First published on the Cleantech Investor website, February 2013

Eos Energy Storage, which is developing a zinc-air battery, has raised US$14.6 million and hopes to take its funding round to US$20, it was revealed in February 2013. 

The Eos battery is appropriate for grid scale storage applications, with energy density of 14 times that of a Lithion Ion battery, according to the company. Zinc air batteries uses ambient reactant  - i.e. air – which massively reduces their size (and makes them comparable with gasoline engines – where air is the reactant for combustion). Eos has entirely redesigned the zinc air battery to permit recharging. It believes its technology provides a battery life of 10,000
cycles, or the equivalent of around 30 years.

The Eos technology and key intellectual property is based around the cell configuration and architecture, the cathode design, materials and catalysts, the electrolyte and additives and the system configuration and electrolyte system. Initially, energy storage looks set to be the most lucrative market for Eos, which expects to delivery MW scale systems by 2014. The firm also aims to work in the automotive and electronics spaces – most probably with a strategic partner such as an automotive OEM, according to the company's President Steve Hellman.