Zr/Ti trace Co-doping induced disordered structure to enhance the cycling stability of Li-rich Mn-based layered oxide cathodes

Due to the ultrahigh energy density, Li-rich Mn-based layered oxide cathodes have attracted great attentions. However, the irreversible structural transformation usually leads to long-cycled capacity decay, which severely restricts their practical applications. Here, a Zr/Ti trace co-doping strategy is proposed to stabilize the structure and obtain excellent electrochemical performance by constructing bulk phase disorder and surface Zr-enriched structures. The designed Li1.2Mn0.53Ni0.13Co0.13Zr0.005Ti0.005O2 (ZT-LRM) not only shows a higher specific ca-pacity but also achieves an excellent long-cycle performance. The capacity retention of ZT-LRM is 69 % after 500 cycles at 5C (1250 mA g-1), which is much higher than that (34 %) of the Li1.2Mn0.54Ni0.13Co0.13O2 cathode. Neutron powder diffraction and transmission electron microscopy are used to demonstrate the disordered structure in the particles and the line scanning proves the surface Zr enrichment. In-situ X-ray diffraction verifies the more stable structural evolutions of the ZT-LRM during cycling. This simple modification method provides a reference for commercial applications of Li-rich Mn-based layered oxide cathodes.