Improvement of electrochemical performance of Li[Ni0.8Co0.15Al0.05]O2 cathode materials by AlF3 coating at various temperatures

A thin AlF(3) layer of similar to 10 nm was uniformly coated on the particle surface of Li[Ni(0.8)Co(0.15)Al(0.05)]O(2). The AlF(3) coating improved cycle performance at 55, 30, and -10 degrees C and improved storage characteristics at 60 degrees C. In studies of differential capacity (dQ/dV) versus voltage, the AlF(3)-coated Li[Ni(0.8)Co(0.15)Al(0.05)]O(2) showed little variation in redox peaks with cycling. Electrochemical impedance spectroscopy suggested that the AlF(3) coating played an important role in stabilizing the interface between the cathode and the electrolyte.