With　the　rising　demand　of　lithium　batteries　from　application　fields　including　electric　vehicles　(EVs)　and　various　electric　aircrafts,　it　is　imperative　to　greatly　enhance　the　energy　density　of　lithium　batteries　by　rational　design.　However,　there　is　still　a　lack　of　design　roadmap　for　high-energy-density　lithium　batteries,　largely　owing　to　the　uncertain　selections　of　electrochemically　active　materials　and　the　complicated　relationships　of　diverse　factors.　In　this　article,　based　on　the　discussion　of　effects　of　key　components　and　prototype　design　of　lithium　batteries　with　different　energy　density　classes,　we　aim　to　tentatively　present　an　overall　and　systematic　design　principle　and　roadmap,　covering　the　key　factors　and　reflecting　crucial　relationships.　This　article　starts　from　the　fundamental　principles　of　battery　design,　and　the　effects　of　cathode,　anode,　electrolyte,　and　other　components　to　realize　highenergy-density　lithium　batteries　have　been　discussed.　Based　on　the　prototype　design　of　high-energy-density　lithium　batteries,　it　is　shown　that　energy　densities　of　different　classes　up　to　1000　Wh/kg　can　be　realized,　where　lithium-rich　layered　oxides　(LLOs)　and　solid-state　electrolytes　play　central　roles　to　gain　high　energy　densities　above　500　Wh/kg.　Lithium　batteries　are　thus　categorized　according　to　different　energy　density　classes,　with　available　component　options,　to　meet　their　most　suitable　application　scenes.