Birmingham researchers develop EV range boosted by microwave energy
Researchers at the University of Birmingham are developing a novel technology called the e-Thermal bank that aims to significantly extend the driving range of electric vehicles (EVs). This system utilizes microwave energy to power the car’s climate control system, reducing the strain on the main battery and consequently increasing the vehicle’s range. The system is to boost EV driving range during hot or cold weather, when using the car’s climate control system can consume a significant amount of electric power, and subsequently reduce the driving range, by as much as 40%.
The method, invented by Birmingham energy expert Professor Yongliang Li during research into technologies for a zero-carbon future, couples a chemical heat pump with microwave energy, and produces heating or cooling on demand, with much higher energy density than battery packs.
Called e-Thermal bank, the system is a secondary energy source for electric vehicles. It is ‘charged’ at the EV charging station by using microwave energy to dissociate a solid-vapour working pair. Additionally, it condenses the vapour into liquid. This charging process stores the microwave energy inside the car, in the e-Thermal bank.
We predict that by replacing conventional HVAC and possibly a small portion of the battery pack, e-Thermal banks would provide efficient cabin temperature control and a range extension of up to 70%, at a lower cost than increasing battery capacity.
Professor Yongliang Li, School of Chemical Engineering
During discharging, feeding the vapor into a reactor reverses the process to generate heat through an exothermic reaction. Simultaneously, a liquid-gas phase change process in an evaporator generates cooling.
Professor Yongliang Li is Chair in Thermal Energy Engineering in Birmingham’s School of Chemical Engineering. His research focuses on thermal energy processes and systems, including thermal energy (heat and cold) storage and refrigeration. He also specializes in air conditioning, carbon capture and storage, and process and system simulation and optimization. The Engineering and Physical Sciences Research Council (EPSRC) supports much of his research.
He said: “Heating and cooling the EV cabin requires considerable energy and is the most significant contributor to EV range reduction. We aimed to offload these thermal management tasks to a microwave driven process. Microwave is a fast heating method because microwaves penetrate uniformly through materials. This allows them to deliver energy evenly into the body of the material. Coupling with a smart meter to charge the system when energy is cheap can minimize the energy cost. The stored energy can then be used at any time.”
“We predict that by replacing conventional HVAC and possibly a small portion of the battery pack, e-Thermal banks would provide efficient cabin temperature control. Additionally, they could offer a range extension of up to 70%, at a lower cost than increasing battery capacity.”
University of Birmingham Enterprise has filed a patent application covering the e-Thermal bank system and method for storing energy. The university is seeking commercial partners for licensing collaboration or co-development.
