Enhancing symmetric supercapacitor performance through spin-coated lithium trivanadate films modified with carbon

Carbon added LiV₃O₈ films were fabricated using polymer-assisted spin coating method. Here, the influence of carbon black and activated carbon on the characteristics of LiV₃O₈ were analysed. The structural and morphological characterizations of the films were done, and the Raman studies confirmed the presence of carbon in the coated films. The existence of 4 + and 5 + oxidation states of vanadium in the carbon added films were validated by the XPS spectrum. The improvement in electrical conductivity of all the samples after the addition of carbon was studied using the four-probe method. The carbon added LiV₃O₈ films displayed better electrochemical performance than the pure LiV₃O₈ working electrode. A maximum specific capacitance of 216 Fg⁻¹ at a current density of 0.5 Ag⁻¹ was achieved by the activated carbon (0.1 wt%) added to the LiV₃O₈ film (LVO:PVA:CH0.1). The symmetric device constructed with LVO:PVA:CH0.1 film exhibited excellent retention rate of 99% after 100 cycles.