Cr3+-doped Li3VO4 for enhanced Li+ storage

Abstract

Li3VO4 has gained significant attention as a promising anode material for lithium-ion batteries owing to its high specific capacity, low cost and safe working potential. Unfortunately, its disappointing electronic conductivity limits its rate performance. To address this problem, a series of Cr[Formula: see text]-doped Li3VO4 compounds are synthesized by solid-state reaction. The obtained Li[Formula: see text]Cr[Formula: see text]V[Formula: see text]O4 compounds ([Formula: see text] and 0.02) have the same orthorhombic crystal structure (Pnm21 space group), suggesting the successful Cr[Formula: see text] doping in Li3VO4. Compared with Li3VO4, Li[Formula: see text]Cr[Formula: see text]V[Formula: see text]O4 exhibits a two orders of magnitude larger electronic conductivity. Additional benefits of the Cr[Formula: see text] doping include the increase of the Li[Formula: see text] diffusion coefficient and the decrease of the particle size. Consequently, Li[Formula: see text]Cr[Formula: see text]V[Formula: see text]O4 displays not only a large reversible capacity (363[Formula: see text]mAh g[Formula: see text] at 60[Formula: see text]mA g[Formula: see text] and superior cyclic stability (86.6% capacity retention after 1000 cycles at 1200[Formula: see text]mA g[Formula: see text] but also decent rate performance (147[Formula: see text]mAh g[Formula: see text] at 1200[Formula: see text]mA g[Formula: see text].