Experimental analysis of a sorption thermal energy storage for air heating and dehumidification in electric vehicles

Electric Vehicles (EVs) will play a crucial role in next years to reach the desired reduction of CO₂ emissions. One of the most critical aspects limiting the spread of this type of vehicle is the shorter range compared to conventional Internal Combustion Vehicles (ICVs). According to recent studies, in cold climate up to 50% of battery energy is used to control climate of passenger compartment.

This paper presents the design, development, and experimental analysis of a prototype open sorption Thermal Energy Storage (TES) system specifically engineered for air heating and dehumidification in EVs. The prototype includes 1 kg of zeolite 13X in spherical beads and a Positive Temperature Coefficient (PTC) heater for regeneration. Experimental results, conducted under representative winter conditions, indicate that the device can provide a dry and warm airflow for 45–90 minutes, depending on the mode of operation. Integrating this TES system into the vehicle's air handling unit significantly reduces the outdoor airflow rate without risk of window fogging. Simulations show that the device can reduce the thermal power required to heat the cabin by up to 50% during vehicle operation. During discharge, energy saving is approximately 1300 Wh when the outdoor temperature is 0 °C.

In conclusion, the proposed open sorption TES prototype demonstrates a viable approach to enhancing energy efficiency and passenger comfort in EVs.