As　one　of　the　most　promising　cathode　materials　for　high　energy　density　lithium　ion　batteries,　LiNi0.6Co0.2Mn0.2O2　with　high　reversible　capacity　suffers　poor　cycling　performances,　especially　at　high　cutoff　potentials.　To　address　this　challenge,　in　this　study,　an　atomic　layer　deposition　is　utilized　to　design　controllable　MgO　coating　layers　onto　LiNi0.6Co0.2Mn0.2O2　cathode　material.　It　is　confirmed　that　the　optimized　LiNi0.6Co0.2Mn0.2O2　cathode　shows　an　improved　electrochemical　performance　comparing　with　the　pristine　material　at　the　cutoff　potentials　of　4.5　V　as　well　as　4.7　V.　After　100　cycles,　the　LiNi0.6Co0.2Mn0.2O2　with　MgO　coating　displays　the　reversible　capacities　of　157　mAh•g-1　and　158　mAh•g-1　at　the　cutoff　potential　of　4.5　V　and　4.7　V,　respectively,　which　is　higher　than　those　of　the　pristine　one　(131　mAh•g-1　and　144　mAh•g-1).　This　study　demonstrates　that　the　ALD　derived　MgO　coating　layer　shows　some　promising　potentials　to　improve　LiNi0.6Co0.2Mn0.2O2　performance　for　lithium　ion　batteries.　This　is　mainly　due　to　the　effective　protection　of　MgO　layer　to　the　material　surface,　that　is,　the　MgO　coating　can　stabilize　the　interface　and　block　the　metal　ion　dissolution　by　reducing　the　direct　connection　between　LiNi0.6Co0.2Mn0.2O2　and　electrolyte.　©　2020,　Editorial　Board　of　Journal　of　the　University　of　Electronic　Science　and　Technology　of　China.　All　right　reserved.