A team of researchers from Case Western Reserve University has found a way to charge an electric vehicle battery while the vehicle is on the move and with higher efficiency. However, it only works on a sunny day. It is made possible by wiring four perovskite solar cells in series to directly photo-charge lithium batteries. The efficiency is expected to be up to 7.8 percent which is believed to be the most efficient configuration till date.
Liming Dai, the leader of the research team said that they had found the right match between the solar cell and battery while others had used polymer solar cells to charge lithium batteries but not with that kind of efficiency. On top of that the coupling appeared to have outperformed all other reported pairings of photo-charging components and compatible batteries or super-capacitors.
Perovskite is chosen as it is one of the most promising solar cell technologies with its ability to convert a broader spectrum of sunlight to electricity when compared to silicon-based cells. It has crystalline material which the structure is identical to the mineral of the same name. The ability of it to perform power conversion and energy saving is considered as the highest in terms of efficiency compared to traditional power sources.
Dai’s team make a single perovskite film from three layers of the cells and wired four of the 1 mm square cells in series. This arrangement achieves solar to electric power conversion efficiency of about 12.65 percent. When this prototype connected to small coin-sized lithium-ion batteries, the team able to achieve conversion and storage efficiency of 7.8 percent and maintained it over a number of cycles.
The panel will then be attached on top of a car which is installed facing to the sky and have a surface about 7 sq m (75 sq ft) giving it a different look than the traditional car look.