Enhanced Electrochemical Performance of Graphene Supported LiNi1/3Co1/3Mn1/3O2/C Hybrid Cathode for Lithium-Ion Batteries.

Here we report a graphene supported carbon-coated-LiNi_1/3Co_1/3Mn_1/3O₂ hybrid cathode material synthesized by combining polyvinyl pyrrolidone and graphene as double carbon sources. In this composite, the amorphous carbon pyrolyzed from polyvinyl pyrrolidone is tightly covered on the surface of LiNi_1/3Co_1/3Mn_1/3O₂ particles and graphene supports or links these LiNi_1/3Co_1/3Mn_1/3O₂ particles. Under the synergistic effect of amorphous carbon coating layer and graphene support, this hybrid cathode possesses superior rate capability and excellent cycle performance in both half and full cells. For example, as an electrode in half cell, it delivers the highest initial capacity of 201.1 mAh g^-1 and the largest capacity retention ratio of 86.6% after 100 cycles at 0.5 C compared with other three LiNi_1/3Co_1/3Mn_1/3O₂ composites. Also, as a cathode electrode in full cell, the graphene supported carbon-coated-LiNi_1/3Co_1/3Mn_1/3O₂ hybrid material still shows better electrochemical performance than pristine LiNi_1/3Co_1/3Mn_1/3O₂. This co-modification method with pyrolytic carbon and graphene provides an economical and effective solution to develop high-voltage layered oxide cathode materials for high performance lithium ion batteries. [ABSTRACT FROM AUTHOR]