Synthesis and electrochemical investigation of highly dispersed ZnO nanoparticles as anode material for lithium-ion batteries

Highly dispersed ZnO nanoparticles were prepared by a versatile and scalable sol-gel synthetic technique. High-resolution transmission electronic microscopy (HRTEM) showed that the as-prepared ZnO nanoparticles are spherical in shape and exhibit a uniform particle size distribution with the average size of about 7 nm. Electrochemical properties of the resulting ZnO were evaluated by galvanostatic discharge/charge cycling as anode for lithium-ion battery. A reversible capacity of 1652 mAh g⁻¹ was delivered at the initial cycle and a capacity of 318 mAh g⁻¹ was remained after 100 cycles. Furthermore, the system could deliver a reversible capacity of 229 mAh g⁻¹ even at a high current density of 1.5 C. This outstanding electrochemical performance could be attributed to the nano-sized features of highly dispersed ZnO particles allowing for the better accommodation of large strains caused by particle expansion/shrinkage along with providing shorter diffusion paths for Li⁺ ions upon insertion/deinsertion.