Battery

Abstract

The invention relates to the technical field of batteries, and discloses a battery which comprises a shell, a battery cell and an electrode terminal, the shell comprises a titanium element, the electrode terminal is electrically connected with the battery cell, at least part of the electrode terminal is welded with the shell to form a welding mark, the electrode terminal is electrically connected with the battery cell, the peel strength between the shell and the electrode terminal is a, the thickness of the shell is T1, and T1 is a. The thickness of the electrode terminal welded with the shell is T2, the content of titanium in the shell is c, c is larger than or equal to 90%, b is equal to T1 / T2-1, and b * c / a is larger than or equal to 0.01 and smaller than or equal to 5. By controlling b * c / a to be within the range, the connection strength between the shell and the electrode terminal is improved, the situation that the shell is separated from the electrode terminal is avoided, the overcurrent capacity between the shell and the electrode terminal is further guaranteed, and temperature rise caused by resistance is reduced; meanwhile, the risk of positive and negative electrode short circuit caused by diaphragm shrinkage due to excessive welding heat damage to the cell is avoided, and the safety performance of the battery is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a battery. BACKGROUND

[0002] A secondary battery is a battery that can restore its performance through a charging process after discharging. Secondary batteries are widely used in consumer electronics, electric vehicles, energy storage systems, and other fields.

[0003] Battery lightweighting is an important direction of current battery technology development, especially in the fields of electric vehicles, portable electronic devices, and aerospace. As the demand for energy efficiency and portability increases, reducing the weight of the battery while maintaining or improving its energy density has become a research hotspot.

[0004] The battery includes a shell and an electric core arranged in the shell. The material of the shell is titanium, which can be referred to as a titanium shell. The titanium shell can achieve lightweighting of the shell body and can be applied to flying cars to improve flying speed. However, when the titanium shell is used as an electrode output terminal of the battery, it is found that the electrical connection between the titanium shell and the electric core is prone to failure when the battery is discharging or the battery is subjected to vibration, affecting the current transmission between the electric core and the titanium shell. SUMMARY

[0005] Therefore, the present application provides a battery to solve the problem that the electrical connection between the titanium shell and the electric core is prone to failure, affecting the current transmission between the electric core and the titanium shell in the prior art.

[0006] The present application provides a battery, comprising: a shell, an electric core and an electrode terminal, the electric core is arranged in the shell, the shell comprises titanium element, the electrode terminal is electrically connected with the electric core, at least part of the electrode terminal is welded with the shell to form a welding mark, the electrode terminal is electrically connected with the electric core, the peeling strength between the shell and the electrode terminal is a, unit N, the thickness of the shell is T1, unit mm, the thickness of the electrode terminal welded with the shell is T2, unit mm, the content of titanium element in the shell is c, wherein c is greater than or equal to 90%, b = |T1 / T2-1|, 0.01≤b×c / a≤5.

[0007] Beneficial effects: by controlling b×c / a in the above range, the connection strength between the shell and the electrode terminal is improved, the separation of the shell and the electrode terminal is avoided, and the overcurrent capacity between the shell and the electrode terminal is ensured, the temperature rise caused by the resistance between the shell and the electrode terminal is reduced, and the safety performance of the battery is improved. BRIEF DESCRIPTION OF DRAWINGS

[0008] To more clearly illustrate the specific embodiments of the present invention 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 the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0009] Figure 1 This is a perspective view of a battery according to an embodiment of the present invention;

[0010] Figure 2 for Figure 1 A top view of the battery shown;

[0011] Figure 3 for Figure 2 A cross-sectional view along the AA direction;

[0012] Figure 4 for Figure 3 A magnified view of part B in the image;

[0013] Figure 5 for Figure 4 A schematic diagram showing the dimensions of the structure is provided.

[0014] Figure 6 This is a partial cross-sectional view of another battery according to an embodiment of the present invention;

[0015] Figure 7 This is a schematic diagram of the first end face and solder mark in an embodiment of the present invention;

[0016] Figure 8 This is a schematic diagram of the structure of the tab portion according to an embodiment of the present invention;

[0017] Figure 9 This is a schematic diagram of the structure of the tabs spaced apart on the winding layer (before winding) according to an embodiment of the present invention;

[0018] Figure 10 This is a schematic diagram of the first end face and the current collector in an embodiment of the present invention;

[0019] Figure 11 This is a schematic diagram of the current collector and solder mark according to an embodiment of the present invention;

[0020] Figure 12 This is a schematic diagram of the structure of the positive and negative electrode tabs located at opposite ends of the battery cell according to an embodiment of the present invention;

[0021] Figure 13 This is a schematic diagram of the stacked structure of the positive electrode, separator, and negative electrode in an embodiment of the present invention.

[0022] Explanation of reference numerals in the attached figures:

[0023] 1, shell; 11, shell body; 12, end wall; 121, recess; 13, first end face; 14, end cover; 2, battery cell; 21, positive electrode tab; 22, negative electrode tab; 23, separator; 3, electrode terminal; 31, tab body; 311, positive electrode tab; 312, negative electrode tab; 32, current collector; 4, weld; 5, insulating piece. DETAILED DESCRIPTION

[0024] To make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0025] The embodiments of the present application are described below with reference to the drawings. Figures 1 to 13 , the embodiments of the present application are described.

[0026] According to the embodiments of the present application, a battery is provided, comprising: a shell 1, a battery cell 2 and an electrode terminal 3, the battery cell 2 is arranged inside the shell 1, the shell 1 comprises titanium element, the electrode terminal 3 is electrically connected with the battery cell 2, at least part of the electrode terminal 3 is welded with the shell 1 to form a weld 4, the peeling strength between the shell 1 and the electrode terminal 3 is a, unit N, the thickness of the shell 1 is T1, unit mm, the thickness of the electrode terminal 3 welded with the shell 1 is T2, unit mm, the content of the titanium element in the shell 1 is c, wherein c≥90%, b=|T1 / T2-1|, 0.01≤b×c / a≤5.

[0027] The battery applying the embodiments can improve the connection strength between the shell 1 and the electrode terminal 3 by controlling b×c / a in the above range, avoid the separation of the shell 1 and the electrode terminal 3, further ensure the overcurrent capacity between the shell 1 and the electrode terminal 3, reduce the temperature rise caused by the resistance between the shell 1 and the electrode terminal 3, meanwhile avoid the excessive welding heat to damage the battery cell 2 and cause the shrinkage of the separator 23 to increase the risk of positive and negative short circuit, and improve the safety performance of the battery.

[0028] It is worth noting that if the value of bxc / a is too large, the connection strength between the electrode terminal 3 and the shell 1 is too low, which leads to a high risk of connection failure between the electrode terminal 3 and the shell 1, affects the current transmission between the electrode terminal 3 and the shell 1, increases the current transmission impedance between the electrode terminal 3 and the shell 1, increases the heat generated in the current transmission process, and affects the safety performance of the battery. If the value of bxc / a is too small, the heat required for welding the electrode terminal 3 and the shell 1 increases, which easily leads to damage to the battery cell 2 and causes the diaphragm 23 to shrink, increasing the risk of positive and negative electrode short circuit.

[0029] Further preferably, the value of bxc / a satisfies 0.06≤bxc / a≤1.2.

[0030] Optionally, the value of bxc / a is any one of 0.01, 0.06, 0.1, 0.5, 0.8, 1, 1.2, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5 or a value between any two values.

[0031] Wherein, a is the value in N, and T1 and T2 are both values in mm.

[0032] Specifically, in an embodiment, the peeling strength a between the shell 1 and the electrode terminal 3 satisfies 100N≤a≤600N. In this way, while avoiding connection failure between the electrode terminal 3 and the shell 1, it also avoids excessive welding heat that leads to damage to the battery cell 2 and short circuit risk.

[0033] It is worth noting that if the value of a is too small, the connection strength between the electrode terminal 3 and the shell 1 is too low, which leads to a high risk of connection failure between the electrode terminal 3 and the shell 1, affects the current transmission between the electrode terminal 3 and the shell 1, increases the current transmission impedance between the electrode terminal 3 and the shell 1, increases the heat generated in the current transmission process, and affects the safety performance of the battery. If the value of a is too large, the heat required for welding the electrode terminal 3 and the shell 1 increases, which easily leads to damage to the battery cell 2 and causes the diaphragm 23 to shrink, increasing the risk of positive and negative electrode short circuit.

[0034] Further preferably, the peeling strength a between the shell 1 and the electrode terminal 3 satisfies 200N≤a≤500N.

[0035] Optionally, the value of a is any one of 100N, 150N, 200N, 250N, 300N, 350N, 400N, 450N, 500N, 550N, 600N or a value between any two values.

[0036] For the test method of the peeling strength, the present application is not limited, and exemplarily, the force data at the time of pulling off can be recorded by vertically opposite pulling force test with a tensile testing machine clamp respectively clamping the shell 1 and the electrode terminal 3 welded with the shell 1.

[0037] Specifically, in one embodiment, the thickness T1 of the shell 1 and the thickness T2 of the electrode terminal 3 welded with the shell 1 satisfy 0.05≤b=|T1 / T2-1|≤6.5. In this way, the welding penetration of the shell 1 and the electrode terminal 3 is ensured, and thus the welding reliability of the shell 1 and the electrode terminal 3 is ensured, and the risk of connection failure of the shell 1 and the electrode terminal 3 is reduced, and at the same time, the risk of damage to the battery cell 2 and short circuit caused by excessive welding heat is avoided.

[0038] It should be noted that if the value of b is too large, that is, the value of |T1 / T2-1| is too large, the difference between the thickness of the shell 1 and the thickness of the electrode terminal 3 welded with the shell 1 is too large. In the welding process of the shell 1 and the electrode terminal 3, the penetration of the welding mark 4 is limited by the one with smaller thickness between the shell 1 and the electrode terminal 3 welded with the shell 1, and thus the welding strength of the shell 1 and the electrode terminal 3 is low, and the risk of connection failure of the shell 1 and the electrode terminal 3 is too large. If the value of b is too small, the required heat increases in the welding process of the shell 1 and the electrode terminal 3, which is easy to cause damage to the battery cell 2, and increase the risk of shrinkage of the separator 23 and positive and negative short circuit.

[0039] Further preferably, the value of b satisfies 0.25≤b≤3.

[0040] Optionally, the value of b is any one of 0.05, 0.1, 0.2, 0.25, 0.3, 0.4, 0.45, 0.5, 0.8, 1, 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.8, 3, 3.5, 3.6, 3.8, 4, 4.5, 5, 5.5, 6, 6.5 or a value between any two values.

[0041] Specifically, in one embodiment, as shown in Figure 5 the thickness T1 of the shell 1 satisfies 0.3mm≤T1≤1.5mm. In this way, the connection strength of the shell 1 and the electrode terminal 3 is ensured, and at the same time, the risk of damage to the battery cell 2 and short circuit caused by excessive welding heat is avoided.

[0042] It should be noted that if the value of T1 is too small, the structural strength of the shell 1 is too low, which causes the connection strength of the shell 1 and the electrode terminal 3 to be too low, and thus the risk of connection failure of the shell 1 and the electrode terminal 3 is increased. If the value of T1 is too large, the heat required for the welding mark 4 to penetrate the shell 1 and connect with the electrode terminal 3 is too high in the welding process, which is easy to cause damage to the battery cell 2, and increase the risk of shrinkage of the separator 23 and positive and negative short circuit.

[0043] Optionally, the value of T1 is any one of 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm or a value between any two values.

[0044] Specifically, in one embodiment, as shown in Figure 5 and Figure 6 The thickness T2 of the electrode terminal 3 welded with the shell 1 satisfies 0.09 mm≤T2≤2 mm. In this way, the connection strength of the shell 1 and the electrode terminal 3 is ensured, and the energy density of the battery is ensured at the same time.

[0045] It is worth noting that if the value of T2 is too small, the thickness of the welding mark 4 that can be accommodated by the electrode terminal 3 welded with the shell 1 is too small, which leads to a low connection strength of the shell 1 and the electrode terminal 3, and further increases the risk of connection failure of the shell 1 and the electrode terminal 3. If the value of T2 is too large, the electrode terminal 3 occupies too much space in the battery, which is likely to affect the energy density of the battery.

[0046] Optionally, the value of T2 is any one of 0.09 mm, 0.1 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.5 mm, 0.55 mm, 0.6 mm, 0.65 mm, 0.7 mm, 0.75 mm, 0.8 mm, 1 mm, 1.2 mm, 1.5 mm, 1.8 mm, 2 mm or a value between any two values.

[0047] Specifically, in one embodiment, the value of the content c of titanium element in the shell 1 satisfies 90%≤c≤99.99%. It is worth noting that c refers to the ratio of the content of titanium element to the total content of various elements in the shell 1.

[0048] Further preferably, the value of c satisfies 97%≤c≤99.99%.

[0049] Optionally, the value of c is any one of 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 99.99% or a value between any two values.

[0050] In one embodiment, as shown in Figures 1 to 4 The shell 1 includes a shell body 11 and an end wall 12 connected to one end of the shell body 11, and the end wall 12 is provided with a recess 121. The electrode terminal 3 includes a tab portion 31 and a current collector plate 32, the tab portion 31 is arranged between the battery cell 2 and the current collector plate 32, the current collector plate 32 is welded with the shell 1 and forms a welding mark 4, the welding mark 4 is located in the recess 121, and the value of b satisfies 0.1≤b≤2.8.

[0051] It is worth noting that by setting the end wall 12 to be partially thinned in the thickness direction to form the recess 121, and welding the end wall 12 (i.e., the remaining part of the end wall 12 after thinning) and the current collector plate 32 at the position of the recess 121, it is easier to penetrate the end wall 12 and weld with the current collector plate 32 during welding, thereby improving the welding quality of the end wall 12 and the current collector plate 32, and improving the welding reliability between the shell 1 and the current collector plate 32, and further improving the current transmission capability between the shell 1 and the current collector plate 32. Therefore, in the present embodiment, the value of b can be further controlled to further reduce the heat required during welding of the shell 1 and the current collector plate 32, thereby further avoiding damage to the battery cell 2 and the risk of short circuit.

[0052] It should be noted that the end wall 12 can be integrally formed with the shell body 11, or can be independently provided with the shell body 11 and then connected by welding or the like (at this time, the end wall 12 is the end cover 14).

[0053] In one embodiment, as shown in Figure 5 the remaining thickness of the shell 1 at the recess 121 is H, which satisfies 0.6mm≤H≤0.9mm. In this way, while improving the welding quality of the shell 1 and the current collector plate 32, the structural strength of the shell 1 is ensured.

[0054] It is worth noting that if the value of H is too large, the improvement effect of the welding mark 4 penetrating the shell 1 during welding of the shell 1 and the current collector plate 32 is not obvious, and therefore the welding reliability between the shell 1 and the current collector plate 32 is not obviously improved. If the value of H is too small, the structural strength of the shell 1 is easily affected.

[0055] Optionally, the value of H is any one of 0.6mm, 0.65mm, 0.7mm, 0.75mm, 0.8mm, 0.85mm, 0.9mm or a value between any two values.

[0056] In one embodiment, as shown in Figure 5 the width of the recess 121 is W, which satisfies 1.4mm≤W≤2.5mm. In this way, while improving the welding strength of the shell 1 and the current collector plate 32, the structural strength of the shell 1 is ensured.

[0057] It is worth noting that if the value of W is too small, the area of the shell 1 used for welding with the current collector plate 32 is too small, which limits the welding area of the welding mark 4 and affects the welding strength of the shell 1 and the current collector plate 32, thereby increasing the risk of connection failure of the shell 1 and the current collector plate 32. If the value of W is too large, the recess 121 is too large, which greatly weakens the structural strength of the shell 1 and easily affects the structural strength of the shell 1.

[0058] Optionally, W is any one of 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, 2.5 mm or a value between any two values.

[0059] In one embodiment, the current collector 32 comprises copper element, and the value of b satisfies 0.1≤b≤2. It should be noted that the melting point of titanium and copper is relatively small, which is convenient for welding, and the thermal conductivity of copper is higher than that of aluminum, which can quickly conduct heat, help to maintain the temperature uniformity of the welding area, and reduce the risk of local overheating. Therefore, by further controlling b in the above range, the connection strength between the shell 1 and the electrode terminal 3 is ensured, and the connection failure caused by the inability to overcurrent is avoided, thereby ensuring the overcurrent capacity between the shell 1 and the electrode terminal 3, reducing the temperature rise caused by resistance, and helping to improve the safety performance of the battery.

[0060] In another embodiment, as shown in Figure 6 , the electrode terminal 3 comprises a tab portion 31, the shell 1 is welded with the tab portion 31 to form a welding mark 4, and the tab portion 31 comprises a plurality of tab pieces 311 stacked, and the value of b satisfies 0.05≤b≤4. That is, directly welding a plurality of layers of tab pieces 311 with the shell 1 will reduce the welding effect of the tab portion 31 and the shell 1, thereby reducing the reliability of the welding of the electrode terminal 3 and the shell 1, and more easily leading to the connection failure of the electrode terminal 3 and the shell 1. Therefore, by further limiting the value of b, the welding strength of the shell 1 and the electrode terminal 3 is further improved, and the risk of connection failure of the shell 1 and the electrode terminal 3 is reduced.

[0061] Specifically, as shown in Figure 5 and Figure 6 , the thickness of the current collector 32 is f, which satisfies 0.35 mm≤f≤1 mm; and the thickness of the tab portion 31 is g, which satisfies 0.09 mm≤g≤2 mm. In this way, while ensuring the connection strength of the shell 1 and the electrode terminal 3, the energy density of the battery is ensured.

[0062] It should be noted that if the values of f and g are too small, the thickness of the current collector 32 or the tab portion 31 capable of accommodating the welding mark 4 is too small, which leads to the connection strength of the shell 1 and the electrode terminal 3 being too low, thereby increasing the risk of connection failure of the shell 1 and the electrode terminal 3. If the values of f and g are too large, the current collector 32 or the tab portion 31 occupies too much space in the battery, which easily affects the energy density of the battery.

[0063] It should be noted that please refer to Figure 5When the electrode terminal 3 includes the tab 31 and the current collector plate 32, the battery cell 2 is connected to the tab 31, the tab 31 is connected to the current collector plate 32, and the current collector plate 32 is welded to the shell 1, at this time, T2=f. Please refer to Figure 6 When the electrode terminal 3 only includes the tab 31, the battery cell 2 is connected to the tab 31, and the tab 31 is welded to the shell 1, at this time, T2=g.

[0064] In one embodiment, as shown in the figure, Figure 5 the depth of the welding mark 4 is d, and 0.08mm≤d≤0.3mm is satisfied; the width of the welding mark 4 is e, and 1mm≤e≤2.5mm is satisfied. As shown in the figure, Figure 7 the welding mark 4 is arranged on the first end surface 13 of the shell 1, the area of the first end surface 13 is S, the area of the orthogonal projection of the welding mark 4 on the first end surface 13 is S1, and the values of S and S1 satisfy 0.0048≤S1 / S≤0.008. In this way, the welding strength of the shell 1 and the electrode terminal 3 is ensured, and at the same time, the welding heat is prevented from being too high to damage the battery cell 2 and cause a short circuit risk.

[0065] It is worth noting that if the values of d, e, and S1 / S are too small, the welding strength between the shell 1 and the electrode terminal 3 is low, the connection reliability of the shell 1 and the electrode terminal 3 is poor, and the risk of connection failure of the shell 1 and the electrode terminal 3 is increased. If the values of d, e, and S1 / S are too large, the heat required during welding is increased, and the risk of damage to the battery cell 2 and short circuit is increased.

[0066] Optionally, the value of d is any one of 0.08mm, 0.1mm, 0.12mm, 0.15mm, 0.18mm, 0.2mm, 0.22mm, 0.25mm, 0.28mm, 0.3mm or a value between any two values.

[0067] Optionally, the value of e is any one of 1mm, 1.2mm, 1.5mm, 1.8mm, 2mm, 2.2mm, 2.5mm or a value between any two values.

[0068] Optionally, the value of S1 / S is any one of 0.0048, 0.005, 0.0052, 0.0055, 0.0058, 0.006, 0.0062, 0.0065, 0.0068, 0.007, 0.0072, 0.0075, 0.0078, 0.008 or a value between any two values.

[0069] In one embodiment, as shown in the figure, Figure 8As shown, the battery cell 2 is in a cylindrical shape, the battery cell 2 includes a plurality of winding layers arranged in a radial direction, the tab portion 31 includes a plurality of tab pieces 311 arranged in a stacking manner, the winding layers are connected with at least one tab piece 311, the tab portion 31 has a first point and a second point arranged in a radial direction, the thickness of the tab portion 31 at the first point is different from the thickness of the tab portion 31 at the second point, and the value range of b satisfies 0.05≤b≤4.

[0070] It is worth noting that after the winding to form the battery cell 2, the plurality of tab pieces 311 are led out from the end face of the battery cell 2, and then the tab pieces 311 need to be folded towards the end face of the battery cell 2, so that the plurality of tab pieces 311 are stacked on the end face of the battery cell 2. At this time, the tab portion 31 has different thicknesses (here, the "thickness" refers to the size in the axial direction of the battery) at different positions in the radial direction of the tab portion 31. Due to the inconsistent thickness of the tab portion 31 at different positions, the welding effect of the tab portion 31 and the shell 1 is reduced, and the risk of connection failure of the tab portion 31 and the shell 1 is increased. Therefore, by further controlling the value of b, the welding strength of the shell 1 and the tab portion 31 is further improved, and the risk of connection failure of the shell 1 and the electrode terminal 3 is reduced.

[0071] It needs to be further explained that the tab pieces 311 connected with the winding layers close to the winding center are folded and arranged in a direction away from the winding center, and the tab pieces 311 connected with the winding layers away from the winding center are folded and arranged in a direction close to the winding center.

[0072] Further, in an embodiment, as shown in Figure 8 The maximum thickness of the tab portion 31 is h1, the minimum thickness of the tab portion 31 is h2, and h1 and h2 satisfy h1-h2≤1.75mm. In this way, the thickness difference of the tab portion 31 at different positions is avoided to be too large, so as to ensure the welding effect of the tab portion 31 and the shell 1, and reduce the risk of connection failure of the tab portion 31 and the shell 1.

[0073] Further, in an embodiment, at the position where the tab portion 31 has the maximum thickness, the number of layers of the tab pieces 311 is not less than 10 layers, and the value range of b satisfies 0.05≤b≤3.5. It is worth noting that the more the number of stacked layers of the tab pieces 311, the worse the welding effect of the tab portion 31 and the shell 1, which leads to an increased risk of connection failure of the tab portion 31 and the shell 1. Therefore, by further controlling the value of b, the welding strength of the shell 1 and the tab portion 31 is further improved, and the risk of connection failure of the shell 1 and the electrode terminal 3 is reduced.

[0074] In an embodiment, as shown in Figure 9As shown, each winding layer is provided with a plurality of tab pieces 311 in the circumferential direction, and the value of b satisfies 0.05≤b≤3. After the tab pieces 311 are folded to the end face of the battery cell 2, the continuity between the tab pieces 311 is poor, which leads to poor welding continuity when the tab part 31 and the shell 1 are welded, resulting in low welding effect of the tab part 31 and the shell 1, and increasing the risk of connection failure of the tab part 31 and the shell 1. Therefore, by further controlling the value of b, the welding strength of the shell 1 and the tab part 31 is further improved, and the risk of connection failure of the shell 1 and the electrode terminal 3 is reduced.

[0075] Further, in one embodiment, as shown in FIG. 6, Figure 9 As shown, the distance between adjacent tab pieces 311 on one winding layer is i, which satisfies 0.01mm≤i≤0.05mm. In this way, the welding effect of the tab part 31 and the shell 1 is improved, and at the same time, the tab pieces 311 are prevented from being too large to cause wrinkles when they are folded.

[0076] It should be noted that if the value of i is too large, the continuity between the tab pieces 311 is too poor, which leads to poor welding continuity when the tab part 31 and the shell 1 are welded, resulting in low welding effect of the tab part 31 and the shell 1, and increasing the risk of connection failure of the tab part 31 and the shell 1. If the value of i is too small, the overall area of the tab pieces 311 is likely to be too large, which is prone to cause wrinkles when the tab pieces 311 are folded, and the gap between the tab pieces 311 after stacking is too large, which affects the flow capacity between the tab part 31 and the shell 1.

[0077] Optionally, the value of i is any one of 0.01mm, 0.015mm, 0.02mm, 0.025mm, 0.03mm, 0.035mm, 0.04mm, 0.045mm, 0.05mm or a value between any two values.

[0078] In one embodiment, as shown in FIG. 6, Figure 9 As shown, the lead-out height of the tab piece 311 is j, which satisfies 2mm≤j≤10mm. In this way, the welding effect of the tab part 31 and the shell 1 is ensured, and the folding of the tab piece 311 and the stacking of the adjacent tab pieces 311 are facilitated.

[0079] It is worth noting that if the value of j is too small, after the tab sheet body 311 is folded to the end face of the battery cell 2, the continuity between the tab sheet bodies 311 is too poor, which leads to poor welding continuity when the tab part 31 and the shell 1 are welded, resulting in lower welding effect of the tab part 31 and the shell 1, and increasing the risk of connection failure of the tab part 31 and the shell 1. If the value of j is too large, when the tab sheet body 311 is folded to the end face of the battery cell 2, it is easy to interfere with other tab sheet bodies 311, affecting the folding of other tab sheet bodies 311.

[0080] Optionally, the value of j is any value in 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm or a numerical value between any two values.

[0081] In one embodiment, the tab part 31 includes a negative tab 313, the negative tab 313 is welded with the shell 1 to form a welding mark 4, and the negative tab 313 includes a copper element. It should be noted that the melting point difference between titanium and copper is relatively small, which is convenient for welding, and the thermal conductivity of copper is higher than that of aluminum, which can quickly conduct heat and help maintain the temperature uniformity of the welding area, reducing the risk of local overheating.

[0082] In one embodiment, as shown in Figure 3 The tab part 31 includes a positive tab 312 and a negative tab 313, the positive tab 312 and the negative tab 313 are located at the same end of the battery cell 2, and the value of b satisfies 0.05≤b≤2.5. It is worth noting that the positive tab 312 and the negative tab 313 are introduced at the same end of the battery cell 2, and the positive tab 312 and the negative tab 313 are arranged opposite to the same wall surface of the shell 1, which limits the welding area of the welding mark 4 formed by welding the tab part 31 and the shell 1, and increases the risk of connection failure of the tab part 31 and the shell 1. Therefore, by further controlling the value of b, the welding strength of the shell 1 and the tab part 31 is further improved, and the risk of connection failure of the shell 1 and the electrode terminal 3 is reduced.

[0083] Further, in one embodiment, as shown in Figure 10 The area of the positive projection of the first end face 13 is S2, the value of S and S2 satisfies S2<0.5S, and the value of b satisfies 0.05≤b≤2.2. In this way, when the current collector plate 32 and the shell 1 are welded, the welding area of the welding mark 4 is small, which increases the risk of connection failure of the tab part 31 and the shell 1. Therefore, by further controlling the value of b, the welding strength of the shell 1 and the tab part 31 is further improved, and the risk of connection failure of the shell 1 and the electrode terminal 3 is reduced.

[0084] Further, in one embodiment, as shown in Figure 11As shown, the current collecting disc 32 has an arc-shaped outer edge, the welding mark 4 is arranged at a distance from the arc-shaped outer edge, and the value of b satisfies 0.05≤b≤2. In this way, when the current collecting disc 32 and the shell 1 are welded, the maximum arc length of the current collecting disc 32 cannot be utilized (the arc-shaped outer edge corresponds to the maximum arc length), which limits the length of the welding mark 4, and thus increases the risk of connection failure of the tab portion 31 and the shell 1. Therefore, by further controlling the value of b, the welding strength of the shell 1 and the tab portion 31 is further improved, and the risk of connection failure of the shell 1 and the electrode terminal 3 is reduced.

[0085] Specifically, as shown in FIG. 4, the current collecting disc 32 has an arc-shaped outer edge, the welding mark 4 is arranged at a distance from the arc-shaped outer edge, and the value of b satisfies 0.05≤b≤2. In this way, when the current collecting disc 32 and the shell 1 are welded, the maximum arc length of the current collecting disc 32 cannot be utilized (the arc-shaped outer edge corresponds to the maximum arc length), which limits the length of the welding mark 4, and thus increases the risk of connection failure of the tab portion 31 and the shell 1. Therefore, by further controlling the value of b, the welding strength of the shell 1 and the tab portion 31 is further improved, and the risk of connection failure of the shell 1 and the electrode terminal 3 is reduced. Figure 11 As shown, in the radial direction, the distance between the arc-shaped outer edge of the current collecting disc 32 and the welding mark 4 is k, which satisfies 3mm≤k≤5mm. In this way, while ensuring the welding strength of the tab portion 31 and the shell 1, the welding process is facilitated, and the risk of scalding of the battery cell 2 is avoided.

[0086] It should be noted that the current collecting disc 32 can have a stepped portion near the outer side edge, and in the present embodiment, the "arc-shaped outer edge of the current collecting disc 32" refers to the outer edge of the planar portion of the current collecting disc 32 where the stepped portion is not formed.

[0087] It should be noted that if the value of k is too small, the distance between the welding mark 4 and the arc-shaped outer edge of the current collecting disc 32 is too close, which is not convenient for the setting of the welding tooling during welding, and the diaphragm 23 of the outer edge of the battery cell 2 is easily scalded. If the value of k is too large, it will further reduce the length of the welding mark 4, which will increase the risk of connection failure of the tab portion 31 and the shell 1.

[0088] Optionally, the value of k is any one of 3mm, 3.2mm, 3.5mm, 3.8mm, 4mm, 4.2mm, 4.5mm, 4.8mm, 5mm or a value between any two of them.

[0089] In another embodiment, as shown in FIG. 5, the tab portion 31 includes a positive electrode tab 312 and a negative electrode tab 313, the positive electrode tab 312 and the negative electrode tab 313 are located at opposite ends of the battery cell 2, the current collecting disc 32 is circular, and the value of b satisfies 0.1≤b≤4. In this way, the welding area of the welding mark 4 is increased, the welding reliability between the shell 1 and the current collecting disc 32 is improved, and the risk of connection failure between the shell 1 and the current collecting disc 32 is reduced. Therefore, in the present embodiment, the value of b can be further controlled to further reduce the heat required during welding of the shell 1 and the current collecting disc 32, thereby further avoiding damage to the battery cell 2 and the risk of short circuit. Figure 12 In one embodiment, as shown in FIG. 6, the tab portion 31 includes a positive electrode tab 312 and a negative electrode tab 313, the positive electrode tab 312 and the negative electrode tab 313 are located at opposite ends of the battery cell 2, the current collecting disc 32 is circular, and the value of b satisfies 0.1≤b≤4. In this way, the welding area of the welding mark 4 is increased, the welding reliability between the shell 1 and the current collecting disc 32 is improved, and the risk of connection failure between the shell 1 and the current collecting disc 32 is reduced. Therefore, in the present embodiment, the value of b can be further controlled to further reduce the heat required during welding of the shell 1 and the current collecting disc 32, thereby further avoiding damage to the battery cell 2 and the risk of short circuit.

[0090] Figure 4 ​As shown, the shell 1 includes a shell body 11 and an end cover 14, at least one end of the shell body 11 is provided with an opening, the end cover 14 is arranged at the opening, the electrode terminal 3 is welded with the end cover 14 and forms the welding mark 4, and the end cover 14 and the battery cell 2 are provided with an insulating piece 5. By arranging the insulating piece 5, the heat transfer from the welding of the electrode terminal 3 and the end cover 14 to the battery cell 2 can be reduced, and further, the safety problem caused by the damage of the battery cell 2 and the short circuit of the positive and negative electrodes can be avoided.

[0091] In one embodiment, as shown in the drawings, Figure 13 As shown, the battery cell 2 includes a positive electrode sheet 21, a negative electrode sheet 22 and a separator 23, the positive electrode sheet 21, the separator 23 and the negative electrode sheet 22 are stacked, and the thickness of the separator 23 is m, which satisfies 4 μm≤m≤15 μm. In this way, the risk of shrinkage of the separator 23 is reduced, and the heat dissipation performance of the battery is ensured.

[0092] It is worth noting that if the value of m is too small, the separator 23 is easy to shrink when the electrode terminal 3 and the shell 1 are welded, which increases the risk of short circuit of the positive and negative electrodes of the battery and affects the safety performance of the battery. If the value of m is too large, the heat generated during the charging and discharging process of the battery is not easy to dissipate, and the risk of thermal runaway of the battery increases.

[0093] Optionally, the value of m is any one of 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm or a value between any two values.

[0094] It is worth noting that the battery cell 2 is formed by stacking the positive electrode sheet 21, the negative electrode sheet 22 and the separator 23 arranged therebetween. The positive electrode sheet 21 includes a positive electrode current collector and a positive electrode active material, the positive electrode current collector can be an aluminum foil, a nickel foil, a stainless steel or a composite foil formed by a metal and an insulating material, and the positive electrode active material includes one or more of a lithium-containing positive electrode active material such as lithium iron phosphate, a ternary material containing nickel, cobalt and manganese, and lithium manganese iron phosphate; the negative electrode sheet 22, similarly, includes a negative electrode current collector and a negative electrode active material, the negative electrode current collector can be a copper foil, an aluminum foil, a stainless steel or a composite foil formed by a metal and an insulating material, and the negative electrode active material includes one or more of a negative electrode active material such as artificial graphite, natural graphite, silicon-carbon, silicon-oxygen and lithium titanate.

[0095] It is worth noting that the material of the pole can be aluminum, aluminum alloy, copper-aluminum composite, nickel or other metal materials.

[0096] It is worth mentioning that the role of the current collector plate 32 is to electrically connect the tab portion 31 drawn out from the battery cell 2 and the shell 1, and to transfer the current of the battery cell 2 to the shell 1.

[0097] The application will be further described in detail below in connection with specific examples, which should not be construed as limiting the scope of the application claimed.

[0098] The preparation of the example battery and the comparative battery includes the following steps:

[0099] (1) Preparation of the positive electrode sheet:

[0100] The prepared positive electrode active material, conductive agent acetylene black, and binder are mixed, a solvent is added, and stirring is performed under the action of a vacuum stirrer until the system is uniform, thereby obtaining a positive electrode slurry. The positive electrode slurry is uniformly coated on both surfaces of the positive electrode current collector aluminum foil, and after air drying at room temperature, it is transferred to an oven for continued drying, followed by cold pressing and slitting to obtain the positive electrode sheet. Specifically, the mass ratio of the positive electrode material: conductive agent: binder satisfies (92-98):(4-1):(4-1).

[0101] (2) Preparation of the negative electrode sheet:

[0102] The negative electrode active material graphite, conductive agent acetylene black, thickening agent CMC, and binder SBR are mixed, deionized water is added as a solvent, and stirring is performed under the action of a vacuum stirrer until the system is uniform, thereby obtaining a negative electrode slurry. The negative electrode slurry is uniformly coated on both surfaces of the negative electrode current collector copper foil, and after air drying at room temperature, it is transferred to an oven for continued drying, followed by cold pressing and slitting to obtain the negative electrode sheet. Specifically, the ratio of the negative electrode graphite: conductive agent: thickening agent: binder is (90-96):(4-2):(2-1):(4-1).

[0103] (3) Preparation of the electrolyte:

[0104] Vinyl carbonate (EC), methyl ethyl carbonate (EMC), and diethyl carbonate (DEC) are mixed in a volume ratio of 1:1:1 to obtain an organic solvent, and then a fully dried lithium salt is dissolved in the mixed organic solvent to prepare an electrolyte with a concentration of 1 mol / L.

[0105] (4) Preparation of the separator:

[0106] A polyethylene film is selected as the separator.

[0107] (5) Preparation of the lithium ion battery:

[0108] The above positive electrode sheet, separator, and negative electrode sheet are stacked in order, wound, or laminated to obtain a bare battery cell; the bare battery cell is placed in an outer packaging shell, dried, and injected with electrolyte, and then packaged, left to stand, formed, and constant volume to obtain a lithium ion battery.

[0109] The positive active material can be selected from one or more of lithium-containing positive active materials including lithium iron phosphate, ternary materials containing nickel, cobalt and manganese, lithium manganese iron phosphate, etc.; the negative active material can be selected from one or more of negative active materials such as artificial graphite, natural graphite, silicon-carbon, silicon-oxygen, lithium titanate, etc.

[0110] In this application, the positive active material is selected from nickel-cobalt-manganese ternary, and the structural formula is LiNi 0.9 Co 0.05 Mn 0.05 O2; and the negative active material is selected from artificial graphite. Optionally, in other embodiments, the positive active material can be selected from one or more of other nickel-cobalt-manganese ternary materials, lithium iron phosphate, lithium manganese iron phosphate; and the negative electrode can also include one or more of silicon-carbon negative electrodes or natural graphite.

[0111] The difference between the batteries of each embodiment and the comparative example is the value of a, b and c, as shown in Table 1.

[0112] The related performance of the batteries in the above embodiments and comparative examples was tested, and the test results are recorded in Table 1, and the test method is as follows:

[0113] 1. Battery overcurrent capacity test

[0114] For each embodiment and comparative example, 10 batteries were taken; the battery was discharged at 0.33C to the lower limit voltage 2.5V, and after standing for 60min, the temperature at this time was measured, recorded as t1, the battery was charged at 1C to the upper limit voltage 4.25V, the cutoff current was 0.05C, the time was recorded as T, and the temperature at this time was measured and recorded as t2, the temperature rise rate was calculated according to the formula temperature rise rate = (t2-t1) / T. If the temperature rise rate is less than or equal to 0.9℃ / min, it is good; if the temperature rise rate is greater than 0.9℃ / min and less than or equal to 1.0℃ / min, it is qualified; if the temperature rise rate is greater than 1.0℃ / min, it is unqualified.

[0115] 2. Battery short circuit test

[0116] For each embodiment and comparative example, 10 batteries were taken; the battery was discharged at 0.33C to the lower limit voltage 2.5V, and after standing for 60min, the voltage between the pole and the shell was tested by connecting one end of the internal resistance meter to the pole and the other end to the shell. If the voltage is between 4.2-4.3V, it is good; if the voltage is between 3.8V and less than 4.2V, it is slightly short-circuited; if the voltage is less than 3.8V, it is short-circuited and the battery cannot be used normally.

[0117] As for the test method of the content of Ti element, X-ray fluorescence spectrometry can be used to detect the content of each element in the shell. The specific steps are as follows:

[0118] (1) Sample preparation: First, the shell sample needs to be properly treated to facilitate X-ray penetration and excitation of fluorescence. This may include steps such as cutting, grinding, polishing, etc. to ensure that the sample surface is flat and free of contamination;

[0119] (2) X-ray excitation: Use high-energy X-rays to irradiate the sample surface to excite characteristic X-ray fluorescence of each element. The wavelength or energy characteristics of these fluorescence spectra correspond to the element species, so that the elements contained in the sample can be determined;

[0120] (3) Spectrum collection and analysis: Collect the X-ray and fluorescence spectra reflected back from the sample surface through the spectrometer. Using the position and intensity of the characteristic spectrum, the type and content of the element can be determined;

[0121] (4) Matrix effect correction: Due to the interaction between various elements in the shell (matrix effect), the collected spectral data needs to be corrected to eliminate the influence of this interaction on the analysis results and improve the accuracy of the analysis;

[0122] (5) Result interpretation: According to the corrected data, the content of each element in the shell can be calculated.

[0123] Table 1:

[0124] c(％) a(N) b b x c / a Overcurrent capability test Short circuit test Example 1 90.5 105 5.72 4.930 Less than or equal to 0.9°C / min Between 4.2-4.3V Example 2 93.6 155 5.12 3.092 Less than or equal to 0.9°C / min Between 4.2-4.3V Example 3 95.5 203 4.53 2.131 Less than or equal to 0.9°C / min Between 4.2-4.3V Example 4 97.2 292 3.58 1.192 Less than or equal to 0.9°C / min Between 4.2-4.3V Example 5 98.5 496 2.96 0.588 Less than or equal to 0.9°C / min Between 4.2-4.3V Example 6 99.5 525 2.35 0.445 Less than or equal to 0.9°C / min Between 4.2-4.3V Example 7 99.95 598 1.54 0.257 Less than or equal to 0.9°C / min Between 4.2-4.3V Example 8 99.2 472 1.25 0.263 Less than or equal to 0.9°C / min Between 4.2-4.3V Example 9 91.2 119 6.48 4.966 Less than or equal to 0.9°C / min Between 4.2-4.3V Example 10 99.99 498 0.05 0.010 Less than or equal to 0.9°C / min Between 4.2-4.3V Example 11 98.6 415 0.26 0.062 Less than or equal to 0.9°C / min Between 4.2-4.3V Example 12 99.5 95 4.56 4.776 Greater than 0.9 and less than or equal to 1.0°C / min Between 4.2-4.3V Example 13 95.6 606 0.10 0.016 Greater than 0.9 and less than or equal to 1.0°C / min Voltage 3.8-4.2V, micro short Example 14 96.5 175 0.18 0.099 Less than or equal to 0.9°C / min Between 4.2-4.3V Example 15 99.2 512 4.53 0.878 Less than or equal to 0.9°C / min Between 4.2-4.3V Example 16 99.99 195 3 1.538 Less than or equal to 0.9°C / min Between 4.2-4.3V Example 17 99.5 472 0.22 0.046 Less than or equal to 0.9°C / min Between 4.2-4.3V Example 18 99.8 346 1.86 0.536 Less than or equal to 0.9°C / min Between 4.2-4.3V Example 19 98.1 235 2.27 0.948 Less than or equal to 0.9°C / min Between 4.2-4.3V Comparative Example 1 99.9 86 7.50 8.712 Greater than 1.0°C / min Voltage 3.8-4.2V, micro short Comparative Example 2 90 592 0.05 0.007 Greater than 1.0°C / min Voltage less than 3.8V Comparative Example 3 95.6 645 0.03 0.004 Greater than 1.0°C / min Voltage less than 3.8V

[0125] As can be seen from Table 1, in Examples 1 to 19, the value of b x c / a is in the range of 0.01 to 5, therefore, the temperature rise rate of the battery in the overcurrent capacity test is less than or equal to 1.0℃ / min, the battery overcurrent capacity test is qualified, the battery voltage in the short circuit test is not less than 3.8V, and the battery short circuit test is qualified.

[0126] As can be seen from Table 1, in Example 12, the value of a is not in the range of 100N to 600N and is less than 100N, resulting in relatively poor connection effect between the electrode terminal 3 and the shell 1, increased current transmission impedance between the electrode terminal 3 and the shell 1, and increased heat generation during current transmission. In Example 13, the value of a is not in the range of 100N to 600N and is greater than 600N, the shrinkage of the separator 23 leads to an increased risk of positive and negative electrode short circuit.

[0127] As can be seen from Table 1, in Comparative Example 1, the value of b x c / a is not in the range of 0.01 to 5 and is greater than 5, therefore, the temperature rise rate of the battery in the overcurrent capacity test is greater than 1.0℃ / min, and the battery overcurrent capacity test is unqualified.

[0128] As can be seen from Table 1, in Comparative Example 2 and Comparative Example 3, the value of b x c / a is not in the range of 0.01 to 5 and is less than 0.01, thus, the battery voltage of the batteries of Comparative Example 2 and Comparative Example 3 is less than 3.8 V in the short circuit test, and the batteries cannot be normally used due to short circuit.

[0129] Although embodiments of the present application have been described in conjunction with the drawings, various modifications and changes can be made by those skilled in the art without departing from the spirit and scope of the present application, and such modifications and changes are intended to fall within the scope of the appended claims.

Claims

1. A battery, characterized in that, include: The device comprises a housing (1), a battery cell (2), and an electrode terminal (3). The battery cell (2) is disposed inside the housing (1). The housing (1) contains titanium. The electrode terminal (3) is electrically connected to the battery cell (2). At least a portion of the electrode terminal (3) is welded to the housing (1) to form a solder mark (4). The peel strength between the housing (1) and the electrode terminal (3) is a, in N. The thickness of the housing (1) is T1, in mm. The thickness of the electrode terminal (3) welded to the housing (1) is T2, in mm. The titanium content in the housing (1) is c, where c ≥ 90%, b = |T1 / T2-1|, and 0.01 ≤ b × c / a ≤ 5.

2. The battery according to claim 1, characterized in that, The peel strength α between the housing (1) and the electrode terminal (3) satisfies 100N ≤ α ≤ 600N; and / or, The thickness T1 of the housing (1) and the thickness T2 of the electrode terminal (3) welded to the housing (1) satisfy 0.05≤b=|T1 / T2-1|≤6.5; and / or, The thickness T1 of the shell (1) satisfies 0.3mm ≤ T1 ≤ 1.5mm; and / or, The thickness T2 of the electrode terminal (3) welded to the housing (1) satisfies 0.09mm≤T2≤2mm.

3. The battery according to claim 1 or 2, characterized in that, The electrode terminal (3) includes a tab (31) and a current collector (32). The tab (31) is disposed between the battery cell (2) and the current collector (32). The current collector (32) is welded to the housing (1) to form the solder mark (4). The thickness of the collector plate (32) is f, which satisfies 0.35mm≤f≤1mm; the thickness of the electrode ear (31) is g, which satisfies 0.09mm≤g≤2mm.

4. The battery according to claim 3, characterized in that, The shell (1) includes a shell body (11) and an end wall (12) connected to one end of the shell body (11). The end wall (12) is provided with a recess (121). The solder mark (4) is located in the recess (121). The value of b is 0.1≤b≤2.

8.

5. The battery according to claim 4, characterized in that, The remaining thickness of the shell (1) in the recess (121) is H, which satisfies 0.6mm≤H≤0.9mm; the width of the recess (121) is W, which satisfies 1.4mm≤W≤2.5mm.

6. The battery according to claim 4, characterized in that, The collector disk (32) includes copper, and the value of b is 0.1≤b≤2.

7. The battery according to claim 1 or 2, characterized in that, The electrode terminal (3) includes an electrode tab (31), the housing (1) is welded to the electrode tab (31) to form the solder mark (4), the electrode tab (31) includes a plurality of (311) electrode tab bodies (311) stacked together, and the value of b is 0.05≤b≤4.

8. The battery according to claim 1 or 2, characterized in that, The weld depth of the weld (4) is d, which satisfies 0.08mm≤d≤0.3mm; the weld width of the weld (4) is e, which satisfies 1mm≤e≤2.5mm; the weld (4) is disposed on the first end face (13) of the shell (1), the area of ​​the first end face (13) is S, and the area of ​​the orthographic projection of the weld (4) on the first end face (13) is S1. The values ​​of S and S1 satisfy 0.0048≤S1 / S≤0.

008.

9. The battery according to claim 1 or 2, characterized in that, The battery cell (2) is cylindrical and includes several wound layers stacked radially. The electrode terminal (3) includes a tab (31) connected to the battery cell (2). The tab (31) includes several tab pieces (311) stacked. The wound layer is connected to at least one tab piece (311). The tab (31) has a first point and a second point spaced radially apart. The thickness of the tab (31) at the first point is different from the thickness of the tab (31) at the second point. The value of b is 0.05≤b≤4.

10. The battery according to claim 9, characterized in that, The maximum thickness of the tab (31) is h1, and the minimum thickness of the tab (31) is h2, where h1 and h2 satisfy h1-h2≤1.75mm.

11. The battery according to claim 10, characterized in that, At the position where the electrode tab (31) has the maximum thickness, the number of layers of the electrode tab body (311) is not less than 10 layers, and the value of b is in the range of 0.05≤b≤3.

5.

12. The battery according to claim 9, characterized in that, Each of the winding layers is provided with a plurality of tabs (311) spaced apart along the circumference, and the value of b is in the range of 0.05≤b≤3.

13. The battery according to claim 12, characterized in that, The distance between adjacent tabs (311) on one of the winding layers is i, which satisfies 0.01mm≤i≤0.05mm.

14. The battery according to claim 9, characterized in that, The lead-out height of the tab body (311) is j, which satisfies 2mm≤j≤10mm.

15. The battery according to claim 9, characterized in that, The tab portion (31) includes a negative tab (313), which is welded to the housing (1) to form the solder mark (4), and the negative tab (313) includes copper.

16. The battery according to claim 9, characterized in that, The electrode section (31) includes a positive electrode (312) and a negative electrode (313), the positive electrode (312) and the negative electrode (313) are located at the same end of the battery cell (2), and the value of b is 0.05≤b≤2.

5.

17. The battery according to claim 16, characterized in that, The electrode terminal (3) further includes a current collector (32), the electrode tab (31) is connected to the current collector (32), the current collector (32) is welded to the housing (1) to form the solder mark (4), the solder mark (4) is disposed on the first end face (13) of the housing (1), the area of ​​the first end face (13) is S, the area of ​​the current collector (32) projected onto the first end face (13) is S2, the values ​​of S and S2 satisfy S2 < 0.5S, and the value range of b satisfies 0.05 ≤ b ≤ 2.

2.

18. The battery according to claim 17, characterized in that, The collector plate (32) has an arc-shaped outer edge, and the solder mark (4) is spaced apart from the arc-shaped outer edge. The value of b is 0.05≤b≤2.

19. The battery according to claim 18, characterized in that, Along the radial direction, the distance between the arc-shaped outer edge of the collector plate (32) and the solder mark (4) is k, which satisfies 3mm≤k≤5mm.

20. The battery according to claim 9, characterized in that, The electrode terminal (3) also includes a current collector (32), the tab (31) is connected to the current collector (32), the current collector (32) is welded to the housing (1) and forms the solder mark (4), the tab (31) includes a positive tab (312) and a negative tab (313), the positive tab (312) and the negative tab (313) are located at opposite ends of the battery cell (2), the current collector (32) is circular, and the value of b satisfies 0.1≤b≤4.

21. The battery according to claim 1 or 2, characterized in that, The housing (1) includes a housing body (11) and an end cap (14). At least one end of the housing body (11) is provided with an opening. The end cap (14) is provided at the opening. The electrode terminal (3) is welded to the end cap (14) to form the solder mark (4). An insulating member (5) is provided between the end cap (14) and the battery cell (2).

22. The battery according to claim 1 or 2, characterized in that, The battery cell (2) includes a positive electrode (21), a negative electrode (22) and a separator (23). The positive electrode (21), the separator (23) and the negative electrode (22) are stacked. The thickness of the separator (23) is m, which satisfies 4μm≤m≤15μm.

Images