Sodium ion cylindrical battery and electric equipment

Abstract

The utility model discloses a sodium ion cylindrical battery and electric equipment, comprising: a housing which is a hollow cylindrical member and is provided with open ends at two ends along the axis direction of the housing; the roll core is mounted in the shell; a positive electrode cap; a positive terminal; a negative electrode bottom cover; the negative pole is mounted in the second mounting hole; the negative current collector is mounted between the second end of the roll core and the negative pole; the anti-explosion valve is mounted in the third mounting hole, the anti-explosion valve comprises an anti-explosion sheet and a nick, and in the axis direction of the shell, the orthographic projection of the anti-explosion sheet is located on the outer side of the orthographic projection of the negative pole; in the thickness direction of the negative electrode bottom cover, the area of the orthographic projection of the negative electrode bottom cover is S1, the area of the orthographic projection of the anti-explosion valve is S2, and S2 / S1 is larger than or equal to 3% and smaller than or equal to 10%. The sodium ion cylindrical battery disclosed by the utility model can release pressure in time and ensure the strength of the negative electrode bottom cover.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of battery, more particularly to a kind of sodium ion cylindrical battery and electric equipment. BACKGROUND

[0002] At present, cylindrical battery gradually becomes new energy industry mainstream product due to high energy density, good capacity consistency, can support large ratio charge-discharge and other advantages, more and more manufacturers continue to pursue compactness optimization of cylindrical battery structure to improve energy density.

[0003] But, while pursuing the more optimal electric performance of cylindrical battery, its safety performance is more worthy of attention.Cylindrical battery of thermal runaway is one of the most serious safety accidents.In prior art, usually by setting a explosion-proof valve to improve safety performance, explosion-proof valve can be damaged preferentially when pressure is too high, release the pressure inside battery, prevent explosion of battery in thermal runaway.The explosion-proof valve of prior art is difficult to meet the requirement of timely leaking cell pressure and cover strength simultaneously. UTILITY MODEL CONTENT

[0004] One purpose of the utility model is to provide a kind of sodium ion cylindrical battery, at least can solve the technical problem that explosion-proof valve of prior art is difficult to meet the requirement of timely leaking cell pressure and cover strength simultaneously.

[0005] Another purpose of the utility model is to provide a kind of electric equipment, including the above-mentioned sodium ion cylindrical battery.

[0006] In order to achieve the above purposes, the utility model provides the following technical solutions.

[0007] According to the sodium-ion cylindrical battery of the first aspect of the present application, the shell is a hollow cylindrical member, and the shell has an open end at each end along the axis direction thereof; the winding core is installed inside the shell; the positive electrode top cover is installed at one open end of the shell, and the positive electrode top cover is provided with a first mounting hole; the positive electrode column is installed in the first mounting hole; the positive electrode busbar is installed between the first end of the winding core and the positive electrode column; the negative electrode bottom cover is installed at the other open end of the shell, and the negative electrode bottom cover is provided with a second mounting hole; the negative electrode bottom cover and the positive electrode top cover are both provided with an insulating layer on the side close to the winding core; the negative electrode bottom cover is provided with a third mounting hole; the negative electrode column is installed in the second mounting hole; the negative electrode busbar is installed between the second end of the winding core and the negative electrode column; the explosion-proof valve is installed in the third mounting hole, and the explosion-proof valve comprises an explosion-proof sheet and a notch provided on the outer periphery of the explosion-proof sheet, wherein, in the axis direction of the shell, the orthographic projection of the explosion-proof valve is located on the outside of the orthographic projection of the negative electrode column; in the thickness direction of the negative electrode bottom cover, the area of the orthographic projection of the negative electrode bottom cover is S1, and the area of the orthographic projection of the explosion-proof valve is S2, and 3%≤S2 / S1≤10%.

[0008] Optionally, the shape of the explosion-proof sheet is circular, oval, arc-shaped or polygonal; and / or, the depth of the notch is 0.12-0.18mm, preferably 0.15mm; and / or, the circumferential edge of the explosion-proof valve is laser welded with the negative electrode bottom cover.

[0009] Optionally, the negative electrode column is located at the center position of the negative electrode bottom cover, and the explosion-proof valve is located at the eccentric side of the negative electrode bottom cover.

[0010] Optionally, the negative electrode busbar comprises a connecting handle, one end of the connecting handle being connected with the negative electrode column, a body, the edge of the body being connected with the other end of the connecting handle, the body being connected with the second end of the winding core, the connecting handle being arranged to be bent relative to the body and being dislocated with the explosion-proof valve, and the body being located between the one end of the connecting handle and the winding core.

[0011] Optionally, the body is provided with a welding area and a relief hole, the welding area being dislocated with the relief hole, the welding area being used to connect with the second end of the winding core, and wherein, in the thickness direction of the body, the relief hole is arranged opposite to the explosion-proof valve.

[0012] Optionally, a first hole is arranged at a central position of the body, and a plurality of second holes are arranged at positions close to the outer edge of the body, one of the second holes serving as the avoiding hole, the second holes being distributed at intervals around the first hole, and the welding area being arranged at a position between two adjacent second holes, one end of the welding area being directed towards the first hole and spaced apart from the first hole, and the other end of the welding area extending to the outer edge of the body.

[0013] Optionally, in the thickness direction of the body, the area of the orthogonal projection of the avoiding hole is greater than the area of the orthogonal projection of the explosion-proof valve.

[0014] Optionally, a groove is arranged on the body at a side close to the negative bottom cover, and a protrusion is arranged on the body at a side close to the winding core, and the groove and the protrusion are opposite in the thickness direction of the body.

[0015] Optionally, the four peripheral edges of the positive top cover and the edges of the open end are laser welded, and / or the four peripheral edges of the negative bottom cover and the edges of the open end are laser welded.

[0016] The electric device according to the second aspect of the present application comprises the sodium-ion cylindrical battery according to any one of the above.

[0017] The sodium-ion cylindrical battery according to the present application combines the shell, the winding core, the positive top cover, the positive column, the positive busbar, the negative bottom cover, the negative column, the negative busbar and the explosion-proof valve, and in the axial direction of the shell, the orthogonal projection of the explosion-proof valve is located on the outer side of the orthogonal projection of the negative column; in the thickness direction of the negative bottom cover, the area of the orthogonal projection of the negative bottom cover is S1, the area of the orthogonal projection of the explosion-proof valve is S2, and 3%≤S2 / S1≤10%, which not only ensures that the internal pressure of the sodium-ion cylindrical battery can be discharged in time, but also does not easily affect the strength of the negative bottom cover.

[0018] Other features and advantages of the present application will become apparent from the following detailed description of exemplary embodiments thereof, taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0019] The accompanying drawings incorporated in and forming a part of the specification, illustrate embodiments of the present application and, together with the description, serve to explain the principles of the application.

[0020] Figure 1 is a partial exploded view of a sodium-ion cylindrical battery according to an embodiment of the present application;

[0021] Figure 2 is a partial exploded view of a sodium-ion cylindrical battery according to an embodiment of the present application;

[0022] Figure 3 is a partial exploded view of a sodium-ion cylindrical battery according to an embodiment of the present application;

[0023] Figure 4 is a partial cross-sectional view of a sodium-ion cylindrical battery according to an embodiment of the present application;

[0024] Figure 5 is an assembly schematic view of a negative bottom cover and a negative busbar of a sodium-ion cylindrical battery according to an embodiment of the present application.

[0025] Reference Signs

[0026] a sodium-ion cylindrical battery 100;

[0027] a housing 1;

[0028] a winding core 2;

[0029] a positive top cover 3;

[0030] a positive busbar 4;

[0031] a negative bottom cover 5; a second mounting hole 51; a third mounting hole 52;

[0032] a negative post 6;

[0033] a negative busbar 7; a connecting handle 71; a body 72; a welding area 721; a first hole 722; a second hole 723; a groove 724;

[0034] an explosion-proof valve 8; an explosion-proof sheet 81; a score 82. DETAILED DESCRIPTION

[0035] Various illustrative embodiments of the present application will now be described in detail with reference to the accompanying figures. It should be noted that the relative arrangements, numerical expressions, and values of components and steps set forth in these embodiments are not limiting to the scope of the present application unless otherwise specifically stated.

[0036] The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the application or its application or uses.

[0037] Techniques, methods, and devices known to those of ordinary skill in the relevant art can not be discussed in detail herein. However, the techniques, methods, and devices should be considered part of the specification, if appropriate.

[0038] In all of the examples shown and discussed herein, any specific values should be interpreted as merely exemplary and not as a limitation. Thus, other examples of the exemplary embodiments can have different values.

[0039] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0040] The sodium-ion cylindrical battery 100 according to an embodiment of the present invention is described in detail below with reference to the accompanying drawings.

[0041] like Figures 1 to 5 As shown, the sodium-ion cylindrical battery 100 according to an embodiment of the present invention includes: a casing 1, a core 2, a positive electrode top cover 3, a positive electrode post, a positive electrode collector 4, a negative electrode bottom cover 5, a negative electrode post 6, a negative electrode collector 7, and an explosion-proof valve 8.

[0042] Specifically, the housing 1 is a hollow cylindrical component with open ends at both ends along its own axis. The core 2 is installed inside the housing 1. The positive electrode top cover 3 is installed at one open end of the housing 1, and the positive electrode top cover 3 has a first mounting hole. The positive electrode post is installed in the first mounting hole. The positive electrode collector 4 is installed between the first end of the core 2 and the positive electrode post. The negative electrode bottom cover 5 is installed at the other open end of the housing 1, and the negative electrode bottom cover 5 has a second mounting hole 51. Both the negative electrode bottom cover 5 and the positive electrode top cover 3 have an insulating layer on the side near the core 2. The negative electrode bottom cover 5 has... There is a third mounting hole 52. The negative electrode post 6 is installed in the second mounting hole 51. The negative electrode manifold 7 is installed between the second end of the core 2 and the negative electrode post 6. The explosion-proof valve 8 is installed in the third mounting hole 52. The explosion-proof valve 8 includes an explosion-proof plate 81 and a groove 82 on the outer periphery of the explosion-proof plate 81. In the axial direction of the housing 1, the orthographic projection of the explosion-proof valve 8 is located outside the orthographic projection of the negative electrode post 6. In the thickness direction of the negative electrode bottom cover 5, the area of ​​the orthographic projection of the negative electrode bottom cover 5 is S1, and the area of ​​the orthographic projection of the explosion-proof valve 8 is S2, where 3%≤S2 / S1≤10%.

[0043] In other words, the sodium-ion cylindrical battery 100 according to the present invention mainly consists of a shell 1, a core 2, a positive electrode top cover 3, a positive electrode post, a positive electrode collector 4, a negative electrode bottom cover 5, a negative electrode post 6, a negative electrode collector 7, and an explosion-proof valve 8.

[0044] The housing 1 is a hollow cylindrical component with open ends at both ends along its own axis. For example, the housing 1 has an internal installation space for installing the winding core 2. The upper end of the housing 1 may have one open end, and the lower end may have another open end. A positive electrode top cover 3 and a negative electrode bottom cover 5 are respectively installed at both ends of the housing 1. Both the negative electrode bottom cover 5 and the positive electrode top cover 3 have an insulating layer on the side near the winding core 2. For example, the insulating layer is an insulating patch, which is easy to install and its shape is easy to adjust.

[0045] Specifically, a positive top cover 3 is mounted on one open end of the shell 1, the positive top cover 3 is provided with a first mounting hole, and a positive post is mounted in the first mounting hole. A positive busbar 4 is arranged between the end of the winding core 2 of the shell 1 and the positive top cover 3, and the positive busbar 4 can be connected with the positive post and the end of the winding core 2 respectively. The positive busbar 4 can also be laser welded with the tab of the winding core 2. The positive post can be welded with the positive busbar 4.

[0046] Moreover, a negative bottom cover 5 is mounted on the other open end of the shell 1, the negative bottom cover 5 is provided with a second mounting hole 51 and a third mounting hole 52, and a negative post 6 is mounted in the second mounting hole 51. A negative busbar 7 is mounted between the end of the winding core 2 and the negative bottom cover 5, and the negative busbar 7 can be connected with the negative post and the end of the winding core 2 respectively. The negative post can be welded with the negative busbar, and the negative busbar 7 can be laser welded with the negative tab of the winding core 2.

[0047] Furthermore, an explosion-proof valve 8 is mounted in the third mounting hole 52, the explosion-proof valve 8 comprises an explosion-proof sheet 81, and the outer periphery of the explosion-proof sheet 81 is provided with a notch 82, that is, the explosion-proof valve 8 is mainly composed of the explosion-proof sheet 81 and the peripheral notch 82. Moreover, the thickness of the notch 82 is smaller than that of other positions of the explosion-proof sheet 81, and when the winding core 2 is out of control, the gas in the shell 1 can rush through the notch 82 to open the explosion-proof valve 8.

[0048] In the axial direction of the shell 1, the orthographic projection of the explosion-proof valve 8 is located outside the orthographic projection of the negative post 6, that is, the explosion-proof valve 8 is designed staggered with the negative post 6, which can avoid mutual interference.

[0049] In addition, in the thickness direction of the negative bottom cover 5, the area of the orthographic projection of the negative bottom cover 5 is S1, and the area of the orthographic projection of the explosion-proof valve 8 is S2, and 3%≤S2 / S1≤10%. It should be noted that if the area of the explosion-proof valve 8 is too small, it is easy to cause the explosion speed to be slow when the explosion is released, and the internal pressure of the sodium-ion cylindrical battery 100 cannot be released in time, which may cause the risk of battery explosion, thermal runaway, etc. However, if the explosion-proof area is too large, it will affect the strength of the negative bottom cover 5, and further affect the strength of the overall structure of the sodium-ion cylindrical battery 100. In the embodiment, the area corresponding to the negative bottom cover 5 of the sodium-ion cylindrical battery 100 is S1, and the area corresponding to the explosion-proof valve 8 is S2, S1 and S2 satisfy the relationship: 3%≤S2 / S1≤10%, for example, the ratio of S2 / S1 is 3%, 4%, 5%, 6%, 7%, 8%, 9% or 10%; within this interval, the explosion speed of the sodium-ion cylindrical battery 100 is appropriate when the explosion is released, and the strength of the negative bottom cover 5 can be taken into account.

[0050] Therefore, according to the sodium-ion cylindrical battery 100 of the embodiment of the utility model, the housing 1, the roll core 2, the positive electrode top cover 3, the positive electrode column, the positive electrode busbar 4, the negative electrode bottom cover 5, the negative electrode column 6, the negative electrode busbar 7 and the explosion-proof valve 8 are combined, in the axial direction of the housing 1, the orthographic projection of the explosion-proof valve 8 is located on the outside of the orthographic projection of the negative electrode column 6, in the thickness direction of the negative electrode bottom cover 5, the area of the orthographic projection of the negative electrode bottom cover 5 is S1, the area of the orthographic projection of the explosion-proof valve 8 is S2, 3%≤S2 / S1≤10%, not only can the internal pressure of the sodium-ion cylindrical battery 100 be discharged in time, but also the strength of the negative electrode bottom cover 5 is not easily affected.

[0051] Optionally, the position of the explosion-proof valve 8 on the negative electrode cover plate 5 can be set as required, and the explosion-proof valve 8 can also be arranged at multiple positions of the negative electrode cover plate 5.

[0052] According to an embodiment of the utility model, the shape of the explosion-proof valve 8 is circular, oval, arc or polygon, etc., which has diversity and flexibility. In addition, the shape of the notch 82 on the outer periphery of the explosion-proof sheet 81 can be consistent with the outer periphery shape of the explosion-proof sheet 81, that is, the shape of the explosion-proof valve 8 is consistent with the shape of the explosion-proof sheet 81, which is convenient for processing the notch 82.

[0053] In some specific embodiments of the utility model, the depth of the notch 82 is 0.12mm-0.18mm, for example, the depth of the notch 82 is 0.12mm, 0.13mm, 0.14mm, 0.15mm, 0.16mm, 0.17mm or 0.18mm, etc. In this embodiment, by adopting the depth of the notch 82 as 0.12mm-0.18mm, not only can the internal pressure of the sodium-ion cylindrical battery 100 be discharged in time, but also the strength of the negative electrode bottom cover 5 is not easily affected, and it is also beneficial to reduce the processing difficulty of realizing 3%≤S2 / S1≤10%, which can ensure the valve opening effect on the basis of 3%≤S2 / S1≤10%.

[0054] Preferably, the depth of the notch 82 is 0.15mm, which can not only adapt to most existing sodium-ion cylindrical batteries, but also have the advantages of explosion-proof effect and not easily affecting the strength of the negative electrode bottom cover 5, etc.

[0055] According to an embodiment of the utility model, the four peripheral edges of the explosion-proof valve 8 are laser welded with the negative electrode bottom cover 5, by adopting the laser welding mode, it is beneficial to reduce the processing difficulty of realizing 3%≤S2 / S1≤10%, which can ensure the valve opening effect on the basis of 3%≤S2 / S1≤10%.

[0056] Optionally, at least one of the material of the explosion-proof sheet and the material of the negative electrode cover plate is aluminum, etc., which can adapt to most existing sodium-ion cylindrical batteries.

[0057] It should be noted that product diversification can be achieved by meeting one or more of the conditions of the shape, material, depth of the notch 82, and laser welding of the explosion-proof valve 8, to meet different needs.

[0058] In some embodiments of the present application, the negative pole 6 is located at the center of the negative bottom cover 5, and the explosion-proof valve 8 is located at the eccentric side of the negative bottom cover 5. That is, the body 72 is circular, the negative pole 6 is installed at the center of the body 72, and the explosion-proof valve 8 is located outside the negative pole 6. In this embodiment, only the negative bottom cover 5 needs to be changed without changing the position and shape of the negative pole 6, etc. It can be adapted to most sodium ion cylindrical batteries 100 in the prior art.

[0059] According to an embodiment of the present application, the negative busbar 7 comprises a connecting handle 71 and a body 72, one end of the connecting handle 71 is connected with the negative pole 6, the connecting handle 71 is staggered with the explosion-proof valve 8, the connecting handle 71 can be bent, the edge of the body 72 is connected with the other end of the connecting handle 71, the body 72 is connected with the second end of the winding core 2, and after the connecting handle 71 is bent, the body 72 is located between one end of the connecting handle 71 and the winding core 2. During installation, the body 72 can be welded with the winding core 2 first, then one end of the connecting handle 71 is welded with the negative pole 6, and then the connecting handle 71 is bent. In this embodiment, the existing bendable negative busbar 7 can be used to connect the winding core 2 and the negative pole 6.

[0060] In some embodiments of the present application, the body 72 is provided with a welding area 721 and a relief hole, the welding area 721 is staggered with the relief hole, the welding area 721 is used to connect with the second end of the winding core 2, that is, in the thickness direction of the body 72, the orthographic projection of the welding area 721 and the orthographic projection of the relief hole are staggered. Among them, in the thickness direction of the body 72, the relief hole is arranged opposite to the explosion-proof valve 8, for example, the explosion-proof valve 8 can be located directly above the relief hole, so that the pressure inside the shell 1 can directly impact the explosion-proof valve 8, which can further ensure that the internal pressure of the sodium ion cylindrical battery 100 can be discharged in time.

[0061] According to one embodiment of the utility model, the center position of the body 72 is provided with a first hole 722, the position close to the outer edge of the body 72 is provided with a plurality of second holes 723, one of the second holes 723 is used as an avoiding hole, the plurality of second holes 723 are distributed at intervals around the first hole 722, the position between the adjacent two second holes 723 is provided with a welding area 721, the welding between the body 72 and the roll core 2 can be realized through the welding area 721. One end of the welding area 721 is towards the first hole 722 and is spaced apart from the first hole 722, the other end of the welding area 721 is extended to the outer edge of the body 72, the welding position can be controlled, the welding difficulty is reduced, and the first hole 722 is prevented from being affected in the welding process. For example, the number of second holes 723 is four, and they are distributed at equal intervals around the first hole 722. In the embodiment, the first hole 722 and the plurality of second holes 723 are arranged on the body 72, which not only reduces the overall weight, but also facilitates the discharge of gas.

[0062] Optionally, the body 72 is a central symmetric structure, facilitating uniform distribution of processing and connection positions.

[0063] Optionally, the shape of the second hole 723 is a triangle, the base is towards the outer edge of the body 72, the shape can be substantially consistent with the shape of the outer edge of the adjacent body 72, the two top angles are respectively towards the adjacent welding area 721, and the middle top angle is towards the first hole 722, which can expand the area of the second hole 723.

[0064] In some specific embodiments of the utility model, in the thickness direction of the body 72, the area of the normal projection of the avoiding hole is greater than the area of the normal projection of the explosion-proof valve 8, which can further ensure that the internal pressure of the sodium-ion cylindrical battery 100 can be discharged in time.

[0065] According to one embodiment of the utility model, the side close to the negative electrode bottom cover 5 of the body 72 is provided with a groove 724, and the side close to the roll core 2 of the body 72 is provided with a protrusion, that is, one side of the body 72 is provided with the groove 724, and the other side is provided with the protrusion. In the thickness direction of the body 72, the groove 724 and the protrusion are opposite, and the groove 724 and the protrusion can be processed at the same time through the embossing method.

[0066] In some specific embodiments of the utility model, the four peripheral edges of the positive electrode top cover 3 and the edges of the open end are laser welded, and / or the four peripheral edges of the negative electrode bottom cover 5 and the edges of the open end are laser welded. For example, the shell 1 is an aluminum shell, the outer periphery of the positive electrode top cover 3 can be laser welded to realize the connection with the shell 1, and the edge of the negative electrode bottom cover 5 can be laser welded with the shell 1 to realize the connection with the shell 1. In the embodiment, the laser welding method is adopted, which is conducive to ensuring the sealing property and the connection reliability of the connection position.

[0067] Optionally, the positive electrode top cover 3 is provided with a liquid injection hole and a sealing aluminum nail for sealing the liquid injection hole. Optionally, the liquid injection hole is in a boss type design and can be sealed by an aluminum nail and laser welding. Optionally, the screen of the aluminum nail is flush with the plane of the positive electrode top cover 3, improving the aesthetics and avoiding interference with other structures.

[0068] Optionally, the sodium ion cylindrical battery 100 can be wrapped with a blue film.

[0069] The sodium ion cylindrical battery 100 according to the embodiments of the present application will be described in detail below in conjunction with specific embodiments.

[0070] Embodiment 1

[0071] The sodium ion cylindrical battery 100 of embodiment 1 includes a shell 1, a roll core 2, and cap assemblies connected to both ends of the shell 1, the two cap assemblies are connected with the shell 1 to form a sealed accommodation space, and the roll core 2 is designed in the accommodation space.

[0072] As shown in Figure 3 , one cap assembly includes a negative electrode bottom cover 5 and a negative electrode busbar 7, the negative electrode bottom cover 5 is provided with a laser welding track, the laser welding track is welded with the tab of the roll core 2, and the negative electrode busbar 7 further includes a rectangular connecting handle 71, which is welded with the positive electrode post on the positive electrode top cover 3. Moreover, the negative electrode bottom cover 5 is designed with a pressure relief valve 8, which is broken when the internal pressure of the battery is too large, and the valve is opened to release pressure to ensure safety.

[0073] As shown in Figure 2 , the other cap assembly includes a positive electrode top cover 3 and a positive electrode busbar 4, and the positive electrode busbar 4 can be welded with the positive electrode post and the tab of the roll core 2 through the same shape of the positive electrode busbar 5 as the negative electrode busbar 7, which is not described here. In addition, the positive electrode top cover 3 is designed with a liquid injection hole for injecting liquid into the sodium ion cylindrical battery 100.

[0074] As shown in Figure 3 , the negative electrode bottom cover 5 is provided with a negative electrode post 6 and a pressure relief valve 8, the pressure relief valve 8 is designed outside the negative electrode post 6; the area of the orthographic projection of the negative electrode bottom cover 5 is S1; the area of the orthographic projection of the pressure relief valve 8 is S2. In embodiment 1, the ratio of S2 / S1 is 3%.

[0075] Embodiment 2

[0076] Different from embodiment 1, the ratio of S2 / S1 is 10%, and the rest of the conditions are the same as embodiment 1.

[0077] Comparative Example 1

[0078] Different from embodiment 1, the ratio of S2 / S1 is 2%, and the rest of the conditions are the same as embodiment 1.

[0079] Comparative Example 2

[0080] Different from Example 1, the ratio of S2 / S1 is 12%, and the rest of the conditions are the same as those in Example 1.

[0081] The test results are shown in Table 1 below by testing the final products of the above examples and examples.

[0082] Table 1 Test results of the battery cell when the ratio of the explosion-proof area to the cover plate area is different

[0083]

[0084] The test conditions are as follows:

[0085] (1) The thermal runaway test procedure includes the following:

[0086] ① After the battery cell is charged to the upper limit voltage at a constant power of 0.5P, the test sample is placed in the thermal runaway test device;

[0087] ② The heating components and temperature sensors are selected according to the requirements of the cylindrical test sample and arranged on the surface of the test sample, the temperature sampling period is set to 1s, and the determination condition of thermal runaway is that three temperature rise rate values are >3℃ / s or fire or explosion is continuously monitored;

[0088] ③ Connect the test sample, the charge and discharge device, and the voltage data sampling line;

[0089] ④ Constant current charging is performed at I=Prc / Unom, heating is started, time, voltage, current, temperature, temperature rise rate are recorded, and test phenomena including swelling, liquid leakage, smoking, fire, explosion, shell rupture and rupture position are recorded;

[0090] ⑤ When the determination condition of thermal runaway is triggered or the temperature reaches 300℃ or the test time reaches 4h, stop charging and heating, observe for 1h, record time, voltage, temperature, temperature rise rate, and record test phenomena including swelling, liquid leakage, smoking, fire, explosion, shell rupture and rupture position;

[0091] ⑥ Disconnect the test sample and the charge and discharge device, remove the heating components and data sampling line, and take out the test sample;

[0092] ⑦ Record the temperature at which thermal runaway occurs as the thermal runaway temperature.

[0093] The determination standard of the thermal runaway test result is that the determination condition of thermal runaway is that three temperature rise rate values are >3℃ / s or fire or explosion is continuously monitored. After testing, the determination results of Example 1 and Example 2 of the present application are both not on fire and not exploded.

[0094] (2) The test conditions of 130°C hot box (thermal shock) include the following:

[0095] ① The battery cell is charged to the upper limit voltage at 0.5C / 0.05C constant current and constant voltage, and is left for 1 h;

[0096] ② The battery cell is placed in a temperature box, and is heated from room temperature to 130±2°C at a heating rate of 5°C / min, and the heating is stopped after being kept at 130±2°C for 30 min;

[0097] ③ Observation for 1 h;

[0098] ④ Video recording.

[0099] The judgment standard of the test results of 130°C hot box is that the battery should not smoke, not catch fire, not explode (according to GB38031, no smoke is an internal additional specification). After the test, the test results of Example 1 and Example 2 of the application both meet the standards of no smoke, no fire and no explosion.

[0100] (3) The test conditions of 85°C, 100% SOC 3D storage include the following:

[0101] ① The battery cell is discharged to the lower limit voltage at 0.5C constant current at 25°C±2°C, and is left for 30 min;

[0102] ② The battery cell is charged to the upper limit voltage cutoff at 0.5C / 0.05C constant current and constant voltage at 25°C±2°C, and is left for 30 min;

[0103] ③ The battery cell is discharged to the lower limit voltage at 0.5C constant current at 25°C±2°C, and is left for 30 min;

[0104] ④ The battery cell is charged to the upper limit cutoff at 0.5C / 0.05C constant current and constant voltage at 25°C±2°C, and is left for 30 min;

[0105] ⑤ The battery cell is stored at 85°C for 3 days;

[0106] ⑥ The battery cell is left for 4 hours after being taken out after storage, and is cooled to room temperature to measure the voltage and internal resistance;

[0107] ⑦ Cycle steps ①-③.

[0108] The judgment standard of the test results of 85°C, 100% SOC 3D storage is that it should not be opened first, and if it passes, the capacity retention rate and recovery rate can be further calculated.

[0109] It can be seen from Table 1 that the ratio S2 / S1 of the area of the explosion-proof valve 8 to the area of the negative bottom cover 5 is between 3% and 10%, and the safety performance of the sodium-ion cylindrical battery 100 is best, which can meet the conditions of not exploding and not opening the valve during high-temperature storage when thermal runaway occurs. When the area of the explosion-proof valve 8 is set unreasonably, the strength of the negative bottom cover 5, the explosion relief speed, the valve opening speed and the like are easily affected.

[0110] In summary, according to the sodium-ion cylindrical battery 100 of the embodiment of the present application, by limiting the ratio of the area of the explosion-proof valve 8 on the negative bottom cover 5 to the area of the negative bottom cover 5, the pressure relief speed and the strength of the negative bottom cover 5 can be considered, and specifically, the pressure relief speed can meet the condition of not exploding during thermal runaway test, and the cover plate strength can meet the condition of not opening the valve during 85℃, 3D test.

[0111] The utility model further provides a kind of electric equipment, and the electric equipment includes the sodium-ion cylindrical battery 100 of any one embodiment described above. Since the sodium-ion cylindrical battery 100 of the embodiment of the present application can consider the pressure relief speed and the strength of the negative bottom cover 5, and the electric equipment of the embodiment of the present application includes the sodium-ion cylindrical battery 100 described above, therefore the electric equipment of the embodiment of the present application has the advantage of strong safety, which will not be repeated here.

[0112] Although some specific embodiments of the present application have been described in detail through examples, those skilled in the art should understand that the above examples are only for illustration, and are not intended to limit the scope of the present application. Those skilled in the art should understand that the above embodiments can be modified without departing from the scope and spirit of the present application. The scope of the present application is defined by the appended claims.

Claims

1. A sodium-ion cylindrical battery (100), characterized in that, The application relates to a battery, which comprises the following parts: a shell (1) which is a hollow cylinder and has two open ends along the axial direction of the shell (1); a winding core (2) which is arranged in the shell (1); a positive electrode top cover (3) which is arranged at one of the open ends of the shell (1) and is provided with a first mounting hole; a positive electrode column which is arranged in the first mounting hole; a positive electrode busbar (4) which is arranged between the first end of the winding core (2) and the positive electrode column; a negative electrode bottom cover (5) which is arranged at the other open end of the shell (1) and is provided with a second mounting hole (51), the negative electrode bottom cover (5) and the positive electrode top cover (3) are both provided with an insulating layer on the side close to the winding core (2), and the negative electrode bottom cover (5) is provided with a third mounting hole (52); a negative electrode column (6) which is arranged in the second mounting hole (51); a negative electrode busbar (7) which is arranged between the second end of the winding core (2) and the negative electrode column (6); an explosion-proof valve (8) which is arranged in the third mounting hole (52) and comprises an explosion-proof sheet (81) and a notch (82) arranged on the outer periphery of the explosion-proof sheet (81), wherein, in the axial direction of the shell (1), the orthographic projection of the explosion-proof valve (8) is located on the outside of the orthographic projection of the negative electrode column (6); in the thickness direction of the negative electrode bottom cover (5), the area of the orthographic projection of the negative electrode bottom cover (5) is S1, the area of the orthographic projection of the explosion-proof valve (8) is S2, and 3%<=S2 / S1<=10%.

2. The sodium-ion cylindrical battery (100) according to claim 1, characterized in that, The explosion-proof valve (8) is circular, oval, arc-shaped or polygonal in shape; and / or The depth of the notch (82) is 0.12mm-0.18mm; and / or The four peripheral edges of the explosion-proof valve (8) are laser-welded with the negative electrode bottom cover (5).

3. The sodium-ion cylindrical battery (100) according to claim 1, characterized in that, The negative electrode column (6) is located at the center of the negative electrode bottom cover (5), and the explosion-proof valve (8) is located at the eccentric side of the negative electrode bottom cover (5).

4. The sodium-ion cylindrical battery (100) according to claim 3, characterized in that, The negative electrode busbar (7) comprises: a connecting handle (71) which is connected with the negative electrode column (6) at one end; a body (72) which is connected with the other end of the connecting handle (71) at the edge, is connected with the second end of the winding core (2), is arranged in a bent mode relative to the body (72) and is dislocated with the explosion-proof valve (8), and is located between the one end of the connecting handle (71) and the winding core (2).

5. The sodium-ion cylindrical battery (100) according to claim 4, characterized in that, The body (72) is provided with a welding area (721) and a avoiding hole, the welding area (721) is dislocated with the avoiding hole, the welding area (721) is used for connecting with the second end of the winding core (2), and the avoiding hole is arranged opposite to the explosion-proof valve (8) in the thickness direction of the body (72).

6. The sodium-ion cylindrical battery (100) according to claim 5, characterized in that, The center of the body (72) is provided with a first hole (722), and the body (72) is provided with a plurality of second holes (723) near the outer edge, one of the second holes (723) is the avoiding hole, the plurality of second holes (723) are distributed around the first hole (722) at intervals, and the position between two adjacent second holes (723) is provided with the welding area (721), one end of the welding area (721) is towards the first hole (722) and is spaced apart from the first hole (722), and the other end of the welding area (721) extends to the outer edge of the body (72).

7. The sodium-ion cylindrical battery (100) according to claim 5, characterized in that, In the thickness direction of the body (72), the area of the orthographic projection of the avoiding hole is greater than the area of the orthographic projection of the explosion-proof valve (8).

8. The sodium-ion cylindrical battery (100) according to claim 5 or 6, characterized in that, The body (72) is provided with a groove (724) near one side of the negative bottom cover (5), and is provided with a protrusion near one side of the core (2), and the positions of the groove (724) and the protrusion are opposite in the thickness direction of the body (72).

9. The sodium-ion cylindrical battery (100) according to claim 1, characterized in that, The four peripheral edges of the positive top cover (3) and the edges of the open end are laser welded, and / or the four peripheral edges of the negative bottom cover (5) and the edges of the open end are laser welded.

10. An electric device, characterized by The sodium-ion cylindrical battery (100) of any one of claims 1-9 is included.

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