Mussel-inspired polydopamine-assisted uniform coating of Li+ conductive LiAlO2 on nickel-rich LiNi0.8Co0.1Mn0.1O2 for high-performance Li-ion batteries

Abstract

A Li+ conductive LiAlO2 coating layer was uniformly covered on the surfaces of a nickel-rich LiNi0.8Co0.1Mn0.1O2 cathode material through a mussel-inspired, adhesive polydopamine-assisted approach. The adhesive and uniform PDA pre-coating on the Ni0.8Co0.1Mn0.1(OH)2 microspherical surfaces could act as a superior mediator to conformally concentrate the Al3+ precursor on the microsphere surfaces through chemical complexation, thus resulting in a uniform LiAlO2 coating on the LiNi0.8Co0.1Mn0.1O2 microspherical surfaces. The PDA-assisted uniform coating layer of Li+ conductive LiAlO2 could offer multifunctional effects, including effective prohibition of side-reactions between the LiNi0.8Co0.1Mn0.1O2 and electrolyte, significant suppression of the Li/Ni mixing in the LiNi0.8Co0.1Mn0.1O2 crystal lattices, and high Li-ion conductivity for fast electrochemical reactions. Therefore, the PDA-assisted LiAlO2 coated LiNi0.8Co0.1Mn0.1O2 cathode material ([email protected]) presents outstanding cycling stability and rate performance with high discharge capacity of 209 mAh/g at the 1st cycle at the current rate of 0.2 C, 178 mAh/g at the 100th cycle at the current rate of 0.2 C, 138 mAh/g at the 200th cycle at the current rate of 2 C, and 114 mAh/g at the 200th cycle at the current rate of 5 C. These encouraging results demonstrate that the mussel-inspired, adhesive PDA-assisted uniform coating of Li+ conductive LiAlO2 is a promising strategy to achieve high performance of nickel-rich layered oxide cathode material for advanced Li-ion secondary batteries.