Ternary molybdenum sulfoselenide based hybrid nanotubes boost potassium-ion diffusion kinetics for high energy/power hybrid capacitors

Abstract

Ternary MoS_2−xSe_x/carbon hybrid nanotubes (denoted as MoS_2−xSe_x/C-HNTs) with a unique disordered layer structure and expanded interplanar spacing were synthesized through a facile two-step method involving oxidative polymerization coating and subsequent thermal annealing treatment using an Sb₂S₃ nanowire template, and they delivered excellent K⁺ storage performance. The higher diffusion coefficient, excellent structural robustness and disordered layer structure could be the possible reasons for the enhanced performance with a high capacity of 237.0 mA h g⁻¹ after 300 cycles at 0.5 A g⁻¹, which is supported by ex situ XRD, Raman spectroscopy and GITT measurements. Importantly, the prominent performance of a potassium-ion hybrid capacitor (KIHC) based on the MoS_2/3Se_4/3/C-HNT anode and a commercial activated carbon (AC) cathode demonstrates its great potential for future practical applications.