Preparation study on novel Li₄Ti₅O₁₂ for hybrid capacitor

A novel pseudo-nanocrystalline Li₄Ti₅O₁₂ spinel was prepared with a new sol-gel processing. We added activated carbon and citric acid, polyvinyl alcohol, polyglycol for additives to the sol. The spinel added with activated carbon and polyglycol showed the best lithiation performance. Its reversible capacity was more than 122.1 mAh/g at a 20 mA/g current density, the first charge-discharge efficiency was 99.2% and its charge-discharge potential was flat and steady. Then, the Li₄Ti₅O₁₂/AC hybrid capacitors using Li₄Ti₅O₁₂ as the anode and activated carbon as the cathode were assembled. Electrochemical tests showed that at a current density 20 mA/g, the specific capacity of Li₄Ti₅O₁₂ electrode was 103.5 mAh/g and the efficiency of hybrid capacitor was 96%. Symmetry and linearity of the charge-discharge curve for the hybrid capacitor kept well, and its resistance was little, high power performance was good.