The NiMH battery is rechargeable, similar to a nickel-cadmium battery except with double to triple the capacity and energy density approaching a lithium-ion battery. Toyota’s new Prius (2) will have a much improved NiMH battery thanks to recent innovations by the company.
Toyota was able to improve the regeneration performance by simply adjusting the composition ratios of the materials inside the battery. There have been no changes made to the size of the battery, only to the materials inside. There are still 168 cells capable of a 201.6V charge from the whole battery and 1.2V per cell.
The company was able to use existing equipment because it made no changes to the size of the battery pack itself, making these adjustments very cost effective. The volume of the whole pack was reduced by 10% thanks to the minimization of the copper wiring and circuit boards.
Of course there is always room for reform, “The performance of the cell can be further improved,” says Toyota. “There are two groups in Toyota, one supporting lithium and the other supporting nickel. They are competing against each other.”
The larger cells, some three times larger than a lithium battery, require a large cooling port which can be seen on the left side of the battery in the above picture. “The improvement in charging performance increased the fuel efficiency of the vehicle by 0.5 to 1%,” according to Toyota.
PEVE, Primearth EV Energy Co., LTD is the company that is responsible for supplying battery to Toyota. PEVE handles the manufacturing and development of the NiMH battery, and production will begin in their plants in 2016.
