Co(OH)₂/TiO₂ Nanotube Composite for High-Rate Performance Supercapacitor

Abstract

The TiO 2 nanotube arrays were prepared on Ti plate by anodizing technology, and then Co (OH) 2 nanoparticles in-situ grew into TiO 2 nanotubes with "Tube-particle bonding" nanocomposited structure. Co (OH) 2 nanoparticles with a particle size of 40.5±8 nm were infiltrated in the TiO 2 nanotube arrays, and the Co (OH) 2 outside the tube presented a nanosheet structure. The specific capacitance of the Co (OH) 2 /TiO 2 nanotube array composite reached 260 F/g at the current density~1 A/g. The capacity retention rate was 82.5 % after 2,000 cycles at the current density~5 A/g. The high-rate performance of the Co (OH) 2 /TiO 2 nanotube array composite reached 210 F/g at the current density~10 A/g.