Improved electrochemical properties of sol-gel prepared ZnO/graphene composite

ZnO/graphene (ZnO/G) composite as anode for lithium-ion batteries was synthesized by a sol-gel method. Sample's structure and morphology were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Morphological characterization shows both spherical and hexagonal ZnO/G particles having a size around 40 nm. Electrochemical properties were investigated by galvanostatic discharge-charge tests and cyclic voltammetry (CV). ZnO/G composite containing only 4 wt% graphene exhibits a discharge capacity of 330 mAh/g after 19 cycles recorded at C/20 rate, which is an improved cycling stability compared to the bare sol-gel ZnO.