Challenges and opportunities using Ni-rich layered oxide cathodes in Li-ion rechargeable batteries: the case of nickel cobalt manganese oxides

This review provides an overview of recent advances in the utilization of Ni-rich nickel–cobalt–manganese (NCM) oxides as cathode materials for Li-ion rechargeable batteries (LIBs). In the past decade, Ni-rich NCM cathodes have been extensively investigated because of their rational capacity and easy accessibility of constituent elements. However, huge capacity fading and irreversible structural disorder, associated with oxygen release, are the major limitations which hinder the desired electrochemical performance of these cathodes. The LIB performance can be improved through several strategies such as doping, coating, composite formation, microstructure manipulation and replacing the Mn ions. Attempts are also made to amend the crystal orientation and achieve additive-induced surface engineering of NCM cathodes. However, the practical application of high-performance LIBs demand an effective modification of the intrinsic properties of NCMs. Substandard thermal stability is another safety aspect to be resolved in the Ni-rich NCMs. However, efforts in this context are not enough. Apart from designing NCM cathodes, there are major issues such as cost-effectiveness, supply and demand for constituent elements, and the reuse of spent batteries, which hinder the realisation of LIBs with high electrochemical performance. Keeping in mind the current research interests, this review article presents concise and in-depth strategies to design NCM cathodes for future energy demands of mankind by considering the cost and Co abundance-related issues.