Ionic　liquids　(ILs)　have　the　advantages　of　adjustable　phase　transition　temperature,　low　non-flammability/volatility,　good　thermal　and　Chemical　stability　in　terms　of　thermal　physical　properties,　and　are　increasingly　receiving　attention　in　the　field　of　thermal　energy　storage.　Recently,　NASA　utilized　eutectic　phase　change　materials　(PCM)　composed　of　functional　ionic　liquids　to　manage　the　extreme　space　environment　(solar　ra-diation　and　extreme　cold/hot)　of　manned　spacecraft　forfuture　deep　exploration.　Although　the　concept　of　storing　latent　heat　during　the　phase　transition　of　ionic　liquids　is　well-known,　it　has　not　yet　been　adopted　in　large-scale　applications,　and　its　potential　still　needs　to　be　further　explored.　At　present,　most　research　focuses　on　the　Performance　of　ionic　liquids　as　heat　transfer　fluids,　with　little　research　and　application　on　their　phase　change　energy　storage.　The　purpose　of　this　article　is　to　provide　necessary　Information　for　selecting　well-researched　ionic　liquids　and　promote　further　research　in　this　field.　The　article　first　discusses　the　defects　of　traditional　phase　change　materials,　and　then　reviews　and　summarizes　common-ly　used　ionic　liquids　from　the　aspects　of　Chemical　structure,　phase　change　mechanism,　and　thermophysical　properties.　Finally,　the　application　of　ionic　liquid-based　phase　change　materials　was　introduced　in　detail.　This　paper　proposed　the　structural　design　optimization　of　ionic　liquids　(ILs),　undercooling　control　strategies,　enthalpy　enhancement　pathways,　and　preparation　cost　control　as　research　entry　points,　providing　direction　for　subsequent　research.　©　2025　Cailiao　Daobaoshe/　Materials　Review.　All　rights　reserved.