Synthesis of Novel Silicon Oxycarbonitride Anode Material and Controllable Chemical Prelithiation
A novel silicon oxycarbonitride(SiOCN)anode material is synthesized through an aldimine condensation of 3-aminopropyl triethoxysilane(APTES)with glutaraldehyde(GA)and simultaneous hydrolysis of APTES,followed by subsequent thermal pyrolysis.A chemical prelithiation method using lithium-biphenyl(Li-BP)as the lithiation reagent and a 2-methyl tetrahydrofuran(2-MeTHF)solution as the reducing solvent is designed to enhance the initial Coulombic efficiency(ICE)for SiOCN anodes.The prelithiation extent can be easily controlled by tuning the reaction time.A solid electrolyte interface layer is formed during chemical prelithiation.After dipping in 1 mol/L lithium reagent for 30 s,prelithiated SiOCN/Li half-cell ICE can be increased from 73.6%to 90.4%.Compared with the original cell,the prelithiated SiOCN/Li half-cell exhibits equivalent cycling performance,delivering a stable specific capacity of 604 mA·h/g after 195 cycles with a retention rate of 98.5%at 1 A/g current density.When matched with an NCM811 cathode,the full cell exhibits an improved ICE from 46.3%to 78.6%.The pre-lithium SiOCN anode shows a performance of high ICE,high capacity and long cycle stability,which promises great application in high-energy lithium batteries.
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