Preparation And Performance Research Of A Novel Carbon-based Composite Phase Change Material For Thermal Management Of Electric Vehicle Power Battery

Under the double crisis of oil resource shortage and environmental pollution,electric vehicles have increasingly become the main bearers of urban transportation tasks.The service life and safety of power batteries are one of the main technical bottlenecks of current electric vehicles.In order to break through this technical bottleneck,it is necessary to control the temperature of the power battery within a certain range and study the thermal management of the power battery.This article analyzed and summarized the common methods of thermal management systems for power batteries.According to the shortcomings of the complex preparation process and low phase change enthalpy of phase change materials currently used in the thermal management of power batteries,new form-stable phase change materials with simple preparation processes and high phase change enthalpies were developed,and their application to battery thermal management was studied.According to the requirements of thermal management of power batteries and the selection principle of phase change materials,the paper selected polyethylene glycol as the core material and inorganic porous material as the carrier to be used in the thermal management system of power batteries.In this paper,a novel mesoporous carbon microsphere was prepared by means of pyrolysis polydopamine microsphere.The results showed that polyethylene glycol/mesoporous carbon microspheres had good thermal stability and heat storage capacity,and the thermal conductivity of polyethylene glycol/mesoporous carbon microspheres was also improved compared with polyethylene glycol.In order to further improve the thermal conductivity of shaped phase change materials,a novel mesoporous carbon microsphere was proposed as an adsorbent to absorb copper ions,and then copper ions were reduced to copper microsphere by in-situ reduction method to obtain hybrid particles of mesoporous carbon microsphere/copper microsphere.With mesoporous carbon microsphere/copper microsphere hybrid particles as the carrier and polyethylene glycol as the core material,the form-stable phase change materials had good thermal stability and heat storage capacity,and their thermal conductivity was greatly improved.The improvement of thermal conductivity is helpful to improve the heat transfer effect and heat transfer efficiency.In this paper,a new type of composite plate is designed for power battery thermal management system,and the feasibility of applying two new type of shape-stabilized shaped phase change materials to the power battery thermal management system is verified by theoretical calculation.The results show that the two new composite shaped phase change materials can maintain the temperature of the power battery in a suitable temperature range during operation.