Boosting the electrochemical performance of LiNi0.8Co0.15Al0.05O2 cathode materials in-situ modified with Li1.3Al0.3Ti1.7(PO4)3 fast ion conductor for lithium-ion batteries

Abstract

In-situ modification with Li1.3Al0.3Ti1.7(PO4)3 (LATP) fast ion conductor powders is introduced to construct the stable structure of LiNi0.8Co0.15Al0.05O2 (NCA) materials, which are characterized by X-ray diffraction, scanning electron microscope, transmission electron microscope, energy disperse spectroscope and X-ray photoelectron spectroscope. The results demonstrate that the particle surface of NCA-1.0 is homogeneously wrapped by a LATP coating layer with a thickness of about 200 nm and the value of Ni2+ ions in the Li layer is 1.58% when the optimal doping proportion of the LATP precursor to the NCA precursor is about 1.0 wt %. The coin cell assembled with NCA-1.0 delivers a remarkable discharge specific capacity of 152.4 mAh g−1 with a capacity retention ratio of 89.5% at 2 C after 150 cycles, a favorable rate capacity of 153.2 mAh g−1 at 5 C, and an increased Li+ diffusion coefficient of 6.65 × 10−10 cm2 s−1. Those outstanding electrochemical properties can be attributed to the synergistic effects of the formed LATP coating and Ti4+ doping, indicating that the in-situ modification way is a promising route to enhance the electrochemical properties of Ni-rich materials for lithium-ion batteries.