Due　to　the　excellent　theoretical　capacity,　silicon-based　electrodes　have　been　extensively　studied　to　develop　high　energy-density　lithium-ion　batteries　(LIBs).　Nevertheless,　the　large　volume　expansion　and　unfavorable　interface　seriously　hamper　its　application,　and　the　underlying　physics　behind　are　still　unclear.　In　this　work,　using　in-situ　environment　scanning　electron　microscopy　(ESEM),　the　morphological　evolution　of　composite　silicon-graphite　electrodes　with　different　ionic　liquids　as　electrolytes　are　compared　in　the　range　of　20　degrees　C-60　degrees　C.　Surprisingly,　combining　the　microstructure　and　surface　reaction　products　from　transmission　electron　microscope　(TEM)　and　Xray　photoelectron　spectroscopy　(XPS),　it　finds　out　that　the　fully　reaction　of　lithium-silicon　does　not　generate　huge　volume　expansion,　while　the　side　reaction　between　graphite　and　electrolyte　decomposition　products　causes　dramatic　volume　expansion　and　hinders　the　further　lithiation　of　silicon.　On　the　other　hand,　the　electrolyte　which　is　capable　of　rapidly　releasing　F-　to　form　LiF-rich　solid　electrolyte　interphase　(SEI)　is　favorable　to　maintain　the　structure　integrity　and　cycling　performance.　This　work　casts　new　understanding　from　the　perspective　of　intrinsic　reaction　between　electrode　and　ionic　liquid　electrolyte,　which　suggests　that　the　practical　application　of　silicon　based　electrodes　with　appropriate　electrolyte　is　a　promising　route　for　high　energy-density　LIBs.