Conceptual design and numerical analysis of a miscibility gap alloy-based solid-state thermal battery for electric vehicles

Heating the passenger cabin of electric vehicles at low temperatures consumes a large amount of battery power, resulting in a significant reduction in cruising range. On-board thermal energy storage is an effective way to improve the cruising range of electric vehicles in winter. Miscibility gap alloy is a new type of shape-stabilized composite phase change material, which has the advantages of high energy storage density, high thermal conductivity, low cost, and good safety. Therefore, using it to heat electric vehicles can increase their cruising range, prolong battery life, and reduce cost. In this paper, the concept of a compact on-board solid-state thermal battery based on miscibility gap alloy is proposed for the first time, and the heat charging, thermal insulation and heat discharging performance of the design are analysed based on numerical simulations. The results show that the thermal battery can reach a heat storage density of 553.8 Wh/L, and the average heat discharging power can reach 1.326 kW. The results of this paper can provide guidance for the engineering development of miscibility gap alloy-based solid-state thermal batteries.