Multi-dimensional modification of mechanical and electrochemical properties in nickel-rich cathode

Particle fragmentation caused by structural instability during the electrochemical cycle of nickel-rich cathodes has hindered its development. Here, we synthesized Ta-doped LiNi0.9Co0.1O2 (NC90) with excellent mechanical and electrochemical properties from four perspectives. Firstly, Ta gets into the transition metal (TM) layer and forms the strongest bond with oxygen among transition metals. And the octahedral structure of TaO6 can well inhibit Li+/Ni2+ disordering and reinforce the structure by decreasing the generation of Ni2+. Secondly, the coating of LiTaO3 resists the damage of the electrolyte and suppresses the generation of micro-cracks, thus enhancing corrosion resistance. Impressively, the primary particles doped with Ta have a smaller size based on the solvothermal method, and the hardness is increased owing to the reduction of effective area. Furthermore, the generation of lithium vacancies and broadening layer spacing accelerate Li+ diffusion. The NC90-Ta1.0 displays high capacity (206.2 mAh/g at 0.5C), and the capacity retention at 1C/5C after 200 cycles reaches 86.9%. Hence, the proposed Ta-doped NC90 has terrific mechanical and electrochemical properties, which provide a viable basis for nickel-rich materials.& COPY; 2023 Elsevier Ltd. All rights reserved.