Renewables
New High Temperature Capacitor For Electric Vehicles
Hybrids and pure electric vehicles rely on high efficiency power conversion and management. The power electronics found in these vehicles require cooling because of limitations in the temperature rating of components such as capacitors, which are used to store electrical energy. This in turns adds weight to the vehicles and drags down their reliability and efficiency.
The researchers explored different compositions and different ways of fabricating them. They measured current at a range of high temperatures using advanced measurement techniques. The most promising materials were optimized to achieve the desired properties. The resulting capacitor is created from a ceramic, based on doped-BiFeO3 compound. Other types of capacitors, for example barium titanate capacitors, can lose up to 85% of their capacitance at working voltage. HITECA also manages to outperform other ceramic chip capacitors in temperature range, lower temperature capacitance change, and lower voltage capacitance change.It can be a breakthrough in automotive power electronics, which according to NPL, represents an emerging $61bn global market. Tatiana Correia, who led the work at NPL, said: "Industrial electronics needs to be able to perform in harsh environments in which they operate. The ability of HITECA capacitors to function at higher temperatures than existing capacitors will help make electronic systems more robust and remove barriers for technologies such as electric vehicles that rely on them," said Tatiana Correia, who led the work at NPL. "The opportunities for electric vehicles are huge, both financially and environmentally, but they are currently being held back by a few technical issues. With this high temperature capacitor we believe we have solved an important one of those issues and will play a vital part in the move towards mass market electric vehicles."
