Unlock instant, AI-driven research and patent intelligence for your innovation.

Preparation method of composite phase change coating beneficial to heat dissipation of lithium ion battery

A lithium-ion battery, composite phase change technology, applied in secondary batteries, battery pack components, circuits, etc., can solve the problems of shortened service life, low thermal conductivity, poor thermal conductivity of paraffin, and improve thermal conductivity and heat dissipation. The effect of large internal surface area and excellent thermal conductivity

Active Publication Date: 2020-01-17
NANJING UNIV OF INFORMATION SCI & TECH
View PDF5 Cites 3 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

According to research, the operating temperature of lithium-ion batteries is generally between -20-60°C. During the use of lithium-ion batteries, due to poor heat dissipation conditions and exceeding the appropriate operating temperature for a long time, the battery will be damaged and the service life will be shortened. Especially when the working environment conditions of the lithium-ion battery are poor, such as short circuit and overcharge, it will also bring about a strong exothermic reaction between the electrolyte and the electrode material. The accumulation of a large amount of heat not only reduces the performance of the battery module, but also in severe cases It can also cause combustion and explosion. Therefore, safety issues are the key to restricting the popularization of lithium-ion batteries
[0004] In order to improve the safety performance of lithium-ion batteries, thermal management of batteries is usually required. Common methods include air cooling, phase change material cooling, liquid cooling, and heat pipe-assisted heat dissipation. The characteristics of large heat absorption and constant temperature are also widely used in the thermal management research of power batteries. However, due to the very low thermal conductivity of simple phase change materials (such as paraffin), the heat dissipation effect is not very ideal. Generally, by adding high thermal conductivity For example, adding heat-conducting particles to the phase change agent, Liu Chenzhen (Guangdong University of Technology) and others compounded paraffin wax and expanded graphite, and made a plate-shaped expanded graphite / paraffin wax composite material through a pressing process. To solve the problem of poor thermal conductivity of paraffin and liquid flow after phase change, or embed phase change agent into porous materials, such as Jinbiao (Guangdong University of Science and Technology), etc. Adsorb paraffin on foamed copper as power lithium battery heat dissipation material, Wang Zichen (Beijing Jiaotong University) and others use aluminum foam as a heat-conducting carrier, and adsorb paraffin as a composite phase-change heat storage material for lithium battery heat dissipation. Although the composite phase-change material in this type of research effectively prevents the battery from thermal runaway, it is relatively large. The volume and quality of the battery increase the occupied volume of the battery, and also increase the operating load of the battery

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Preparation method of composite phase change coating beneficial to heat dissipation of lithium ion battery
  • Preparation method of composite phase change coating beneficial to heat dissipation of lithium ion battery

Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0029] The invention provides a method for preparing a composite phase-change coating that is beneficial to heat dissipation of lithium-ion batteries. The phase-change precursor is made by encapsulating the phase-change agent in attapulgite with a channel structure, and then the phase-change precursor is Mix with alumina sol to make a slurry, then coat lithium batteries, and form a composite phase change coating after drying; the phase change agent is paraffin; the attapulgite has a purity ≥ 85%, and the attapulgite used in the present invention Attapulgite is a kind of phase change agent adsorption carrier. Attapulgite is a hydrous aluminum-magnesium silicate mineral with two-dimensional nanoscale crystals (about 20nm in diameter and about 100-200μm in length). The series of crystal channels have small volume and mass, but large internal surface area, and have good adsorption performance, which can increase the adsorption amount of paraffin phase change agent while reducing th...

Embodiment 1

[0039] Under the condition of 80°C water bath, melt the paraffin wax, add an appropriate amount of attapulgite (Jiangsu Xuyi, purity ≥ 85%), the mass ratio of attapulgite to paraffin wax is 1.5:1, and stir evenly to obtain a phase change precursor; Aluminum alkoxide was configured into a 1mol / L aqueous solution at 90°C, and the pH of the solution was adjusted to 3 with nitric acid, and the stirring was continued until the solution was clear, and the alumina sol was obtained after standing for 24 hours; Mix at 1:15 and disperse by ball milling to obtain a uniform slurry, then coat to form a coating with a thickness of less than 20 μm, and vacuum dry at room temperature for more than 24 hours to obtain a composite phase change coating.

Embodiment 2

[0041] Under the condition of 80°C water bath, melt the paraffin wax, add an appropriate amount of attapulgite (Jiangsu Xuyi, purity ≥ 85%), the mass ratio of attapulgite to paraffin wax is 2:1, and stir evenly to obtain a phase change precursor; Aluminum alkoxide was configured into a 0.8mol / L aqueous solution at 90°C, and the pH of the solution was adjusted to 4 with nitric acid, and the stirring was continued until the solution was clear, and left to stand for 24 hours to obtain alumina sol; the phase change precursor and alumina sol were mixed by mass Mix at a ratio of 1:20, and disperse by ball milling to obtain a uniform slurry, and then coat to form a coating with a thickness of less than 20 μm, and dry it in vacuum at room temperature for more than 24 hours to obtain a composite phase change coating.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
thicknessaaaaaaaaaa
diameteraaaaaaaaaa
lengthaaaaaaaaaa
Login to View More

Abstract

The invention provides a preparation method of a composite phase change coating beneficial to heat dissipation of a lithium ion battery. The preparation method comprises the following steps of under awater bath condition of 80 DEG C, melting a phase-change agent paraffin, adding attapulgite, encapsulating a phase-change agent in the attapulgite with a pore structure to form a phase-change precursor, mixing the phase-change precursor with alumina sol, carrying out ball-milling dispersion to obtain the uniform slurry, and coating to form the composite phase-change coating. According to the method, the paraffin is used as the phase change agent, so that the phase change latent heat is large; the attapulgite is used as a phase change agent adsorption carrier, and the internal surface area islarge, so that the composite phase change coating has the good adsorption performance, the adsorption quantity of the paraffin phase change agent is increased while the thickness of the coating is reduced; the aluminum oxide sol is used as a film forming matrix, with the excellent heat conductivity of the aluminum oxide sol, the defect of low heat conductivity coefficient of paraffin can be overcome, and the heat conduction and heat dissipation performance of the coating is effectively improved; a battery shell is coated with the composite phase change coating, so that the internal temperatureof the battery can be reduced by 2-5 DEG C, and the purpose of efficient heat dissipation is achieved.

Description

technical field [0001] The invention belongs to the technical field of new energy, and in particular relates to a preparation method of a composite phase-change coating which is beneficial to heat dissipation of a lithium-ion battery. Background technique [0002] In recent years, due to the advantages of green and environmental protection, electric vehicles have occupied an important position in new energy vehicles and have considerable development prospects. They are also the key development targets of the country and major automobile companies. Power batteries are the core components of electric vehicles. , its performance has a great impact on the performance of the vehicle. Lithium-ion batteries have the advantages of high specific energy and specific power, high average output voltage, low self-discharge rate, good cycle performance, and fast charge and discharge speed. They are ideal power for electric vehicles. Battery. With the rapid development of lithium-ion batt...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): H01M10/613H01M10/625H01M10/659H01M10/654H01M2/02
CPCH01M10/613H01M10/625H01M10/654H01M10/659H01M50/124Y02E60/10
Inventor 刘斌刘凯韦加雯周凯姚义俊唐华剑范栋梁成敏孙国民
Owner NANJING UNIV OF INFORMATION SCI & TECH