Uniform Li_1.2Ni_0.13Co_0.13Mn_0.54O₂ hollow microspheres with improved electrochemical performance by a facile solvothermal method for lithium ion batteries

Here, we designed a facile solvothermal method to prepare Li_1.2Ni_0.13Co_0.13Mn_0.54O₂ hollow microspheres with considerable uniformity and monodispersity. In this method, lithium ions and transition metal carbonate have been simultaneously precipitated in the ethanol-polyethylene glycol mixed solvent system to form carbonate precursors, which subsequently transform into self-assembled hollow microspheres by a heat treatment. As cathode material for lithium ion batteries, its unique structure makes for sufficient contact between electrode and electrolyte to provide more reaction sites and shorter paths for Li⁺ transportation, contributing to remarkable cycling stability and excellent rate capability with improved electrochemical kinetics properties. Specifically, Li_1.2Ni_0.13Co_0.13Mn_0.54O₂ hollow microspheres achieve a high initial discharge capacity of 287 mAh g⁻¹ at 0.1 C and 234 mAh g⁻¹ at 1 C, with capacity retentions of 85.7% and 81.3% after 100 cycles, respectively. Besides, it exhibits a high rate capacity of 150 mAh g⁻¹ even at 5 C. Moreover, the present synthesis method could also provide an effective and promising strategy for the preparation of high energy density cathode materials for lithium ion batteries.