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

Abstract

Here we report a graphene supported carbon-coated-LiNi1/3Co1/3Mn1/3O2 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 LiNi1/3Co1/3Mn1/3O2 particles and graphene supports or links these LiNi1/3Co1/3Mn1/3O2 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 LiNi1/3Co1/3Mn1/3O2 composites. Also, as a cathode electrode in full cell, the graphene supported carbon-coated-LiNi1/3Co1/3Mn1/3O2 hybrid material still shows better electrochemical performance than pristine LiNi1/3Co1/3Mn1/3O2. 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.