Thermal runaway mitigation battery

Abstract

The application belongs to the technical field of battery thermal runaway inhibition, and particularly relates to a thermal runaway inhibition battery, which comprises a shell with an opening, a plurality of negative electrode sheets, a plurality of positive electrode sheets, a plurality of separators arranged alternately with the negative electrode sheets and the positive electrode sheets in the shell, a mylar film wrapped around the periphery of the negative electrode sheets, the positive electrode sheets and the separators, and filled with electrolyte and phase change material between the shell, the phase change material being changed into a gas phase when heated, a cover plate connected to the shell and blocking the opening, a negative electrode column connected to the cover plate and connected to the negative electrode sheets, a positive electrode column connected to the cover plate and connected to the positive electrode sheets, and a pressure relief valve connected to the cover plate.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of battery thermal runaway inhibition, and particularly relates to a thermal runaway inhibition battery. BACKGROUND

[0002] Lithium / sodium ion batteries have high energy density and long cycle life, and are widely used in pure electric vehicles, low-speed electric vehicles, electrochemical energy storage and other fields.

[0003] In practical application, lithium / sodium ion battery safety accidents occur frequently, which are mainly caused by thermal runaway caused by external damage and internal micro-short circuit.

[0004] At present, lithium / sodium ion battery thermal runaway is mainly inhibited from the aspect of electrical safety protection. This kind of technical scheme cannot effectively and timely and efficiently export the heat when lithium / sodium ion battery thermal runaway occurs, and cannot effectively avoid safety accidents.

[0005] The present application is proposed in view of the existence of the above technical defects.

[0006] It should be noted that the disclosure of the above background art content is only used to assist in understanding the inventive concept and technical solutions of the present application, and it does not necessarily belong to the prior art of the present patent application. In the absence of clear evidence that the above content has been disclosed on the filing date of the present application, the above background art should not be used to evaluate the novelty and inventiveness of the present application. SUMMARY

[0007] The purpose of the present application is to provide a thermal runaway inhibition battery to overcome or alleviate at least one aspect of the known technical defects.

[0008] The technical solution of the present application is:

[0009] A thermal runaway inhibition battery comprises:

[0010] A shell having an opening thereon;

[0011] A plurality of negative electrode sheets;

[0012] A plurality of positive electrode sheets;

[0013] A plurality of separators are arranged between each negative electrode sheet and positive electrode sheet in the shell;

[0014] A mylar film is wrapped around the periphery of each negative electrode sheet, positive electrode sheet and separator, and is filled with a phase change material between the shell and the mylar film; the phase change material changes into a gas phase when heated;

[0015] A cover plate is connected to the shell to block the opening;

[0016] A negative electrode column is connected to the cover plate and connected to each negative electrode sheet;

[0017] Positive pole, connected to the cover plate, connected to each positive sheet;

[0018] Pressure relief valve, connected to the cover plate.

[0019] According to at least one embodiment of the present application, in the thermal runaway suppression battery described above, the inner side of the mylar film is tightly attached to the two layers of separators.

[0020] According to at least one embodiment of the present application, in the thermal runaway suppression battery described above, the inner side of the mylar film, each negative sheet, positive sheet, and separator are wrapped with a polyimide tape.

[0021] According to at least one embodiment of the present application, in the thermal runaway suppression battery described above, the outer wall of the mylar film is shaped with a plurality of flow guide grooves.

[0022] According to at least one embodiment of the present application, in the thermal runaway suppression battery described above, the phase change material occupies 50% to 80% of the space between the shell and the mylar film.

[0023] According to at least one embodiment of the present application, in the thermal runaway suppression battery described above, the phase change material is a liquid-gas phase change material, which is an ester material.

[0024] According to at least one embodiment of the present application, in the thermal runaway suppression battery described above, the phase change material contains a flame retardant.

[0025] The present application has at least the following beneficial effects:

[0026] A thermal runaway suppression battery is provided, which is designed to fill a phase change material between the shell and the mylar film. When the battery temperature rises, the phase change material will be heated to become a gas phase, absorbing a large amount of heat in the form of phase change. When the battery temperature rises sharply, a large amount of gas will be generated, causing the pressure in the shell to rise sharply, thereby causing the pressure relief valve provided on the shell to open, and the gas to be discharged through the pressure relief valve, thereby relieving the pressure in the shell. On the one hand, it can prevent the shell from exploding due to excessive internal pressure. On the other hand, the gas carries a large amount of heat when it is discharged, which can timely and efficiently discharge the heat, suppress the thermal runaway of the battery, and avoid safety accidents. BRIEF DESCRIPTION OF DRAWINGS

[0027] Fig. 1 is a schematic diagram of the thermal runaway suppression battery provided by the embodiment of the present application;

[0028] Fig. 2 is a partial schematic diagram of the mylar film provided by the embodiment of the present application;

[0029] Among them:

[0030] 1 - housing; 2 - negative tab; 3 - positive tab; 4 - separator; 5 - mylar film; 6 - cover plate; 7 - negative post; 8 - positive post; 9 - pressure relief valve.

[0031] In order to better illustrate the present embodiment, some components in the drawings can be omitted, enlarged or reduced, and do not represent the actual size of the product. In addition, the drawings are only used for illustrative purposes and cannot be understood as a limitation on the present patent. DETAILED DESCRIPTION

[0032] In order to make the technical solutions of the present application and its advantages clearer, the technical solutions of the present application will be further clearly and completely described in detail below in combination with the drawings. It should be understood that the specific embodiments described herein are only some embodiments of the present application, which are used to explain the present application, but not to limit the present application. It should be noted that, for the purpose of description, only parts related to the present application are shown in the drawings, and other related parts can be referred to the general design. In the case of no conflict, the embodiments in the present application and the technical features in the embodiments can be combined to obtain new embodiments.

[0033] In addition, unless otherwise defined, the technical terms or scientific terms used in the present application description should be the general meaning understood by the general technical personnel in the field to which the present application belongs. The words indicating the relative direction or position relationship, such as "upper", "lower", "left", "right", "center", "vertical", "horizontal", "inner", "outer" and the like used in the present application description are only used to indicate the relative direction or position relationship, and not to imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and the relative position relationship may also change accordingly when the absolute position of the described object changes, therefore, it cannot be understood as a limitation on the present application. The "first", "second", "third" and similar terms used in the present application description are only for the purpose of description, and are used to distinguish different components, and cannot be understood as indicating or implying relative importance. The "one", "an" or "the" and similar terms used in the present application description should not be understood as an absolute limitation on the quantity, but should be understood as the existence of at least one. The "include" or "contain" and similar terms used in the present application description mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, and do not exclude other elements or objects.

[0034] In addition, it needs to be explained that, unless otherwise explicitly specified and limited, the "installation", "connection", "connection" and similar words used in the description of the application should be understood broadly, for example, the connection can be fixed connection, or detachable connection, or integral connection; can be mechanical connection, or electrical connection; can be directly connected, or indirectly connected through intermediate medium, or the internal communication of two elements, and those skilled in the art can understand the specific meaning of the application according to the specific circumstances.

[0035] The application will be further described below in conjunction with the accompanying drawings Figs. 1-2 The application will be further described below in conjunction with the accompanying drawings

[0036] A thermal runaway inhibition battery comprises:

[0037] A shell 1 with an opening thereon, which can be made of aluminum;

[0038] A plurality of negative electrode sheets 2, which can be made by stirring and uniformly mixing negative electrode materials in a certain proportion, coating the negative electrode materials on the positive electrode current collector, and then performing baking, rolling and cutting processes;

[0039] A plurality of positive electrode sheets 3, which can be made by stirring and uniformly mixing negative electrode materials in a certain proportion, coating the negative electrode materials on the positive electrode current collector, and then performing baking, rolling and cutting processes;

[0040] A plurality of separators 4, which are arranged between each of the negative electrode sheets 2 and the positive electrode sheets 3 in the shell 1;

[0041] A mylar film 5, which is wrapped around the outer periphery of each of the negative electrode sheets 2, the positive electrode sheets 3 and the separators 4, is located in the shell, has a closed bottom end and an open top end, is filled with electrolyte, and is filled with phase change material between the shell 1; the phase change material changes into gas phase when heated;

[0042] A cover plate 6, which is connected to the shell 1, specifically can be laser welded, and seals the opening; the phase change material can be filled before the cover plate 6 is connected, the electrolyte can be filled through a liquid injection hole formed on the cover plate 6, and the liquid injection hole is sealed with a sealing nail after the filling is completed, and the cover plate 6 is laser welded;

[0043] A negative electrode post 7, which is connected to the cover plate 6 and connected to each of the negative electrode sheets 2, specifically can be connected through a pin;

[0044] A positive electrode post 8, which is connected to the cover plate 6 and connected to each of the positive electrode sheets 3, specifically can be connected through a pin;

[0045] A pressure relief valve 9, which is connected to the cover plate 6.

[0046] For the thermal runaway suppression battery disclosed in the above embodiment, those skilled in the art can understand that when the temperature of the battery rises, the phase change material filled between the shell 1 and the mylar film 5 will be heated to become a gas phase, absorbing a large amount of heat in the form of phase change. When the temperature of the battery rises sharply, a large amount of gas will be generated, causing the pressure in the shell 1 to rise sharply, so that the pressure relief valve 9 is opened, and the gas is discharged through the pressure relief valve 9 to relieve the pressure in the shell. On the one hand, it can prevent the shell 1 from exploding due to excessive pressure, and on the other hand, the gas carries a large amount of heat when it is discharged, so that the heat can be discharged in time and efficiently, suppressing the thermal runaway of the battery and avoiding safety accidents. The opening pressure of the pressure relief valve 9 can be set by the relevant technical personnel according to the actual needs when applying the present application, and will not be further limited here.

[0047] In some optional embodiments, in the thermal runaway suppression battery described above, the inner side of the mylar film 5 is tightly attached to the two layers of diaphragm 4, which has a protective effect.

[0048] In some optional embodiments, in the thermal runaway suppression battery described above, the inner side of the mylar film 5, each negative plate 2, positive plate 3, and diaphragm 4 can be combined in a laminated or wound manner and wrapped with a polyimide tape for fastening.

[0049] In some optional embodiments, in the thermal runaway suppression battery described above, the outer wall of the mylar film 5 is shaped with a plurality of flow guide grooves to guide the gas generated by the phase change material, so that the gas can be efficiently discharged through the pressure relief valve 9 when the pressure in the shell 1 is too high.

[0050] In some optional embodiments, in the thermal runaway suppression battery described above, the phase change material occupies 50% to 80% of the space between the shell 1 and the mylar film 5, leaving a space margin for the phase change of the phase change material to avoid the initial stage of phase change, even if the pressure in the shell 1 is too high, causing the pressure relief valve 9 to open and the gas to be discharged, reducing the loss of the phase change material and maintaining the stability of the overall structure.

[0051] In some optional embodiments, in the thermal runaway inhibition battery described above, the phase change material is a liquid-gas phase change material, which can be further selected from ester materials. The ester material is compatible with the general electrolyte, does not react with the electrolyte, does not affect the properties of the electrolyte, can ensure the performance of the battery, and can be a butanediol ester compound. The ester material can also be selected from R134a composite phase change materials. When the R134a composite phase change material is filled, it needs to be injected under pressure, and the injection pressure is not less than 1 Mpa to ensure that it is in a liquid state. The liquid-gas phase change material is designed to undergo phase change in the range of 50° to 60°, so as to maintain the battery temperature below 60°, avoid high temperature, and prevent safety accidents. In addition, a flame retardant can be added to the phase change material to further reduce the risk of explosion caused by rapid temperature rise of the battery.

[0052] The embodiments in the description are described in a progressive manner, and each embodiment focuses on the difference from other embodiments. The same or similar parts of each embodiment can be referred to each other.

[0053] So far, the technical solution of the application has been described in combination with the preferred embodiments shown in the drawings. Those skilled in the art should understand that the protection scope of the application is obviously not limited to these specific embodiments. Without deviating from the principles of the application, those skilled in the art can make equivalent changes or replacements to the related technical features. The technical solutions after the changes or replacements will fall within the protection scope of the application.

Claims

1. A thermal runaway inhibition battery, characterized by, The application relates to a thermal runaway inhibition battery, which comprises the following parts: a shell (1) with an opening on the top; a plurality of negative electrode sheets (2); a plurality of positive electrode sheets (3); a plurality of separators (4) arranged between the negative electrode sheets (2) and the positive electrode sheets (3) in the shell (1); a mylar film (5) wrapped around the periphery of the negative electrode sheets (2), the positive electrode sheets (3) and the separators (4), and filled with electrolyte, and the shell (1) is filled with phase change material; the phase change material is changed into gas phase by heat; a cover plate (6) connected to the shell (1) and sealing the opening; a negative electrode column (7) connected to the cover plate (6) and connected to the negative electrode sheets (2); a positive electrode column (8) connected to the cover plate (6) and connected to the positive electrode sheets (3); a pressure relief valve (9) connected to the cover plate (6); the outer wall of the mylar film (5) is formed with a plurality of flow guide grooves.

2. The thermal runaway inhibition battery according to claim 1, wherein the inner side of the mylar film (5) is tightly attached to the two separators (4).

3. The thermal runaway inhibition battery according to claim 1, wherein the inner side of the mylar film (5) is wrapped with a polyimide adhesive tape.

4. The thermal runaway inhibition battery according to claim 1, wherein the phase change material occupies 50%-80% of the space between the shell (1) and the mylar film (5).

5. The thermal runaway inhibition battery according to claim 1, wherein the phase change material is a liquid-gas phase change material, which is an ester material.

6. The thermal runaway inhibition battery according to claim 5, wherein the phase change material is doped with a flame retardant.

Images