High-entropy　materials　(HEMs)　have　attracted　considerable　research　attention　in　battery　applications　due　to　exceptional　properties　such　as　remarkable　structural　stability,　enhanced　ionic　conductivity,　superior　mechanical　strength,　and　outstanding　catalytic　activity.　These　distinctive　characteristics　render　HEMs　highly　suitable　for　various　battery　components,　such　as　electrodes,　electrolytes,　and　catalysts.　This　review　systematically　examines　recent　advances　in　the　application　of　HEMs　for　energy　storage,　beginning　with　fundamental　concepts,　historical　development,　and　key　definitions.　Three　principal　categories　of　HEMs,　namely　high-entropy　alloys,　high-entropy　oxides,　and　high-entropy　MXenes,　are　analyzed　with　a　focus　on　electrochemical　performance　metrics　such　as　specific　capacity,　energy　density,　cycling　stability,　and　rate　capability.　The　underlying　mechanisms　by　which　these　materials　enhance　battery　performance　are　elucidated　in　the　discussion.　Furthermore,　the　pivotal　role　of　machine　learning　in　accelerating　the　discovery　and　optimization　of　novel　high-entropy　battery　materials　is　highlighted.　The　review　concludes　by　outlining　future　research　directions　and　potential　breakthroughs　in　HEM-based　battery　technologies.