The phosphate cathodes for aqueous zinc-ion batteries

Rechargeable zinc-ion batteries employing a metallic zinc anode and aqueous electrolytes have received significant attention since they are safe, cost-effective, and environmentally friendly. Thanks to the introduction of orthophosphate ions, vanadium phosphates exhibit a higher working voltage as cathodes for zinc-ion batteries than other vanadium-based materials. However, due to the poor cycling stability and complex mechanism, stricter requirements are put forward on their manufacturing technique. Herein, a comprehensive review of the recent research progress in vanadium phosphate electrode materials is presented, focusing on modification strategies based on different crystal structures and the energy storage behaviors of zinc ions in operation. Moreover, research directions and prospects are discussed.