Ultrathin NiO/NiFe2O4 Nanoplates Decorated Graphene Nanosheets with Enhanced Lithium Storage Properties
By Dejian Du and Wenbo Yue and Xialu Fan and Kun Tang and Xiaojing Yang
Published in Electrochimica Acta
2016
Abstract
As anode materials for lithium-ion batteries, bicomponent metal oxide composites show high reversible capacities; but the morphology and particle size of the composites are hardly controllable, which may reduce their electrochemical properties. In this work, ultrathin NiO/NiFe2O4 nanoplates with a diameter of 5 ? 7 nm and a thickness of ?2 nm are controllably fabricated on the graphene derived from NiFe layered double hydroxides (NiFe-LDHs), and exhibit superior electrochemical performance compared to pure NiO/NiFe2O4 aggregates without graphene. The nanosized NiO and NiFe2O4 plates are separated from each other and the graphene substrate can prevent the aggregation of NiO/NiFe2O4 as well as enhance the electronic conductivity of the composite, which is beneficial to improving the electrochemical performance. Moreover, the effects of the content and the particle size/component of NiO/NiFe2O4 on the electrochemical performances are also studied in order to achieve optimal performance. Ultrathin NiO/NiFe2O4 nanoplates are further encapsulated by graphene nanosheets and show slightly decreased performance compared to those supported by graphene nanosheets. The different electrochemical behaviors of graphene-containing composites may be attributed to the different interactions between graphene nanosheets and NiO/NiFe2O4 nanoplates.