As　one　of　the　high-energy　cathode　materials　of　lithium-ion　batteries　(LIBs),　lithium-rich-layered　oxide　with　＂single-crystal＂　characteristic　(SC-LLO)　can　effectively　restrain　side　reactions　and　cracks　due　to　the　reduced　inner　boundaries　and　enhanced　mechanical　stabilities.　However,　there　are　still　high　challenges　for　SC-LLO　with　diverse　performance　requirements,　especially　on　their　cycle　stability　improvement.　Herein,　a　novel　concentration　gradient　＂single-crystal＂　LLO　(GSC-LLO),　with　gradually　decreasing　Mn　and　increasing　Ni　contents　from　center　to　surface,　is　designed　and　prepared　by　combining　co-precipitation　and　molten-salt　sintering　methods,　yielding　a　capacity　retention　of　97.6%　and　an　energy　density　retention　of　95.8%　within　100　cycles　at　0.1　C.　The　enhanced　performance　is　mostly　attributed　to　the　gradient-induced　stabilized　structure,　free　of　cracks　and　less　spinel-like　structure　formation　after　long-term　cycling.　Furthermore,　the　gradient　design　is　also　beneficial　to　the　safety　of　LLOs　as　suggested　by　the　improved　thermal　stability　and　reduced　gas　release.　This　study　provides　an　effective　strategy　to　prepare　high-energy,　high-stability,　and　high-safety　LLOs　for　advanced　LIBs.