Lion Cells

Founded in 2006, this Silicon Valley start-up aims to make small but powerful lithium ion batteries--which discharge energy as lithium ions move from an anode to a cathode--for power tools, but also has its eye on larger devices like motorcycles and cars. The three-pronged sell: higher energy density (the amount of charge the battery holds), higher power density (strength to rev up larger devices) and increased cycles (the number of times the battery can be recharged). The batteries also offer a vent to release potentially dangerous pressure that builds up from heat generated by those bouncing ions. Backed by Battery Ventures, Lion licenses its technology from SRI, a non-profit sponsor of technology development. According to Chief Executive Jeff Depew, the company's products should hit the market in 2009, if not sooner.