Kinetically Controlled Synthesis of LiNi0.5Mn1.5O4 Micro- and Nanostructured Hollow Spheres as High-Rate Cathode Materials for Lithium Ion Batteries

Spinel LiNi 0.5 Mn 1.5 O 4 hollow spheres with micro- and nanostructures have been successfully synthesized based on the coprecipitation method followed by postheat treatment. A uniform and spherical precursor was obtained by controlling the reaction kinetics in the nucleation–crystallization process of forming nickel and manganese carbonates simply by employing NaHCO 3 instead of Na 2 CO 3 as precipitating agent. Single-shelled and double-shelled LiNi 0.5 Mn 1.5 O 4 hollow spheres were derived of the spherical carbonate precursors via tuning the calcination kinetics. The as-prepared LiNi 0.5 Mn 1.5 O 4 hollow spheres deliver a discharge capacity of 128.9 mAh g –1 at 0.1 C rate and maintain a capacity retention of 95% at 0.5 C after 100 cycles. Importantly, even at high rate of 30 C, it can still exhibit a discharge capacity of 100 mAh g –1 . The excellent rate capability and cycling stability are mainly attributed to its hollow micro- and nanostructure, which could shorten Li + ions’ diffusion path and buffer the volume change during repeated Li + insertion–extraction processes.