World's first zinc-nickel-air flow battery energy-storage system passes full-scale test

[Photo provided to chinadaily.com.cn]

The world's first zinc-nickel-air flow-battery energy-storage system (ESS) completed a trouble-free one-month trial operation in Shaoxing, Zhejiang province on Nov 13. Developed under China's national key R&D program "High-flux Evaluation and Demonstration of Zinc-Nickel-Air Flow Batteries", the system was jointly designed by State Grid Shaoxing Power Supply Company, Beijing University of Chemical Technology, and Beijing Xinhua Storage Technology Co. An authoritative third party has already issued a formal validation report, signaling a major domestic breakthrough in long-duration storage technology. The advancement adds a new layer of security to the grid and promises consumers greener, more stable electricity.

"The stand-out features are safety, high efficiency, long life, environmental friendliness and low cost," said Professor Xiang Zhonghua, project leader and professor at Beijing University of Chemical Technology, pointing to the container-sized unit. "The electrolyte is only mildly alkaline, and the stack dispenses with the conventional ion-exchange membrane. Put simply, it will not catch fire or explode, and even if the electrolyte leaks there is no environmental contamination — families with children or elderly members have nothing to worry about."

Grid operators are equally enthusiastic. "Round-trip efficiency exceeds 85 percent — meaning more than 8.5 kilowatt-hours are produced out of every 10-kWh stored — and the battery can complete over 6,000 stable cycles, which translates into a calendar life of more than ten years, well above the national benchmark," added the project manager from State Grid Shaoxing Power Supply. "On a full-life-cycle basis the cost is at least 30 percent lower than vanadium-redox or lithium-ion alternatives, making large-scale roll-out economically attractive."

For Shengzhou's distribution network, the ESS functions as a combined "power bank and voltage stabiliser". "Solar and wind capacity here is growing fast, but generation is weather-driven: surplus at noon, shortage after sunset," explained Xu Feng, an operations engineer at State Grid Shengzhou Power Supply. "The new system stores the daytime surplus and feeds it back during evening peaks or whenever renewable output dips. The net effect is to flatten the daily curve — no more flickering lights when every household switches on air-conditioners in summer or heaters in winter."

State Grid Shaoxing Power Supply plans to deploy the technology in centralized storage parks, campus-scale microgrids, and solar-storage-charging integrated stations. "Imagine an EV charging plaza that tops up cars at night with electrons captured from its own rooftop PV during the day — drivers enjoy lower tariffs and the grid gains an extra buffer," the project manager said. As manufacturing scales up, both system reliability and the end-user experience are expected to improve further.