Battery

Abstract

The utility model belongs to the technical field of batteries, and discloses a battery which comprises a shell, a positive pole and a winding battery cell, the positive pole is mounted on the shell and insulated from the shell, the winding battery cell is arranged in the shell and comprises a positive plate, a negative plate and a winding diaphragm, the negative plate wraps the positive plate, and the winding diaphragm wraps the positive plate. And the winding diaphragm is arranged between the positive plate and the negative plate. The outermost side of the wound positive plate is provided with a positive leading-out end, the negative current collecting strip of the negative plate is electrically connected with the shell, and the positive leading-out end is electrically connected with the positive column through the positive current collecting strip. The processing technology of the battery is simple, the strength of the shell can be ensured, a circuit can be timely disconnected from the inside under the condition of external short circuit, and the battery has relatively high safety performance.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a battery. Background Art

[0002] Lithium-ion battery is a lithium primary battery with the highest specific energy and the widest operating temperature range among the current commercial battery products. It can be roughly divided into two categories according to its structure: power type and energy type. Energy type battery adopts a carbon package structure and is mainly used in scenarios with low power and long service life. Power type battery adopts a winding structure and is mainly used in scenarios that require continuous high power pulses.

[0003] Since the battery has a very high chemical specific energy, the positive and negative electrode reaction area of ​​the power battery is large and the internal resistance is small, once a short circuit occurs, the short circuit current of the battery will quickly reach tens of amperes, which will cause the temperature inside the battery to rise rapidly. Within tens of seconds, the internal air pressure will rise sharply, and it is very likely to explode. When the explosion occurs, the highly corrosive electrolyte inside, some metal parts and external steel shell fragments will be sprayed everywhere, leading to serious consequences.

[0004] In recent years, people have made improvements in two aspects to solve the safety problem of lithium-ion power batteries when they are accidentally short-circuited. First, fuses, PTC and other components are installed on the outside of the battery to prevent the battery from short-circuiting, but this will increase the complexity of the battery's deep processing technology and increase the cost. At the same time, there are still safety hazards when users disassemble and abuse it without authorization. Second, use methods such as notching on the battery shell to form a weak point. When the battery is short-circuited, when the internal air pressure rises to a certain value, the battery shell will rupture and discharge in a predictable manner, but this method will still release highly corrosive electrolytes. At the same time, the accuracy of the notches is extremely high. If the notches are too deep, the strength of the battery shell may decrease, causing it to rupture during normal use. If the notches are too shallow, the effect of rupture when needed cannot be achieved.

[0005] Therefore, there is an urgent need to propose a high-safety battery with a simple processing technology, which can ensure the strength of the battery shell and can disconnect the internal circuit in time in the event of an external short circuit. Utility Model Content

[0006] The utility model aims to provide a battery, which has a simple processing technology, can not only ensure the strength of the shell, but also can disconnect the internal circuit in time in the case of external short circuit, and has high safety performance.

[0007] To achieve this purpose, the utility model adopts the following technical solutions:

[0008] The utility model discloses a battery, comprising: a shell; a positive pole, the positive pole is mounted on the shell and is insulated from the shell; a wound battery cell, the wound battery cell is arranged inside the shell, the wound battery cell comprises a positive electrode sheet, a negative electrode sheet and a wound diaphragm, the negative electrode sheet is arranged to wrap the positive electrode sheet, and the wound diaphragm is arranged between the positive electrode sheet and the negative electrode sheet: wherein: the outermost side of the wound positive electrode sheet has a positive lead-out terminal, the negative electrode collector bar of the negative electrode sheet is electrically connected to the shell, and the positive electrode lead-out terminal is electrically connected to the positive pole via the positive electrode collector bar.

[0009] In some embodiments, the battery further includes a first insulating member installed inside the housing and located between the positive electrode column and an end of the wound battery cell.

[0010] In some specific embodiments, the diameter D of the first insulating member satisfies the relationship: a-1.8≤D≤a-1, where a is the inner diameter of the housing, and the unit is millimeter; and / or:

[0011] The thickness of the first insulating member is 0.1 mm-0.3 mm.

[0012] In some specific embodiments, the first insulating member is provided with an avoidance hole and a leakage hole, the avoidance hole is used to avoid the positive electrode current collecting bar, and the leakage hole is used to circumvent the electrolyte.

[0013] In some embodiments, the length of the positive electrode sheet is less than that of the negative electrode sheet, and a difference A between the length of the negative electrode sheet and the length of the positive electrode sheet satisfies the relationship: 0.55b≤A≤0.65b, where b is the outer diameter of the shell.

[0014] In some embodiments, the positive electrode current collector bar includes a first connecting portion, a middle portion, and a second connecting portion that are connected to each other, the first connecting portion is connected to the positive electrode lead-out terminal, and the second connecting portion is connected to the positive electrode column.

[0015] In some specific embodiments, the width B of the first connecting portion is 1.5mm-4mm, and the length C of the first connecting portion is 3mm-6mm; and / or: the width D of the middle portion is 0.5mm-1.5mm, and the length E of the middle portion is 2mm-5mm; and / or: the width F of the second connecting portion is 1.5mm-4mm.

[0016] In some embodiments, the negative electrode sheet includes two lithium strips, the negative electrode current collector bar is sandwiched between the two lithium strips, the distance between the lead-out position of the negative electrode current collector bar and the end of the lithium strip is H, and H satisfies the relationship: H = (a-2c-2d) / 2×3.14, with a tolerance of ±2mm; wherein: a is the inner diameter of the outer shell, c is the thickness of the lithium strip, and d is the thickness of the wound separator; and / or: the thickness of the negative electrode current collector bar is 0.05mm-0.1mm.

[0017] In some embodiments, the housing includes a shell and a cover plate, the positive electrode column is mounted on the cover plate, and one end of the negative electrode collector bar is connected between the inner circumferential wall of the shell and the outer circumferential wall of the cover plate.

[0018] In some embodiments, the battery includes a bottom diaphragm and a second insulating member, wherein the bottom diaphragm is arranged in the outer shell and is located between the bottom wall of the outer shell and the wound battery cell, and the second insulating member is arranged in the outer shell and is located between the bottom diaphragm and the bottom wall of the outer shell.

[0019] The beneficial effects of the utility model are as follows: in the case of an external short circuit, the current of the battery will quickly reach tens of amperes. Since the positive lead-out end of the wound battery cell is connected to the positive electrode column through the positive electrode collector bar, the positive electrode collector bar has a small cross-sectional area and a large resistance value, and a large amount of heat will be generated instantly. The heat accumulates quickly, and the positive electrode collector bar melts and cuts off the circuit. At the same time, since the internal resistance of the positive electrode sheet of the battery on the electrode sheet plane is different, during DC discharge, especially during high-current DC discharge, the chemical reaction near the positive electrode collector bar occurs first. The positive electrode collector bar, which is easy to generate heat, is placed on the outer ring of the wound battery cell to facilitate heat dissipation. Except for the extremely high current situation such as short circuit, the ordinary high-current pulse working state will not cause the heat to accumulate to cause the external circuit to be disconnected. Therefore, the battery of this embodiment realizes the conduction between the wound battery cell and the positive electrode column by setting the positive electrode collector bar on the outer ring of the wound battery cell, which can disconnect the circuit in time in the case of an external short circuit, and has a high safety performance. The battery of this embodiment does not need to adopt the existing technology to install a fuse or other structures on the outside of the battery, and does not need to process notches on the outer shell. On the one hand, it simplifies the manufacturing process of the battery and facilitates the processing of the battery. On the other hand, it ensures the strength of the outer shell and improves the reliability of the battery.

[0020] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the battery of the utility model;

[0022] Figure 2 It is a structural schematic diagram of the first insulating member of the utility model;

[0023] Figure 3 It is a structural schematic diagram of the positive electrode sheet and the positive electrode current collector of the utility model;

[0024] Figure 4 It is a structural schematic diagram of the negative electrode sheet and the negative electrode current collector of the utility model.

[0025] Reference numerals:

[0026] 100, housing; 110, shell; 120, cover plate;

[0027] 200, positive pole;

[0028] 300, wound battery cell; 310, positive electrode sheet; 320, negative electrode sheet; 330, wound separator; 340, positive electrode current collector bar; 341, first connecting portion; 342, middle portion; 343, second connecting portion; 350, negative electrode current collector bar;

[0029] 400, first insulating member; 410, avoidance hole; 420, leakage hole;

[0030] 500, bottom diaphragm; 600, second insulating member; 700, sealing nail. DETAILED DESCRIPTION

[0031] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only the parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0032] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0034] In the description of this embodiment, the terms "upper", "lower", "right", etc., are based on the directions or positions shown in the drawings, and are only for the convenience of description and simplified operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0035] The utility model discloses a battery, such as Figure 1As shown, the battery includes a housing 100, a positive electrode column 200 and a wound battery cell 300, wherein the positive electrode column 200 is mounted on the housing 100 and is insulated from the housing 100, and the wound battery cell 300 is arranged inside the housing 100, and the wound battery cell 300 includes a positive electrode sheet 310, a negative electrode sheet 320 and a wound separator 330, wherein the negative electrode sheet 320 wraps the positive electrode sheet 310, and the wound separator 330 is arranged between the positive electrode sheet 310 and the negative electrode sheet 320. The outermost side of the wound positive electrode sheet 310 has a positive lead-out terminal, the negative electrode current collector bar 350 of the negative electrode sheet 320 is electrically connected to the housing 100, and the positive lead-out terminal is electrically connected to the positive electrode column 200 through the positive electrode current collector bar 340. It is understandable that in the case of an external short circuit, the current of the battery will quickly reach tens of amperes. Since the positive lead-out end of the wound battery cell 300 is connected to the positive column 200 through the positive current collector bar 340, the positive current collector bar 340 has a small cross-sectional area and a large resistance, a large amount of heat will be generated instantly, and the heat will accumulate quickly, and the positive current collector bar 340 will melt and cut off the circuit. At the same time, since the internal resistance of the positive electrode sheet 310 of the battery on the electrode sheet plane is different, during DC discharge, especially during high-current DC discharge, the chemical reaction near the positive current collector bar 340 occurs first, and the positive current collector bar 340, which is easy to generate heat, is placed on the outer circle of the wound battery cell 300 to facilitate heat dissipation. Except for the extremely high current situation such as short circuit, the normal high-current pulse working state will not cause the heat to accumulate to cause the external circuit to be disconnected. Therefore, the battery of this embodiment realizes the conduction between the wound battery cell 300 and the positive electrode column 200 by means of the positive electrode current collector bar 340 arranged on the outer ring of the wound battery cell 300, which can disconnect the circuit in time inside in the case of an external short circuit, and has a high safety performance. The battery of this embodiment does not need to adopt the structure such as installing a fuse on the outside of the battery in the prior art, and does not need to process notches on the shell 100, which simplifies the manufacturing process of the battery and facilitates the processing of the battery, and ensures the strength of the shell 100 and improves the reliability of the battery.

[0036] refer to Figure 1 As shown, the housing 100 includes a housing 110 and a cover plate 120, the positive electrode column 200 is mounted on the cover plate 120, and one end of the negative electrode current collector bar 350 is connected between the inner peripheral wall of the housing 110 and the outer peripheral wall of the cover plate 120. It can be understood that the negative electrode current collector bar 350 is directly buckled between the cover plate 120 and the upper end of the housing 110, eliminating the process step of spot welding the negative electrode current collector bar 350 to the housing 100.

[0037] refer to Figure 1 As shown, the positive current collector bar 340 and the negative current collector bar 350 are located on both sides of the wound battery cell 300 along its width direction, thereby ensuring that the negative current collector bar 350 is away from the positive current collector bar 340, eliminating the risk of the positive current collector bar 340 melting and bridging the negative current collector bar 350 in the event of an external short circuit.

[0038] refer to Figure 1 As shown, the battery also includes a first insulating member 400, which is installed inside the housing 100 and is located between the positive pole 200 and the end of the wound battery cell 300. It can be understood that after the winding of the wound battery cell 300 is completed, the inner and outer rings are aligned neatly, and the insulation of the entire wound battery cell 300 is intact. However, in the subsequent processing (such as the winding battery cell 300 is put into the shell) and the use process (for example: vibration and collision during transportation), there is a small probability that the neat alignment of the inner and outer rings of the wound battery cell 300 is destroyed, and the outer ring pole piece is displaced in the direction of the positive pole 200, forming a "pagoda" shape as a whole. As a result, the battery may have a short circuit at the top of the housing 100, causing a safety risk. In this embodiment, the added first insulating member 400 can reduce the occurrence of the short circuit at the top of the housing 100, thereby improving the reliability of the battery.

[0039] Optionally, the first insulating member 400 is a mica sheet. The mica sheet has good thermal stability, insulation, chemical corrosion resistance, and wear resistance, and can be stably present in the internal environment of the battery. At the same time, since the mica sheet is an inorganic mineral, the structural strength is relatively large, and it will not adsorb the top of the housing 100 during the liquid injection and vacuuming, which plays an insulating role without affecting the liquid injection process.

[0040] Optionally, the diameter D of the first insulating member 400 satisfies the relationship: a-1.8≤D≤a-1, where a is the inner diameter of the outer shell 100, and the unit is millimeter. It is understandable that during the battery production process, the wound battery cell 300 needs to be injected with liquid after being put into the shell, and the diameter of the first insulating member 400 needs to be smaller than the outer shell 100 to ensure that the electrolyte can immerse the wound battery cell 300. If the diameter of the first insulating member 400 is too small, the risk of short circuit caused by contact with the top of the outer shell 100 will be increased. In this embodiment, the difference between the inner diameter of the outer shell 100 and the diameter of the first insulating member 400 is controlled between 1mm-1.8mm, which can ensure that the electrolyte can immerse the wound battery cell 300 and reduce the risk of short circuit caused by contact with the top of the outer shell 100. The difference between the inner diameter of the housing 100 and the diameter of the first insulating member 400 can be 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm. Of course, in other embodiments of the present invention, the diameter D of the first insulating member 400 and the inner diameter a of the housing 100 can also be set according to actual needs, and are not limited to the description of this embodiment.

[0041] Optionally, the thickness of the first insulating member 400 is 0.1 mm-0.3 mm. The thickness of the first insulating member 400 can be 0.12 mm, 0.14 mm, 0.16 mm, 0.18 mm, 0.2 mm, 0.22 mm, 0.24 mm, 0.26 mm, 0.28 mm, 0.3 mm. Of course, the thickness of the first insulating member 400 can be selected from other ranges according to actual needs, and is not limited to the description of this embodiment.

[0042] refer to Figure 1 As shown, the battery includes a bottom diaphragm 500 and a second insulating member 600. The bottom diaphragm 500 is disposed in the housing 100 and is located between the bottom wall of the housing 100 and the wound battery cell 300. The second insulating member 600 is disposed in the housing 100 and is located between the bottom diaphragm 500 and the bottom wall of the housing 100. Thus, the insulation between the bottom of the wound battery cell 300 and the housing 100 can be ensured, which is beneficial to improve the safety of the battery.

[0043] refer to Figure 2 As shown, the first insulating member 400 is provided with an avoidance hole 410 and a leakage hole 420, wherein the avoidance hole 410 is used to avoid the positive electrode current collector bar 340, and the leakage hole 420 is used to circulate the electrolyte. It can be understood that the avoidance hole 410 is used to avoid the positive electrode current collector bar 340, which can limit the shaking of the mica sheet, and the leakage hole 420 can ensure that the electrolyte can immerse the wound battery cell 300.

[0044] Optionally, the length of the positive electrode sheet 310 is less than the length of the negative electrode sheet 320, and the difference A between the length of the negative electrode sheet 320 and the length of the positive electrode sheet 310 satisfies the relationship: 0.55b≤A≤0.65b, where b is the outer diameter of the housing 100. It can be understood that the length of the positive electrode sheet 310 is less than the length of the negative electrode sheet 320, which can ensure that the positive electrode sheet 310 and the negative electrode sheet 320 are completely insulated, which is conducive to gathering all the heat on the positive current collector bar 340 in the case of an external short circuit.

[0045] like Figure 3 As shown, the positive current collector bar 340 includes a first connection portion 341, a middle portion 342, and a second connection portion 343 connected to each other, the first connection portion 341 is connected to the positive lead-out terminal, and the second connection portion 343 is connected to the positive electrode column 200. It can be understood that the first connection portion 341 and the second connection portion 343 can facilitate the connection of the positive current collector bar 340 with the positive lead-out terminal, and the middle portion 342 can be quickly fused in the case of an external short circuit to ensure safety.

[0046] Optionally, the width B of the first connection portion 341 is 1.5mm-4mm. The width B of the first connection portion 341 can be 1.5mm, 1.6mm, 1.7mm, 1.8m, 1.9mm, 2.1mm, 2.2mm, 2.3mm, 2.4m, 2.5mm, 2.6mm, 2.7mm, 2.8m, 2.9mm, 3.1mm, 3.2mm, 3.3mm, 3.4m, 3.5mm, 3.6mm, 3.7mm, 3.8m, 3.9mm, 4mm. Of course, in other embodiments of the utility model, the width of the first connection portion 341 can also be selected according to actual needs.

[0047] Optionally, the length C of the first connection portion 341 is 3 mm-6 mm. The length C of the first connection portion 341 can be 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, or 6 mm. Of course, in other embodiments of the present invention, the length C of the first connection portion 341 can also be selected according to actual needs.

[0048] Optionally, the width D of the middle portion 342 is 0.5 mm-1.5 mm. The width D of the middle portion 342 can be 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. Of course, in other embodiments of the present invention, the width D of the middle portion 342 can also be selected according to actual needs.

[0049] Optionally, the length E of the middle portion 342 is 2 mm-5 mm. The length C of the middle portion 342 can be 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, or 5 mm. Of course, in other embodiments of the present invention, the length C of the middle portion 342 can also be selected according to actual needs.

[0050] Optionally, the width F of the second connection portion 343 is 1.5mm-4mm. The width F of the second connection portion 343 can be 1.5mm, 1.6mm, 1.7mm, 1.8m, 1.9mm, 2.1mm, 2.2mm, 2.3mm, 2.4m, 2.5mm, 2.6mm, 2.7mm, 2.8m, 2.9mm, 3.1mm, 3.2mm, 3.3mm, 3.4m, 3.5mm, 3.6mm, 3.7mm, 3.8m, 3.9mm, 4mm. Of course, in other embodiments of the utility model, the width F of the second connection portion 343 can also be selected according to actual needs.

[0051] like Figure 2As shown, the first insulating member 400 is provided with an avoidance hole 410, which is used to avoid the positive electrode current collector 340, and the length of the avoidance hole 410 is greater than the width of the middle portion 342, and less than the width of the first connecting portion 341 and the second connecting portion 343. Thus, the limiting effect of the positive electrode current collector 340 on the first insulating member 400 can be enhanced, which is conducive to improving the function of the first insulating member 400 to prevent the top of the housing 100 from contacting the end.

[0052] like Figure 4 As shown, the negative electrode sheet 320 includes two lithium ribbons, and the negative electrode current collector bar 350 is sandwiched between the two lithium ribbons. The distance between the lead-out position of the negative electrode current collector bar 350 and the end of the lithium ribbon is H, and H satisfies the relationship: H = (a-2c-2d) / 2×3.14, with a tolerance of ±2mm; wherein: a is the inner diameter of the outer shell 100, c is the thickness of the lithium ribbon, and d is the thickness of the wound diaphragm 330.

[0053] Optionally, the thickness of the negative electrode current collector bar 350 is 0.05 mm-0.1 mm. The thickness of the negative electrode current collector bar 350 can be 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm, 0.1 mm. Of course, in other embodiments of the utility model, the thickness of the negative electrode current collector bar 350 can also be selected according to actual needs.

[0054] The specific assembly process of the battery of this embodiment is described below.

[0055] The middle portion 342 is connected to the first connection portion 341 (the length C of the first connection portion 341 is 3 mm, the length E of the middle portion 342 is 2 mm, the width B of the first connection portion 341 is 3.5 mm, and the width D of the middle portion 342 is 1 mm), and the middle portion 342 passes through the avoidance hole 410 on the first insulating member 400 (the width of the strip hole is 2 mm), and then is welded to the second connection portion 343 (the width F of the second connection portion 343 is 3.5 mm);

[0056] Spot weld the spot-welded positive electrode current collector bar 340 (the thickness of the entire positive electrode current collector bar 340 is 0.05 mm) as a whole on the edge of the positive electrode sheet 310. (The thickness of the positive electrode sheet 310 is 1 mm, the length is 350 mm, and the width is 40 mm);

[0057] The negative electrode current collector bar 350 (the negative electrode current collector bar 350 has a width of 3.5 mm and a thickness of 0.05 mm) is sandwiched between two lithium strips (the length of the lithium strip is 380 mm and the width is 40 mm, and the negative electrode current collector bar 350 is 50 mm away from the edge of the lithium strip) with the same thickness of 0.25 mm, and formed into a whole by a roller press;

[0058] The negative electrode sheet 320 is completely wrapped with a separator of appropriate length and width, and the end of the positive electrode sheet 310 without the positive electrode current collector bar 340 is aligned with the end of the negative electrode sheet 320 without the negative electrode current collector bar 350, and the wound cells 300 are fixed with a chemically resistant tape;

[0059] The other end of the positive electrode current collector bar 340 is spot welded to the positive electrode column 200, and the second insulating member 600 and the bottom separator 500 are placed in the outer shell 100, and then the wound battery cell 300 is inserted, so that the first insulating member 400 is smoothly inserted into the outer shell 100 along with the wound battery cell 300;

[0060] Fold the lead end of the negative electrode current collector bar 350 to the outside of the housing 100, press the cover plate 120 into the housing 100, sandwich the negative electrode current collector bar 350 between the inner wall of the housing 100 and the outer wall of the cover plate 120, minus the part of the negative electrode current collector bar 350 in the housing 100, and use laser welding to weld the cover plate 120 and the housing 100;

[0061] The electrolyte is injected into the battery, and the sealing nail 700 is pressed into the injection port on the cover plate 120 to complete the assembly.

[0062] After the battery is assembled, a short-circuit test is performed on the assembled battery. Two thermocouples are attached to the outer shell 100, respectively located at the two ends of the diameter of the middle height section of the battery (respectively marked as position 1 and position 2), and the short-circuit current and temperature change of the battery are measured. During the test, no discharge occurs in the battery. When a short circuit occurs, the external temperature of the battery rises (the temperature of the positive electrode collector bar 340 rises sharply to the melting point), and then the positive electrode collector bar 340 melts, and the battery temperature drops.

[0063] In the description of this specification, the description with reference to the terms "some embodiments", "other embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0064] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the implementation methods of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the scope of protection of the present invention. It is not necessary and impossible to list all implementation methods here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the scope of protection of the claims of the present invention.

Claims

1. A battery, characterized in that: include: Housing (100); A positive electrode column (200), the positive electrode column (200) being mounted on the housing (100) and being insulated from the housing (100); A wound battery cell (300), wherein the wound battery cell (300) is arranged inside the housing (100), the wound battery cell (300) comprises a positive electrode sheet (310), a negative electrode sheet (320) and a wound separator (330), wherein the negative electrode sheet (320) wraps the positive electrode sheet (310), and the wound separator (330) is arranged between the positive electrode sheet (310) and the negative electrode sheet (320): The outermost side of the wound positive electrode sheet (310) has a positive electrode lead-out terminal, the negative electrode current collector bar (350) of the negative electrode sheet (320) is electrically connected to the housing (100), and the positive electrode lead-out terminal is electrically connected to the positive electrode column (200) via the positive electrode current collector bar (340).

2. The battery according to claim 1, characterized in that The battery further comprises a first insulating member (400), wherein the first insulating member (400) is installed inside the housing (100) and is located between the positive electrode column (200) and the end of the wound battery cell (300).

3. The battery according to claim 2, characterized in that The diameter D of the first insulating member (400) satisfies the relationship: a-1.8≤D≤a-1, where a is the inner diameter of the housing (100) and the unit is millimeter; and / or: The thickness of the first insulating member (400) is 0.1 mm-0.3 mm.

4. The battery according to claim 2, characterized in that The first insulating member (400) is provided with an avoidance hole (410) and a liquid leakage hole (420), wherein the avoidance hole (410) is used to avoid the positive electrode current collecting bar (340), and the liquid leakage hole (420) is used to circulate electrolyte.

5. The battery according to claim 1, characterized in that The length of the positive electrode sheet (310) is smaller than the length of the negative electrode sheet (320), and a difference A between the length of the negative electrode sheet (320) and the length of the positive electrode sheet (310) satisfies the relationship: 0.55b≤A≤0.65b, where b is the outer diameter of the housing (100).

6. The battery according to claim 1, characterized in that The positive electrode current collector bar (340) comprises a first connecting portion (341), a middle portion (342) and a second connecting portion (343) which are connected to each other. The first connecting portion (341) is connected to the positive electrode lead-out terminal, and the second connecting portion (343) is connected to the positive electrode column (200).

7. The battery according to claim 6, characterized in that The width B of the first connecting portion (341) is 1.5 mm to 4 mm, and the length C of the first connecting portion (341) is 3 mm to 6 mm; and / or: The width D of the middle portion (342) is 0.5 mm to 1.5 mm, and the length E of the middle portion (342) is 2 mm to 5 mm; and / or: The width F of the second connecting portion (343) is 1.5 mm-4 mm.

8. The battery according to claim 1, characterized in that The negative electrode sheet (320) comprises two lithium strips, the negative electrode current collector bar (350) is sandwiched between the two lithium strips, and the distance between the lead-out position of the negative electrode current collector bar (350) and the end of the lithium strip is H, and H satisfies the relationship: H=(a-2c-2d) / 2×3.14, with a tolerance of ±2 mm; wherein: a is the inner diameter of the housing (100), c is the thickness of the lithium ribbon, and d is the thickness of the wound separator (330); and / or: The thickness of the negative electrode current collector bar (350) is 0.05 mm-0.1 mm.

9. The battery according to claim 1, characterized in that The housing (100) comprises a shell (110) and a cover plate (120), the positive electrode column (200) is mounted on the cover plate (120), and one end of the negative electrode collector bar (350) is connected between the inner peripheral wall of the shell (110) and the outer peripheral wall of the cover plate (120).

10. The battery according to claim 1, characterized in that The battery further comprises a bottom diaphragm (500) and a second insulating member (600), wherein the bottom diaphragm (500) is arranged in the outer shell (100) and is located between the bottom wall of the outer shell (100) and the wound battery cell (300), and the second insulating member (600) is arranged in the outer shell (100) and is located between the bottom diaphragm (500) and the bottom wall of the outer shell (100).

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