Herein, we demonstrate the enhanced pseudocapacitive performance of a MoS 2 -based flexible supercapacitor by the co-doping strategy of cations and anions. The MoS 2 nanosheet arrays on carbon cloth are directly doped with N and Co atoms through a simple hydrothermal process. The obtained cation and anion co-modified MoS 2 (N-Co-MoS 2 ) shows improved electron transport efficiency and enhanced active sites for MoS 2 . According to the first-principles calculations, N-Co-MoS 2 has a unique band structure and high electrical conductivity. As expected, N-Co-MoS 2 shows higher capacitive performance with 5072.5 mF cm −2 and a better cycle life (retaining 100% capacitance after 10,000 cycles) than pure MoS 2 . Furthermore, a solid-state flexible N-Co-MoS 2 supercapacitor device is fabricated to demonstrate excellent mechanical stability with a specific capacitance of 3236 mF cm −2 and a stable cycle capacitance of 75.56% after 5000 cycles. In our work, we have provided a reference for preparing MoS 2 -based materials with good supercapacitive performance.

In this work, nitrogen-doped graphene quantum dots (N-GQDs) are introduced into the honeycomb structure of NiCo2S4 nanoarrays on a carbon cloth by electrodeposition, which significantly enhances the electrochemical performances of NiCo2S4 as an electrode of hybrid supercapacitors. The honeycomb framework structure of NiCo2S4 nanosheets not only increases more active sites but also improves the structural stability of the electrode material. At the same time, the introduction of N-GQDs improves the wettability of NiCo2S4 and effectively reduces its internal resistance. As an electrode material, the NiCo2S4/N-GQDs@CC composite shows outstanding capacitive properties with an areal capacity of 1803 mC cm–2 at 3 mA cm–2. In addition, the assembled symmetric supercapacitor device can provide a high energy density of 127 μWh cm–2 at a power density of 1000 μW cm–2, good rate performance, and cycle stability. After 2500 cycles, the capacity retention rate can still reach 83%. The outstanding charge storage capability may be due to the synergistic effect between its unique honeycomb structure, high porosity, and improved electrical properties of N-GQDs. This simple and controllable synthesis strategy provides a reference for energy storage applications.

No abstract

With increasing attention on environmental impacts and sustainable development, the conversion of underutilised bagasse (BG) or low-value fibre waste into biosorbents has considerable potential applications. In this study, BG carboxymethyl...