Advancing Li3VO4 with high coulombic efficiency and super lithium storage by interface in situ regulation

Abstract

Li₃VO₄ (LVO) is one of the most promising anode materials for lithium-ion batteries; however, its low electronic conductivity and initial coulombic efficiency pose significant challenges for further applications. To address these issues, an innovative catalysis mechanism is proposed by uniformly depositing nickel (Ni) on the surface of the LVO material, aiming to reconstruct the solid electrolyte interface (SEI) and enhance overall lithium storage performance. These embedded ultra-small Ni metallic nanoparticles not only serve as active centers that catalyze the preferential reduction of lithium salts but also improve the conductivity of the composite, thereby facilitating a reaction pathway with reduced activation energy. Notably, the initial coulombic efficiency of the LVO/Ni/C composite reaches an impressive 78.2%, marking a substantial improvement of 14.1% compared to that of unmodified LVO/C and surpassing that of previously reported LVO-based anode materials. Such a high initial coulombic efficiency is demonstrated relevant to the reconstruction of a thin and dense SEI layer with improved reaction kinetics, giving rise to excellent performance. The LVO/Ni/C electrode exhibits an improved discharge capacity of 547.5 mA h g⁻¹ after 200 cycles at 0.5 A g⁻¹, and a high capacity retention of 98.9% after 1500 cycles at 4.0 A g⁻¹. The exceptional electrochemical performance is attributed to the high catalytic activity and excellent conductivity of the nano-sized Ni particles dispersed throughout the material.