Synthesis and characterization of core-shell high-nickel cobalt-free layered LiNiMgAlO@LiZrO cathode for high-performance lithium ion batteries.

High-nickel cobalt-free layered cathode is regarded as a highly potential cathode material for the next generation lithium ion batteries (LIBs) because of its high energy density, low cost and environmentally benign. However, the poor cycle performance caused by its intrinsic unstable structure and chemo-mechanical instability frustrates its practical applications. Herein, we have developed a new core-shell high-nickel cobalt-free layered LiNiMgAlO@LiZrO (LZO-NMA9523) cathode for high-performance LIBs. The LiZrO coating layer firstly helps to suppress and reduce the degree of Li/Ni cation mixing during the material preparation process. In addition, the LiZrO coating layer can not only accommodate the volume variations and enhance the electricity of the active materials, but also effectively inhibit the harmful irreversible phase transition during the charging/discharging process, thus greatly stabilizing the structure of the high-nickel cobalt-free cathode. As an advanced cathode for LIBs, the LZO-NMA9523 exhibits an excellent reversible capacity of 146.9 mAh g after 100 cycles at 0.5 C with capacity retention of about 80%. This study provides a possible high-nickel cobalt-free layered cathode material for the next generation LIBs.