Nano-porous structure architectonics of MoS2 nanosheets with flexible electrode membrane for designing ultrastable sodium-ion hybrid capacitor

Abstract

In the realm of large-scale energy storage, sodium-ion hybrid capacitors (SICs) have emerged as promising contenders due to their impressive fusion of high energy density and power density. However, the challenge lied in addressing the slow reaction kinetics of the Faraday battery-type anode, which was difficult to match with the capacitive-type cathode. In this work, the porous structure architecture was designed by chemically bonding retiform MoS2 nanosheets onto the interpenetrating network electrode membrane (EM) in-situ, creating an integrated electrode (CM@MoS2). The structural synergy between MoS2 and EM facilitated the optimal environment for Na+ transportation and storage, greatly enhancing the reaction kinetics. As the Faraday battery-type anodes, a remarkable reversible capacity retention rate of 94.2% was achieved even after undergoing 1000 cycles at 0.2 A g−1. Matching with capacitive-type cathode of activated carbon (AC), the assembling CM@MoS2//AC SICs also exhibited an impressive reversible capacity retention rate of 87.7% even after 10,000 cycles at 1 A g−1, and achieving 117 Wh kg−1 of the energy density at a power density of 100 W kg−1, showcasing outstanding dual-function features. The application of architectonics to Faraday battery-type anodes holds promised for providing insights and concepts for the future rational design of sodium storage materials with enhanced electrochemical properties in SICs.