Synthesis of nickel silicate/reduced graphene oxide composite for long-life lithium-ion storage

Abstract

To improve the electrochemical performance of nickel silicate as anode material of lithium ion batteries, nickel silicate nanosheets anchored on reduced graphene oxide composite is synthesized via hydrothermal method using sandwich-like silica/graphene oxide as raw material. Nickel silicate nanosheets anchor on both sides of the reduced graphene oxide and cross each other to form net-like structure. The thickness of the nanosheets is about 15 nm. The composite shows an optimal electrochemical performance as lithium ion battery anode material. The initial capacity is 1525.7 mAh g−1 and the capacity retains 815.5 mAh g−1 after 50 cycles at the current density of 50 mA g−1. It exhibits good rate performance. When the current density is increased to 5000 mA g−1, the average capacity is as high as 415.8 mAh g−1. The composite also demonstrates an exceptional high cycling stability with the capacity of 423.4 mAh g−1 after 1000 cycles.