Boosting the Deep Discharging/Charging Lithium Storage Performances of Li₃VO₄ through Double-Carbon Decoration

With high theoretical capacity, good ionic conductivity, and suitable working plateaus, Li₃VO₄ has emerged as an eye-catching intercalation anode material for lithium storage. However, Li₃VO₄ suffers from poor electrical conductivity and 20% volume variation under deep discharging/charging conditions. Herein, we present a "double-carbon decoration" strategy to tackle both issues. Deflated balloon-like Li₃VO₄/C/reduced graphene oxide (LVO/C/rGO) microspheres with continuous electron transport pathways and sufficient free space for volume change accommodation are fabricated through a facile spray-drying method. Under deep discharging/charging conditions (0.02-3.0 V), LVO/C/rGO achieves a high intercalation capacity of 591 mA h g^-1. With high capacity and outstanding stability, LVO/C/rGO outperforms other intercalation anode materials (such as graphite, Li₄Ti₅O₁₂, and TiO₂). In situ X-ray diffraction measurement reveals that the lithium storage is realized through both solid-solution reaction and two-phase reaction mechanisms. A LVO/C/rGO//LiNi_0.8Co_0.15Al_0.05O₂ lithium-ion full cell is also assembled. In such full cell, LVO/C/rGO also demonstrates high specific capacity and excellent cycling stability. The above results manifest that the LVO/C/rGO anode has the potential to be applied in the next-generation high-performance lithium-ion batteries.