Design of LiAlO2 mosaic structure for preparing high nickel-based LiNi0.88Co0.07Al0.05O2 cathode material by simple hydrolysis method

Abstract

Abstract In order to restrain the capacity decay of nickel-rich materials for lithium-ion batteries (LIBs) in advanced energy applications, a Ni-rich cathode (LiNi0.88Co0.07Al0.05O2, LANCA) with high-rate capability and cycle life was designed and prepared by coating γ-LiAlO2 and doping Al3+ on the surface and inside of the secondary particles, respectively. Specifically, the γ-LiAlO2-coated and Al3+-doped LANCA samples were synthesized by a simple strategy of pre-coating Ni0.88Co0.07Al0.05(OH)2, based on aluminum isopropoxide hydrolysis combined with a post-sintering lithiation process. With the γ-LiAlO2 and Al3+, the capacity retention ratio of the cathode is tremendously improved from 61.7 to 83.6% at 1 C rate after 100 cycles. Even at a heavy current density of 10 C for the LANCA cathode, a high reversible capacity of 154.4\xa0mA h g−1 can be acquired, which amount to the 82.5% capacity retention at 0.2 C. Detailed morphology and structure observation shows that the side reaction at the electrolyte-cathode interface was suppressed, the structural degradation and intergranular cracking were suppressed, while the diffusion of Li+ and conductivity were improved. Therefore, this ingenious structural design has certain reference significance for the development and commercialization of high-performance cathode materials for electric power.