Australian redox flow battery maker Allegro secures fresh cash to scale to mass production

Australian redox flow battery startup Allegro Energy has secured AUD 1.85 million ($1.16 million) of federal funding to help scale up its energy storage devices to mass production.

The startup, which was spun out of the University of Newcastle, in NSW, secured AUD 17.5 million in a series A funding round in September led by US-based venture capital investor The Grantham Foundation and Australian utility Origin Energy.

Allegro says the microemulsion electrolyte used in its products is non-flammable and cheap, uses abundant material, and is easily recyclable.

Thomas Nann, CEO and co-founder of Allegro, told pv magazine Australia, how he had come up with the idea of combining a water-based, aqueous electrolyte with an organic solvent medium between battery cathode and anode.

Nann, Newcastle University Head of School for the School of Mathematical and Physical Sciences, said the aqueous electrolytes used in flow batteries were typically only stable to 1.23 V and then split into hydrogen and oxygen. While organic solvents were more electrochemically stable, he said, they were much more expensive and potentially toxic.

Using the analogy of “adding dishwashing liquid and oil to water,” Nann explained the micromulsion electrolyte his team came up with consisted of water and a hydrophobic liquid which bond on a micro level courtesy of a surfactant in the mix.

Nann said Allegro’s electrolyte would cost $0.10 per liter or kilogram, versus $10/l for electrolytes typically used in flow batteries at the time. The professor stated an intent to initially use the material in supercapacitors before moving on to long-duration energy storage batteries. The addition of a fast-responding but low-storage-capacity supercapacitor to Allegro’s flow batteries solves the problem Nann reported, in 2017, of flow batteries offering sluggish response times to grid demand.

Series A investor in Allegro, Origin Energy, in 2023 acquired a 5% stake in the redox flow startup and agreed to install a 100 kW/800 kWh pilot version of the company’s technology as part of its battery energy storage system development at the coal-fired Eraring Power Station site in Hunter Valley, NSW.

Announcing the award of AUD 1.85 million to Allegro from Australia’s Industry Growth Program (IGP), Minister for Industry and Science Ed Music explained the AUD 400 million IGP makes early stage commercialization awards of up to AUD 250,000 and commercialization and growth grants of up to AUD 5 million. Startups which grow as a result can then become eligible for co-investment from the AUD 15 billion National Reconstruction Fund.