Ultrahigh Capacity Retention of Li2ZrO3-Coated Ni-rich LNCM811 Cathode Material through Covalent Interfacial Engineering
Nickel-rich LiNiCoMnO (LNCM811) is a promising lithium-ion battery cathode material, whereas the surface-sensitive issues (i.e., side reaction and oxygen loss) occurring on LNCM811 particles significantly degrade their electrochemical capacity retentions. A uniform LiZrO coating layer can effectively mitigate the problem by preventing these issues. Instead of the normally used weak hydrogen-bonding interaction, we present a covalent interfacial engineering for the uniform LiZrO coating on LiNiCoMnO materials. Results indicate that the strong covalent interactions between citric acid and NiCoMn(OH) precursor effectively promote the adsorption of ZrO coating species on NiCoMn(OH) precursor, which is eventually converted to uniform LiZrO coating layers of about 7 nm after thermal annealing. The uniform LiZrO coating endows LNCM811 cathode materials with an exceptionally high capacity retention of 98.7% after 300 cycles at 1 C. This work shows the great potential of covalent interfacial engineering for improving the electrochemical cycling capability of Ni-rich lithium-ion battery cathode materials.