Graphene‐Assisted Interfacial Engineering to Develop Binder‐ and Dispersant‐Free Cast Si Alloy/Nanocarbon Anodes for High‐Performance Li‐Ion Batteries

Abstract

Highly oxidized nanocarbon materials, capable of being dispersed in aqueous solutions without dispersants, can enable the fabrication of highly conductive electrodes for Li‐ion batteries (LIBs). This paper introduces a novel binder‐free casting approach to enhance the performance of Si‐based anodes in LIBs by incorporating a network of highly oxidized single‐walled carbon nanotubes (Ox‐SWCNTs) and size‐controlled graphene oxide (GO) nanosheets, both dispersed in aqueous solutions without dispersants. LIB anodes are prepared using binder‐free slurries containing a Si alloy, Ox‐SWCNTs, and GO (94.5/5/0.5 wt.%). The addition of 2D GO significantly improves the cycling stability of the anodes, whereas those without GO exhibit reduced capacity owing to poor interfacial stability. The anode stability is further enhanced through deoxygenation and nitrogen doping (5.83%) via chemical reduction with hydrazine fumes. The inorganic‐rich solid‐electrolyte interphase in situ hybridized with N‐doped SWCNTs and reduced GO contributes to a low interfacial resistance (1.15 Ω) after cycling. The resulting anodes exhibit remarkable initial capacities (1100 mAh g⁻¹) with stable retention behaviors (82.2% after 100 cycles at 0.5 C) even without binder materials. A LIB full‐cell achieving a high energy density of 418 Wh kg⁻¹ demonstrates the excellent performance of the binder‐free Si‐based anodes.