Welcome to the Aqueous Battery Brief. In this week’s roundup: Idemitsu Australia’s proposed 108 MW VRFB, Eos’ fresh $263M, and fresh top LDES rankings. • Not yet a subscriber? Join here.
Idemitsu Australia Proposes 108 MW VRFB
Idemitsu Australia, the Australian arm of Japanese energy company Idemitsu Kosan, is proposing a 108 MW/864 MWh vanadium flow battery at a decommissioned coal mine in New South Wales, Australia.
The firm is already collaborating with Swedish renewable energy developer OX2 on a separate energy storage initiative on the same site.
Eos to Raise $263M for Frontier
Zinc battery powerhouse Eos Energy Enterprises is expected to raise $263M for Frontier Power USA, its joint vehicle with Cerberus Capital Management to build and deploy Eos technology.
The raise brings Frontier’s total available funds to $1B from multiple sources. Separately, Frontier’s pipeline now includes approximately 16 GWh of opportunities, 5 of which have already been purchased, selected, or are under active diligence.
Learn more in Pulse 2.0.
CellCube, Rongke Power Top Operational Rankings
Austrian vanadium redox flow manufacturer CellCube is the top non-lithium LDES OEM in Q2 2026, ranked by both operational energy capacity and operational project count. Chinese VRFB manufacturer Rongke Power leads the cumulative rankings since the industry’s start.
The assessments come from energy storage analysis provider FairGreen. See the full rankings.
At 250, the U.S. Needs Aqueous Storage

As the U.S. hits this milestone year, the country faces new urgency to secure energy independence, global AI leadership, and military dominance.
Fostering aqueous energy storage is critical to the country achieving all three.
Read why in the latest opinion piece from Octet CEO & Founder, Onas Bolton.
Mark Your Calendars
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Volta Foundation’s Women in Batteries Conference. July 28 – 30, Silicon Valley. Details & Registration.
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Clean Energy Group‘s webinar will spotlight iron-air giant Form Energy. Hear from Sarah Jackson, Form’s Director of Government Affairs. Time: August 6th 2026 @ 1PM ET. Details & Registration
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Volta Foundation’s Battery Forum features two tracks: Next-Gen Chemistry and Cost Reduction. August 26, 11:00 AM – 1:00 PM ET. Virtual Conference. Details & Registration
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Flow Batteries North America, the second annual flow battery-dedicated event in North America. October 19-22, Phoenix, Arizona. Details & Registration
📆 Get ahead of your planning with the Aqueous Energy Events Calendar in our December 29th Aqueous Battery Brief.
Who’s Hiring
Seeking a new role — or know someone who is? Start with the quick links to aqueous firms’ open roles pages below.
Have a specific open position you’d like to highlight? Send us an e-mail.
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