This ultra-cheap, water-based iron battery could last 16 years without degrading

Chinese researchers reported an all-iron, water-based flow battery that ran for more than 6,000 cycles with no measurable capacity loss.

The design uses abundant materials and avoids flammable solvents, which could make it cheaper and safer than lithium-ion for grid storage.

Lab tests showed strong efficiency and power performance, but the technology has not yet reached pilot or commercial scale.