Understanding　the　volume　expansion　behavior　of　Si　anodes　and　their　interaction　with　electrolyte　environments　is　crucial　for　developing　high-performance　lithium-ion　batteries　(LIBs).　This　study　utilizes　a　graphene　liquid　cell　for　in　situ　imaging　to　systematically　investigate　the　volume　expansion　and　etching　behavior　of　Si　anode　nanoparticles　in　different　electrolyte　environments.　Comparative　experiments　on　Si@C　core-shell　nanoparticles　assess　their　volume　expansion　dynamics.　The　findings　reveal　significant　variation　in　the　expansion　rate　of　nano　Si　depending　on　the　electrolyte　environment,　with　chemical　etching　observed　under　specific　conditions.　Conversely,　Si@C　core-shell　structures　show　mitigated　expansion　due　to　the　confinement　effect　of　the　carbon　matrix.　Battery　performance　experiments　validate　these　results,　demonstrating　the　excellent　cycling　stability　of　Si@C　anodes.　Various　coating　agents　are　explored　to　optimize　Si@C　structures,　with　dopamine　thin　layer　coating　exhibiting　the　best　cycling　stability.　This　study　offers　fundamental　insights　into　Si　anode　expansion,　electrolyte　effects,　and　carbon　coating　impacts,　advancing　LIB　technology.