Battery shell and lithium battery

Abstract

The utility model provides a battery shell and a lithium battery, and relates to the technical field of batteries, a far infrared ceramic coating is arranged on the outer side surface of a shell body, when the battery is charged at low temperature at low power for self-heating, the self-heating temperature of the battery is released outwards through the shell body, the far infrared ceramic coating absorbs the heat released by the shell body, and the lithium battery is charged at low power. The absorbed heat is converted into far infrared radiation, and then the heat is transferred back to the interior of the battery in a radiation heating mode. The radiated heat can increase the temperature in the battery shell, so that the self-heating capacity and the heat preservation performance of the battery are improved, the radiation characteristic of the coating is beneficial to reducing rapid reduction of the temperature of the battery and avoiding heat loss, and compared with a traditional heating film or heat preservation cotton, the mode has the advantages that the space occupation is reduced, and meanwhile, the heat preservation efficiency is improved. And the heat preservation effect is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery technology field especially relates to a battery shell and lithium cell. BACKGROUND

[0002] Temperature has great influence on the performance of power battery, when the vehicle using power battery is used in high-cold area, the capacity and voltage of battery charging and discharging will be greatly reduced, influence the use of vehicle. Therefore, for the power battery used in cold environment, it is necessary to take heat preservation measures to ensure that the battery has sufficient power, so that the power performance and endurance mileage of the whole vehicle can be improved, and the economy of the whole vehicle is improved.

[0003] In the prior art, heat preservation is carried out by adding a heating film or heat preservation cotton at the bottom of the battery pack, but the use of heating film will cause the heating film to fall off and shift, and further cause thermal runaway; the use of heat preservation cotton will occupy the space at the bottom of the battery shell and further reduce the space utilization, and the heat preservation cotton is easy to separate between the bottom plate and the bottom guard plate of the battery pack, so that heat preservation failure will occur during long-term use. SUMMARY

[0004] Therefore, the utility model provides a battery shell and lithium cell, which improves the low-temperature heat preservation capacity of the battery shell.

[0005] The technical scheme of the utility model is as follows:

[0006] On the one hand, the utility model provides a battery shell, which comprises a shell body, and a far-infrared ceramic coating is arranged on the outer side of the shell body.

[0007] On the basis of the above technical scheme, preferably, the far-infrared ceramic coating is composed of at least one ceramic material, and the ceramic material is selected from one or more of alumina, titania, silicon nitride and zircon.

[0008] On the basis of the above technical scheme, preferably, the far-infrared ceramic coating has a radiation rate greater than 0.8 in the far-infrared wave band of 8-14 mu m.

[0009] On the basis of the above technical scheme, preferably, the thermal reflectivity of the far-infrared ceramic coating is greater than 80%.

[0010] On the basis of the above technical scheme, preferably, the far-infrared ceramic coating has a microporous structure, and the porosity of the far-infrared ceramic coating is 5-40%.

[0011] On the basis of the above technical scheme, preferably, the thickness of the far-infrared ceramic coating is 0.5-10 mu m.

[0012] On the basis of the above technical scheme, preferably, the far-infrared ceramic coating is applied on the outer side of the shell body by spraying, sputtering, dipping or chemical vapor deposition process.

[0013] On the basis of the above technical scheme, preferably, the outer surface of the far-infrared ceramic coating is further provided with a blue film.

[0014] In the second aspect, the utility model discloses a lithium battery, including core package, top cap and the battery shell of first aspect, the core package sets up in the battery shell, and top cap fixedly arranged in the opening end of battery shell is electrically connected with core package.

[0015] The utility model has the following beneficial effects relative to the prior art:

[0016] (1) by setting far-infrared ceramic coating on the outer side of the shell body, when the battery is heated at low temperature at low power, the temperature of the battery is released outward through the shell body, the far-infrared ceramic coating absorbs the heat released by the shell body, converts the absorbed heat into far-infrared radiation, and then transfers the heat back to the battery interior by radiation heating. The radiated heat can increase the temperature inside the battery shell, thereby helping to improve the self-heating capacity and heat retention performance of the battery. The radiation characteristics of the coating help to reduce the rapid reduction of battery temperature and avoid heat loss. Compared with traditional heating films or heat-retaining cotton, this method reduces the space occupation while improving the heat retention effect.

[0017] (2) the far-infrared ceramic coating is arranged on the vertical side of the shell body, and the bottom surface of the shell body is not arranged. In this way, when multiple batteries are grouped, the heat released by the battery charging and discharging is absorbed by the far-infrared ceramic coating and radiated into the battery interior, avoiding heat transfer to the outside of the battery. To some extent, the temperature diffusion between the batteries can be inhibited, and at the same time, the high temperature generated during the discharging process of the battery can be directly transferred downward from the bottom of the shell body, realizing the directional discharge of the heat released by the battery from the bottom of the shell body, and avoiding the diffusion of the heat released by the battery from the side of the battery to other surrounding batteries.

[0018] (3) by setting the far-infrared ceramic coating, its emissivity in the far-infrared waveband of 8 μm ~ 14 μm is greater than 0.8. The coating with an emissivity greater than 0.8 has strong heat radiation capacity, especially in the far-infrared waveband of 8 μm ~ 14 μm, the high emissivity of the coating enables it to efficiently absorb and radiate heat, thereby accelerating the temperature rise of the battery, especially in a low-temperature environment, which can significantly improve the temperature rise efficiency of the battery, optimize the low-temperature charging performance, and avoid performance degradation and safety hazards caused by excessively low temperature.

[0019] (4) The thermal reflectivity of the far-infrared ceramic coating is greater than 80%. The coating with a thermal reflectivity greater than 80% can effectively reflect the heat generated by the pole piece back to the inside of the battery, thereby accelerating the temperature rising speed of the battery. Combined with the characteristics of far-infrared radiation, the coating with high reflectivity can ensure that the heat cannot quickly spread to the outside of the battery, but is reflected and maintained in the battery, thereby quickly raising the temperature of the battery. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, a brief introduction will be given to the drawings needed in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0021] Figure 1 A perspective view of the battery shell according to the present application is shown in the figure.

[0022] Figure 2 A top view of the battery shell according to the present application is shown in the figure.

[0023] Figure 3 A Figure 2 A plane section view at A-A.

[0024] Figure 4 A perspective view of the lithium battery according to the present application is shown in the figure.

[0025] Reference signs:

[0026] 1, battery shell; 11, shell body; 12, far-infrared ceramic coating; 13, blue film; 2, core package; 3, top cover. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0028] As Figure 1 shown, in combination with Figures 2-3 , the embodiments of the present application disclose a battery shell 1, which comprises a shell body 11. The shell body 11 can be a square shell or a cylindrical shell with one end open. The shell body 11 is made of metal. The shell body 11 is the outer shell of the battery, which serves as a structure to protect the inside of the battery, such as the core package 2 and the electrolyte.

[0029] The battery can be started at low power for self-heating at low temperature, and the heat generated at this time has a temperature difference with the environment, forming temperature diffusion, resulting in low self-heating efficiency. In the traditional technology, the battery is usually installed inside the battery pack box. In order to keep the battery warm in a low temperature environment, a heating film or thermal insulation cotton is usually added to the bottom or side of the battery for heat preservation. However, the heating film may fall off or shift, which may cause the risk of thermal runaway. The thermal insulation cotton occupies space, affects the space utilization rate of the battery pack, and is easy to separate and cause failure.

[0030] To this end, the scheme adopted by the embodiment is to provide a far-infrared ceramic coating 12 on the outer side of the shell body 11. When the battery is charged at low power for self-heating at low temperature, the temperature of the battery self-heating is released outward through the shell body 11, the far-infrared ceramic coating 12 absorbs the heat released by the shell body 11, converts the absorbed heat into far-infrared radiation, and then transmits the heat back to the inside of the battery through the radiation heating mode. The radiated heat can increase the temperature inside the battery shell 1, thereby helping to improve the self-heating capacity and heat preservation performance of the battery.

[0031] The far-infrared radiation of the far-infrared ceramic coating 12 not only improves the self-heating capacity of the battery, but also improves the heat preservation performance of the battery in a cold environment. The radiation characteristics of the coating help to reduce the rapid reduction of the battery temperature and avoid heat loss. Compared with the traditional heating film or thermal insulation cotton, this way reduces the space occupation while improving the heat preservation effect.

[0032] It is worth noting that the far-infrared ceramic coating 12 in the embodiment is only provided on the outer side of the shell body 11. For example, in a square shell, the far-infrared ceramic coating 12 is provided on the four vertical sides of the shell body 11, and the bottom surface of the shell body 11 is not provided. In this way, when multiple batteries form a battery module, under the action of the far-infrared ceramic coating 12, the heat released by the battery during charging and discharging is absorbed by the far-infrared ceramic coating 12 and radiated into the battery, avoiding heat transfer to the outside of the battery. To some extent, it can inhibit the temperature diffusion between the batteries, and at the same time, the high temperature generated during the discharging process of the battery can be directly transmitted downward from the bottom of the shell body 11. In actual use, a liquid cooling plate can be laid on the bottom surface of the battery to realize directional discharge of the heat released by the battery from the bottom of the liquid cooling plate, avoiding the spread of the heat released by the battery to other batteries around the battery from the side of the battery.

[0033] As some preferred embodiments, the far-infrared ceramic coating 12 is composed of at least one ceramic material selected from one or more of alumina, titanium oxide, silicon nitride, and zircon.

[0034] Ceramic materials such as aluminum oxide (Al203), titanium oxide (Ti02), silicon nitride (Si3N4), and zirconium oxide (Zr02) have high emissivity in the far infrared band, which enables them to effectively absorb and reflect heat. The properties of these materials enable the coating to convert the heat released by the self-heating of the battery into far infrared radiation and reflect the heat back to the shell body 11, thereby heating the inside of the shell body 11 and increasing the temperature of the battery.

[0035] In this embodiment, the far infrared ceramic coating 12 has an emissivity greater than 0.8 in the far infrared band of 8-14 microns. A coating with an emissivity greater than 0.8 has strong heat radiation capability, especially in the far infrared band of 8-14 microns, the high emissivity of the coating enables it to efficiently absorb and radiate heat, thereby accelerating the temperature rise of the battery, especially in a low temperature environment, which can significantly improve the temperature rise efficiency of the battery, optimize the low temperature charging performance, and avoid performance degradation and safety hazards caused by excessively low temperature.

[0036] As some preferred embodiments, the far infrared ceramic coating 12 has a thermal reflectivity greater than 80%. A coating with a thermal reflectivity greater than 80% can effectively reflect the heat released by the shell body 11, lock the heat in the shell body 11, and reduce the release of heat to the outside of the shell body 11, thereby accelerating the temperature rise of the battery. Combined with the characteristics of far infrared radiation, this high reflectivity coating can ensure that the heat does not quickly spread to the outside of the battery, but is reflected and maintained inside the battery, rapidly increasing the temperature of the battery.

[0037] As some preferred embodiments, the far infrared ceramic coating 12 has a microporous structure, and the porosity of the far infrared ceramic coating 12 is 5%-40%.

[0038] The main function of the far infrared ceramic coating 12 is to regulate the temperature of the battery by reflecting and radiating heat. Appropriate porosity helps to improve the reflectivity and radiativity of the ceramic coating. A low porosity (such as 5%-40%) can increase the density of the coating and improve the thermal reflectivity of the coating, making it more effective in reflecting heat. A low porosity helps to reduce the thermal conductivity of the coating. The thermal conductivity of ceramic materials is relatively strong, and by controlling the porosity, the thermal conductivity of the ceramic coating can be adjusted to enhance its thermal insulation performance. In addition, the low porosity of the far infrared ceramic coating 12 helps to improve the smoothness of its surface and reduce surface roughness, enhancing the mechanical properties of the coating and its adhesion to the outer wall of the shell body 11.

[0039] Preferably, the thickness of the far-infrared ceramic coating 12 is 0.5-10 μm. The thickness of the far-infrared ceramic coating 12 is small because its main function is heat reflection and radiation, and such heat management function does not depend on the thickness, and only a thin enough coating is needed to efficiently reflect heat, so that the coating does not occupy a large space on the battery shell 1, and the energy density of the battery in the integrated battery pack is improved under the premise of ensuring that the battery can be kept warm.

[0040] As some embodiments, the far-infrared ceramic coating 12 is applied on the surface of the shell body 11 by spraying, sputtering, dipping, or chemical vapor deposition process. The process can be flexibly selected during the preparation of the ceramic coating to achieve the purposes of optimizing adhesion, controlling coating thickness, improving thermal performance, ensuring coating uniformity, and improving the stability of the coating. Reasonable selection of a suitable coating process can ensure the application effect of the ceramic coating on the shell body 11, thereby improving the overall battery performance, prolonging the service life, and optimizing the thermal management performance of the battery.

[0041] As some preferred embodiments, the outer surface of the far-infrared ceramic coating 12 is further provided with a blue film 13. The setting of the blue film 13 can improve the insulation performance of the shell body 11, avoid short circuit between the shell bodies 11 of two adjacent batteries, and at the same time, the blue film can protect the coating to a certain extent, avoid scratching the coating, and cause the heat preservation performance to decrease.

[0042] The utility model discloses a lithium battery, refer to the attached Figure 4 As shown in the figure, including core package 2, top cover 3 and the battery shell 1 disclosed in the above embodiment, the core package 2 is arranged in the battery shell 1, and the top cover 3 is fixedly arranged at the opening end of the battery shell 1 and electrically connected with the core package 2.

[0043] The lithium battery disclosed in the embodiment uses the battery shell 1 with the far-infrared coating. In a low-temperature environment, the far-infrared radiation of the far-infrared ceramic coating 12 can not only improve the self-heating capacity of the lithium battery, but also improve the heat preservation performance of the battery in a cold environment. The radiation characteristics of the coating help to reduce the rapid decrease of the temperature of the lithium battery and avoid heat loss. In addition, the coating is thin and does not affect the overall volume of the lithium battery. Under the premise of ensuring that the battery can be kept warm, the energy density of the lithium battery in the group is improved.

[0044] The above only describes the preferred embodiments of the utility model, and does not limit the utility model. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the utility model should be included in the protection scope of the utility model.

Claims

1. A battery case characterized by: The battery shell (1) comprises a shell body (11), the outer side of the shell body (11) is provided with a far infrared ceramic coating (12); the far infrared ceramic coating (12) has a radiation rate greater than 0.8 in the far infrared wave band of 8-14 μm; the thermal reflectivity of the far infrared ceramic coating (12) is greater than 80%.

2. The battery case of claim 1, wherein: The far infrared ceramic coating (12) has a microporous structure, and the porosity of the far infrared ceramic coating (12) is 5%-40%.

3. The battery case of claim 1, wherein: The thickness of the far infrared ceramic coating (12) is 0.5-10 μm.

4. The battery case of claim 1, wherein: The far infrared ceramic coating (12) is applied on the outer side of the shell body (11) by spraying, sputtering, dipping or chemical vapor deposition process.

5. The battery case of claim 1, wherein: The outer surface of the far infrared ceramic coating (12) is further provided with a blue film (13).

6. A lithium battery, characterized by The battery shell (1) of any one of claims 1-5, a core package (2) arranged in the battery shell (1), and a top cover (3) fixedly arranged at the opening end of the battery shell (1) and electrically connected with the core package (2).

Images