The 2010 Toyota Prius hybrid has officially been revealed at the 2009 Detroit Auto Show. Click here for all the details and images.

Toyota will be delaying the introduction of its next-gen hybrids models because of fears that the new lithium-ion technology is unsafe. There were plans to launch more than a dozen hybrid models with the longer-life lithium-ion batteries in the US between 2008 and 2010, however, developers will instead rely on older nickel-metal-hydride batteries until 2011.

Toyota execs have revealed to the Wall Street Journal that the decision was made because of fears that the batteries could overheat, catch fire or even explode. Last year, Sony had to recall some laptop computers because of similar fears of exploding batteries.

Current hybrids with the nickel-metal-hydride batteries average roughly 40 to 50mpg, while the new lithium-ion promises mileage rates of up to 70mpg in mixed driving. The most important model getting delayed is the next-gen Prius, but Toyota will also be delaying plans for its hybrid Tundra and Sequoia SUVs.