One-time sintering process to synthesize ZrO(2)-coated LiMn(2)O(4) materials for lithium-ion batteries

Herein, different amounts of ZrO(2)-coated LiMn(2)O(4) materials are successfully prepared by one-time sintering ZrO(2)-coated Mn(3)O(4) and Li(2)CO(3). Scanning and transmission electron microscopy results confirm that the ZrO(2) coating layer on the surface of Mn(3)O(4) can still be maintained on the surface of the final LiMn(2)O(4) particles even after long-term high-temperature heat-treatment. Three key factors to realize ZrO(2)-coated LiMn(2)O(4) materials via the one-time sintering process are as follows: (i) the Mn(3)O(4) precursor is coated by ZrO(2) in advance; (ii) the ionic radius of Zr(4+) is much larger than those of Mn(3+) and Mn(4+); (iii) the pre-calcination temperature is set in the reaction temperature range between Li(2)CO(3) and Mn(3)O(4) and lower than that between Li(2)CO(3) and ZrO(2). The 3 wt% ZrO(2)-coated LiMn(2)O(4) material exhibits excellent electrochemical properties with an initial specific discharge capacity of 118.8 mA h g(−1) and the capacity retention of 90.1% after 400 cycles at 25 °C and 88.9% after 150 cycles at 55 °C. Compared with the conventional coating method, the one-time sintering process to synthesize ZrO(2)-coated LiMn(2)O(4) materials is very simple, low-cost, environmentally friendly, and easy to scale up for large-scale industrial production, which also provides a valuable reference for preparing other coating-type cathode materials for lithium-ion batteries.