Stabilizing ultrahigh-nickel cobalt-free cathode materials by using tri-element doping engineering

Ultrahigh nickel cobalt-free layered oxide cathode is considered to be one of the most promising lithium-ion cathode materials due to its high specific capacity and low price. Unfortunately, high nickel cathode materials have problems such as high cation mixing, thermal stability and structure instability, and how to address these problems has been the direction of researchers. Introducing heteroatoms into bulk phase is an essential and effective method for dealing with the above issues. In this paper, the comprehensively reinforced crystal and framework structure has been obtained in LiNi 0.9 Mn 0.1 O 2 (NM-WMM) cathode material by the synchronously doping of W 6+ , Mg 2+ and Mo 6+ . Thanks to the pillar function of all the doping elements and robust metal-O bond of W 6+ and Mo 6+ , the structural and chemical stability of the designed materials have been effectively strengthened, contributing to enhance their cycling performance and high-temperature properties, and optimize the reaction kinetics synchronously. As expected, NM-WMM materials deliver a prominent capacity retention rate at both 25 °C (91 %, 200 cycles, 1 C) and 50 °C (93.9 %, 100 cycles, 1 C). This proves that the multi-element doping modification strategy is beneficial to improve the cyclic performance and thermal stability of Ni-rich Co-free cathode materials.