A green Al2O3 metal oxide coating method for LiNi0.5Co0.2Mn0.3O2 cathode material to improve the high voltage performance

Poor cycling and rate performance are considered one of the greatest obstacles to the large-scale commercialisation of Ni-rich layered cathode material , especially at high cut-off voltages. In this study, we successfully prepared amorphous Al 2 O 3 -coated LiNi 0.5 Co 0.2 Mn 0.3 O 2 (NCM523) cathode material by the straightforward carboxymethyl cellulose (CMC)-assisted wet chemical method . As the cathode material for lithium-ion batteries, the amorphous Al 2 O 3 -coated NCM523 maintains capacity retention of 86.30% in the range of 3.0–4.6 V after 100 cycles at 1C and 86.57% at 8C after 50 cycles, which is higher than that of pristine NCM523 under the same conditions (76.40% and 63.20%, respectively). The uniform Al 2 O 3 coating layer greatly inhibits transition metal dissolution on the surface of NCM523 cathode materials at high cut-off voltage. In addition, the structural damage of the NCM523 cathode is effectively retarded due to the consumption of HF by Al 2 O 3 . This work will provide inspiration for the design of new methods for the commercialisation of Ni-rich layered cathode material.