Design and host-involved in situ fabrication of La4NiLiO8 coating on Ni-rich cathode materials towards superior structural stability

Abstract

Although Ni-rich cathodes have been considered as prospective candidates for lithium-ion batteries (LIBs) due to their high capacities and low consumption, the poor cycling and rate performances hinder their commercialization. Herein, we report a strategy for the in situ preparation of a La₄NiLiO₈ coating on the LiNi_0.8Co_0.1Mn_0.1O₂ cathode material through partially sacrificing Ni ions from the cathode substrate by a primitive solid-state method. The La₄NiLiO₈ coating has a continuous interface and ultra-strong bonding with the LiNi_0.8Co_0.1Mn_0.1O₂ cathode material, which gives the modified LiNi_0.8Co_0.1Mn_0.1O₂ cathode an extremely high structural stability. Besides, the La₄NiLiO₈ coating endows LiNi_0.8Co_0.1Mn_0.1O₂ with a high surface electronic transfer rate. The Ni vacancies generated in the host phase due to the Ni participation in the fabrication of the coating is beneficial to reducing the Li⁺/Ni²⁺ disorder and boosting the Li⁺ diffusion kinetic characteristics of LiNi_0.8Co_0.1Mn_0.1O₂. Therefore, the La₄NiLiO₈-modified LiNi_0.8Co_0.1Mn_0.1O₂ displayed enhanced long-term cycling performances, in which the capacity retention of the modified LiNi_0.8Co_0.1Mn_0.1O₂ increased from 18.90% to 83.80% after 300 cycles at 5C, and the rate performance was improved.