Li-rich　materials,　due　to　their　high　capacity　(＞　250　mAh.g(-1)),　have　recently　been　considered　as　an　alternative　to　the　current　generation　of　cathode　materials　for　Li-ion　batteries　(LIBs).　However,　their　inferior　cycling　stability　limits　their　practical　applicability.　Doping　is　a　common　technique　to　solve　this　problem.　However,　anion　doping　remains　relatively　underexplored.　Fluorine　(F)　is　one　of　the　most　effective　anion　dopants　owning　to　the　improved　capacity,　cycling　stability,　and　rate　performance　in　batteries.　The　explanations　and　experimental　results,　however,　vary　significantly　from　study　to　study.　Herein,　we　find　that　bulk　F-doping　significantly　improves　both　rate　performance　and　cycling　stability,　likely　driven　by　charge　compensation　and　greater　electronegativity.　Additionally,　bulk　F-doping　occasionally　improves　capacity　via　enhanced　activation　and　occasionally　decreases　capacity　by　preventing　activation　from　occurring.　Surface　F-doping　has　similar　effects　to　bulk　F-doping　on　capacity　and　stability,　while　significantly　hindering　the　rate　performance.　Furthermore,　the　improvements　in　surface-doped　materials　do　not　appear　to　be　a　result　of　specific　surface　modification,　and　instead　can　be　ascribed　to　the　effect　of　fluorine　on　the　near-surface　bulk　material.　Greater　understanding　of　fluorine＇s　influence　on　activation,　in　particular,　is　required　to　unlock　the　full　potential　of　synergistic　cation/anion　co-doping.