Composites　Li[Li　xNi　0.34-xMn　0.47Co　0.19]O　2　(0.18　≤　x　≤　0.21)　were　prepared　by　a　solid　state　reaction　method　assisted　with　co-precipitating.　The　chemical　composition,　structure,　morphology,　and　specific　surface　area　of　as-prepared　composites　were　systematically　characterized　by　ICP,　XRD,　SEM,　and　BET,　respectively.　The　electrochemical　performances　of　the　composites　were　evaluated　as　high-voltage　cathode　for　lithium-ion　batteries.　Among　all　the　composites,　sample　SN　exhibited　a　best　electrochemical　performance.　Except　for　the　initial　decay,　no　obvious　capacity　fading　was　observed　after　cycling　30　cycles　at　different　rates.　The　discharge　capacities　were　maintained　steadily　as　the　current　density　increased　up　to　500　mA　g　-1.　The　improved　electrochemical　performance　of　sample　SN　was　attributed　to　the　compromise　effect　between　the　increased　Li　2MnO　3　phase　and　the　enhanced　Li/Ni　disorder.　©　2012　Elsevier　Ltd.　All　rights　reserved.