Preparation and performance characterization of AlF3 as interface stabilizer coated Li1.24Ni0.12Co0.12Mn0.56O2 cathode for lithium-ion batteries

Li1.24Ni0.12Co0.12Mn0.56O2 (LNCM) with high specific capacity is a potential cathode for commercial lithium-ion batteries (LIBs). To improve the high-rate capacity and cyclic stability, LNCM sample is successfully coated by minor AlF3. The crystal structure and electrochemical properties of the bare and coated samples are investigated by X-ray diffractometry (XRD), scanning and transmission electron microscopy (SEM, TEM), cyclic voltammetry (CV), galvanostatic intermittent titration technique (GITT), and charge/discharge measurements. The coating layer AlF3 efficiently plays a positive role in enhancing rate performance and cyclic stability of LNCM. At 0.5 A g−1, the specific discharge capacity of LNCM@2%AlF3 is 149 mAh g−1 much higher than 35 mAh g−1 in bare LNCM. At 20 mA g−1, the specific discharge capacity of LNCM@2%AlF3 is 223 mAh g−1 at the 60th cycle in comparison with 203 mAh g−1 in bare LNCM. Moreover, a proper AlF3 coating layer efficiently ensures the stability of LNCM cathode operated at higher temperature. LNCM@2%AlF3 operated at 55 °C remains 219 mAh g−1 at the 50th cycle, much higher than bare LNCM only remains 99 mAh g−1 at the 40th cycle.