Despite the distractions of bankruptcy and reorganization, General Motors Co. last year more than doubled its output of technology patents in alternative-powered vehicles.
An international database of patent activity reports that GM filed 629 patent applications in the alternative-power area last year, up from 261 the year before.
That was the second-highest volume in the industry, behind Toyota Motor Corp., according to Derwent World Patents Index, of London. Toyota led in the alternative-power field with 2,058 new patent applications last year, down from 2,379 in 2008.
GM leapfrogged past Nissan Motor Co., Hyundai Motor Co., Honda Motor Co. and two of Japan's most prolific technology suppliers, Denso Corp. and Panasonic Corp., according to Derwent.
The field of alternative-powered vehicles covers a range of technologies related to nontraditional autos. The patent applications might include innovations in electric drives, hybrid-power vehicles, lithium ion batteries, clean fuels, compressed gas, liquefied natural gas or nickel-metal hydride components.
GM has been devoting resources to developing its upcoming Chevrolet Volt extended-range electric vehicle, scheduled to go on sale late this year. The automaker designed and engineered more than 140 unique parts for the car's hybrid propulsion system and is building plants to manufacture battery packs in-house.
The Derwent patent database monitors patent filings in 41 of the world's largest markets.