Optimizing high-nickel and lithium-rich manganese-based oxide cathodes through microstructure manipulations for lithium-ion batteries

The cobalt (Co)-free and lithium (Li)-rich manganese (Mn)-based oxides, possessing a low manufacturing cost and a high energy density, have been regarded as competitive cathodes for high-performance lithium-ion batteries (LIBs), yet still confronted with ambiguous synthesis routes/conditions and fast capacity/voltage decays. Herein, the unique high-nickel (Ni) and Li-rich Mn-based oxides in the composition of 0.6 Li2MnO3-0.4LiNiO(2) were synthesized via a typical high-temperature sintering method utilizing the commercial hydroxide precursors. Specifically, the pronounced impacts of calcination temperatures on the microstructures of Li1.6Mn0.6Ni0.4O2.6 cathodes were revealed. Concurrently, the valence states of transition metal ions and oxygen vacancies within the cathode materials were further fine-tuned. Upon forming a well-defined layered structure at 800 degrees C in high-Ni and Li-rich Mn-based oxide, the optimized cathode material could deliver a large initial discharging capacity of 188 mAh g(-1) at 0.1C, a high capacity retention of 89.2% over 100 cycles at 0.2 C, and a desirable rate capability of 102 mAh g(-1) at 3 C. This work would contribute to the fundamental research on synthetic routes and structure regulations of Co-free and Li-rich Mn-based oxide cathodes for next-generation LIBs.