Fabrication and characterization of dinickel orthosilicate nanosheets as high performance anode material for lithium-ion batteries

Abstract

Metal silicates are a class of high capacity anode materials for rechargeable lithium-ion batteries (LIBs). Nickel silicate (Ni2SiO4, NSO) was successfully synthesized through the process of chemical precipitation-calcination-alkali washing as a potential anode for LIBs in this work. The characterizations of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), transmission electron microscope (TEM) and Brunauer Emmett Teller (BET) were conducted to examine the surface and structural properties of the NSO. The results indicate the products are pure Ni2SiO4 and in petal-like nanosheet morphology with a specific surface area of 30.29 m2 g−1. A high reversible capacity of 874.7 mAh g−1 is obtained after 50 cycles at a current density of 0.1 A g−1, with 81.8% of the capacity being maintained. In addition, the NSO nanosheets hold a superior reversible capacity of 473.9 mAh g−1 at a current density of 1.6 A g−1. Furthermore, cyclic voltammetry tests and electrochemical impedance spectra were applied to investigate the electrochemical process in the battery. The NSO nanosheets display good cycling stability and excellent rate capacity. The obtained results show that dinickel orthosilicate nanosheets can be considered as a promising anode candidate for LIBs.