Novel High-Rate Performance of Dual Carbon-Coated Li₃V₂(PO₄)₃ Materials Used in an Aqueous Electrolyte

Abstract

Lithium vanadium phosphate (Li3V2(PO4)3) coated with dual carbon–citric acid and polyvinylpyrrolidone (PVP), are used as the cathode materials for the novel aqueous rechargeable lithium-ion batteries (ARLBs). Li+ diffusion coefficient of Li3V2(PO4)3/C (LVP/C) is first calculated and reported for the ARLBs. The primary discharge specific capacities of LVP/C reaches 125.8 mA h g–1 (1 C), 122.7 mA h g–1 (2 C), 113.6 mA h g–1 (5 C) and 101.6 mA h g–1 (10 C), respectively. Particularly, at 50 C (equivalent to an ampere density of 6.6 A g–1), the capacity has almost no decrease after 300 cycles. At a novel 100 C (13.2 A g–1), 94.9% of capacity retention is achieved after 1000 cycles, and the Coulombic efficiency approximates equal to 100%. Lithium vanadium phosphate with a NASCION structure is regarded as the great promising candidate material for power batteries owing to its high safety, superior structural stability, and excellent electrochemical performance.