International Battery, one of many companies racing to a cheaper, more efficient rechargeable lithium-ion battery, has brought in $35 million so far in a third round of venture funding that remains open.
Unlike many of its competitors, the company is geared toward grid-scale batteries that can be used by electric utilities to meet peak demand and make renewable sources of energy like wind and solar more reliable and easier to integrate. While Panasonic, Siemens and General Electric are working on this problem too, most of them are innovating batteries for automotive applications.