Superior electrochemical properties of Li(Ni1/3Co1/3Mn1/3)O2/C synthesized by the precursor solid-phase method

Abstract

Li(Ni1/3Co1/3Mn1/3)O2 as a cathode material for lithium batteries is synthesized by the precursor solid-phase method. Firstly, the precursor Ni1/3Co1/3Mn1/3(OH)2 is prepared. And then, Li(Ni1/3Co1/3Mn1/3)O2 is synthesized. In order to improve the electrochemical performance of the material, the Li(Ni1/3Co1/3Mn1/3)O2 is coated with a carbon layer. Electrochemical performance shows that the as-prepared pristine Li(Ni1/3Co1/3Mn1/3)O2 exhibits a high initial discharge capacity of 189.7 mAh g−1, and the specific capacity increases to 219.6 mAh g−1 modified by carbon coating. Moreover, it exhibits excellent cycling maintaining 95.04 % of its initial discharge capacity after 100 charge–discharge cycles, which is much higher than the pristine Li(Ni1/3Co1/3Mn1/3)O2. Moreover, when cycles at 1 C, the discharge of Li(Ni1/3Co1/3Mn1/3)O2 is only 132.5 mAh g−1, it increases to 211.3 mAh g−1 due to the appropriate carbon layer. All the tests show that Li(Ni1/3Co1/3Mn1/3)O2/C has excellent electrochemical performance, which is attributed to avoid the core material direct contact with the acidic electrolyte and suppression of Mn+ dissolution into electrolyte via carbon layer and greatly improve the electronic and ionic conductivities.