Mass‐Producible, Quasi‐Zero‐Strain, Lattice‐Water‐Rich Inorganic Open‐Frameworks for Ultrafast‐Charging and Long‐Cycling Zinc‐Ion Batteries

Abstract Low‐cost and high‐safety aqueous Zn‐ion batteries are an exceptionally compelling technology for grid‐scale energy storage. However, their development has been plagued by the lack of stable cathode materials allowing fast Zn 2+ ‐ion insertion and scalable synthesis. Here, a lattice‐water‐rich, inorganic‐open‐framework (IOF) phosphovanadate cathode, which is mass‐producible and delivers high capacity (228 mAh g −1 ) and energy density (193.8 Wh kg −1 or 513 Wh L −1 ), is reported. The abundant lattice waters functioning as a “charge shield” enable a low Zn 2+ ‐migration energy barrier, (0.66 eV) even close to that of Li + within LiFePO 4 . This fast intrinsic ion‐diffusion kinetics, together with nanostructure effect, allow the achievements of ultrafast charging (71% state of charge in 1.9 min) and an ultrahigh power density (7200 W kg −1 at 107 Wh kg −1 ). Equally important, the IOF exhibits a quasi‐zero‐strain feature (<1% lattice change upon (de)zincation), which ensures ultrahigh cycling durability (3000 cycles) and Coulombic efficiencies of 100%. The cell‐level energy and power densities reach ≈90 Wh kg −1 and ≈3320 W kg −1 , far surpassing commercial lead–acid, Ni–Cd, and Ni–MH batteries. Lattice‐water‐rich IOFs may open up new opportunities for exploring stable and fast‐charging Zn‐ion batteries.