Battery

Abstract

Battery comprising a battery cell, a housing, a positive battery terminal assembly and a negative battery terminal assembly, wherein the battery cell is located in the housing, wherein the positive battery terminal assembly and the negative battery terminal assembly are arranged on the housing, wherein the battery cell comprises a cell body, a positive terminal tab and a negative terminal tab, wherein, in the longitudinal direction of the battery, the positive terminal tab and the negative terminal tab each extend from both ends of the cell body, wherein the positive terminal tab and the negative terminal tab are connected to the positive battery terminal assembly and the negative terminal tab, respectively.the negative battery terminal assembly is welded, wherein the battery has a length of L, where L ≥ 400 mm, where a thickness of the positive terminal tab is greater than a thickness of the negative terminal tab, where a width of the negative terminal tab in the width direction of the battery is W1 and a width of the positive terminal tab in the width direction of the battery is W2, where W1 > W2.

Description

Technical field

[0001] The present application relates to the field of battery technology, in particular a battery. Technical background

[0002] A battery comprises a positive terminal, a negative terminal, a positive battery terminal assembly, and a negative battery terminal assembly, with the positive and negative terminals welded to the positive and negative battery terminal assemblies, respectively, to form a charging and discharging circuit. If the connection between the positive or negative terminal and the positive or negative battery terminal assembly breaks, the battery's electrical connection fails, impairing reliable battery operation. An unbalanced overcurrent capability of the positive and negative electrodes results in poor overall overcurrent protection of the battery. Content of the invention

[0003] The objective of the present application is to provide a battery with higher energy density and higher reliability.

[0004] The battery provided by the present application comprises a battery cell, a housing, a positive battery terminal assembly, and a negative battery terminal assembly, wherein the battery cell is located in the housing, wherein the positive battery terminal assembly and the negative battery terminal assembly are arranged on the housing, wherein the battery cell comprises a cell body, a positive terminal tab, and a negative terminal tab, wherein, in the longitudinal direction of the battery, the positive terminal tab and the negative terminal tab are each extended from both ends of the cell body, wherein the positive terminal tab and the negative terminal tab are connected to the positive battery terminal assembly and the negative terminal tab, respectively.the negative battery terminal assembly is welded, wherein the battery has a length of L, where L ≥ 400 mm, where a thickness of the positive terminal tab is greater than a thickness of the negative terminal tab, where a width of the negative terminal tab in the width direction of the battery is W1 and a width of the positive terminal tab in the width direction of the battery is W2, where W1 > W2.

[0005] Since the battery length is greater than or equal to 400 mm, the cell body is also relatively long. The longer the cell body, the better the battery's energy density can be improved. Because the negative terminal of the battery is relatively thin (its thickness is less than that of the positive terminal), a single negative terminal (multiple single negative terminals stacked on top of each other to form a single negative terminal) is also relatively thin (its thickness is less than that of a single positive terminal). Consequently, the current collector of a negative electrode sheet of the cell body (the single negative terminal extending from the current collector of the negative electrode sheet of the cell body) is also relatively thin.For a given thickness of the negative electrode sheet, the following applies: the thinner the current collector of the negative electrode sheet, the thicker the active material layer coated on both sides of the current collector of the negative electrode sheet; the thicker the active material layer, the more it contributes to increasing the energy density of the battery. Therefore, the battery has a higher energy density.

[0006] Because the negative terminal tab is relatively thin (its thickness is less than that of the positive terminal tab), the connection between the negative terminal tab and the negative battery terminal assembly is prone to breakage, leading to poor battery reliability. Furthermore, the battery is relatively long. The longer the battery, the greater the stress on the connection between the negative terminal tab and the negative battery terminal assembly at one end of the battery along its length, further increasing the risk of breakage at this connection point.In the present application, by making the width of the negative terminal tab larger than the width of the positive terminal tab, the strength of the connection point between the negative terminal tab and the negative battery terminal assembly is improved and the risk of breakage at the connection point between the negative terminal tab and the negative battery terminal assembly is reduced, thereby giving the battery a higher reliability. Images Fig. Figure 1 shows an exploded view of an embodiment of a battery provided by the present application; Fig. 2 shows a view of the battery of Fig. 1. In the assembled state from another perspective; Fig. Figure 3 shows a schematic top view of the battery cell and the cover plate made of Fig. 1; Fig. Figure 4 shows an enlarged view of a section containing the negative terminal tab after an insulating protective cap of a negative electrode has been inserted. Fig. 1 was hidden; Fig. Figure 5 shows an enlarged view of an insulating protective cap of a positive electrode made of Fig. 1; Fig. Figure 6 shows a simplified representation of the structure of a cell body of an embodiment of the battery provided by the present application; and Fig. Figure 7 shows a simplified representation of the structure of a housing of an embodiment of the battery provided by the present application. Reference symbol list

[0007] 1-Housing, 11-Housing body, 11a-Protrusion, 11b-Recess, 12-Cover plate, C-Liquid filling opening; 2-battery cell, 21-cell body, 22-positive terminal tab, 23-negative terminal tab; 31-positive battery terminal assembly, 32-negative battery terminal assembly; 4-adapter piece; 51-insulating protective cap of a positive electrode, 52-insulating protective cap of a negative electrode, 5a-first support section, A-first side wall, 5b-second support section, B-second side wall, 5c-tab receptacle. Description of embodiments

[0008] The present application provides a battery. To enable the person skilled in the art to better understand the technical solution of the present application, the present application is described in more detail below with reference to the attached drawings and specific embodiments.

[0009] As in the Fig. As shown in Figures 1 to 4, the battery comprises a housing 1, a battery cell 2, and a battery terminal assembly. The housing 1 is equipped with a liquid filling opening C (see Figure 1 to 4). Fig. 2) provided with an electrolyte being filled into the housing 1 through the liquid filling opening C. The battery cell 2 is located in the housing 1. The battery terminal assembly is arranged on the housing 1. The battery terminal assembly comprises a positive battery terminal assembly 31 and a negative battery terminal assembly 32. The positive battery terminal assembly 31 comprises at least one positive battery terminal and can optionally be provided with an adapter piece 4. The negative battery terminal assembly 32 comprises at least one negative battery terminal and can optionally be provided with an adapter piece 4.

[0010] The battery cell 2 comprises a cell body 21 and terminal tabs. The terminal tabs include a positive terminal tab 22 and a negative terminal tab 23. Along the length of the battery, the positive terminal tab 22 and the negative terminal tab 23 extend from the two ends of the cell body 21. The battery is essentially rectangular and comprises two opposing large surfaces and four small surfaces located between the two large surfaces. The direction of the long edge of the large surface is the length direction of the battery, the direction of the short edge of the large surface is the width direction of the battery, and the direction perpendicular to the large surface is the thickness direction of the battery. The length, width, and thickness directions of the battery are pairwise perpendicular to each other.

[0011] The positive terminal tab 22 is welded to the positive battery terminal assembly 31, and the negative terminal tab 23 is welded to the negative battery terminal assembly 32. If the positive battery terminal assembly 31 is not fitted with an adapter 4, the positive terminal tab 22 is welded to the positive battery terminal. If the positive battery terminal assembly 31 is fitted with an adapter 4, the positive terminal tab 22 is welded to one side of the adapter 4, and the positive battery terminal is welded to the other side of the adapter 4. If the negative battery terminal assembly 32 is not fitted with an adapter 4, the negative terminal tab 23 is welded to the negative battery terminal.If the negative battery terminal assembly 32 is provided with an adapter piece 4, the negative connection tab 23 is welded to one side of the adapter piece 4 and the negative battery terminal is welded to the other side of the adapter piece 4.

[0012] The cell body 21 comprises a positive electrode sheet and a negative electrode sheet arranged alternately, with a separator provided between adjacent positive and negative electrode sheets. In some embodiments, the positive and negative electrode sheets are arranged alternately in the thickness direction of the battery, so that the cell body 21 has a stacked structure. In some embodiments, the positive and negative electrode sheets are wound, with the positive and negative electrode sheets arranged alternately in a direction perpendicular to the winding centerline, so that the cell body 21 has a wound structure.

[0013] The positive and negative electrode sheets have similar structures and each comprises a current collector and an active material layer coated on both sides of the current collector. The active material layer of the positive electrode sheet comprises a positive electrode active material, a conductive agent, and a binder, etc., with the positive electrode active material being a ternary nickel-cobalt-manganese material, a lithium iron phosphate material, a lithium iron manganese phosphate material, a lithium nickel manganese oxide material, etc. The active material layer of the negative electrode sheet comprises a negative electrode active material, a conductive agent, and a binder, etc. The negative electrode active material is a synthetic graphite, a natural graphite, and a silicon-based material, etc.The material of the current collector is not restricted in the present application, as long as it is conductive and does not cause adverse chemical changes in the battery. For example, the current collector may be made of stainless steel, aluminum, nickel, titanium, or calcined carbon; alternatively, it may be made of aluminum or stainless steel whose surface is treated with a coating of carbon, nickel, titanium, silver, or the like.

[0014] The portion of the current collector of the positive electrode sheet that is not coated with any active material extends beyond the portion coated with active material to form a positive single-terminal tab. Several positive single-terminal tabs are stacked on top of each other to form a positive terminal tab 22. The portion of the current collector of the negative electrode sheet that is not coated with any active material extends beyond the portion coated with active material to form a negative single-terminal tab. Several positive single-terminal tabs are stacked on top of each other to form a negative terminal tab 23.

[0015] The battery length is L, where L ≥ 400 mm. For example, L can be 500 mm, 600 mm, or 700 mm. The longer the battery length, the longer the cell body 21, which is more advantageous for increasing the battery's energy density.

[0016] The thickness of the positive terminal tab 22 is greater than the thickness of the negative terminal tab 23. The thickness of the positive single terminal tab is greater than the thickness of the negative single terminal tab. The thickness of the positive terminal tab 22 is equal to the number of positive single terminal tabs multiplied by the thickness of the positive single terminal tab. The thickness of the negative terminal tab 23 is equal to the number of negative single terminal tabs multiplied by the thickness of the negative single terminal tab. Since the negative single terminal tab extends out of the current collector of the negative electrode sheet, the thickness of the current collector decreases as the thickness of the negative single terminal tab decreases.For a given thickness of the negative electrode sheet, the following applies: the thinner the current collector of the negative electrode sheet, the thicker the active material layer of the negative electrode sheet; the thicker the active material layer, the better it contributes to increasing the energy density of the battery.

[0017] The width of the negative terminal tab 23 in the width direction of the battery is W1, and the width of the positive terminal tab 22 in the width direction of the battery is W2, where W1 > W2.

[0018] Because the negative terminal tab is relatively thin (the thickness of the negative terminal tab 23 is less than the thickness of the positive terminal tab 23), the connection between the negative terminal tab 23 and the negative battery terminal assembly 32 is prone to breakage, leading to poor battery reliability. In addition, the battery is relatively long (greater than or equal to 400 mm). The longer the battery, the greater the stress at the connection point between the negative terminal tab 23 and the negative battery terminal assembly 32 at one end of the battery along its length, further increasing the risk of breakage at this connection point.In the present application, by making the width of the negative terminal tab 23 larger than the width of the positive terminal tab 22, the strength of the connection point between the negative terminal tab 23 and the negative battery terminal assembly 32 is improved and the risk of breakage at the connection point between the negative terminal tab 23 and the negative battery terminal assembly 32 is reduced, thereby giving the battery a higher reliability.

[0019] Furthermore, due to the thinner thickness of the negative terminal 23 (the thickness of the negative terminal 23 is less than the thickness of the positive terminal 22), the overcurrent capability of the negative electrode is lower than that of the positive electrode, resulting in a poor overall overcurrent capability of the battery. In addition, the battery is relatively long (greater than or equal to 400 mm). The longer the battery, the greater the impedance, which further exacerbates the difference between the overcurrent capability of the negative electrode and the overcurrent capacity of the positive electrode.In the present application, by making the width of the negative terminal tab 23 larger than the width of the positive terminal tab 22, the width of the welding area between the negative terminal tab 23 and the negative battery terminal assembly 32 can be made larger than the width of the welding area between the positive terminal tab 22 and the positive battery terminal assembly 31, thereby increasing the overcurrent capability of the negative electrode, thus making the overcurrent capability of the positive electrode and the overcurrent capability of the negative electrode more balanced and thereby improving the overall overcurrent capability of the battery.

[0020] By comprehensively controlling the ratio between the battery length L and W1-W2, the consistency of the connection strength between the positive terminal tab 22 and the positive battery terminal assembly 31, as well as the connection strength between the negative terminal tab 23 and the negative battery terminal assembly 32, can be improved, thus preventing failure of the connection between the thinner negative terminal tab 23 and the negative battery terminal assembly 32. Specifically, the range of L / (W1-W2) is controlled to 9 ≤ L / (W1-W2) ≤ 600. For example, L / (W1-W2) can be 9, 10, 30, 60, 100, 200, 300, or 500. If this ratio is too large, it means that L is too large and / or W1-W2 is too small. If W1-W2 is too small, it means that W2 is too large or W1 is too small.If W1 is too small, the connection strength between the negative terminal tab 23 and the negative battery terminal assembly 32 is insufficient, leading to breakage and reduced battery reliability. If W2 is too large, the positive terminal tab 22 excessively restricts the electrolyte flow in the housing 1 from the end where the positive terminal tab 22 extends to the cell body 21, hindering rapid and uniform wetting of the cell body 21 by the electrolyte. If this ratio is too small, it means that L is too small and / or W1-W2 is too large. If W1-W2 is too large, it means that W2 is too small or W1 is too large.If W1 is too large, the negative terminal tab 23 excessively restricts the electrolyte flow in the housing 1 from the end where the negative terminal tab 23 extends to the cell body 21, hindering rapid and uniform wetting of the cell body 21 by the electrolyte. If W2 is too small, the connection strength between the positive terminal tab 22 and the positive battery terminal assembly 31 is insufficient, leading to breakage and low battery reliability. The range of 9 ≤ L / (W1 - W2) ≤ 600 not only ensures rapid and uniform wetting of the cell body 21 but also guarantees high battery reliability. Furthermore, this range results in the battery length L being positively correlated with the width W1 of the negative terminal tab 23 for a given width W2 of the positive terminal tab 22; i.e.,The larger L is, the larger W1 is, and the smaller L is, the smaller W1 is. The larger L is, the greater the stress at the connection point between the negative terminal tab 23 and the negative battery terminal assembly 32, and the greater the risk of breakage at the connection point between the negative terminal tab 23 and the negative battery terminal assembly 32.

[0021] Therefore, the width W1 of the negative terminal tab 23 must be made slightly larger in order to further increase the strength of the connection point between the negative terminal tab 23 and the negative battery terminal assembly 32.

[0022] In some embodiments, 0.05 ≤ (W - W1) / (W - W2) ≤ 0.98. For example, (W - W1) / (W - W2) can be equal to 0.1, 0.4, 0.6, 0.8, or 0.9, where W is the width of the cell body in the longitudinal direction of the battery. If this ratio is too large, it means that W - W1 is too large and / or W - W2 is too small, leading to an imbalance in the connection strength between the positive or negative terminal tab and the positive or negative battery terminal assembly. If this ratio is too small, it means that W - W1 is too small and / or W - W2 is too large, also leading to an imbalance in the connection strength between the positive or negative terminal tab and the positive or negative battery terminal assembly.

[0023] In some embodiments, 10 mm ≤ W - W1 ≤ 100 mm. For example, W - W1 can be 10 mm, 15 mm, 20 mm, 50 mm, 70 mm, 90 mm, or 100 mm. If this difference is too large, W1 is too small, resulting in poor contact strength between the negative terminal tab 23 and the negative battery terminal assembly 32. This creates an imbalance in the contact strength between the positive and negative terminal tabs and the positive and negative battery terminal assemblies, respectively, and prevents the overcurrent capability of the negative electrode from being effectively increased. Consequently, the reduced overcurrent capability of the negative electrode, caused by the smaller thickness of the negative terminal tab 23 compared to the thickness of the positive terminal tab 22, cannot be compensated for. If this difference is too small, W1 is too large.This results in the negative terminal tab 23 excessively restricting the electrolyte in the housing 1 from flowing from the end where the negative terminal tab 23 extends to the cell body 21, which is detrimental to rapid and uniform wetting of the cell body 21 by the electrolyte. Specifically, the width W1 of the negative terminal tab 23 in the width direction of the battery can be 15 mm ≤ W1 ≤ 80 mm. For example, W1 can be 15 mm, 30 mm, 50 mm, 60 mm, or 80 mm.

[0024] In some embodiments, 12 mm ≤ W - W2 ≤ 100 mm. For example, W - W2 can be 13 mm, 20 mm, 50 mm, 70 mm, or 90 mm. If this difference is too large, W2 is too small, resulting in poor contact strength between the positive terminal 22 and the positive battery terminal assembly 31 and causing an imbalance in the contact strength between the positive and negative terminals and their respective battery terminal assemblies. Conversely, if this difference is too small, W2 is too large. This causes the positive terminal 22 to excessively restrict electrolyte flow from the end where it extends to the cell body 21, hindering rapid and uniform wetting of the cell body 21 by the electrolyte.Specifically, the width W2 of the positive terminal tab 22 in the width direction of the battery can be 13 mm ≤ W2 ≤ 60 mm. For example, W2 can be 20 mm, 40 mm, or 50 mm.

[0025] In some embodiments, 1.1 ≤ W3 / W4 ≤ 8. For example, W3 / W4 can be equal to 1.1, 2, 3, 5, 6, 6.5, or 8. Here, W3 is the width of a weld area between the negative terminal tab 23 and the negative battery terminal assembly 32 in the width direction of the battery, while W4 is the width of a weld area between the positive terminal tab 22 and the positive battery terminal assembly 31 in the width direction of the battery. Since the lower limit of this ratio is greater than 1, W3 is greater than W4. W3 > W4 compensates for the reduced overcurrent capability of the negative electrode caused by the smaller thickness of the negative terminal tab 23 compared to the thickness of the positive terminal tab 22. If this ratio is too large, W3 is too large.An excessively high value of W3 results in the overcurrent capability of the positive terminal being lower than that of the negative terminal, leading to poor overall overcurrent capability of the battery. Conversely, if this ratio is too small, W3 is too small. An excessively low value of W3 cannot compensate for the reduced overcurrent capability of the negative electrode caused by the thinner negative terminal 23 compared to the thickness of the positive terminal 22.

[0026] In some embodiments, 0.1 ≤ (W1 - W3) / (W2 - W4) ≤ 20. For example, (W1 - W3) / (W2 - W4) can be 0.1, 1, 5, 10, or 15. If this ratio is too large, it means that W1 - W3 is too large and / or W2 - W4 is too small. If W1 - W3 is too large, this results in insufficient connection strength between the negative terminal tab 23 and the negative battery terminal assembly 32. If this ratio is too small, it means that W2 - W4 is too large and / or W1 - W3 is too small. If W2 - W4 is too large, this results in insufficient connection strength between the positive terminal tab 22 and the positive battery terminal assembly 31.The range 0.1 ≤ (W1 - W3) / (W2 - W4) ≤ 20 can ensure that both the connection strength between the negative terminal tab 23 and the negative battery terminal assembly 32 and the connection strength between the positive terminal tab 22 and the positive battery terminal assembly 31 are sufficient and relatively balanced.

[0027] In some embodiments, 5 mm ≤ W1 - W3 ≤ 70 mm applies. W1 - W3 represents the width of the portion of the negative terminal tab 23 that is not welded to the negative battery terminal assembly 32. The larger W1 - W3 is, the higher the bond strength between the negative terminal tab 23 and the negative electrode sheet. However, this means that W3 is smaller, and therefore the bond strength between the negative terminal tab 23 and the negative battery terminal assembly 32 is lower. The range 5 mm ≤ W1 - W3 ≤ 70 mm ensures that the bond strength between the negative terminal tab 23 and the negative battery terminal assembly 32, as well as the negative electrode sheet, is relatively high and balanced. Specifically, the width W3 of the welding area between the negative terminal tab 23 and the negative battery terminal assembly 32 can be 10mm ≤ W3 ≤ 55mm in the width direction of the battery.For example, W3 could be 20 mm, 40 mm, or 50 mm.

[0028] In some embodiments, 8 mm ≤ W2 - W4 ≤ 75 mm applies. W2-W4 represents the width of the portion of the positive terminal 22 that is not welded to the positive battery terminal assembly 31. The larger W2 - W4 is, the higher the bond strength between the positive terminal 22 and the positive electrode plate. However, this means that W4 is smaller, and therefore the bond strength between the positive terminal 22 and the positive battery terminal assembly 31 is lower. The range 8 mm ≤ W2 - W4 ≤ 75 mm ensures that the bond strength between the positive terminal 22 and the positive battery terminal assembly 31, as well as the positive electrode plate, is relatively high and balanced. Specifically, the width W4 of the welding area between the positive connection tab 22 and the positive battery terminal assembly 31 can be 5 mm ≤ W4 ≤ 50 mm in the width direction of the battery.For example, W4 can be 5 mm, 10 mm, 30 mm, 40 mm, 50 mm.

[0029] In some embodiments, the orthogonal projection of the negative terminal tab 23 onto a plane containing the liquid filling port overlaps at least partially with the liquid filling port. This design allows the width W1 of the negative terminal tab 23 to be made wider for a given battery width, and consequently, the width W3 of the weld area between the negative terminal tab 23 and the negative battery terminal assembly 32 can also be made wider. This sufficiently compensates for the reduced overcurrent capability of the negative electrode caused by the thinner negative terminal tab 23 compared to the thickness of the positive terminal tab 22, and also ensures sufficient connection strength between the negative terminal tab 23 and the negative battery terminal assembly 32.Furthermore, in the overlapping arrangement, the negative terminal 23 prevents the electrolyte flowing in through the liquid filling opening from coming into direct contact with the cell body, thus protecting the cell body. In this case, the range of W - W1 can be further limited to 10 mm ≤ W - W1 ≤ 85 mm.

[0030] In some embodiments, the orthogonal projection of the positive terminal tab 22 onto the plane in which the liquid filling port is located overlaps at least partially with the liquid filling port. This design allows the width W2 of the positive terminal tab 22 to be made wider for a given battery width, thus ensuring sufficient connection strength between the positive terminal tab 22 and the positive battery terminal assembly 31. Furthermore, in the overlapping arrangement, the positive terminal tab 22 can prevent the electrolyte flowing in through the liquid filling port from directly contacting the cell body, thereby protecting the cell body. In this case, the range of W - W2 can be further limited to 15 mm ≤ W - W2 ≤ 100 mm.

[0031] In some embodiments, the orthogonal projection of the negative terminal tab 23 onto the plane in which the liquid filling port is located does not overlap with the liquid filling port. This design allows the width W1 of the negative terminal tab 23 to be made narrower for a given battery width, thus preventing uneven wetting by the electrolyte due to an excessively wide negative terminal tab 23.

[0032] In some embodiments, the orthogonal projection of the positive terminal 22 onto the plane in which the liquid filling port is located does not overlap with the liquid filling port. This design allows the width W2 of the positive terminal 22 to be made narrower for a given battery width, thus preventing uneven wetting by the electrolyte due to an excessively wide positive terminal 22.

[0033] In some embodiments, the liquid filling port is located at an end from which the positive terminal 22 extends, and an orthogonal projection of the positive terminal 22 onto a plane containing the liquid filling port does not overlap with the liquid filling port. Since the positive terminal 22 is thicker and impedes electrolyte flow more effectively, the non-overlapping arrangement of the positive terminal 22 and the liquid filling port reduces the obstruction of electrolyte flow by the positive terminal 22, thereby compensating for the uneven wetting by the electrolyte caused by the thicker positive terminal 22. In this case, the distance between the liquid filling port and the cell body in the longitudinal direction of the battery is L1, where 2 mm ≤ L1 ≤ 10 mm.Since the positive terminal 22 and the liquid filling opening do not overlap, the electrolyte comes into direct contact with the cell body during filling. The area of ​​2 mm ≤ L1 ensures that the impact force of the electrolyte on the electrode sheet is not too great. L1 must also not be too large, as an excessive distance can lead to excessive flow resistance of the electrolyte on its way to the cell body, which is detrimental to uniform wetting of the cell body 21 by the electrolyte.

[0034] In some embodiments, such as in Fig. As shown in Figure 6, a transition is provided between the negative terminal tab 23 and the cell body 21, which acts as a buffer and reduces the probability of breakage between the negative terminal tab 23 and the cell body 21. Therefore, the width W3 of the weld area of ​​the negative terminal tab 23 can be made larger to increase the connection strength between the negative terminal tab 23 and the negative battery terminal assembly 32. The radius of the transition between the negative terminal tab 23 and the cell body is R1. The larger R1, the more advantageous it is for reducing the probability of breakage between the negative terminal tab 23 and the cell body. Thus, the larger R1, the larger W3 can be set, and the smaller W1 × W3. Consequently, R1 × (W1 - W3) should lie within a certain range. Specifically, this range can be 6 mm² ≤ R1 × (W1 - W3) ≤ 350 mm².For example, R1 × (W1 - W3) can be 10 mm2, 50 mm2, 100 mm2, 200 mm2, 300 mm2.

[0035] In some embodiments, such as in Fig. As shown in Figure 6, a transition is provided between the positive terminal tab 22 and the cell body 21, which acts as a buffer and reduces the probability of breakage between the positive terminal tab 22 and the cell body 21. Therefore, the width W4 of the weld area of ​​the positive terminal tab 22 can be made larger to increase the connection strength between the positive terminal tab 22 and the positive battery terminal assembly 31. The radius of the transition between the positive terminal tab 22 and the cell body 21 is R2. The larger R2, the more advantageous it is for reducing the probability of breakage between the positive terminal tab 22 and the cell body. Thus, the larger R2, the larger W4 can be set, and the smaller W2 × (W2 - W4) becomes. Consequently, R2 × (W2 - W4) should be within a certain range. Specifically, the area can be 10 mm2 ≤ R2 × (W2 - W4) ≤ 360 mm2.For example, R2 × (W2 - W4) can be 10 mm2, 50 mm2, 100 mm2, 200 mm2, 300 mm2, 350 mm2, 360 mm2.

[0036] In some embodiments, such as in Fig. As shown in Figure 7, the housing 1 comprises a housing body 11 and two cover plates 12, wherein the housing body 11 is provided with an opening at each end in the longitudinal direction of the battery, and wherein the two cover plates 12 each close the openings at the two ends, wherein the positive battery terminal assembly 31 is arranged on one of the cover plates 12 and the negative battery terminal assembly 32 is arranged on the other cover plate 12. The liquid filling opening C is arranged on one of the cover plates 12.

[0037] In some embodiments, such as in Fig. As shown in Figure 1, the housing 1 comprises a housing body 11 and a cover plate 12. In the thickness direction of the battery, the housing body 11 has an opening on one side, which is closed by the cover plate 12. In the length direction of the battery, the positive battery terminal assembly 31 and the negative battery terminal assembly 32 are each arranged at both ends of the cover plate 12. Also in the length direction of the battery, the housing body 11 has a recess 11b at each end and a projection 11a in the middle, wherein the cell body 21 is located in the projection 11a, and wherein the positive terminal tab 22 and the negative terminal tab 23 are each located in the two recesses 11b. The recesses 11b can be used to accommodate the battery terminal assemblies of adjacent batteries when grouping batteries, thus improving the space utilization of the battery box.When forming a recess 11b, transition corners are created at both ends of the recess in the width direction (also in the width direction of the battery). The negative terminal tab 23 must avoid these transition corners of the recess in which it is located. Therefore, in the width direction of the battery, the distance D between the negative terminal tab 23 and the side wall of the recess in which it is located must have a lower limit. If D is too large, this results in an insufficient width for the negative terminal tab 23. Therefore, D should also have an upper limit. Specifically, the range of D can be 2 mm ≤ D ≤ 20 mm. For example, D can be 3 mm, 5 mm, 10 mm, or 15 mm.

[0038] In some embodiments, such as in Fig. As shown in Figure 1, the battery includes insulating protective caps, comprising an insulating protective cap for a positive electrode 51 and an insulating protective cap for a negative electrode 52. The insulating protective cap of the positive electrode 51 is located in the housing 1, specifically in a recess 11b in which the positive terminal 22 is located, and serves to insulate the positive battery terminal assembly 31 from the cell body 21. The insulating protective cap of the negative electrode 52 is located in the housing 1, specifically in a recess 11b in which the negative terminal 23 is located, and serves to insulate the negative battery terminal assembly 32 from the cell body 21.

[0039] The insulating protective cap of the positive electrode 51 and the insulating protective cap of the negative electrode 52 have similar structures, in which, as in Fig.Figure 5 shows that, in the width direction of the battery, a first support section 5a, a tab receptacle 5c, and a second support section 5b are provided successively, wherein a first side wall A is provided on a side of the first support section 5a located near the tab receptacle 5c, and a second side wall B is provided on a side of the second support section 5b located near the tab receptacle 5c. The insulating protective cap is also equipped with a hinged cover (not shown in the figures). After the connecting tab has been connected to the battery terminal assembly, the hinged cover is closed. The closed hinged cover engages with the first side wall A and the second side wall B.

[0040] In some embodiments, at least one of the first side wall A and the second side wall B of the insulating protective cap of the negative electrode 52 is partially recessed in a direction away from the tab receptacle 5c to form a concave chamber and / or is partially provided with a hole, wherein a portion of the negative terminal tab 23 is located in the concave chamber and / or the hole. In this way, sufficient space can be provided to accommodate the wider negative terminal tab 23. The concave chambers formed on the first side wall A and the second side wall B can increase the strength of the first side wall A and the second side wall B.

[0041] The principles and embodiments of the present application are illustrated above by means of specific examples. The preceding description of the exemplary embodiments is intended only to aid in understanding the method of the present application and its core ideas. It should be noted that the person skilled in the art can make several improvements and modifications to the present application without departing from the principle of the present application, and these improvements and modifications also fall within the scope of protection of the present application.

[0042] The present invention provides a battery and relates to the field of battery technology. The battery comprises a battery cell, a housing, a positive battery terminal assembly, and a negative battery terminal assembly, wherein the battery cell is located in the housing, wherein the positive battery terminal assembly and the negative battery terminal assembly are arranged on the housing, wherein the battery cell comprises a cell body, a positive terminal tab, and a negative terminal tab, wherein, in the longitudinal direction of the battery, the positive terminal tab and the negative terminal tab extend from both ends of the cell body, respectively, and wherein the positive terminal tab and the negative terminal tab are connected to the positive battery terminal assembly and the negative terminal assembly, respectively.The negative battery terminal assembly is welded together, the battery length being greater than or equal to 400 mm, the thickness of the positive terminal tab being greater than the thickness of the negative terminal tab, and the width of the negative terminal tab (in the width direction of the battery) being greater than the width of the positive terminal tab (in the width direction of the battery). The battery features high energy density, high reliability, and good overall overcurrent protection.

Claims

[1] Battery comprising a battery cell, a housing, a positive battery terminal assembly and a negative battery terminal assembly, wherein the battery cell is located in the housing, wherein the positive battery terminal assembly and the negative battery terminal assembly are arranged on the housing, wherein the battery cell comprises a cell body, a positive terminal tab and a negative terminal tab, wherein in the longitudinal direction of the battery the positive terminal tab and the negative terminal tab are each extended from both ends of the cell body, wherein the positive terminal tab and the negative terminal tab are connected to the positive battery terminal assembly and the negative terminal tab respectively.the negative battery terminal assembly is welded, wherein the battery has a length of L, where L ≥ 400 mm, where a thickness of the positive terminal tab is greater than a thickness of the negative terminal tab, where a width of the negative terminal tab in the width direction of the battery is W1 and a width of the positive terminal tab in the width direction of the battery is W2, where W1 > W2. [2] Battery according to claim 1, characterized by , that the ratio of L to W1 - W2 is in the range of 9 ≤ L / (W1 - W2) ≤ 600. [3] Battery according to claim 1, characterized by , that a width of the cell body in the lateral direction of the battery is W, where 0.05 ≤ (W - W1) / (W - W2) ≤ 0.98 applies. [4] Battery according to claim 3, characterized by 10 mm ≤ W - W1 ≤ 100 mm and / or 12 mm ≤ W - W2 ≤ 100 mm. [5] Battery according to claim 1, characterized by, that a width of a weld area between the negative terminal tab and the negative battery terminal assembly in the width direction of the battery is W3 and a width of a weld area between the positive terminal tab and the positive battery terminal assembly in the width direction of the battery is W4, where 1,1 <_ W3 / W4 ≤ 8 holds. [6] Battery according to claim 1, characterized by , that a width of a welding area between the negative terminal tab and the negative battery terminal assembly in the width direction of the battery is W3 and a width of a welding area between the positive terminal tab and the positive battery terminal assembly in the width direction of the battery is W4, where 0.1 ≤ (W1 - W3) / (W2 - W4) ≤ 20. [7] Battery according to claim 6, characterized by 5 mm ≤ W1 - W3 ≤ 70 mm and / or 8 mm ≤ W2 - W4 ≤ 75 mm. [8] Battery according to any one of claims 1 to 7, characterized by, that the housing is provided with a liquid filling opening, wherein an orthogonal projection of the positive connecting tab onto a plane in which the liquid filling opening is located overlaps at least partially with the liquid filling opening and / or an orthogonal projection of the negative connecting tab onto the plane in which the liquid filling opening is located overlaps at least partially with the liquid filling opening. [9] Battery according to any one of claims 1 to 7, characterized by , that the housing is provided with a liquid filling opening, wherein an orthogonal projection of the positive connecting tab onto a plane in which the liquid filling opening is located does not overlap with the liquid filling opening and / or an orthogonal projection of the negative connecting tab onto the plane in which the liquid filling opening is located does not overlap with the liquid filling opening. [10] Battery according to any one of claims 1 to 7, characterized by , that the housing is provided with a liquid filling opening, wherein the liquid filling opening is arranged at an end from which the negative terminal tab extends, wherein an orthogonal projection of the negative terminal tab onto a plane in which the liquid filling opening is located overlaps at least partially with the liquid filling opening, wherein the width of the cell body in the width direction of the battery is W, where 10 mm ≤ W - W1 ≤ 85 mm. [11] Battery according to any one of claims 1 to 7, characterized by, that the housing is provided with a liquid filling opening, wherein the liquid filling opening is arranged at an end from which the positive terminal tab is brought out, wherein an orthogonal projection of the positive terminal tab onto a plane in which the liquid filling opening is located does not overlap with the liquid filling opening, wherein the width of the cell body in the width direction of the battery is W, where 15 mm ≤ W - W2 ≤ 100 mm. [12] Battery according to claim 11, characterized by , that in the longitudinal direction of the battery there is a distance between the liquid filling opening and the cell body L1, where 2 mm ≤ L1 ≤ 10 mm. [13] Battery according to any one of claims 1 to 7, characterized by, that a transition is provided between the negative terminal tab and the cell body which has a radius of R1, wherein a width of a weld area between the negative terminal tab and the negative battery terminal assembly in the width direction of the battery W3 is, wherein 6 mm 2 ≤ R1 × (W1 - W3) ≤ 350mm 2 applies; and / or, that a transition is provided between the positive terminal tab and the cell body having a radius of R2, wherein a width of a weld area between the positive terminal tab and the positive battery terminal assembly in the width direction of the battery is W4, wherein 10 mm 2 ≤ R2 × (W2 - W4) ≤ 360mm 2 applies. [14] Battery according to any one of claims 1 to 7, characterized by, that the housing comprises a housing body and two cover plates, wherein in the longitudinal direction of the battery the housing body is provided with an opening at each end, wherein the two cover plates each close the openings at the two ends, wherein the positive battery terminal assembly and the negative battery terminal assembly are each arranged on the two cover plates. [15] Battery according to any one of claims 1 to 7, characterized by, that the housing comprises a housing body and a cover plate, wherein, in the thickness direction of the battery, the housing body is provided with an opening on one side, the cover plate closing the opening, wherein, in the length direction of the battery, the positive battery terminal assembly and the negative battery terminal assembly are each arranged at both ends of the cover plate, wherein, in the length direction of the battery, the housing body is provided with a recess at both ends, wherein the negative terminal tab is located in one of the recesses, wherein, in the width direction of the battery, a distance D between the negative terminal tab and a side wall of the recess in which the negative terminal tab is located is, where 2 mm ≤ D ≤ 20 mm. [16] Battery according to claim 15, characterized by, that the battery comprises an insulating protective cap of a negative electrode, wherein the insulating protective cap of the negative electrode is located in the recess in which the negative terminal tab is located, wherein in the width direction of the battery the insulating protective cap of the negative electrode is successively provided with a first support section, a tab receptacle and a second support section, wherein on a side of the first support section located near the tab receptacle or on a side of the second support section located near the tab receptacle a first side wall ora second side wall is provided, wherein at least one of the first side wall and the second side wall of the insulating protective cap of the negative electrode is partially recessed in a direction away from the tab receptacle to form a concave chamber and / or is partially provided with a hole, wherein part of the negative terminal tab is located in the concave chamber and / or the hole. [17] Battery according to any one of claims 1 to 16, characterized by , that a single connecting tab of the positive connecting tab has a thickness that is greater than the thickness of a single connecting tab of the negative connecting tab. [18] Battery according to any one of claims 1 to 17, characterized by , that the width W1 of the negative terminal tab in the width direction of the battery lies in a range of 15 mm ≤ W1 ≤ 80 mm. [19] Battery according to any one of claims 1 to 18, characterized by, that the width W2 of the positive terminal tab in the width direction of the battery lies in a range of 13 mm ≤ W2 ≤ 60 mm. [20] Battery according to any one of claims 5 to 19, characterized by , that the width W3 of the welding area between the negative terminal tab and the negative battery terminal assembly in the width direction of the battery lies in a range of 10 mm ≤ W3 ≤ 55 mm. [21] Battery according to any one of claims 5 to 20, characterized by , that the width W4 of the welding area between the positive terminal tab and the positive battery terminal assembly in the width direction of the battery lies in a range of 5 mm ≤ W4 ≤ 50 mm.

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