Co/N Co-Doped MoS₂ with High Pseudocapacitive Performance for Solid-State Flexible Supercapacitors

Herein, we demonstrate the enhanced pseudocapacitive performance of a MoS₂-based flexible supercapacitor by the co-doping strategy of cations and anions. The MoS₂ 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 MoS₂ (N-Co-MoS₂) shows improved electron transport efficiency and enhanced active sites for MoS₂. According to the first-principles calculations, N-Co-MoS₂ has a unique band structure and high electrical conductivity. As expected, N-Co-MoS₂ shows higher capacitive performance with 5072.5 mF cm^–2 and a better cycle life (retaining 100% capacitance after 10,000 cycles) than pure MoS₂. Furthermore, a solid-state flexible N-Co-MoS₂ 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 MoS₂-based materials with good supercapacitive performance.