Breaking Barriers: Binder-Assisted NiS/NiS₂ Heterostructure Anode with High Initial Coulombic Efficiency for Advanced Sodium-Ion Batteries

Developing sodium-ion batteries (SIBs) with high initialcoulombicefficiency (ICE) and long-term cycling stability is crucial to meetenergy storage device requirements. Designing anode materials thatcould exhibit high ICE is a promising strategy to realize enhancedenergy density in SIBs. A trifunctional network binder substantiallyimproves the electrochemical performance and ICE, providing excellentmechanical properties and strong adhesion strength. A rationally designedelectrode material and binder can achieve high ICE, long cycling performance,and excellent specific capacity. Here, a NiS/NiS2 heterostructureas an anode material and a trifunctional network binder (SA-g-PAM)are designed for SIBs. Unprecedently, the anode comprising of an SA-g-PAMbinder achieved the highest ICE of 90.7% and remarkable cycling stabilityfor 19000 cycles at a current density of 10 A g(-1) and maintained the specific capacity of 482.3 mAh g(-1) even after 19000 cycles. This exciting work provides an alternatedirection to the battery industry for developing high-performanceelectrode materials and binders with high ICE and excellent cyclingstability for energy storage devices.