Storage start-up seals $35m

US energy storage start-up Ambri has locked up $35m in equity financing to push its liquid metal battery (LMB) concept towards commercialisation.

The funding, which came from venture capitalist KLP Enterprise, the “family office” of Karen Pritzker and Michael Vlock, and Swiss insurance company Building Insurance Bern, goes into the pot with existing investment from Khosla Ventures, Bill Gates and oil giant Total.

“This round of investment is a milestone for Ambri that will accelerate our commercialisation efforts,” says chief executive Phil Giudice. “We are building a world-class team that is developing a solution to the energy challenges of the 21st century.”

The LMB cells are made of three liquid components — a salt solution (electrolyte) and two separate metal layers (electrodes) which, when charged up, create a voltage. To discharge, the voltage drives electrons from one electrode, delivering power and creating an alloy between the salt and other electrode, which can then be separated by recharging, returning the cell to its three distinct layers.

Some of the most recent funding round will be put towards a first commercial-scale manufacturing plant, as well as to continued technology development.

Ambri, which opened a prototype cell factory in Massachusetts last autumn, has demonstrator LMBs in Massachusetts, Hawaii, New York and Alaska, alongside project partners that include First Wind, Con Edison, Energy Excelerator and Raytheon.

“Ambri’s solution is highly distinguished from others in the marketplace on cost and performance, thanks to a simple manufacturing process, use of cheap and safe materials, and significantly longer lifetime compared to other approaches we’ve seen,” says Khosla Ventures’ Andrew Chung.

“Large-scale, cost-effective electricity storage will be a critical part of reinventing our global electric grid infrastructure.”

Total vice-president Sophie de Richecour adds: “We see enormous potential for this technology to revolutionise the way electricity grids are operated globally, especially in integrating solar resources."

The Ambri LMB was invented by Massachusetts Institute of Technology professors Donald Sadoway and David Bradwell.