ALD Derived Coatings Enhancing Cycling Performance Of Cathode Materials With High Specific Capacities For Lithium Ion Batteries

Improving the cycle stability and rate capability of LiNi0.8Co0.1 Mn0.1O2(NCM811)and Li1.2Co0.13Ni0.13Mn0.56O2(LMR)with high specific capacities has been challenging for lithium ions batteries.The surface of NCM811 and LMR cathode materials were modified via an atomic layer deposition(ALD)technology.(1)The conductivity of Pd modified NCM81 1 was increased,but the coating layer may not be continuous.The composite coating layer of Pd and Fe2O3 was continuous,which can both protect cathode materials and decrease charge transfer resistance.specific discharge capacity of 2Pd3Fe2O3-ALD@811 is increased with 30 mAh/g at 5C,and its capacity retention rate is enhanced with 11.6%at 1C.(2)The ALD-Al2O3 coating layer can improve the cycle performance of the LMR material originating from preventing the cathode materials from the electrolyte.The capacity retention rate of LMR is increased with 8.6%via a 3 ALD-cycles derived coating layer.(3)The composite coating layer of Al2O3,ZnO/Zn was improved conductivity of LMR.With the help of the composite coating of 3 ALD-cycles Al2O3 and 3 ALD-cycles ZnO/Zn,the capacity retention rate of LMR is increased with 18.5%,and its discharge specific capacity is enhanced almost 100 mAh/g at 5C.