Modification study of Mg/W-doped LiNi0.9Mn0.1O2 layered oxide cathode materials for lithium-ion batteries

Abstract

Owing to the supply bottlenecks and high-cost cobalt, high-nickel, cobalt-free layered cathodes is regarded as the most affordable and representative option for lithium-ion batteries (LIBs). However, the commercialization of low-cost LiNi_0.9Mn_0.1O₂ cathodes has been hindered by their poor chemo-mechanical stability and limited cycling performance. In this study, Mg/W co-doping was employed to improve lithium batteries cycling stability by changing the lattice size. The capacity retention of the Mg/W co-doping LiNi_0.9Mn_0.1O₂ samples (Mg&W-LNMO) was 96.51% at a discharge rate of 0.5 C and a voltage interval of 2.8–4.3 V after 100 cycles electrochemical cycle tests, which was 16.7% higher than that of the LiNi_0.9Mn_0.1O₂ samples (LNMO) cathode, while maintaining intact particle morphology. The combined effect of Mg and W effectively prevented Ni/Li mixing and segregation, suppressed the leaching of transition metal ions, inhibited the phase transformation from a layered structure to a spinel configuration, and improved the structural stability of the material. These results offered an uncomplicated, productive, and scalable approach for designing cobalt-free, nickel-rich cathodes in the development of cost-effective lithium-ion batteries.