Battery and electric device

Abstract

The application relates to the technical field of lithium ion batteries, and specifically discloses a battery and a power utilization device. The battery comprises a battery cover plate, a valve piece and a memory alloy plate. The valve piece is connected with the battery cover plate and covers a valve hole, and the valve piece comprises a main body area and a thinning area. The memory alloy plate is located between an electrode assembly and the battery cover plate; the memory alloy plate comprises a plate body and a deformation part, the plate body is connected with the battery cover plate, and the deformation part is oppositely arranged with the thinning area of the valve piece along the thickness direction of the battery cover plate. When the temperature is higher than or equal to a first temperature threshold, the deformation part is warped towards the direction of the thinning area and pierces the thinning area. When the battery disclosed in the application is in thermal runaway, the temperature in the shell rises and a large amount of gas is generated; the deformation part of the memory alloy plate is relatively sensitive to temperature change, starts to be warped and pierces the thinning area on the valve piece to actively exhaust, the process is moderate, and the valve piece is prevented from being broken by strong internal gas pressure and splashing.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lithium ion batteries, and in particular to a battery and an electric device. BACKGROUND

[0002] Lithium ion batteries have been widely used in new energy vehicles and energy storage fields due to their high charging efficiency, large energy density, low maintenance cost, long cycle life and other advantages. However, with the continuous improvement of the energy density of lithium ion batteries, the safety problem of lithium ion batteries has become one of the key factors hindering their further development.

[0003] When a thermal runaway reaction occurs in a lithium ion battery, the positive electrode material in the battery will react violently with the organic solvent in the electrolyte, releasing a large amount of flammable gas. If the flammable gas is not discharged in time, it may cause the battery to explode and other dangers. In order to solve this problem, the battery internal high pressure gas is directly discharged through the battery explosion-proof valve, so as to achieve the purpose of explosion prevention and reduce the risk of thermal runaway.

[0004] However, in the related art, the explosion-proof valve mostly relies on the sudden change of the gas pressure in the battery for passive protection. When the battery is in thermal runaway, the valve body is severely deformed, and there is a lack of active protection means. SUMMARY

[0005] Therefore, the present application provides a battery and an electric device to at least solve the technical problem that in the related art, the explosion-proof valve mostly relies on the sudden change of the gas pressure in the battery for passive protection, the valve body is severely deformed, and there is a lack of active protection means.

[0006] In a first aspect, the present application provides a battery, comprising a shell, an electrode assembly, a battery cover plate, a valve sheet and a memory alloy plate. The shell has a receiving cavity, the electrode assembly is arranged in the receiving cavity, and the battery cover plate is connected with the shell and covers the receiving cavity. The battery cover plate has a valve hole and a thickness direction, the valve sheet is connected with the battery cover plate and covers the valve hole; the valve sheet comprises a main body region and a thinned region located in the middle of the main body region, and the thickness of the thinned region is smaller than the thickness of the main body region along the thickness direction of the battery cover plate. The memory alloy plate is arranged in the receiving cavity and located between the electrode assembly and the battery cover plate; the memory alloy plate comprises a plate body and a deformation portion arranged on the plate body, the plate body is connected with the battery cover plate, and the deformation portion is arranged opposite to the thinned region of the valve sheet along the thickness direction of the battery cover plate. When the temperature in the receiving cavity is higher than or equal to a first temperature threshold, the deformation portion is warped towards the direction of the thinned region and pierces the thinned region.

[0007] Further, the present application has at least the following beneficial effects:

[0008] The battery disclosed in this application has a housing opening covered with a memory alloy plate and a battery cover, each of which is provided with a deformed portion. The battery cover is provided with a valve plate, and the valve plate has a thinned area. When the battery experiences thermal runaway, the temperature inside the housing rises and a large amount of gas is generated, the deformed portion of the memory alloy plate, which is sensitive to temperature changes, begins to warp upward and puncture the thinned area on the valve plate to actively vent gas. This gentle process prevents the valve plate from being ruptured by the strong internal air pressure and causing splashing.

[0009] In some embodiments, the connection between the main area of ​​the valve sheet and the valve hole of the battery cover is a breakable area, and along the thickness direction of the battery cover, the thickness of the breakable area is less than the thickness of the main area; when the pressure in the accommodating cavity is greater than or equal to the first pressure threshold, the breakable area breaks.

[0010] In some embodiments, the first pressure threshold is 0.5 MPa to 0.9 MPa.

[0011] In some embodiments, the plate body of the memory alloy plate has a pressure relief hole, and along the thickness direction of the battery cover, the pressure relief hole is arranged opposite to at least a portion of the fragile area.

[0012] In some embodiments, the battery also includes an anti-corrosion film, which is arranged in the accommodating cavity, and the anti-corrosion film is located between the electrode assembly and the memory alloy plate, and seals and isolates the electrolyte in the accommodating cavity and the memory alloy plate; when the temperature is equal to or higher than the first temperature threshold, the anti-corrosion film partially or completely melts.

[0013] In some embodiments, the anti-corrosion film includes a membrane body and a covering wax. The membrane body is connected to the battery cover through a connecting glue. The membrane body has multiple through holes, and the covering wax is respectively sealed in the multiple through holes. When the temperature in the accommodating cavity is higher than or equal to the first temperature threshold, the covering wax melts. When the temperature in the accommodating cavity is greater than or equal to the second temperature threshold, the connecting glue melts. The second temperature threshold is greater than the first temperature threshold.

[0014] In some embodiments, the first temperature threshold is 60° C. to 70° C., the second temperature threshold is 65° C. to 80° C., and the second temperature threshold is greater than the first temperature threshold.

[0015] In some embodiments, male buckles are provided at both ends of the plate body of the memory alloy plate, and female buckles are provided on both sides of the battery cover in the length direction, and the male buckles are snap-connected with the female buckles.

[0016] In some embodiments, both ends of the body of the memory alloy plate are provided with mortise and tenon ends, and both sides of the battery cover plate in the length direction are provided with mortise and tenon grooves, and the mortise and tenon ends and the mortise and tenon grooves are connected by locating pins and mortise and tenon joints.

[0017] In a second aspect, the present application further provides an electrical device, comprising the battery in the first aspect, wherein the battery provides the electrical energy required for the electrical device to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the specific implementation methods or the description of the prior art. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0019] Specifically, the accompanying drawings are described as follows:

[0020] Figure 1 This is a schematic structural diagram of a battery according to an embodiment of the present application;

[0021] Figure 2 An exploded view of a battery according to an embodiment of the present application;

[0022] Figure 3 A top view of the valve plate according to an embodiment of the present application;

[0023] Figure 4 A top view of the memory alloy plate according to an embodiment of the present application;

[0024] Figure 5 This is a side cross-sectional view of the memory alloy plate and battery cover plate described in an embodiment of the present application at normal temperature;

[0025] Figure 6 for Figure 5 Schematic diagram of the enlarged structure at A;

[0026] Figure 7 A side cross-sectional view of the memory alloy plate and the battery cover plate according to an embodiment of the present application when the first temperature threshold is reached;

[0027] Figure 8 This is a side cross-sectional view of the memory alloy plate and battery cover plate described in an embodiment of the present application when the second temperature threshold is reached.

[0028] Figure 9 This is a schematic structural diagram of the anti-corrosion film described in an embodiment of the present application;

[0029] Figure 10 This is a structural schematic diagram of the mortise and tenon connection between the memory alloy plate and the battery cover plate described in an embodiment of the present application.

[0030] Specifically, the reference numerals are described as follows:

[0031] 100. Battery; 110. Shell; 120. Electrode assembly; 130. Battery cover; 131. Post; 140. Valve plate; 141. Main body; 142. Thinning area; 143. Breakable area; 150. Memory alloy plate; 151. Plate body; 152. Deformation part; 153. Pressure relief hole; 154. Connecting part; 1541. Male buckle; 1542. Mortise and tenon end; 1543. Positioning pin; 160. Anti-corrosion film; 161. Film body; 162. Covering wax; 170. Plastic plate. DETAILED DESCRIPTION

[0032] To make the purpose, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of this application.

[0033] The following combination Figures 1 to 10 The embodiments of the present application are described in detail.

[0034] First, refer to Figures 1 to 3 and Figure 5 and Figure 7 The present application provides a battery 100, comprising a housing 110, an electrode assembly 120, a battery cover 130, a valve plate 140, and a memory alloy plate 150. The housing 110 has a receiving cavity, the electrode assembly 120 is disposed within the receiving cavity, and the battery cover 130 is connected to the housing 110 and covers the receiving cavity. The battery cover 130 has a valve hole and a thickness direction, and the valve plate 140 is connected to the battery cover 130 and covers the valve hole; the valve plate 140 includes a main body area 141 and a thinned area 142 located in the middle of the main body area 141. Along the thickness direction of the battery cover 130, the thickness of the thinned area 142 is less than the thickness of the main body area 141. The memory alloy plate 150 is disposed within the accommodating cavity and is located between the electrode assembly 120 and the battery cover 130. The memory alloy plate 150 includes a plate body 151 and a deformable portion 152 disposed on the plate body 151. The plate body 151 is connected to the battery cover 130. The deformable portion 152 and the thinned region 142 of the valve plate 140 are disposed opposite each other along the thickness direction of the battery cover 130. When the temperature within the accommodating cavity is greater than or equal to a first temperature threshold, the deformable portion 152 warps toward the thinned region 142 and punctures the thinned region 142.

[0035] Further, the battery 100 disclosed in the present application is sequentially covered with the memory alloy plate 150 and the battery cover plate 130 at the opening of the shell 110, the memory alloy plate 150 is provided with the deformation part 152, the battery cover plate 130 is provided with the valve sheet 140, and the valve sheet 140 is provided with the thinning area 142. When the battery 100 is in thermal runaway, the temperature in the shell 110 rises and a large amount of gas is generated. The deformation part 152 of the memory alloy plate 150 is more sensitive to temperature changes, starts to tilt up and pierces the thinning area 142 on the valve sheet 140 to actively exhaust, the process is gentle, and the valve sheet 140 is avoided from being broken by the strong internal gas pressure and splashing.

[0036] Specifically, the memory alloy plate 150 can be made of memory alloy material as a whole, or can be made of memory alloy material only in the deformation part 152, wherein the memory alloy material includes but is not limited to nickel-titanium-based shape memory alloy (Ni-Ti SMA), copper-based shape memory alloy (Cu SMA), and iron-based shape memory alloy (Fe SMA).

[0037] More specifically, referring to Figure 4 , the deformation area is preferably a triangle with four apexes gathered together, having a one-way temperature control characteristic. When the temperature reaches 70℃, the four apexes of the triangle start to tilt up and pierce the thinning area 142 of the valve sheet 140.

[0038] In some embodiments, referring to Figure 3 , Figure 5 and Figure 8 , the connection between the main body area 141 of the valve sheet 140 and the valve hole of the battery cover plate 130 is the easy-to-break area 143, and the thickness of the easy-to-break area 143 is less than the thickness of the main body area 141 in the thickness direction of the battery cover plate 130; when the pressure in the accommodating cavity is greater than or equal to the first pressure threshold, the easy-to-break area 143 breaks.

[0039] In some embodiments, the first pressure threshold is 0.5MPa to 0.9MPa.

[0040] Further, the valve sheet 140 has the easy-to-break area 143, which breaks to quickly release pressure when the gas pressure in the accommodating cavity is too high, so as to avoid the situation that when the battery 100 is in severe thermal runaway, a large amount of gas is accumulated in the accommodating cavity in a short time, and the deformation part 152 pierces the thinning area 142 and cannot exhaust in time, resulting in explosion of the battery 100.

[0041] Specifically, the valve piece 140 is preferably integrally formed with the battery cover plate 130, and a breakable groove is formed between the valve piece 140 and the battery cover plate 130 by cutting. The breakable groove can be distributed along the entire circumference of the valve piece 140, or only 1 / 2 or 3 / 4 of the circumference of the valve piece 140, so as to avoid the valve piece 140 and the battery cover plate 130 from being separated and splashing when the breakable area 143 breaks.

[0042] In some embodiments, with reference to Figure 4 , Figure 5 and Figure 8 , the plate body 151 of the memory alloy plate 150 has a pressure relief hole 153, which is arranged opposite to the breakable area 143 in the thickness direction of the battery cover plate 130.

[0043] Further, the memory alloy plate 150 is provided with the pressure relief hole 153, which is opposite to the breakable area 143, so as to facilitate the exhaust of the breakable area 143 when the gas pressure in the accommodating cavity is too large.

[0044] It should be noted that when the gas pressure in the accommodating cavity is too large, the area of the breakable area 143 opposite to the pressure relief hole 153 receives a larger pressure and is more likely to break earlier than other areas of the breakable area 143, thereby completing the exhaust work first.

[0045] In addition, the application can also not be provided with the pressure relief hole 153 on the memory alloy plate 150, and the memory alloy plate 150 is not completely sealed and isolated from the accommodating cavity. In the case of not setting the pressure relief hole 153, the gas in the accommodating cavity can break the breakable area 143 from the deformation area or other gaps, and the same effect of rapid exhaust can be achieved. The above embodiments still belong to the protection scope of the application.

[0046] In some embodiments, with reference to Figure 5 and Figure 7 , the battery 100 further comprises an anti-corrosion film 160 arranged in the accommodating cavity, and the anti-corrosion film 160 is located between the electrode assembly 120 and the memory alloy plate 150 and seals and isolates the electrolyte in the accommodating cavity from the memory alloy plate 150; when the temperature is equal to or higher than the first temperature threshold, the anti-corrosion film 160 partially or completely melts.

[0047] In some embodiments, with reference to Figure 9The anti-corrosion film 160 includes a film body 161 and a covering wax 162. The film body 161 is connected to the battery cover 130 through a connecting glue. The film body 161 has a plurality of through holes, and the covering wax 162 is respectively sealed in the plurality of through holes; when the temperature in the accommodating cavity is higher than or equal to the first temperature threshold, the covering wax 162 melts; when the temperature in the accommodating cavity is greater than or equal to the second temperature threshold, the connecting glue melts; wherein, the second temperature threshold is greater than the first temperature threshold.

[0048] In some embodiments, the first temperature threshold is selected in a range of 60° C. to 70° C., the second temperature threshold is selected in a range of 65° C. to 80° C., and the second temperature threshold is greater than the first temperature threshold.

[0049] Furthermore, the anti-corrosion film 160 is primarily used to prevent the electrolyte from corroding the memory alloy plate 150 during normal use of the battery 100. Furthermore, the melting of the anti-corrosion film 160 is preferably synchronized with the puncturing of the thinned area 142 by the deformed portion 152. When the temperature within the accommodating chamber reaches a first temperature threshold, the covering wax 162 begins to melt, exposing the through-hole, and the deformed portion 152 begins to warp upward and puncture the thinned area 142. The gas within the accommodating chamber flows from the through-hole to the punctured thinned area 142 and then discharges from the battery 100. When the temperature within the accommodating chamber reaches a second temperature threshold, the battery 100 experiences severe thermal runaway, the connecting glue melts, the anti-corrosion film 160 falls off the battery cover 130, and simultaneously the fragile area 143 of the valve plate 140 breaks. The gas within the accommodating chamber is no longer blocked by the membrane body 161 of the anti-corrosion film 160, allowing it to be easily discharged from the broken fragile area 143.

[0050] Specifically, membrane body 161 includes, but is not limited to, anti-corrosion functional materials such as linear polyethylene and polypropylene. Covering wax 162 is preferably a thin layer of paraffin wax with a melting point of 60°C to 70°C. The through-holes covered by covering wax 162 have a diameter of 3mm to 5mm. Furthermore, the melting point of anti-corrosion membrane 160 and the connecting adhesive is 65°C to 80°C.

[0051] In some embodiments, reference Figure 6 Male buckles 1541 are provided at both ends of the plate body 151 of the memory alloy plate 150, and female buckles are provided on both sides of the length direction of the battery cover plate 130, and the male buckles 1541 are snap-connected with the female buckles.

[0052] In some embodiments, reference Figure 10 The two ends of the plate body 151 of the memory alloy plate 150 are provided with mortise and tenon ends 1542, and the two sides of the battery cover 130 in the length direction are provided with mortise and tenon grooves, and the mortise and tenon ends 1542 and the mortise and tenon grooves are connected by mortise and tenon through positioning pins 1543.

[0053] Furthermore, both ends of the plate body 151 of the memory alloy plate 150 are connecting parts 154. The connecting parts 154 and the battery cover plate 130 can be connected in a variety of ways, preferably a snap connection or a mortise and tenon connection, which is firm and easy to manufacture.

[0054] In a second aspect, the present application further provides an electrical device, comprising the battery 100 in the first aspect, wherein the battery 100 provides the electrical energy required for the electrical device to operate.

[0055] Specifically, the electric device in the second aspect includes the battery 100 in the first aspect, and thus the electric device in the second aspect has all the beneficial effects of the battery 100 in the first aspect.

[0056] It should be noted that the battery 100 and the electrical equipment of the present application also include other components. Only the components related to this solution are listed here, but this does not limit the composition of the battery 100 and the electrical equipment. For example, Figure 2 The battery 100 further includes a plastic plate 170, which is disposed in the receiving cavity and between the battery cover 130 and the electrode assembly 120. Figure 2 In the figure, the valve plate 140, the memory alloy plate 150 and the anti-corrosion film 160 are assembled together with the battery cover 130 and are not shown separately. Figure 1 The battery cover 130 is further provided with a pole 131 , which is electrically connected to the electrode assembly 120 and will not be described in detail here.

[0057] Although the embodiments of the present application have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present application, and such modifications and variations shall fall within the scope defined by the appended claims.

Claims

1. A battery, characterized in that: include: A housing (110), wherein the housing (110) has a receiving cavity; an electrode assembly (120), the electrode assembly (120) being disposed in the accommodating cavity; A battery cover plate (130), the battery cover plate (130) is connected to the housing (110) and covers the accommodating cavity; the battery cover plate (130) has a valve hole; the battery cover plate (130) has a thickness direction; a valve plate (140), the valve plate (140) being connected to the battery cover plate (130) and covering the valve hole, the valve plate (140) comprising a main body region (141) and a thinning region (142) located in the middle of the main body region (141), and along the thickness direction of the battery cover plate (130), the thickness of the thinning region (142) is less than the thickness of the main body region (141); A memory alloy plate (150), the memory alloy plate (150) being disposed in the accommodating cavity and being located between the electrode assembly (120) and the battery cover plate (130); the memory alloy plate (150) comprising a plate body (151) and a deformation portion (152) disposed on the plate body (151); the plate body (151) being connected to the battery cover plate (130); the deformation portion (152) and the thinning area (142) of the valve plate (140) being arranged relative to each other along the thickness direction of the battery cover plate (130); when the temperature in the accommodating cavity is higher than or equal to a first temperature threshold, the deformation portion (152) warps toward the thinning area (142) and punctures the thinning area (142); An anti-corrosion film (160), wherein the anti-corrosion film (160) is disposed in the accommodating cavity, and the anti-corrosion film (160) is located between the electrode assembly (120) and the memory alloy plate (150), and seals and isolates the electrolyte in the accommodating cavity from the memory alloy plate (150); when the temperature is equal to or higher than the first temperature threshold, the anti-corrosion film (160) partially or completely melts.

2. The battery according to claim 1, characterized in that The connection between the main body area (141) of the valve plate (140) and the valve hole of the battery cover (130) is a breakable area (143). Along the thickness direction of the battery cover (130), the thickness of the breakable area (143) is less than the thickness of the main body area (141); when the pressure in the accommodating cavity is greater than or equal to a first pressure threshold, the breakable area (143) breaks.

3. The battery according to claim 2, characterized in that The first pressure threshold is 0.5 MPa to 0.9 MPa.

4. The battery according to claim 2, characterized in that The plate body (151) of the memory alloy plate (150) has a pressure relief hole (153), and along the thickness direction of the battery cover plate (130), the pressure relief hole (153) is arranged opposite to at least a part of the fragile area (143).

5. The battery according to claim 1, characterized in that The anti-corrosion film (160) includes a film body (161) and a covering wax (162), wherein the film body (161) is connected to the battery cover (130) via a connecting glue, and the film body (161) has a plurality of through holes, wherein the covering wax (162) is respectively sealed in the plurality of through holes; when the temperature in the accommodating cavity is higher than or equal to the first temperature threshold, the covering wax (162) melts; when the temperature in the accommodating cavity is higher than or equal to a second temperature threshold, the connecting glue melts; wherein the second temperature threshold is higher than the first temperature threshold.

6. The battery according to claim 5, characterized in that The first temperature threshold is 60° C. to 70° C., the second temperature threshold is 65° C. to 80° C., and the second temperature threshold is greater than the first temperature threshold.

7. The battery according to any one of claims 1 to 6, characterized in that Male buckles (1541) are provided at both ends of the plate body (151) of the memory alloy plate (150), and female buckles are provided on both sides in the length direction of the battery cover plate (130), and the male buckles (1541) are snap-connected with the female buckles.

8. The battery according to any one of claims 1 to 6, characterized in that The plate body (151) of the memory alloy plate (150) is provided with mortise and tenon ends (1542) at both ends, and the battery cover plate (130) is provided with mortise and tenon grooves on both sides in the length direction. The mortise and tenon ends (1542) and the mortise and tenon grooves are connected by mortise and tenon cooperation via positioning pins (1543).

9. An electrical device, characterized in that: The battery (100) comprises the battery (100) according to any one of claims 1 to 8, wherein the battery (100) provides the electrical energy required for the electrical device to operate.

Images