Piranha Solution-Assisted Surface Engineering Enables Silicon Nanocrystals with Superior Wettability and Lithium Storage

Silicon anodes with a high theoretical capacity possess great potential applications in power batteries for electric vehicles, while their volume expansion always leads to crystal pulverization and electrode polarization. An ideal solution alleviate such polarization of silicon crystals is simultaneously use nano-sized introduce viscosity elasticity polymer binders. This work has achieved the adjustable introduction hydroxyl groups nanocrystals under optimal reaction temperature (e.g., 80 °C) appropriate piranha composition H2SO4/H2O2 = 3:1 v/v), ultimately forming an amorphous coating layer ~1.3 nm on surface. The optimized anode exhibits superior electrochemical performance (with initial Coulombic efficiency 85.5%; 1121.4 mA h g−1 at 1 A after 200 cycles) improved hydrophilicity. introduced significantly enhance hydrophilicity electrolyte activity anodes. achieve stronger bonding between binders, improving mechanical strength stability electrode. hydrophily functional surface can be explored as active strategy solve above issues. engineering method could extended more fields infiltrating silicon-based materials.