Synthesis of high-performance Li₄Ti₅O₁₂ and its application to the asymmetric hybrid capacitor

Abstract

In this work, granule Li₄Ti₅O₁₂ was successfully synthesized by spray drying a precursor slurry, followed by the solid-state reaction method. The precursor slurry was prepared from a solution of lithium carbonate (Li₂CO₃) and titanium dioxide (TiO₂) in deionized water. A hybrid capacitor was fabricated which comprised a granule Li₄Ti₅O₁₂ anode and activated carbon cathode. For comparison, an electrical double-layer capacitor (EDLC) cell was fabricated by using activated carbon electrodes in the same way. The electrochemical performance of the hybrid capacitor and the EDLC was characterized by constant current charge/discharge curves and cycle performance testing. The electrochemical testing results showed that the capacitance of the hybrid capacitor is approximately 2.5 times higher than that of the EDLC. Furthermore, the capacitance of the EDLC and the hybrid capacitor barely decreased after 1,000 cycles. The results of this study demonstrate that the hybrid capacitor has the advantages of the high rate capability of a supercapacitor (EDLC) and high battery capacity.