Much has been made of the fact that Toyota is seemingly behind General Motors and other manufacturers in the race to adopt lithium-ion batteries as the future battery of the hybrid and electric vehicle market. Lithium-ion batteries pack more energy into less space than nickel metal hydride batteries, which are the current industry standard in hybrids. Could this delay in the adoption of lithium ion technology be because they have something better up their corporate sleeves for the next-next Prius? According to reports from Japan, Toyota may be investing in zinc-air batteries, which are currently popular only in your grandpa's hearing-aid. If the rumors are true, these new batteries would make up a big chunk of Toyota's plan on offering a hybrid version of every car it sells by 2020. In the meantime, expect to see lithium-ion batteries in future Toyota hybrid models until it's ready to unveil its newest battery technology, whatever that may be.

[Source: Automotive News, sub. req'd]