China and India unveil advanced battery prototypes for long‑duration renewable storage

Researchers at Fudan University and the Chinese Academy of Sciences have created a flowing zinc slurry battery that ran continuously for 5,128 hours and retained 81 % of its capacity after 5,500 charge‑discharge cycles, achieving a Coulombic efficiency of 99.94 %. The design replaces a fixed zinc electrode with a circulating slurry of zinc nanoparticles, promising scalable, durable energy storage for solar and wind power.

In Chennai, deep‑tech start‑up Meine Electric announced an iron‑air battery that can be fully charged in six hours and deliver power for over 18 hours. Independent testing by the US‑based CES Battery Laboratory confirmed the performance across seven test cycles. The company holds four patents and has filed seven more, with two pilot orders secured and a grid‑connected deployment expected in early 2027. Both developments aim to provide cost‑effective, long‑duration storage solutions to support rapid renewable‑energy expansion in their respective regions.