The　growing　demand　of　advanced　electrochemical　energy　storage　devices　for　various　applications,　including　portable　electronic　products,　electric　vehicles,　and　large-scale　energy　storage　grids,　hastriggered　extensive　research　interests　and　efforts　on　various　rechargeable　batteries　such　as　lithium/sodium-ion　batteries　(LIBs/NIBs),　aluminium-ion　batteries　(AIBs),　liquid　metal　batteries　(LMBs),　andmolten-air　batteries　(MABs)　in　the　past　decades.　A　key　issue　to　push　forward　the　development　of　thesebatteries　is　the　exploration　of　high-performance　electrodes　and　electrolytes,　which　calls　for　efficientand　versatile　synthetic　methods.　Molten　salts　(MSs),　liquid-phase　ionic　compounds　or　mixtures,provide　an　effective　platform　to　widen　the　reaction　temperatures　and　enrich　the　chemical　environ-ments　for　the　synthesis　of　novel　electrode　materials　and　electrolytes.　In　this　review,　the　generalprinciples　of　molten　salts　and　recent　research　progresses　on　molten　salt-based　battery　materials　aresurveyed.　Molten-salt　synthesis　of　electrode　materials,　including　sintering　and　electrolysis,　areemerging　as　competitive　substitutes　for　conventional　synthesis　techniques.　These　methods　haveshown　their　effectiveness　and　uniqueness　in　adjusting　the　crystal　structure,　morphology,　andperformance　of　electrode　materials　for　LIBs/NIBs,　as　suggested　by　recent　progresses　and　applicationsof　diverse　cathodes　(layered　oxides,　spinel　oxides,　polyanions,　etc.)　and　anodes　(metal　oxides,　alloys,carbons,　etc.).　Furthermore,　the　applications　of　molten　salts　as　effective　electrolytes　are　demonstratedin　representative　new-type　secondary　batteries　including　AIBs,　LMBs　and　MABs.　Finally,　the　emergingopportunities,　challenges,　and　interesting　research　trends　are　envisioned　to　promote　the　further　development　of　molten-salt　methodology　for　rechargeable　batteries