Abstract:
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 prepared samples were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Raman spectroscopy, Micromeritics 3Flex adsorption analyzer, and X-ray absorption spectroscopy (XAS). The electrochemical performance of coin cell batteries was tested by Galvanostatic charge/discharge via the battery testing station. By varying the carbonization temperature (500-800oC), all prepared samples showed the orthorhombic structure. The crystallinity percentages of 98.14, 98.17, 98.37, and 99.80 were observed for the samples carbonized at 500, 600, 700, and 800oC, Rod-shaped particles appeared at high carbonization temperatures. The RHAC exhibited a mesoporous structure. The specific surface (149.36, 153.46, 158.38, and 163.96 m2g-1) and the carbon crystallite size (2.3, 3.01, 3.14 และ 3.41 nm) increase with increased of carbonization temperature. The edge energy of prepared samples indicated V5+. The degree of V5+ increases with an increase in carbonization temperature. The coin cell batteries from the RHAC/V2O5 composite materials carbonized at 800oC showed excellent electrochemical performance, with a specific capacitance of 350 mAhg-1 (at 0.1C). Moreover, a capacity loss of 28% was observed after 100 cycles at 0.2C. The superior capacity could be attributed to the high crystallinity of V2O5 (99.80%), high degree of V5+ (86.4%), and maximum specific surface area (163.96 m2g-1). The results suggested that RHAC/V2O5 could be used as a promising cathode material for lithium-ion batteries.