Next-gen battery startup Seeo raises $15M

A next-gen, lithium-ion battery startup — backed by Vinod Khosla’s Khosla Ventures — called Seeo has raised another $15 million from investors, according to a filing. Khosla Partner Pierre Lamond (who joined Khosla Ventures in early 2009 from Sequoia) is listed on this latest filing, as is investor Atiq Raza and GSR Ventures investor Richard Lim. Seeo previously raised at least $10.6 million.

Seeo has been rather quiet about its battery innovation, but we do know that the company has been developing a nano-structured, lithium-polymer battery, and in particular, has been working on a solid electrolyte that was developed at Lawrence Berkeley National Lab. The material, which Seeo began licensing from the lab in 2007, allows for a more stable battery with higher energy density, in contrast to the more easily flammable liquid electrolyte that can present a safety risk in some conventional lithium-ion batteries.

Seeos batteries are supposed to be able to be operated at a much higher temperature than competing batteries, which means they could be used in environments with extreme temperatures — like outdoors attached to a solar system — and the team is looking at using the batteries for electric vehicle applications, too.

Seeo lists other investors on its website including Google’s (s goog) philanthropic arm and Presidio Ventures, and Seeo also won a $6.2 million grant from the Department of Energy to develop and deploy a 25 kWh prototype battery for the power grid. Back when that was awarded, the DOE described Seeo’s grid project as demonstrating “the substantial improvements offered by solid state lithium-ion technologies for energy density, battery life, safety, and cost,” and the technology as targeting “utility-scale operations, particularly community energy storage projects.”