In this study, LiMn2O4 (LMO) nanoparticles were fabricated using polyacrylonitrile (PAN) templates and the annealing process. In order to optimize their electrochemical performance for LIBs, we adjusted the annealing temperatures to 600, 700, 800, and 900 oC. For comparison, the LMO particles were prepared using the solid-state reaction method. Interestingly, due to the limited grain growth and aggregation of the LMO by the PAN templates, the samples prepared by the PAN templates annealed at 700 oC revealed the nanoparticles below ~ 150 nm in size. As compared to other samples, the LMO nanoparticles prepared at 700 oC showed a superb specific discharge capacity of ~103.6 mAh/g at 100 cycles (capacity retention of ~ 82.7%) and a good high-rate performance (~ 81.8 mAh/g at 5 C). These outstanding electrochemical performances are due to the shorted diffusion distance of Li+ by the LMO nanoparticles thanks to the PAN templates and the improved electroactive sites by the correct stoichiometric LMO phases without impurities at the optimum annealing temperature. Thus, these results indicate that the LMO nanoparticles formed via the PAN templates annealed at 700 oC could be used as promising cathode materials for high-performance LIBs.

Keywords: Lithium-ion batteries, Cathodes, LiMn2O4, Nanoparticles, Polyacrylonitrile templates