Bill Gates, investors, back sodium battery startup Aquion Energy

Bill Gates is continuing to fund next-generation battery startups. On Tuesday, battery startup Aquion Energy announced that it is working on raising another round of $35 million, with a first close on that round from Bill Gates, as well Bright Capital, Gentry Venture Partners, and existing investors Kleiner Perkins and Foundation Capital.

Aquion Energy, based in Pittsburgh and founded in 2007, is using basic materials like sodium and water to build modular batteries that will be able to provide energy storage services for the power grid. The technology was developed out of Carnegie Mellon University by founder and chief technology officer Jay Whitacre.

The company’s battery pairs a carbon anode with a sodium-based cathode, and a water-based electrolyte shuttles ions between the two electrodes during charging and discharging. Many batteries have solvent-based electrolytes.

Aquion Energy employees assembling batteries at a rotary dial table
Aquion Energy employees assembling batteries at a rotary dial table

The purpose of using basic materials is to make a battery that is super low cost. That’s one reason why Aquion is focused on stationary applications, like the grid, where lower energy density can be an acceptable trade-off for lower costs and longer life. The battery can also withstand a wide range of temperatures without losing storage capacity, so could be installed alongside a solar installation without sapping a lot of energy for air conditioning to keep the batteries cool.

Aquion EnergyAquion Energy has been planning on building a factory in Pennsylvania that could make its sodium batteries starting this year. About a year ago Aquion said it had leased a facility from the Regional Industrial Development Corporation in Westmoreland County, Pennsylvania, and the company hopes the factory could create 400 jobs by the end of 2015.

Such a factory could cost between $75 million and $80 million to build, so it’s likely this funding will go towards moving into production. In the summer of 2011 Aquion raised $20 million. The Department of Energy has also supported Aquion’s technology development with a $5 million stimulus grant.

Kleiner Perkins’ David Wells played a key role in helping incubate this technology. Whitacre and Wells started talking in late 2007 and a year later Kleiner sponsored an incubator at Carnegie Mellon for Whitacre to develop the tech. Following that, Whitacre spun off the venture and began to work on commercializing the battery.

Bill Gates has also invested in battery startup Ambri (formerly called Liquid Metal Battery), which like Aquion is building a grid battery and looking to begin production in the coming years. Gates has backed at least 5 battery startups, according to a talk he gave back in 2010.