Ultrasonic synthesis of CoO/graphene nanohybrids as high performance anode materials for lithium-ion batteries
(1. School of Materials Science and Engineering, Tongji University, Shanghai 201804, China;
2. Institute for Advanced Materials and Nano Biomedicine,
College of Medicine, Tongji University, Shanghai 200092, China)
2. Institute for Advanced Materials and Nano Biomedicine,
College of Medicine, Tongji University, Shanghai 200092, China)
Abstract: A facile ultrasonic method was used to synthesize CoO/graphene nanohybrids by employing Co4(CO)12 as a cobalt precursor. The nanohybrids were characterized by SEM, TEM and XPS, and the results show that CoO nanoparticles (3-5 nm) distribute uniformly on the surface of graphene. The CoO/graphene nanohybrids display high performance as an anode material for lithium-ion battery, such as high reversible lithium storage capacity (650 mA∙h/g after 50 cycles, almost twice that of commercial graphite anode), high coulombic efficiency (over 95%) and excellent cycling stability. The extraordinary performance arises from the structure of the nanohybrids: the nanosized CoO particles with high dispersity on conductive graphene substrates are beneficial for lithium-ion insertion/extraction, shortening diffusion length for lithium ions and improving conductivity, thus the lithium storage performance was improved.
Key words: lithium-ion battery; graphene; CoO; anode material; ultrasonic synthesis