NiS-MoS2 Hetero-nanosheet Arrays on Carbon Cloth for High-Performance Flexible Hybrid Energy Storage Devices

Coupling two-dimensional (2D) electroactive species with 3D carbon substrates is a very promising strategy to fabricate advanced electrodes for high-performance flexible electrical energy storage devices. However, the intractable coupling between them has prevented the wide applications of such a strategy. Herein, we develop a facile one-step hydrothermal synthesis technique to directly construct NiS-MoS2 hetero-nanosheet arrays on carbon cloth (NiS-MoS2 HNSAs/CC) via introducing sodium dodecyl sulfate as the surfactant together with Ni, Mo, and S sources. Such vertically aligned nanosheet heterostructures constructed an integrated 3D open framework, helping improve the performance of electrodes from various aspects. Consequently, the NiS-MoS2 HNSAs/CC electrode achieves a very high areal capacity and specific capacity (0.76 mAh·cm–2 and 271.7 mAh·g–1, respectively, at a current density of 2.5 mA·cm–2) and good rate capability (39% at 40 mA·cm–2). With the NiS-MoS2 HNSAs as a positive electrode and typical activated carbon as a negative electrode, the fabricated solid-state hybrid capacitors have a high output cell voltage of 1.6 V and thus deliver a high energy density of 3.75 mWh·cm–3 at a power density of 31.6 mW·cm–3 with excellent flexibility and charging–discharging stability.