A simple synthesis method for carbon-composited lithium titanium vanadium oxide as a high-energy positive electrode material for lithium-ion batteries

Improvements in energy density and cycle stability are in high demand, particularly for all-solid-state batteries, which are expected to become the next generation of batteries. Li_8/7Ti_2/7V_4/7O₂ has recently been reported as a positive electrode active material with a high theoretical capacity and has shown no degradation in sulfide-based solid-state lithium-ion batteries. This study focuses on a facile and effective method for synthesizing carbon-composited Li_8/7Ti_2/7V_4/7O₂. This approach involves concentrating a homogeneous solution containing Li, Ti, and V, followed by heat treatment at 600 °C under an Ar atmosphere for 6 h. Notably, the resulting composite (Li_8/7Ti_2/7V_4/7O₂/C) exhibited a relatively high specific capacity of over 330 mAh g⁻¹ (Li_8/7Ti_2/7V_4/7O₂/C) at 0.13 mA cm⁻² and 25 °C in a sulfide-based solid-state battery without the addition of further conductive additives, such as acetylene black.