Apparently the production hybrid pioneer is not yet convinced of the safety of lithium ion in an automotive application. The rising rates of quality issues and recalls that Toyota has been experiencing of late may be causing them to be somewhat more cautious about introducing the new technology. Toyota CEO Katsuaki Watanabe had previously indicated that the next-generation Prius would be using lithium ion batteries. So far there is no indication if this means the new Prius introduction will be delayed or they will just continue with nickel metal hydride batteries.