Protective carbon-coated silicon nanoparticles with graphene buffer layers for high performance anodes in lithium-ion batteries

다국어 초록 (Multilingual Abstract)

<P><B>Abstract</B></P> <P>Silicon is a promising anode material for use in lithium-ion batteries (LIBs). However, its volume expansion problem can cause critical issues that deteriorate efficiency, cycle life, and result in sudden breakage of battery cells. Herein, polyethylene glycol derived thin carbon-coated Si nanoparticles (Si/c-PEG) and graphene wrapping were used to block electrolyte contact and buffer volume changes, respectively. The hierarchical graphene-wrapped Si/c-PEG (Si/c-PEG/G) exhibited outstanding performance with a gravimetric capacity of ∼1820 mAh/g at 0.1 A/g and 99.5% Coulombic efficiency at the 10th cycle. Moreover, the full-cell configuration using Si/c-PEG/G anodes with commercial lithium cobalt oxides (LiCoO<SUB>2,</SUB> LCO) cathodes demonstrated stable operation during repeated charge/discharge cycles at 0.1 and 1 C rates. Micelle coating of PEG with graphene layers was a useful method for minimizing the exposed area of silicon to the electrolyte during lithium-ion storage.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Protective carbon coated Si nanoparticles with graphene buffer layers were prepared. </LI> <LI> Carbon coating prevents a direct contact between Si and electrolyte for stable SEI. </LI> <LI> Graphene layers buffer the volume expansion of Si to ensure cycle-stability. </LI> <LI> The Si/c-PEG/G electrode showed a stable operation in full-cell configuration. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>