Improving the performance of lithium-ion batteries by using spinel nanoparticles

In this work, we examined the use of nanospinels to construct batttery electrodes. We chose two spinels suitable as cathode materials (LiMn2O4 and LiNi0.5Mn1.5O4, which are representative of 4 and 5 V versus Li metal, resp.) and one providing good results as anode (Li4Ti5O12). In order to ensure good cell performance, nanometric particles must meet another requirement; thus they should contain few surface or bulk defects (i.e., they should be highly crystalline). Because the synthesis of such spinels usually requires a thermal treatment, ensuring that they will meet both requirements entails accuratly controlling in the synthesis conditions. Thermal decomposition of nanooxalate in the spinel-conaining elements obtained by mechanochenical activation in the presence of polymers provides a simple, effective route for this purpose. We prepared two types of hybrid lithium-ion batteries using LiMn2O4 and LiNi0.5Mn1.5O4 as cathode materials, and Li4Ti5O12 as anode material. The electrochemical properties of these cells were compared with those of a similar configuration made from micrometric particles. The nano-nano configuration exhibited higher reversibility and better performance than the micro-micro configuartion in both types of cells, possibly as a result of lithium ions in the former being able to migrate more easily into the electrode material. Copyright (c) 2008 J.C. Arrebola et al.