The World's Largest Prismatic Battery Cell Just Entered Production in China

Envision Energy opened the doors to what it calls the world’s first 100-gigawatt-hour energy storage megafactory on Wednesday in Yichang, China. The first batch of cells rolling off the line — 790 amp-hour prismatic wound cells, the largest of their kind on the market — are already on their way to Germany.

Built by the China Construction Second Engineering Bureau, the Yichang site is more than just a single factory. It is a full-chain production base covering everything from individual cells to finished storage systems. Phase one, which delivers 40 GWh of cell capacity annually, broke ground in October 2025 and hit production in under a year — a fast timeline by any standard.

Phase two adds another 60 GWh of cell capacity alongside 60 GWh of system integration capacity. Construction started in April 2026. Once fully ramped, the entire site will be one of the largest vertically integrated battery campuses anywhere in the world.

The cell itself is the headline act. Each 790 Ah prismatic cell packs a volumetric energy density above 440 watt-hours per liter, a cycle life exceeding 12,000 charge-discharge cycles, and a round-trip efficiency of 96%. Those numbers matter: longer cycle life means fewer replacements over a 20-year solar or wind farm lifetime, and higher efficiency means less energy wasted as heat during charge and discharge.

Envision says it solved the usual trade-off between cell size and safety through material science innovations and full-process AI quality control across the production line. The 790 Ah cell passed multiple high-risk abuse tests and received certification from independent testing bodies — a necessary credential for the European and North American utility-scale markets it intends to serve.

The timing is not accidental. Global battery storage deployments are expected to more than double between 2025 and 2030 as grids push to absorb larger shares of intermittent renewable generation. China alone is on track to install more than 200 GW of storage capacity by decade end. Envision, which also builds wind turbines and smart grid software, is betting that owning the full vertical chain — from cell chemistry to system integration — gives it a cost and reliability edge over competitors that buy cells from third-party suppliers.

For now, the factory’s capacity is largely spoken for. The German shipment is a signal that European utility buyers are already placing orders, and the Yichang site has room to expand further on its existing land.