Resorption thermal energy storage strategy based on CaCl2/MnCl2-NH3 working pair for battery electric vehicles

Abstract

To break through the limitation of existing battery thermal management and heat pump technology for battery electric vehicles (BEVs), a kind of resorption thermal energy storage strategy (RTES) based on CaCl2/MnCl2-NH3 working pair for BEVs is reported. RTES could effectively store municipal electric energy during vehicle charging in the form of chemical energy by resorption reaction, and the stored energy is used as thermal energy for battery thermal management and heat pump. The experiments and calculation show that RTES owns the coefficient of performance (COP) of 0.994 and energy storage density of 350.4 kJ∙kg−1, which consequently increases the driving range (DR) of BEVs by up to 61.4%. The power consumption with RTES per 100 km per unit mass of BEVs is as low as 7.11 Wh∙(100 km)-1∙kg−1, which is only 56.4% of the parameter calculated for BEVs without RTES. The conditions of the same weight for RTES and ternary lithium batteries (TLBs) are further compared, and DR of BEVs with RTES is improved by 173%-262% of that with TLBs. Additionally, the ratio of DR and energy storage quantity of RTES increases by 1.71–2.60 times than that of TLBs. The study shows that RTES has excellent potential for combined function of heat pump and battery thermal management for BEVs.