Lithium-ion　batteries　(LIBs)　are　considered　to　be　indispensable　in　modern　society.　Major　advances　in　LIBs　depend　on　the　development　of　new　high-performance　electrode　materials,　which　requires　a　fundamental　understanding　of　their　properties.　First-principles　calculations　have　become　a　powerful　technique　in　developing　new　electrode　materials　for　high-energy-density　LIBs　in　terms　of　predicting　and　interpreting　the　characteristics　and　behaviors　of　electrode　materials,　understanding　the　charge/discharge　mechanisms　at　the　atomic　scale,　delivering　rational　design　strategies　for　electrode　materials,　etc.　In　this　review,　we　present　an　overview　of　first-principles　calculation　methods　and　highlight　their　valuable　role　in　contemporary　research　on　LIB　cathode　materials.　This　overview　focuses　on　three　LIB　cathode　scenarios,　which　are　divided　by　their　cationic/anionic　redox　mechanisms.　Then,　representative　examples　of　rational　cathode　design　based　on　theoretical　predictions　are　presented.　Finally,　we　present　a　personal　perspective　on　the　current　challenges　and　future　directions　of　first-principles　calculations　in　LIBs.