Recent Progress and Perspective of Advanced High-Energy Co-Less Ni-Rich Cathodes for Li-Ion Batteries: Yesterday, Today, and Tomorrow

With the ever-increasing requirement for high-energy density lithium-ion batteries (LIBs) to drive pure/hybrid electric vehicles (EVs), considerable attention has been paid to the development of cathode materials with high energy densities because they ultimately determine the energy density of LIBs. Notably, the cost of cathode materials is still the main obstacle hindering the extensive application of EVs, with the cost accounting for 40% of the total cost of fabricating LIBs. Therefore, enhancing the energy density and simultaneously decreasing the cost of LIBs are essential for the success of EV/hybrid EV industries. Among the existing commercial cathodes, Ni-rich layered cathodes are widely employed because of their high energy density, relatively good rate capability, and reasonable cycling performance. Ni-rich layered cathodes containing Co are now being reconsidered due to the increasing price of Co, which is much higher than that of Ni and Mn. In this report, the recent developments and strategies in the improvement of the stabilities of the bulk and surface for Co-less Ni-rich layered cathode materials are reviewed.