The biggest factor holding it back is safety fears, revealed Toyota's executive vice president for R&D Kazuo Okamoto during an interview with Automotive News. Instead, engineers will concentrate on improving the efficiency of current nickel-metal hydride technology. Lithium ion batteries are smaller and lighter than nickel-metal hydride but they tend to overheat and can even catch on fire.
Okamoto wasn’t willing to give a timeline for the introduction of the new batteries, explaining that there are still a lot of problems to solve.
Though lithium-ion batteries are the power source of choice for a new generation of plug-in hybrids, Toyota is still focusing on rolling out the new electric vehicles despite the expected delays in battery technology. The carmaker has just announced the formation of a new partnership with power utility Electricite de France SA (EDF) to develop electricity infrastructure for plug-in vehicles.