A lithium-ion battery casing and a lithium-ion battery

Abstract

This invention discloses a lithium-ion battery casing and a lithium-ion battery. The lithium-ion battery casing includes a battery compartment and a cover. The battery compartment has a receiving cavity for housing the battery body. The battery compartment includes a first cavity wall with a first opening communicating with the receiving cavity. A pressure-sensitive plug is provided on the first opening to seal it. When the pressure within the receiving cavity exceeds a preset value, the pressure-sensitive plug disengages from the first opening. The cover is disposed on the receiving cavity and, together with the first cavity wall, forms a liquid storage cavity containing a flame-retardant liquid. This invention can mitigate or prevent the combustion of flammable gases when the battery body generates a large amount of flammable gas due to thermal runaway, thereby improving the safety of the lithium-ion battery during use.

Description

Technical Field

[0001] This invention relates to the field of battery safety technology, and in particular to a lithium-ion battery casing and a lithium-ion battery. Background Technology

[0002] With the widespread adoption of new energy technologies, lithium-ion batteries are increasingly used, gradually permeating all aspects of people's lives. For example, power supply systems in various terminal devices utilize lithium-ion batteries. This means that people are inevitably much closer to lithium batteries in space, even in products used close to the body. However, when a lithium battery experiences thermal runaway, it instantly releases large amounts of flammable and toxic gases. The flammable gases mainly consist of CO, H2, alkanes, and alkenes. These gases can ignite upon contact with burning debris or dust from the exploding lithium battery, intensifying the combustion process. If these gases are released onto surrounding objects, they may ignite them. The toxic gases mainly consist of highly toxic products such as acrolein, propionitrile, malononitrile, naphthalene, and butenone, which can damage the respiratory tract, conjunctiva, and skin, potentially causing death. Therefore, improving the safety of lithium batteries in the event of a safety hazard has become a pressing issue for the industry.

[0003] Therefore, it is particularly important to design a lithium-ion battery casing and lithium-ion battery that can solve the above problems. Summary of the Invention

[0004] The purpose of this invention is to provide a lithium-ion battery casing and a lithium-ion battery, which can slow down or prevent the combustion of combustible gases by using flame retardant liquid when the battery body generates a large amount of combustible gas due to thermal runaway, thereby improving the safety of lithium-ion batteries during use.

[0005] To achieve the above objectives, the present invention provides a lithium-ion battery casing, comprising:

[0006] A battery compartment has a receiving cavity formed inside it. The receiving cavity is used to place the battery body. The battery compartment includes a first cavity wall with a first opening that communicates with the receiving cavity. A pressure-sensitive plug is provided on the first opening to seal the first opening. When the pressure inside the receiving cavity exceeds a preset value, the pressure-sensitive plug leaves the first opening.

[0007] A cover is disposed on the battery compartment and together with the first cavity wall of the battery compartment forms a liquid storage cavity, which stores flame retardant liquid.

[0008] Optionally, a filter element is further provided in the accommodating cavity. The filter element is located between the first cavity wall and a predetermined position of the battery body. The filter element is used to filter solid particles and allow gas to pass through.

[0009] Optionally, the liquid storage chamber also stores a foaming agent;

[0010] The cover has a second opening at one end away from the first cavity wall. The second opening is connected to the liquid storage cavity. The second opening is provided with a liquid-absorbing and foaming component. The liquid-absorbing and foaming component is used to mix the gas generated by the battery body in the accommodating cavity with the liquid in the liquid storage cavity to form foam.

[0011] Optionally, the liquid storage chamber also stores a thickener, which is used to stabilize the foam formed by mixing the gas generated by the battery body in the accommodating cavity with the liquid in the liquid storage chamber.

[0012] Optionally, the lithium-ion battery casing further includes a fixing structure, which includes a first fixing member and a second fixing member. The first fixing member and the second fixing member are disposed in the second opening, and a retaining space is formed between the first fixing member and the second fixing member. The liquid-absorbing foaming member is located in the retaining space, and the first fixing member and the second fixing member fix the liquid-absorbing foaming member.

[0013] Optionally, the distance from the first fixing member to the liquid storage cavity is less than the distance from the second fixing member to the liquid storage cavity. The first fixing member has a porous structure for allowing liquid and gas to enter the liquid-absorbing foaming member, and the second fixing member has a hollow structure for allowing the foam formed on the liquid-absorbing foaming member to permeate.

[0014] Optionally, the battery compartment includes multiple cavity walls that form the receiving cavity. The first cavity wall is one of the multiple cavity walls. The pressure-sensitive plug is integrally formed with the first cavity wall. The thickness of the connection between the pressure-sensitive plug and the first cavity wall is less than the thickness of any of the cavity walls of the battery compartment.

[0015] Optionally, the pressure-sensitive plug is made of an elastic material, and when the pressure-sensitive plug is placed in the first opening, the first cavity wall squeezes the pressure-sensitive plug to seal the first opening.

[0016] Optionally, the area of ​​the second opening is smaller than the bottom area of ​​the liquid storage cavity.

[0017] To achieve the above objectives, the present invention also discloses a lithium-ion battery, comprising the lithium-ion battery casing as described above and

[0018] A battery body is placed inside the accommodating cavity. The battery body is provided with a positive electrode lead and a negative electrode lead. The positive electrode lead is connected to the positive terminal of the battery body, and the negative electrode lead is connected to the negative terminal of the battery body. The positive electrode lead and the negative electrode lead extend out from the battery compartment.

[0019] The lithium-ion battery casing of the present invention includes a battery compartment and a cover. The battery compartment contains a receiving cavity for holding the battery body. A first opening is provided on the first cavity wall of the battery compartment, and the first opening communicates with the receiving cavity. A pressure-sensitive plug is provided on the first opening to seal it. The cover is disposed on the battery compartment and, together with the first cavity wall of the battery compartment, forms a liquid storage cavity containing flame-retardant liquid. When the battery body in the receiving cavity experiences thermal runaway and generates a large amount of flammable gas, the gas pressure in the receiving cavity will increase significantly. When the gas pressure exceeds a preset value, the pressure-sensitive plug leaves the first opening, thereby connecting the liquid storage cavity with the receiving cavity. The flame-retardant liquid in the liquid storage cavity can slow down or prevent the combustion of flammable gas, which is beneficial to improving the safety of the lithium-ion battery during use. Attached Figure Description

[0020] Figure 1 This is a cross-sectional schematic diagram of the lithium-ion battery casing according to an embodiment of the present invention.

[0021] Figure 2 for Figure 1 An enlarged schematic diagram of part A in the middle.

[0022] Figure 3 This is a cross-sectional schematic diagram of a lithium-ion battery casing according to another embodiment of the present invention.

[0023] Figure 4 This is a three-dimensional structural diagram of a lithium-ion battery according to an embodiment of the present invention.

[0024] Figure 5 This is a schematic diagram of the exploded structure of a lithium-ion battery according to an embodiment of the present invention.

[0025] Figure 6 This is a cross-sectional schematic diagram of a lithium-ion battery according to an embodiment of the present invention. Detailed Implementation

[0026] To illustrate the technical content and structural features of the present invention in detail, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0027] Please see Figures 1 to 3This invention provides a lithium-ion battery casing, including a battery compartment 1 and a cover 2. The battery compartment 1 has a receiving cavity 11 for placing the battery body. The battery compartment 1 includes a first cavity wall 12 with a first opening 16 communicating with the receiving cavity 11. The first opening 16 has a pressure-sensitive plug 14 that seals the first opening 16. When the pressure inside the receiving cavity 11 exceeds a preset value, the pressure-sensitive plug 14 leaves the first opening 16. The cover 2 is disposed on the battery compartment 1 and together with the first cavity wall 12 of the battery compartment 1, forms a liquid storage cavity 21, which stores flame-retardant liquid.

[0028] The lithium-ion battery casing of the present invention includes a battery compartment 1 and a cover 2. The battery compartment 1 has a receiving cavity 11 for placing the battery body. The first cavity wall 12 of the battery compartment 1 has a first opening 16, which communicates with the receiving cavity 11. The first opening 16 is provided with a pressure-sensitive blocking member 14, which seals the first opening 16. The cover 2 is disposed on the battery compartment 1 and together with the first cavity wall 12 of the battery compartment 1, forms a liquid storage cavity 21. The liquid storage cavity 21 stores flame retardant liquid. When the battery body in the receiving cavity 11 experiences thermal runaway and generates a large amount of combustible gas, the gas pressure in the receiving cavity 11 will increase significantly. When the gas pressure exceeds a preset value, the pressure-sensitive blocking member 14 leaves the first opening 16, thereby connecting the liquid storage cavity 21 with the receiving cavity 11. The flame retardant liquid in the liquid storage cavity 21 can slow down or prevent the combustion of combustible gas, which is beneficial to improving the safety of the lithium-ion battery during use.

[0029] Specifically, the bottom of the liquid storage cavity 21 can be the entire first cavity wall 12 or a part of the first cavity wall 12, as long as the first opening 16 and the pressure-sensitive plug 14 are located inside the liquid storage cavity 21.

[0030] Please see Figure 1 The battery compartment 1 includes multiple cavity walls, which together form a receiving cavity 11. The first cavity wall 12 is one of the multiple cavity walls. The receiving cavity 11 can be sealed or it can have holes for leading out battery leads. As long as the air pressure inside the receiving cavity 11 can force open the pressure-sensitive blockage 14 when the battery body experiences thermal runaway, this application does not impose specific limitations here.

[0031] It is understandable that flame retardant liquids can be bromine-containing compounds, chlorinated alicyclic hydrocarbons, organophosphorus compounds, etc.

[0032] Please see Figure 1 and Figure 5Specifically, a filter element 13 is also provided inside the accommodating cavity 11. The filter element 13 is located between the first cavity wall 12 and a predetermined position on the battery body. The filter element 13 is used to filter solid particles and allow gas to pass through. By intercepting solid particles splashed by the battery body during combustion within the accommodating cavity 11 through the filter element 13, the safety risks during the use of lithium batteries can be reduced.

[0033] Specifically, the predetermined position of the battery body refers to the highest position of the battery body when it is placed in the receiving cavity 11. Preferably, the filter element 13 can be attached to the surface of the first cavity wall 12 facing the receiving cavity 11.

[0034] It is understood that the filter element 13 can be a filter screen with a porous structure, the size of which can block solid particles and allow gas to pass through.

[0035] Please see Figure 1 , Figure 3 and Figure 5 In some embodiments, the liquid storage chamber 21 also stores a foaming agent; the end of the cover 2 away from the first cavity wall 12 is provided with a second opening 24, which connects to the liquid storage chamber 21. The second opening 24 is provided with a liquid-absorbing foaming element 22, which is used to mix the gas generated by the battery body in the accommodating cavity 11 with the liquid in the liquid storage chamber 21 to form foam. Through the cooperation of the liquid-absorbing foaming element 22 and the foaming agent, the flammable and harmful gas generated by the battery body can be foamed, thereby encapsulating a certain amount of harmful gas and reducing the risk of sudden leakage of harmful gas that may injure people who are unable to escape.

[0036] Specifically, the liquid-absorbing foaming component 22 can be a porous and loosely structured sponge. The liquid-absorbing foaming component 22 can absorb the liquid in the liquid storage cavity 21, thereby preventing the liquid from overflowing. When the battery body experiences thermal runaway, the large amount of gas generated will mix with the liquid in the liquid storage cavity 21 and be squeezed to the liquid-absorbing foaming component 22 under the action of gas pressure to form foam.

[0037] Understandably, the foaming agent could be sodium dodecyl sulfate.

[0038] Please see Figure 1 Specifically, the liquid storage chamber 21 also stores a thickener, which is used to stabilize the foam formed by mixing the gas generated by the battery body in the accommodating cavity 11 with the liquid in the liquid storage chamber 21. By adding a thickener to the liquid in the liquid storage chamber 21, the generated foam is less likely to collapse.

[0039] It is understandable that thickeners can be various fatty alcohols and fatty acids.

[0040] Please see Figure 1 and Figures 3 to 5In some embodiments, the lithium-ion battery casing further includes a fixing structure 23, which includes a first fixing member 231 and a second fixing member 232. The first fixing member 231 and the second fixing member 232 are disposed in the second opening 24, and a retaining space 25 is formed between the first fixing member 231 and the second fixing member 232. The liquid-absorbing foaming member 22 is located in the retaining space 25, and the first fixing member 231 and the second fixing member 232 fix the liquid-absorbing foaming member 22. The fixing structure 23 can fix the liquid-absorbing foaming member 22 at the second opening 24 of the cover 2, preventing the liquid-absorbing foaming member 22 from shifting.

[0041] Please see Figure 1 and Figures 3 to 5 Furthermore, the distance from the first fixing member 231 to the liquid storage cavity 21 is less than the distance from the second fixing member 232 to the liquid storage cavity 21. The first fixing member 231 has a porous structure for allowing liquid and gas to enter the liquid-absorbing foaming member 22. The second fixing member 232 has a hollow structure for allowing the foam formed on the liquid-absorbing foaming member 22 to permeate.

[0042] Please see Figure 1 and Figure 2 In some embodiments, the battery compartment 1 includes multiple cavity walls forming a receiving cavity 11. A first cavity wall 12 is one of these cavity walls. A pressure-sensitive plug 14 is integrally formed with the first cavity wall 12. The thickness of the connection 15 between the pressure-sensitive plug 14 and the first cavity wall 12 is less than the thickness of any other cavity wall in the battery compartment 1. When the air pressure inside the receiving cavity 11 increases suddenly, the connection 15 between the pressure-sensitive plug 14 and the first cavity wall 12 is the weakest point. Under the action of air pressure, the connection 15 is prone to breakage, causing the pressure-sensitive plug 14 to detach from the first cavity wall 12, thus connecting the liquid storage cavity 21 with the receiving cavity 11.

[0043] It is understandable that when the pressure-sensitive plug 14 is integrally formed with the first cavity wall 12, the first opening 16 refers to the notch formed by the pressure-sensitive plug 14 separating from the first cavity wall 12. The pressure-sensitive plug 14 can be a part of the first cavity wall 12, and the connection 15 between this part and other parts is less than the thickness of any part of the cavity wall of the battery compartment 1. This connection 15 can be formed by high-pressure imprinting. Therefore, the preset pressure value refers to the force that the connection 15 between the pressure-sensitive plug 14 and the first cavity wall 12 can withstand.

[0044] Please see Figure 3In some embodiments, the pressure-sensitive plug 14 is made of an elastic material. When the pressure-sensitive plug 14 is placed in the first opening 16, the first cavity wall 12 squeezes the pressure-sensitive plug 14 to seal the first opening 16. The pressure-sensitive plug 14 presses against the first opening 16 through its own elastic deformation, thereby sealing the first opening 16. When the air pressure in the accommodating cavity 11 increases suddenly, the pressure-sensitive plug 14 is subjected to pressure away from the accommodating cavity 11, and thus leaves the first opening 16.

[0045] Please see Figure 1 and Figure 3 Specifically, the area of ​​the second opening 24 is smaller than the bottom area of ​​the liquid storage cavity 21. This arrangement increases the pressure of the gas inside the liquid storage cavity 21 on the liquid-absorbing and foaming element 22, which is beneficial for foam formation.

[0046] It is understandable that the cross-sectional shape of the liquid storage cavity 21 can be frustum-shaped, that is, the area of ​​the bottom of the liquid storage cavity 21 gradually decreases towards the top.

[0047] Please see Figure 1 and Figures 4 to 6 The present invention also discloses a lithium-ion battery, characterized in that it includes a lithium-ion battery casing as described above and a battery body 3. The battery body 3 is placed inside a receiving cavity 11. The battery body 3 is provided with a positive electrode lead 31 and a negative electrode lead 32. The positive electrode lead 31 is connected to the positive electrode of the battery body 3, and the negative electrode lead 32 is connected to the negative electrode of the battery body 3. The positive electrode lead 31 and the negative electrode lead 32 extend out from the battery compartment 1. The positive electrode lead 31 and the negative electrode lead 32 extending out from the battery compartment 1 can be used to connect to electrical equipment and provide power to the electrical equipment.

[0048] Specifically, the cavity wall of the battery compartment 1 is provided with two lead holes 33. The two lead holes 33 are used to lead out the positive lead 31 and the negative lead 32 respectively. After the positive lead 31 and the negative lead 32 are passed out, the two lead holes 33 can be sealed by filling the gap between the positive lead 31 and the negative lead 32 and the two lead holes 33 with curing adhesive.

[0049] The above-disclosed examples are merely preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, any equivalent variations made in accordance with the claims of the present invention are within the scope of the present invention.

Claims

1. A lithium-ion battery casing, characterized in that, include: A battery compartment has a receiving cavity formed inside it. The receiving cavity is used to place the battery body. The battery compartment includes a first cavity wall with a first opening that communicates with the receiving cavity. A pressure-sensitive plug is provided on the first opening to seal the first opening. When the pressure inside the receiving cavity exceeds a preset value, the pressure-sensitive plug leaves the first opening. A cover is disposed on the battery compartment and together with the first cavity wall of the battery compartment forms a liquid storage cavity, which stores flame retardant liquid. The liquid storage chamber also stores a foaming agent; The cover is provided with a second opening at one end away from the first cavity wall. The second opening is connected to the liquid storage cavity. The second opening is provided with a liquid-absorbing foaming element. The liquid-absorbing foaming element is a porous and loosely structured sponge. The liquid-absorbing foaming element is used to mix the gas generated by the battery body in the accommodating cavity with the liquid in the liquid storage cavity to form foam. It also includes a fixing structure, which includes a first fixing member and a second fixing member. The first fixing member and the second fixing member are disposed in the second opening, and a retaining space is formed between the first fixing member and the second fixing member. The liquid-absorbing foaming member is located in the retaining space, and the first fixing member and the second fixing member fix the liquid-absorbing foaming member. The distance from the first fixing member to the liquid storage cavity is less than the distance from the second fixing member to the liquid storage cavity. The first fixing member has a porous structure for allowing liquid and gas to enter the liquid-absorbing foaming member. The second fixing member has a hollow structure for allowing the foam formed on the liquid-absorbing foaming member to permeate.

2. The lithium-ion battery casing according to claim 1, characterized in that, The accommodating cavity is also provided with a filter element, which is located between the first cavity wall and a predetermined position of the battery body. The filter element is used to filter solid particles and allow gas to pass through.

3. The lithium-ion battery casing according to claim 1, characterized in that, The liquid storage chamber also stores a thickener, which is used to stabilize the foam formed by mixing the gas generated by the battery body in the accommodating cavity with the liquid in the liquid storage chamber.

4. The lithium-ion battery casing according to claim 1, characterized in that, The battery compartment includes multiple cavity walls that form the accommodating cavity. The first cavity wall is one of the multiple cavity walls. The pressure-sensitive plug is integrally formed with the first cavity wall. The thickness of the connection between the pressure-sensitive plug and the first cavity wall is less than the thickness of any of the cavity walls of the battery compartment.

5. The lithium-ion battery casing according to claim 1, characterized in that, The pressure-sensitive plug is made of an elastic material. When the pressure-sensitive plug is placed in the first opening, the first cavity wall squeezes the pressure-sensitive plug to seal the first opening.

6. The lithium-ion battery casing according to claim 1, characterized in that, The area of ​​the second opening is smaller than the bottom area of ​​the liquid storage cavity.

7. A lithium-ion battery, characterized in that, Including the lithium-ion battery casing as described in any one of claims 1-6 and A battery body is placed inside the accommodating cavity. The battery body is provided with a positive electrode lead and a negative electrode lead. The positive electrode lead is connected to the positive terminal of the battery body, and the negative electrode lead is connected to the negative terminal of the battery body. The positive electrode lead and the negative electrode lead extend out from the battery compartment.

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