Surface coating for high-nickel cathode materials to achieve excellent cycle performance at elevated temperatures

摘要

As the battery continues working to generate heat, the temperature of the electrode rises, which will accelerate the failure of the battery by amplifying the phase transition and the side reactions. Therefore, improving the cycle stability of high-nickel cathode materials at elevated temperature is a problem that needs to be solved urgently. For this reason, we successfully modified LiAlO2@Al2O3 on LiNi0.88Co0.09Al0.03O2(NCA). With the synergetic effect of LiAlO2 and Al2O3, the modified NCA material has significantly improved cycle stability at 45 degrees C. Its capacity retention exceeds 88.4% after 100 cycles at 1.0 C, while the bare cathode can only retain 73.7% capacity. The full cell assembled from modified NCA and graphite has an excellent capacity retention (94.9%) after being charged and discharged for 700 cycles at a current density of 1.0 C. All these indicates that the LiAlO2@Al2O3 coating significantly improves the capacity retention and cycle life of NCA for lithium-ion batteries at elevated temperatures. (C) 2020 Elsevier B.V. All rights reserved.