Rice husk-activated carbon (RHAC) composited with V₂O₅ for lithium-ion batteries

This work reports the synthesis and electrochemical performance of rice husk-activated carbon (RHAC) composited with V₂O₅ for lithium-ion batteries. The sol–gel method was used, followed by the carbonization and activation processes. The specific capacity and the stability of the RHAC/V₂O₅ cathode which has been carbonized at 500–800 °C were investigated. The V₂O₅ structural characterization revealed an orthorhombic structure typical of the V⁵⁺ species. The degree of V⁵⁺, sizes of graphite crystallites, and surface area increased with the increase in carbonization temperature. The maximum specific capacity of 350 mAh g⁻¹ (at 0.1 °C) was observed for the RHAC/V₂O₅ carbonized at 800 °C. Moreover, high-rate cycling (at 0.2 °C) in common carbonated-based electrolytes after 100 cycles was observed. The results suggested that the V₂O₅ composite with RHAC improved the stability of the electrode. Moreover, the cathode with a high degree of V⁵⁺, high surface area, and high graphite crystallite size contains a higher specific capacitance.