Modification of spinel-based CoV2O4 materials through Mn substitution as a potential anode material for Li-ion storage

Spinel structure comprising Co and Mn with formula of Co(1-x)MnxV2O4 (x = 0, 0.25, 0.50, and 0.75) nanocomposite materials were successfully synthesized using solvothermal technique and incorporated in anode material for Li-ion storage for the first time. The specific surface area was tuned by altering the Co and Mn atomic ratios in the CoV2O4 structure. The specific surface areas of 26.94, 25.49, 29.82, and 8.54 m(2)/g were obtained for CoV2O4, Co0.75Mn0.25V2O4, Co0.50Mn0.50V2O4, and Co0.75Mn0.25V2O4, respectively. Besides, the resultant product physicochemical and electrochemical properties were systematically characterized. An eco-friendly and water-based carboxyl methyl cellulose with styrene butadiene rubber (CMC/SBR) binder was used to prepare an active electrode. The sample with equal concentrations of Co and Mn in the V-O matrix exhibited a higher reversible specific capacity and rate performance than other concentration of Mn-doped samples. A specific capacity of 1364.47 mAh/g was obtained at a current density of 0.1 A/g over 100 cycles. The high cyclic and rate performance were mainly attributed to a large surface area with fine adhesion between active materials and a current collector. The theoretical calculations of CoV2O4 and Co0.5Mn0.5V2O4 indicated that band gaps decreased after Mn substitution, which could explain rate capability of Mn-substitute one demonstrate much better performance. The results indicate that composition-optimized Co0.5Mn0.5V2O4 anode is a potential candidate for Li-ion battery applications.