Core−shell coaxially structured NiCo2S4@TiO2 nanorod arrays as advanced electrode for solid-state asymmetric supercapacitors

An integrated electrode of core–shell coaxially structured NiCo2S4@TiO2 nanorod arrays/carbon cloth (NiCo2S4@TiO2@CC) have been fabricated, via a two-step hydrothermal method. Comprehensive structural and compositional analyzes are performed to understand the effects of the NiCo2S4 shell on the TiO2 core. Such core–shell arrays structure can significantly provide abundant electroactive sites for redox reactions, convenient ion transport paths, and favorable structure stability. The NiCo2S4@TiO2@CC electrode represents a splendid specific capacitance (650 F g−1 at 1 A g−1) and enhanced cycling stability (capacitance retention of 97% over 10 000 cycles at 5 A g−1). Additionally, the assembled NiCo2S4@TiO2@CC//CNT@CC solid-state asymmetric supercapacitors exhibit a maximal energy density of 0.6 mWh cm−3 at 32.4 W cm−3, and topping cycling stability (85% capacitance retention after 5000 cycles at 5 mA cm−2). The results demonstrate that the well-designed NiCo2S4@TiO2@CC presented in this work are applicable for the development of electrode materials in energy storage devices.