Affiliation:
1. Shenzhen Key Laboratory of Advanced Energy Storage Department of Mechanical and Energy Engineering Southern University of Science and Technology Shenzhen 518055 China
2. SUSTech Energy Institute for Carbon Neutrality Southern University of Science and Technology Shenzhen 518055 China
3. Institute of High Energy Physics Chinese Academy of Sciences (CAS) Beijing 100049 China
4. School of Materials Science and Engineering Dongguan University of Technology Dongguan 523808 China
Abstract
AbstractThe cycling stability of LiNi0.8Co0.1Mn0.1O2 under high voltages is hindered by the occurrence of hybrid anion‐ and cation‐redox processes, leading to oxygen escape and uncontrolled phase collapse. In this study, an interfacial engineering strategy involving a straightforward mechanical ball milling and low‐temperature calcination, employing a Se‐doped and FeSe2&Fe2O3‐modified approach is proposed to design a stable Ni‐rich cathode. Se2− are selectively adsorbed within oxygen vacancies to form O─TM─Se bond, effectively stabilizing lattice oxygen, and preventing structural distortion. Simultaneously, the Se‐NCM811//FeSe2//Fe2O3 self‐assembled electric field is activated, improving interfacial charge transfer and coupling. Furthermore, FeSe2 accelerates Li+ diffusion and reacts with oxygen to form Fe2O3 and SeO2. The Fe2O3 coating mitigates hydrofluoric acid erosion and acts as an electrostatic shield layer, limiting the outward migration of oxygen anions. Impressively, the modified materials exhibit significantly improved electrochemical performance, with a capacity retention of 79.7% after 500 cycles at 1C under 4.5 V. Furthermore, it provides an extraordinary capacity retention of 94.6% in 3–4.25 V after 550 cycles in pouch‐type full battery. This dual‐modification approach demonstrates its feasibility and opens new perspective for the development of stable lithium‐ion batteries operating at high voltages.
Funder
National Natural Science Foundation of China