Facile interface functionalization of Ni-rich layered LiNi0.8Co0.1Mn0.1O2 cathode material by dually-modified phosphate and aluminum precursor for Li-ion batteries

Abstract

To improve high temperature cycling performance of Ni-rich NCM cathode materials, dually-functionalized Ni-rich NCM cathode materials are developed. In detail, aluminum phosphate (AP), composed of Al and PO4 functional groups, is used for surface modification of Ni-rich NCM cathode materials, which can be accomplished by one-step thermal treatment process. Our surface characterization analyses indicate that Al and PO4-functionalized cathode-electrolyte interphases (CEI) layers are well developed on the surface of Ni-rich NCM cathode materials which can effectively suppress undesired reactions such as electrolyte decomposition and dissolution of transition metal components. In cycling performances, AP-modified Ni-rich NCM cathode materials exhibit markedly improved cycling retention at high temperature even after 150 cycles. Among these, the cell cycled with 0.5-AP NCM811 cathode material presents the highest retention while the cell cycled with non-modified NCM811 cathode material suffers from poor cycling retention.