Abstract
Wire-shaped electrodes for solid-state cable-type supercapacitors (SSCTS) with high device capacitance and ultrahigh rate capability are prepared by depositing poly(3,4-ethylenedioxythiophene) onto self-doped TiO2 nanotubes (D-TiO2) aligned on Ti wire via a well-controlled electrochemical process. The large surface area, short ion diffusion path, and high electrical conductivity of these rationally engineered electrodes all contribute to the energy storage performance of SSCTS. The cyclic voltammetric studies show the good energy storage ability of the SSCTS even at an ultrahigh scan rate of 1000 V s(-1), which reveals the excellent instantaneous power characteristics of the device. The capacitance of 1.1 V SSCTS obtained from the charge-discharge measurements is 208.36 mu F cm(-1) at a discharge current of 100 mu A cm(-1) and 152.36 mu F cm(-1) at a discharge current of 2000 mu A cm(-1), respectively, indicating the ultrahigh rate capability. Furthermore, the SSCTS shows superior cyclic stability during long-term (20 000 cycles) cycling, and also maintains excellent performance when it is subjected to bending and succeeding straightening process.