately led-out tab occupies a large amount of internal space and reduces the energy density of the battery.

[0004] In a first aspect, this utility model provides a battery, including an electrode and a separator. The electrode includes a positive electrode and a negative electrode, which are alternately arranged along the thickness direction of the battery. The separator is located between adjacent positive and negative electrodes. The electrode has a first side and a second side that are parallel to each other, and a third side and a fourth side connected to both ends of the second side. The electrode includes a functional portion, a foil portion, and a notch. The electrode includes an active material layer formed on the functional portion, and a boundary line is formed between the functional portion and the foil portion. At least a portion of the structure of the first side and the third side of the positive electrode, and the first side and the third side... The first inclined side formed between the two sides and the boundary line together enclose the empty foil portion; the notch is located between the first side and the fourth side; the empty foil portion of the negative electrode sheet is located between the first side and the fourth side of the negative electrode sheet, and in the thickness direction of the battery, the projection of the empty foil portion of the negative electrode sheet and the notch of the positive electrode sheet at least partially overlap; the notch of the negative electrode sheet is located between the first side and the third side; the angle between the first inclined side and the third side of the positive electrode sheet away from the functional portion of the empty foil portion of the positive electrode sheet is greater than 90°, and / or, the angle between the first inclined side and the fourth side of the negative electrode sheet away from the functional portion of the empty foil portion of the negative electrode sheet is greater than 90°.

[0005] In one alternative embodiment, the boundary line of the positive electrode is parallel to the first inclined side of the positive electrode; and / or, the boundary line of the negative electrode is parallel to the first inclined side of the negative electrode.

[0006] In one alternative embodiment, the functional portion of the positive electrode sheet is a positive electrode functional portion, and the functional portion of the negative electrode sheet is a negative electrode functional portion; in the thickness direction of the battery, the projection of the negative electrode functional portion at least covers the positive electrode functional portion.

[0007] In one alternative embodiment, the projection of the separator in the thickness direction of the battery at least covers the negative electrode functional portion and the positive electrode functional portion.

[0008] In one optional embodiment, the notch in the positive electrode forms a second oblique edge between the first and fourth side edges; the notch in the negative electrode forms a second oblique edge between the first and third side edges; the separator has a first edge and a second edge, and on the projection plane along the battery thickness direction, the second oblique edge of the negative electrode is located between the boundary line of the first edge and the positive electrode; the boundary line of the negative electrode is located between the second edge and the second oblique edge of the positive electrode; on the projection plane along the battery thickness direction, the negative electrode... The distance between the second inclined edge and the first edge is L1, 0.4mm≤L1≤3mm; and / or, the distance between the boundary line of the second inclined edge of the negative electrode and the positive electrode is L2, 0.6mm≤L2≤2mm; and / or, on the projection plane along the thickness direction of the battery, the distance between the boundary line of the negative electrode and the second edge is L1', 0.4mm≤L1'≤3mm; and / or, the distance between the boundary line of the negative electrode and the second inclined edge of the positive electrode is L2', 0.6mm≤L2'≤2mm.

[0009] In one alternative embodiment, a bent portion is formed in the empty foil portion between the first inclined edge and the boundary line; the bent portion has a first bent portion near the first inclined edge and a second bent portion near the boundary line; the first bent portion bends toward the direction closer to the battery, and the second bent portion bends toward the direction away from the battery; the distance between the first bent portion and the boundary line is H1, 0.3mm≤H1≤4mm; and / or, the distance between the second bent portion and the boundary line is H2, 0.2mm≤H2≤3mm.

[0010] In one alternative embodiment, the battery further includes an adapter connected to the empty foil portion; wherein the adapter is perpendicular to the first side or the adapter is perpendicular to the boundary line.

[0011] In one alternative embodiment, the adapter overlaps at least partially with the empty foil portion to form an overlap area; the overlap area includes a solder area near the boundary line and a margin area near the first bevel; the area of ​​the solder area is S, 0.8 mm. 2 ≤S≤20mm 2 ; and / or, the area ratio of the surplus area to the empty foil section is η1, 0.05≤η1≤0.6.

[0012] In one alternative embodiment, the battery further includes a gel attached to the adapter; wherein the distance between the first inclined side and the gel is L3mm, the distance between the first inclined side and the boundary line is L4mm, and 1.5≤L3 / L4≤4.

[0013] In one optional embodiment, the battery further includes a packaging shell covering the outside of the electrode and the separator, with an adhesive attached to the edge of the packaging shell; wherein the packaging shell has a sealing area on the adhesive, the adhesive including a first side near the empty foil portion and a second side away from the empty foil portion; the distance between the sealing area and the first side is X, 0.3mm≤X≤1.1mm; and / or, the distance between the sealing area and the second side is Y, 0mm≤Y≤1.5mm.

[0014] Secondly, this utility model also provides an electrical device, including: a battery as described above.

[0015] This invention utilizes a novel technical solution where an empty foil portion is provided at the end corner of the electrode sheet. This empty foil portion is not coated or has its active layer removed to form a tab. In other words, the foil material of the electrode sheet itself serves as the tab, eliminating the need for additional tabs and reducing the internal space occupied by the battery. Furthermore, the empty foil portion is formed by the electrode sheet's own structure. The first bevel of the empty foil portion is typically formed by cutting the empty foil portion, i.e., removing part of the empty foil portion's structure to form the first bevel. This minimizes the area occupied by the empty foil portion, increasing the battery's energy density. Additionally, the angle between the first bevel and the third side of the positive electrode sheet is greater than 90°. That is, the connection between the first bevel and the third side of the positive electrode sheet is an obtuse angle, without sharp corners. This obtuse angle design prevents stress concentration at sharp corners. Compared to empty foil portions with sharp corners, the battery of this application has a larger supporting area for the first bevel when dropped, and the first bevel can effectively disperse the impact force generated during the drop, reducing the risk of electrode edge tearing or deformation and improving drop safety. Similarly, the angle between the first inclined side and the fourth side of the negative electrode is greater than 90°. That is, the connection between the first inclined side and the fourth side of the negative electrode forms an obtuse angle, without any sharp corners. This obtuse angle design avoids stress concentration at sharp corners, improving drop safety. The battery and electrical device of this invention utilize the empty foil portion as the tab, improving the battery's drop safety and significantly reducing the area occupied by the tab, thereby increasing the battery's energy density. Attached Figure Description

[0016] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of a positive electrode sheet according to an embodiment of the present invention;

[0018] Figure 2This is a schematic diagram of the structure of a negative electrode sheet according to an embodiment of the present utility model;

[0019] Figure 3 This is an exploded view of a positive electrode, a negative electrode, and a separator according to an embodiment of the present invention.

[0020] Figure 4 This is a structural diagram of a positive electrode, a negative electrode, and a separator in a stacked state according to an embodiment of the present invention;

[0021] Figure 5 This is a schematic diagram of the structure of the bent portion of a tab group in a flattened state according to an embodiment of the present utility model;

[0022] Figure 6 This is a schematic diagram showing the positional relationship between the empty foil portion, the adapter, and the colloid in an embodiment of this utility model;

[0023] Figure 7 This is a schematic diagram showing the positional relationship between the empty foil portion, the adapter, and the colloid in another embodiment of the present utility model.

[0024] Figure 8 This is a schematic diagram of another adapter according to an embodiment of the present utility model;

[0025] Figure 9 This is a schematic diagram of the structure of a battery according to an embodiment of the present utility model;

[0026] Figure 10 This is a schematic diagram of the structure of another battery according to an embodiment of the present utility model;

[0027] Figure 11 This diagram illustrates the positional relationship between the colloid and the packaging shell in an embodiment of this utility model.

[0028] Explanation of reference numerals in the attached figures:

[0029] 1. Electrode; 1a. Positive electrode; 1b. Negative electrode; 11. First side edge; 12. Second side edge; 13. Third side edge; 14. Fourth side edge; 15. First inclined edge; 151. First inclined edge of positive electrode; 152. First inclined edge of negative electrode; 16. Second inclined edge; 161. Second inclined edge of positive electrode; 162. Second inclined edge of negative electrode; 17. Boundary line; 171. Boundary line of positive electrode; 172. Boundary line of negative electrode; 18. Functional section; 181. Positive functional section; 182. Negative functional section; 19. Empty foil section; 191. Positive empty foil section; 192. Negative empty foil section; 20. Bending section; 201. First bending section; 202. Second bending section;

[0030] 2. Diaphragm; 21. First edge; 22. Second edge;

[0031] 3. Adapter; 31. Overlapping area; 311. Solder stamp area; 312. Allowance area; 32. Third bevel;

[0032] 4. Colloid; 41. First side; 42. Second side;

[0033] 5. Packaging shell; 51. Sealing edge; 510. Sealing area. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0035] The following is combined Figures 1 to 11 The following describes embodiments of the present invention.

[0036] According to an embodiment of the present invention, a battery is provided. The electrical device includes a plurality of electrode sheets 1 and a plurality of separators 2 stacked along the thickness direction of the battery, with each separator 2 disposed between two adjacent electrode sheets 1. Specifically, the electrode sheet 1 includes a positive electrode sheet 1a and a negative electrode sheet 1b, which are alternately arranged along the thickness direction of the battery, and the separator 2 is located between adjacent positive electrode sheets 1a and negative electrode sheets 1b. The thickness direction of the battery is also... Figure 3 The P direction is shown in the diagram.

[0037] Specifically, such as Figure 1 and Figure 2 As shown, the electrode 1 has a first side 11 and a second side 12 that are parallel to each other, and a third side 13 and a fourth side 14 connecting the two ends of the second side 12. The electrode 1 includes a functional portion 18, a hollow foil portion 19, and a notch. An active material layer is disposed on the functional portion 18, and a boundary line 17 exists between the functional portion 18 and the hollow foil portion 19. The hollow foil portion 19 also has a first inclined edge 15 away from the functional portion 18, and the notch forms a second inclined edge 16 on the functional portion 18.

[0038] More specifically, in the positive electrode 1a of the electrode 1, the aforementioned first oblique edge 15 is formed between the first side 11 and the third side 13, that is, the empty foil portion 19 of the positive electrode 1a is located between the first side 11 and the third side 13 of the positive electrode 1a. At least a portion of the structure of the first side 11 and the third side 13 of the positive electrode 1a, the first oblique edge 15 formed between the first side 11 and the third side 13, and the boundary line 17 together enclose the empty foil portion 19. The aforementioned second oblique edge 16 is formed between the first side 11 and the fourth side 14, that is, the notch of the positive electrode 1a is located between the first side 11 and the fourth side 14 of the positive electrode 1a.

[0039] In the negative electrode 1b of electrode 1, the aforementioned first oblique edge 15 is formed between the first side 11 and the fourth side 14, that is, the empty foil portion 19 of the negative electrode 1b is located between the first side 11 and the fourth side 14 of the negative electrode 1b. At least a portion of the structure of the first side 11 and the fourth side 14 of the negative electrode 1b, the first oblique edge 15 formed between the first side 11 and the fourth side 14, and the boundary line 17 together enclose the empty foil portion 19. In the thickness direction of the battery, the projection of the empty foil portion 19 of the negative electrode 1b at least partially overlaps with the notch of the positive electrode 1a. The aforementioned second oblique edge 16 is formed between the first side 11 and the third side 13, that is, the notch of the negative electrode 1b is located between the first side 11 and the third side 13 of the negative electrode 1b. In the thickness direction of the battery, the projection of the empty foil portion 19 of the positive electrode 1a at least partially overlaps with the notch of the negative electrode 1b.

[0040] Furthermore, the functional portion 18 of the positive electrode 1a is the positive electrode functional portion 181, and the empty foil portion 19 of the positive electrode 1a is the positive electrode empty foil portion 191. The boundary line 17 of the positive electrode 1a is the positive electrode boundary line 171. The first inclined edge 15 of the empty foil portion 19 of the positive electrode 1a away from the functional portion 18 is the first inclined edge 151 of the positive electrode, which is formed between the first side edge 11 and the third side edge 13. The second inclined edge 16 formed by the notch of the positive electrode 1a on the functional portion 18 is the second inclined edge 161 of the positive electrode, which is formed between the first side edge 11 and the fourth side edge 14.

[0041] In some embodiments, the angle between the first inclined side 151 of the positive electrode and the third side 13 of the positive electrode 1a is greater than 90°.

[0042] Furthermore, the functional portion 18 of the negative electrode 1b is the negative electrode functional portion 182, and the empty foil portion 19 of the negative electrode 1b is the negative electrode empty foil portion 192. The boundary line 17 of the negative electrode 1b is the negative electrode boundary line 172. The first inclined edge 15 of the empty foil portion 19 of the negative electrode 1b away from the functional portion 18 is the first inclined edge 152 of the negative electrode, and the first inclined edge 151 of the negative electrode is formed between the first side edge 11 and the fourth side edge 14. The second inclined edge 16 formed by the notch of the negative electrode 1b on the functional portion 18 is the second inclined edge 162 of the negative electrode, and the second inclined edge 162 of the negative electrode is formed between the first side edge 11 and the third side edge 13.

[0043] In some embodiments, the included angle between the first inclined side 152 of the negative electrode and the fourth side 14 of the negative electrode 1b is greater than 90°.

[0044] Alternatively, in some embodiments, the angle between the first inclined side 151 of the positive electrode and the third side 13 of the positive electrode 1a is greater than 90°, and the angle between the first inclined side 152 of the negative electrode and the fourth side 14 of the negative electrode 1b is greater than 90°.

[0045] This invention does not specifically limit the angle values ​​between the first inclined side 151 of the positive electrode and its third side 13, and between the first inclined side 152 of the negative electrode and its fourth side 14. The two angles can be the same or different, as long as at least one of them has an angle greater than 90°. Preferably, the angles between the first inclined side 151 of the positive electrode and its third side 13, and between the first inclined side 152 of the negative electrode and its fourth side 14, are both greater than 90°.

[0046] Conventional electrode 1 is usually a rectangular structure. In this invention, the first hypotenuse 15 and the second hypotenuse 16 of electrode 1 can be formed by cutting two adjacent corners of the rectangular structure. This arrangement allows for more space at the corners of the battery, which can act as a buffer during battery cycling when side reactions produce gas.

[0047] Understandably, the electrode 1 of this invention is hexagonal. In some embodiments, the first side 11 and the second side 12 of the electrode 1 are parallel to each other, and the third side 13 and the fourth side 14 are parallel to each other. Figure 1 As shown, the first side 11 and the second side 12 are parallel and spaced apart in direction L, and the third side 13 and the fourth side 14 are parallel and spaced apart in direction W. Direction L intersects direction W, and both intersect the thickness direction of the battery, that is, direction P. Preferably, the third side 13 and the fourth side 14 are both perpendicular to the first side 11 and to the second side 12. In this case, direction L is perpendicular to direction W, and direction P can be perpendicular to both direction L and direction W.

[0048] Furthermore, the electrode 1 typically includes a foil layer and an active material layer coated on the surface of the foil layer. The foil layer is a metal sheet or strip, such as gold, silver, copper, aluminum, or other metals or alloys. The active material layer is a coating composed of active material, conductive agent, and binder. The electrode 1 includes a functional portion 18 and an empty foil portion 19. The functional portion 18 is the part of the electrode 1 coated with the active layer; the empty foil portion 19 is the part of the electrode 1 without an active layer or with the active layer removed, forming an electrode tab.

[0049] The empty foil section 19 can be obtained through the following:

[0050] Method 1: Electrode 1 is rolled, and the coated electrode 1 is rolled with a pressure roller to achieve the required thickness and compaction density; Electrode 1 is die-cut, and one end corner of the rolled electrode 1 is die-cut to remove the active layer at that end corner.

[0051] Method 2: Electrode 1 roll pressing: The coated electrode 1 is rolled using a pressure roller to achieve the required thickness and compaction density; Laser cleaning: One corner of the rolled electrode 1 is laser cleaned to remove the active layer at that corner; Adhesive application: After cleaning, insulating adhesive is applied at the junction of the portion of the electrode 1 with the active layer removed and the portion with the active layer; Die cutting: The electrode 1 after adhesive application is die-cut.

[0052] Understandably, such as Figure 3 and Figure 4 As shown, in the thickness direction of the battery, among adjacent positive electrode plates 1a and negative electrode plates 1b, the empty foil portion 19 of the positive electrode plate 1a and the notch of the negative electrode plate 1b are located at the same end corner of the battery, and the projection of the empty foil portion 19 of the positive electrode plate 1a at least partially overlaps with the notch of the negative electrode plate 1b. At this time, at least a portion of the structure of the positive electrode empty foil portion 191 protrudes from the second inclined edge 162 of the negative electrode plate. Specifically, at least a portion of the structure of the positive electrode empty foil portion 191 protrudes from the second inclined edge 162 of the negative electrode plate in a direction perpendicular to the positive electrode plate boundary line 171.

[0053] Correspondingly, the empty foil portion 19 of the negative electrode 1b and the notch of the positive electrode 1a are located at the same end corner of the battery, and the projection of the empty foil portion 19 of the negative electrode 1b at least partially overlaps with the notch of the positive electrode 1a. At this time, at least a portion of the structure of the empty foil portion 192 of the negative electrode protrudes from the second inclined edge 161 of the positive electrode, specifically, at least a portion of the structure of the empty foil portion 192 of the negative electrode protrudes from the second inclined edge 161 of the positive electrode in a direction perpendicular to the boundary line 172 of the negative electrode.

[0054] Thus, the empty positive foil portions 191 of the multiple positive electrode plates 1a of the battery can contact and connect through the notches of the negative electrode plates 1b to form a positive electrode tab group; correspondingly, the empty negative foil portions 192 of the multiple negative electrode plates 1b of the battery can contact and connect through the notches of the positive electrode plates 1a to form a negative electrode tab group. The multiple empty positive foil portions 191 forming the positive electrode tab group and the multiple empty negative foil portions 192 forming the negative electrode tab group can be connected by welding, or by other methods such as adhesive bonding with conductive glue, as long as the connected tab group can have the function of carrying current.

[0055] In the above embodiments, positive electrode empty foil portions 191 and negative electrode empty foil portions 192 are respectively provided at different end corners of the battery. The positive electrode empty foil portions 191 and negative electrode empty foil portions 192 can respectively form positive electrode tab groups and negative electrode tab groups. That is, the battery tabs are formed using the foil material of the electrode sheet 1 itself, eliminating the need for additional tabs and reducing the internal space occupied by the battery. Furthermore, a first inclined edge 15 is provided in the empty foil portion 19 of the electrode sheet 1, minimizing the area occupied by the empty foil portion 19. The battery and electrical device of this invention utilize the empty foil portion 19 as the tab, greatly reducing the area occupied by the tabs, thereby improving the energy density of the battery.

[0056] Furthermore, the angle between the first inclined side 151 of the positive electrode and the third side 13 of the positive electrode 1a is greater than 90°. That is, the connection between the first inclined side 151 of the positive electrode and the third side 13 of the positive electrode 1a forms an obtuse angle, without any sharp corners. This obtuse angle design can prevent stress concentration at sharp corners. Similarly, the angle between the first inclined side 152 of the negative electrode and the fourth side 14 of the negative electrode 1b is greater than 90°. That is, the connection between the first inclined side 152 of the negative electrode and the fourth side 14 of the negative electrode forms an obtuse angle, without any sharp corners. This obtuse angle design can prevent stress concentration at sharp corners. Compared to the empty foil portion with sharp corners, the battery of this application has a larger supporting area for the first inclined side 15 when dropped, and the first inclined side 15 can effectively disperse the impact force generated during the drop, reducing the risk of tearing or deformation of the electrode 1 edge and improving drop safety.

[0057] Furthermore, compared to the conventional electrode 1 with external tabs, the empty foil portion 19 of this solution is formed from the foil layer of the electrode 1. That is, the material of the empty foil portion 19 and the electrode 1 is continuous. There are no stress concentration points caused by geometric abrupt changes or material discontinuities at the connection positions between the empty foil portion 19 and the electrode 1. Therefore, the tab formed by the empty foil portion 19 in this application has better toughness and strength, which helps to improve the mechanical stability of the tab during charging and discharging and reduce damage caused by expansion and contraction.

[0058] Furthermore, in some embodiments, the included angle between the first inclined side 151 of the positive electrode sheet and the first side 11 of the positive electrode sheet 1a is greater than 90°, that is, the corner of the positive electrode sheet 1a with the empty foil portion 19 is formed into an obtuse trapezoidal structure. Compared with a sharp corner, the obtuse trapezoidal structure at the corner in this application has a larger support area when falling and can more effectively disperse the impact force generated during the fall, thereby improving fall safety.

[0059] Preferably, the angle between the first inclined side 151 of the positive electrode sheet and the first side 11 of the positive electrode sheet 1a is the same as or close to the angle between the first inclined side 151 of the positive electrode sheet and the third side 13 of the positive electrode sheet 1a. This ensures uniform stress distribution on the empty foil portion 19 when it is welded to the adapter 3. If the angle between the first inclined side 151 of the positive electrode sheet and the first side 11 of the positive electrode sheet 1a deviates too much from the angle between the first inclined side 151 of the positive electrode sheet and the third side 13 of the positive electrode sheet 1a, the welding area may be biased to one side when welding the adapter 3, resulting in excessive stress distribution on the empty foil portion 19 and causing tearing of the empty foil portion 19; or the connection may be unstable due to the welding area of ​​the empty foil portion 19 and the adapter 3 being biased to one side, leading to poor current conductivity.

[0060] Furthermore, in some embodiments, the included angle between the first inclined side 152 of the negative electrode sheet and the first side 11 of the negative electrode sheet 1b is greater than 90°, that is, the corner of the negative electrode sheet 1b where the empty foil portion 19 is provided is formed into an obtuse trapezoidal structure. Compared with a sharp corner, in this application, the obtuse trapezoidal structure at the corner has a larger support area when falling and can more effectively disperse the impact force generated during the fall, thereby improving fall safety.

[0061] Preferably, the angle between the first inclined side 152 of the negative electrode sheet and the first side 11 of the negative electrode sheet 1b is the same as or close to the angle between the first inclined side 152 of the negative electrode sheet and the fourth side 14 of the negative electrode sheet 1b. Similarly, when the empty foil portion 19 is welded to the adapter 3, the uniformity of the force on the empty foil portion 19 can be ensured.

[0062] Furthermore, the functional part 18 and the empty foil part 19 have the aforementioned boundary line 17, specifically the aforementioned positive electrode boundary line 171 and negative electrode boundary line 172. The boundary line 17 can be a curve, a straight line, a broken line, or other irregular shapes.

[0063] In some embodiments, the positive electrode boundary line 171 is a straight line, and the positive electrode boundary line 171 is parallel to the first inclined side 151 of the positive electrode.

[0064] In some embodiments, the negative electrode boundary line 172 is a straight line, and the negative electrode boundary line 172 is parallel to the first inclined side 152 of the negative electrode.

[0065] In some embodiments, the positive electrode boundary line 171 and the negative electrode boundary line 172 are both straight lines. The positive electrode boundary line 171 is parallel to the first inclined side 151 of the positive electrode, and the negative electrode boundary line 172 is parallel to the first inclined side 152 of the negative electrode.

[0066] Furthermore, the battery also includes an adapter 3, which is connected to the empty foil portion 19. More specifically, there are two adapters 3, which are respectively connected to the positive electrode tab group formed in the positive electrode empty foil portion 191 and the negative electrode tab group formed in the negative electrode empty foil portion 192, usually by welding.

[0067] In the above embodiment, the boundary line 17 is parallel to the first inclined side 15, and the empty foil portion 19 is trapezoidal. The trapezoidal shape of the empty foil portion 19 can minimize the area of ​​the empty foil portion 19 while ensuring a sufficiently large soldering area with the adapter 3, thereby saving internal space of the battery; and can also minimize the overall weight of the battery, thereby improving the mass energy density of the battery.

[0068] In actual production, the initial shape of the empty foil portion 19 can be triangular, that is, it is directly formed by the end corner of the rectangular electrode sheet 1. After the electrode tab group formed by the empty foil portion 19 is connected to the adapter 3, the top corner of the empty foil portion 19 is cut to form the first inclined side 15 mentioned above, thereby reducing the area and weight of the empty foil portion 19.

[0069] Specifically, such as Figure 1 As shown, when the positive electrode boundary line 171 is a straight line, it intersects with the first side 11 and the third side 13 of the positive electrode 1a, forming an angle θ1 with the first side 11 and an angle θ2 with the third side 13. The values ​​of θ1 and θ2 are both within the range of 5°-85°. Preferably, the values ​​of θ1 and θ2 are both within the range of 30°-60°. In some cases, the first side 11 and the third side 13 are perpendicular, and the sum of θ1 and θ2 is 90°.

[0070] like Figure 2 As shown, when the negative electrode boundary line 172 is a straight line, it intersects with the first side 11 and the fourth side 14 of the negative electrode 1b, forming an angle θ1' with the first side 11 and an angle θ2' with the fourth side 14. The values ​​of θ1' and θ2' are both within the range of 5°-85°. Preferably, the values ​​of θ1' and θ2' are both within the range of 30°-60°. In some cases, the first side 11 and the fourth side 14 are perpendicular, and the sum of θ1' and θ2' is 90°.

[0071] Preferably, the included angles θ1 and θ2 of the positive electrode 1a are both 45°, and the included angles θ1' and θ2' of the negative electrode 1b are both 45°. With this configuration, the solder area between the empty foil portion 19 and the adapter 3 is maximized, without affecting the bending and cutting of the empty foil portion 19. Furthermore, in some embodiments, such as... Figure 5 As shown, a bent portion 20 is formed in the empty foil portion 19 between the first inclined edge 15 and the boundary line 17. It can be understood that the bent portion 20 can be formed between the first inclined edge 151 and the boundary line 171 of the positive electrode 1a, or between the first inclined edge 152 and the boundary line 172 of the negative electrode 1b. The bent portion 20 has a first bent portion 201 near the first inclined edge 15 and a second bent portion 202 near the boundary line 17. The first bent portion 201 bends towards the direction closer to the battery, and the second bent portion 202 bends away from the battery. In this embodiment, the empty foil portion 19 forms the bent portion 20 through two bends. The bent portion 20 can provide better cushioning for the battery tabs when the battery is impacted by a heavy object, thus improving battery safety.

[0072] It should be noted that, Figure 5 A schematic diagram of the bent portion 20 in its flattened state is shown. Further, the distance between the first bent portion 201 and the boundary line 17 is H1, 0.3mm ≤ H1 ≤ 4mm, preferably 0.9mm ≤ H1 ≤ 3mm. It should be noted that, as... Figure 5 As shown, the distance H1 between the first bent portion 201 and the boundary line 17 specifically refers to the distance between the first bent portion 201 and the boundary line 17 when the empty foil portion 19 is in the flattened state. And / or, the distance H2 between the second bent portion 202 and the boundary line 17 is 0.2mm ≤ H2 ≤ 3mm, preferably 0.6mm ≤ H2 ≤ 1.2mm. It should be noted that, as... Figure 5 As shown, the distance H2 between the second bend 202 and the boundary line 17 refers to the distance between the second bend 202 and the boundary line 17 when the empty foil portion 19 is in the flattened state. It can be understood that the first bend 201 is located on the side of the second bend 202 away from the boundary line 17; therefore, the distance H1 between the first bend 201 and the boundary line 17 is greater than the distance H2 between the second bend 202 and the boundary line 17.

[0073] Typically, the first bend 201 and the second bend 202 tend to be parallel to the boundary line 17 after bending and are close to the functional part 18, occupying a small volume of the battery cell, which is almost negligible. However, the non-bending area of ​​the remaining empty foil portion 19 is used for welding the adapter 3 and needs to extend away from the functional part 18, occupying a larger volume of the battery cell. In this embodiment, the distance H1 between the first bend 201 and the boundary line 17 and the distance H2 between the second bend 202 and the boundary line 17 are both large, meaning that the first bend 201 and the second bend 202 occupy a large area of ​​the empty foil portion 19. Therefore, the area of ​​the non-bending area of ​​the remaining empty foil portion 19 is small, and its extension away from the functional part 18 is also small, reducing the volume of the battery cell occupied by the non-bending area, thereby reducing the overall volume of the battery and increasing the energy density of the battery.

[0074] In actual production, the empty foil portions 19 of the battery are usually connected to form a group of electrode tabs before being bent to form a bent portion 20 on each empty foil portion 19. Specifically, at least one empty foil portion 19 in the electrode tab group may be bent to form the bent portion 20; a portion of the empty foil portions 19 may be bent to form the bent portion 20; or all the empty foil portions 19 may be bent to form the bent portion 20.

[0075] Furthermore, in some embodiments, along the thickness direction of the battery, i.e. direction P, the projection of the negative electrode functional portion 182 at least covers the positive electrode functional portion 181, so as to ensure that the active material layer on the negative electrode functional portion 182 can cover the active material layer on the positive electrode functional portion 181, thereby avoiding lithium plating problems.

[0076] Furthermore, in some embodiments, the projection of the separator 2 in the thickness direction of the battery at least covers the negative electrode functional part 182 and the positive electrode functional part 181, so as to avoid the negative electrode functional part 182 and the positive electrode functional part 181 from coming into contact and causing a short circuit, thereby ensuring the reliability of the battery application.

[0077] Specifically, the electrical equipment includes a first end corner and a second end corner located at opposite ends of the direction W. Along the direction P, the positive electrode empty foil portion 191 and the second inclined side 162 of the negative electrode plate are located at the first end corner, and the negative electrode empty foil portion 192 and the second inclined side 161 of the positive electrode plate are located at the second end corner.

[0078] Accordingly, the diaphragm 2 is provided with a first notch at both the first and second end corners. The first notch is used to provide clearance space for the positive electrode empty foil portion 191 and the negative electrode empty foil portion 192, so as to allow adjacent positive electrode empty foil portions 191 to connect to form a positive electrode tab group and adjacent negative electrode empty foil portions 192 to connect to form a negative electrode tab group.

[0079] More specifically, such as Figure 3As shown, at the first corner of the battery, the separator 2 has a first edge 21, that is, one of the first notches forms the first edge 21 on the separator 2. At the second corner of the battery, the separator 2 has a second edge 22, that is, another first notch forms the second edge 22 on the separator 2.

[0080] Among them, such as Figure 4 As shown, on the projection plane along the battery thickness direction, that is, on the plane containing directions L and W, at the first end corner, the second inclined edge 162 of the negative electrode sheet is located between the first edge 21 and the boundary line 17 of the positive electrode sheet 1a, that is, between the first edge 21 and the boundary line 171 of the positive electrode sheet. At the second end corner, the boundary line 17 of the negative electrode sheet 1b is located between the second edge 22 and the second inclined edge 161 of the positive electrode sheet, that is, the boundary line 172 of the negative electrode sheet is located between the second edge 22 and the second inclined edge 161 of the positive electrode sheet. Thus, the separator 2 can completely cover the negative electrode functional part 182 and the positive electrode functional part 181 to prevent short circuits; and the negative electrode functional part 182 can completely cover the positive electrode functional part 181 to prevent lithium plating.

[0081] Furthermore, in some embodiments, on the projection plane along the thickness direction of the battery, the distance between the second inclined edge 162 of the negative electrode and the first edge 21 is L1, where 0.4mm ≤ L1 ≤ 3mm. With L1 in the range of 0.4mm-3mm, during battery manufacturing, it is possible to avoid contact between the positive electrode 1a and the negative electrode 1b due to misalignment of the separator 2 and the electrode 1 or shrinkage of the separator 2, thereby reducing or even eliminating the risk of short circuits.

[0082] In some embodiments, on the projection plane along the thickness direction of the battery, the distance between the second inclined edge 162 of the negative electrode and the boundary line 17 of the positive electrode 1a is L2, 0.6mm≤L2≤2mm. L2 is in the range of 0.6mm-2mm, which allows the functional layer of the negative electrode 1b to provide sufficient lithium insertion sites for the functional layer of the positive electrode 1a, avoiding the risk of lithium plating.

[0083] In some embodiments, on the projection plane along the thickness direction of the battery, the distance between the boundary line 17 of the negative electrode 1b and the second edge 22 is L1', 0.4mm≤L1'≤3mm. When L1' is in the range of 0.4mm-3mm, during the battery manufacturing process, it is possible to avoid the positive electrode 1a and the negative electrode 1b coming into contact due to misalignment of the separator 2 and the electrode 1 or shrinkage of the separator 2, thereby reducing or even eliminating the risk of short circuit.

[0084] In some embodiments, on the projection plane along the thickness direction of the battery, the distance between the boundary line 17 of the negative electrode 1b and the second inclined edge 161 of the positive electrode is L2', 0.6mm≤L2'≤2mm. L2' is in the range of 0.6mm-2mm, which allows the functional layer of the negative electrode 1b to provide sufficient lithium insertion sites for the functional layer of the positive electrode 1a, avoiding the risk of lithium plating.

[0085] Furthermore, such as Figure 9 and Figure 10 As shown, the battery also includes a packaging shell 5 and two adapters 3, which are respectively connected to the positive electrode tab group and the negative electrode tab group. The packaging shell 5 covers the outside of the electrode sheet 1 and the separator 2, and has two second notches located at the first and second end corners of the battery, respectively. At least a portion of the structure of each adapter 3 extends out of the packaging shell 5 at the two second notches. Understandably, the adapters 3 are specifically connected to the empty foil portion 19 forming the positive and negative electrode tab groups, typically by welding.

[0086] In some embodiments, after the adapter 3 is connected to the empty foil portion 19, the adapter 3 is perpendicular to the first side 11, that is, the adapter 3 extends along direction L, so that the adapter 3 extends out of the packaging shell 5 along the length direction of the battery, such as... Figure 9 As shown.

[0087] For example, such as Figure 8 As shown, the adapter 3 can be constructed as a trapezoid, having a third inclined side 32 and two side edges located at both ends of the third inclined side 32. The third inclined side 32 is parallel to the boundary line 17 of the electrode plate 1, and the two side edges are perpendicular to the first side edge 11, allowing the adapter 3 to extend along the direction L. At this time, the third inclined side 32 forms included angles θ3 and θ4 with the two adjacent side edges, respectively, and the sum of angles θ3 and θ4 is 180°. When the adapter 3 is connected to the positive electrode tab group formed by the positive electrode empty foil portion 191, angles θ4 and θ2 are equal; when the adapter 3 is connected to the negative electrode tab group formed by the negative electrode empty foil portion 192, angles θ4 and θ2' are equal.

[0088] For example, the adapter 3 can also be constructed as a rectangle. After the adapter 3 is connected to the empty foil portion 19, the adapter 3 can be bent to extend along the direction L. Alternatively, the adapter 3 can also be constructed as an irregular shape so that the end of the adapter 3 away from the empty foil portion 19 can extend along the direction L.

[0089] Alternatively, in some other embodiments, after the adapter 3 is connected to the empty foil portion 19, the adapter 3 can also be perpendicular to the boundary line 17, which facilitates the processing and manufacturing of the adapter 3. In this case, the positional relationship between the adapter 3 and the packaging shell 5 is as follows: Figure 10 As shown.

[0090] Furthermore, in some embodiments, such as Figure 6 and Figure 7 As shown, the adapter 3 and the empty foil portion 19 overlap at least partially to form an overlap area 31. This overlap area 31 includes a solder area 311 near the boundary line 17 and a reserve area 312 near the first inclined edge 15. Understandably, the solder area 311 is the area formed after the adapter 3 and the empty foil portion 19 are soldered together, and the reserve area 312 is the portion of the empty foil portion 19 that overlaps with the adapter 3 but is not soldered. The area of ​​the solder area 311 is S, 0.8 mm. 2 ≤S≤20mm 2 ; and / or, the area ratio of the surplus area 312 to the empty foil section 19 is η1, 0.05≤η1≤0.6.

[0091] In this embodiment, the area S of the solder area 311 is 0.8 mm. 2 -20mm 2 Within this range, the area of ​​the solder area 311 is larger than that between the conventional tab and electrode 1, which enhances current distribution, improves conductivity, reduces internal resistance, and improves battery charge and discharge efficiency. The area ratio η1 of the excess area 312 to the empty foil portion 19 is in the range of 0.05-0.6. If η1 is less than 0.05, the area of ​​the excess area 312 is too small, which can easily affect the welding quality of the solder area 311, causing a risk of poor soldering near the edge of the excess area 312 and reducing the reliability of battery application. If η1 is greater than 0.6, the area of ​​the excess area 312 is too large, and the excess area 312 will occupy too much battery space, reducing the energy density of the battery. Therefore, in this embodiment, η1 is in the range of 0.05-0.6, which can ensure both the welding quality of the solder area 311 and the energy density of the battery. Understandably, the allowance area 312 can be constructed as a rectangle, pentagon, hexagon, etc., and its specific shape depends on the connection position between the adapter 3 and the empty foil part 19.

[0092] Furthermore, such as Figure 6 As shown, the battery also includes a gel 4, which is connected to the adapter 3 and to the edge of the packaging shell 5, specifically the edge of the second notch in the packaging shell 5. When the adapter 3 extends out of the packaging shell 5 through the second notch, the gel 4 ensures the seal at the adapter 3.

[0093] In some embodiments, the empty foil portion 19 is connected to the colloid 4 on the adapter 3, wherein the distance between the first inclined edge 15 of the empty foil portion 19 and the colloid 4 is L3mm, and the distance between the first inclined edge 15 and the boundary line 17 is L4mm, and 1.5≤L3 / L4≤4. In this embodiment, the ratio of L3 to L4 is between 1.5 and 4, which can both prevent the empty foil portion 19 from being too large, ensuring the energy density of the battery, and ensure the sealing of the battery, avoiding leakage and other phenomena.

[0094] Furthermore, in some embodiments, such as Figure 9 and Figure 10 As shown, sealing portions 51 are formed at the two second notches of the packaging shell 5. Figure 11 As shown, the sealing portion 51 falls onto the adhesive 4 to improve the sealing effect.

[0095] Specifically, the sealing portion 51 has a sealing area 510, the projection of which falls onto the colloid 4. The colloid 4 includes a first side 41 near the empty foil portion 19 and a second side 42 away from the empty foil portion 19. The distance between the sealing area 510 and the first side 41 is X, 0.3mm ≤ X ≤ 1.1mm; and / or, the distance between the sealing area 510 and the second side 42 is Y, 0mm ≤ Y ≤ 1.5mm. In this embodiment, the distance X between the sealing area 510 and the first side 41 is between 0.3mm and 1.1mm, and / or the distance Y between the sealing area 510 and the second side 42 is between 0mm and 1.5mm, which ensures the sealing performance of the battery encapsulation while minimizing the overall size of the packaging shell 5 and improving the overall energy density of the battery.

[0096] According to an embodiment of the present invention, another aspect provides an electrical device including a battery as described in any of the above embodiments. Since the electrical device of the present invention includes the aforementioned battery, it has the same technical effects as the battery of the present invention, and will not be described again here.

[0097] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A battery, characterized in that, The battery includes an electrode (1) and a separator (2). The electrode (1) includes a positive electrode (1a) and a negative electrode (1b). Along the thickness direction of the battery, the positive electrode (1a) and the negative electrode (1b) are alternately arranged. The separator (2) is located between adjacent positive electrode (1a) and negative electrode (1b). The electrode (1) has a first side (11) and a second side (12) that are parallel to each other, and a third side (13) and a fourth side (14) that are connected to both ends of the second side (12); The electrode (1) includes a functional part (18), a blank foil part (19) and a notch. The electrode (1) includes an active material layer formed on the functional part (18). There is a boundary line (17) between the functional part (18) and the blank foil part (19). At least a portion of the structure of the first side (11) and the third side (13) of the positive electrode (1a), the first inclined side (15) formed between the first side (11) and the third side (13), and the boundary line (17) together enclose the empty foil portion (19); the notch is located between the first side (11) and the fourth side (14); The empty foil portion (19) of the negative electrode (1b) is located between the first side (11) and the fourth side (14) of the negative electrode. In the thickness direction of the battery, the projection of the empty foil portion (19) of the negative electrode (1b) and the notch of the positive electrode (1a) at least partially overlap; the notch of the negative electrode (1b) is located between the first side (11) and the third side (13). The angle between the first inclined edge (151) of the positive electrode portion (19) away from the functional portion (18) and the third side edge (13) of the positive electrode (1a) is greater than 90°, and / or the angle between the first inclined edge (152) of the negative electrode portion (19) away from the functional portion (18) and the fourth side edge (14) of the negative electrode (1b) is greater than 90°.

2. The battery according to claim 1, characterized in that, The boundary line (17) of the positive electrode (1a) is parallel to the first inclined side (151) of the positive electrode; and / or, The boundary line (17) of the negative electrode (1b) is parallel to the first inclined side (152) of the negative electrode.

3. The battery according to claim 1, characterized in that, The functional part (18) of the positive electrode (1a) is a positive electrode functional part (181), and the functional part (18) of the negative electrode (1b) is a negative electrode functional part (182). In the thickness direction of the battery, the projection of the negative electrode functional part (182) at least covers the positive electrode functional part (181).

4. The battery according to claim 3, characterized in that, In the thickness direction of the battery, the projection of the separator (2) covers at least the negative electrode functional part (182) and the positive electrode functional part (181).

5. The battery according to claim 4, characterized in that, The notch of the positive electrode (1a) forms a second oblique edge (161) between the first side (11) and the fourth side (14); the notch of the negative electrode (1b) forms a second oblique edge (162) between the first side (11) and the third side (13); The separator (2) has a first edge (21) and a second edge (22). On the projection plane along the thickness direction of the battery, the second oblique edge (162) of the negative electrode is located between the first edge (21) and the boundary line (17) of the positive electrode (1a); the boundary line (17) of the negative electrode (1b) is located between the second edge (22) and the second oblique edge (161) of the positive electrode. On the projection plane along the thickness direction of the battery, the distance between the second inclined edge (162) of the negative electrode and the first edge (21) is L1, 0.4mm≤L1≤3mm; and / or, the distance between the second inclined edge (162) of the negative electrode and the boundary line (17) of the positive electrode (1a) is L2, 0.6mm≤L2≤2mm; and / or, On the projection plane along the thickness direction of the battery, the distance between the boundary line (17) of the negative electrode (1b) and the second edge (22) is L1', 0.4mm≤L1'≤3mm; and / or, the distance between the boundary line (17) of the negative electrode (1b) and the second inclined edge (161) of the positive electrode is L2', 0.6mm≤L2'≤2mm.

6. The battery according to any one of claims 1-5, characterized in that, Between the first inclined edge (15) and the boundary line (17), the empty foil portion (19) has a bent portion (20); the bent portion (20) has a first bent portion (201) near the first inclined edge (15) and a second bent portion (202) near the boundary line (17); the first bent portion (201) bends toward the direction of the battery, and the second bent portion (202) bends toward the direction of the battery. The distance between the first bend (201) and the boundary line (17) is H1, 0.3mm ≤ H1 ≤ 4mm; and / or, The distance between the second bend (202) and the boundary line (17) is H2, 0.2mm≤H2≤3mm.

7. The battery according to any one of claims 1-5, characterized in that, The battery also includes an adapter (3) connected to the empty foil portion (19); wherein the adapter (3) is perpendicular to the first side (11), or the adapter (3) is perpendicular to the boundary line (17).

8. The battery according to claim 7, characterized in that, The adapter (3) overlaps with at least a portion of the structure of the empty foil portion (19) to form an overlapping area (31); the overlapping area (31) includes a solder area (311) near the boundary line (17) and a margin area (312) near the first inclined edge (15); The area of ​​the solder area (311) is S, 0.8 mm. 2 ≤S≤20mm 2 ; and / or, The area ratio of the surplus area (312) to the empty foil portion (19) is η1, where 0.05≤η1≤0.

6.

9. The battery according to claim 7, characterized in that, The battery also includes a gel (4), which is disposed on the adapter (3); wherein the distance between the first inclined side (15) and the gel (4) is L3mm, the distance between the first inclined side (15) and the boundary line (17) is L4mm, and 1.5≤L3 / L4≤4.

10. The battery according to claim 9, characterized in that, The battery also includes a packaging shell (5) covering the outside of the electrode (1) and the separator (2), and the colloid (4) is connected to the edge of the packaging shell (5); The packaging shell (5) has a sealing area (510) on the colloid (4), and the colloid (4) includes a first side (41) close to the empty foil portion (19) and a second side (42) away from the empty foil portion (19); The distance between the sealing area (510) and the first edge (41) is X, 0.3mm ≤ X ≤ 1.1mm; and / or, The distance between the sealing area (510) and the second side (42) is Y, where 0mm≤Y≤1.5mm.

11. An electrical appliance, characterized in that, include: The battery as described in any one of claims 1 to 10.

Images