Flexible carbon fiber membranes with ultrafine NiS nanocrystals for enhanced lithium storage kinetics

The rise of portable wearable devices has driven research in flexible lithium-ion batteries (FLIBs), necessitating advancements in the mechanical properties, electrochemical kinetics, and structural stability of FLIB anodes. This study presents the successful development of a binder-free, flexible, self-supporting membrane material (PVP-NiS/CFs) as an FLIB anode using an electrospinning technique. The material demonstrates both flexibility and a homogeneous distribution of ultrafine NiS nanocrystals embedded in carbon fibers, facilitated by a polyvinylpyrrolidone (PVP) pore-forming agent. Moreover, the three-dimensionally interconnected carbon fiber framework enhances electron/ion transport efficiency, demonstrating superior capacitance contribution of 56.24 %. The self-supporting anode membrane exhibits outstanding stability and cycling durability, maintaining a specific capacity of 859.9 mAh/g after 600 cycles at a current density of 1 A/g. Additionally, as a flexible material, the resistance exhibited negligible change after undergoing 200 continuous bending cycles. This study offers Novel insights and approaches for developing FLIB anode materials with superior electrochemical performance.