Amorphous Li-Zr-O layer coating on the surface of high-Ni cathode materials for lithium ion batteries

Improving cycle performance and rate-capability of lithium ion batteries is necessary in moving toward their use in electric vehicles. Working towards this goal, we propose an amorphous Li-Zr-O coating on the surface of a high-Ni layered transition metal oxide (LiNi0.8Co0.1Mn0.1O2) via a simple wet process. By using residual Li on the surface of as-prepared LiNi0.8Co0.1Mn0.1O2 particles as a Li source, a non-stoichiometric Li-Zr-O compound can be successfully formed on the surface of LiNi0.8Co0.1Mn0.1O2 particles at a low temperature of 400 °C. The formation of an amorphous Li-Zr-O layer is beneficial in minimizing undesirable side reactions associated with residual Li at the surface and, by extension, improving the cycle performance and rate-capability of LiNi0.8Co0.1Mn0.1O2. The amorphous Li-Zr-O coated LiNi0.8Co0.1Mn0.1O2 exhibits a high reversible capacity of more than 190 mAh g−1 with improved cycle performance. This simple approach offers easy control of the surface characteristics of LiNi0.8Co0.1Mn0.1O2, improving the surface stability and enhancing the thermal stability. Amorphous Li-Zr-O coating layers can be uniformly formed on the surface of the particles, which is advantageous in providing suitable Li+ pathways and improving structural stability. In this work, the residual Li on the surface of as-prepared LiNi0.8Co0.1Mn0.1O2 particles can be partially utilized as a Li source for the formation of an amorphous Li-Zr-O coating layer during the coating process. [Display omitted] •A non-stoichiometric Li-Zr-O compound is introduced on the surface of NCM811 particles via a wet-process at a temperature of 400 °C.•An amorphous Li-Zr-O layer is beneficial in minimizing undesirable side reactions associated with residual Li.•The amorphous Li-Zr-O coated NCM811 exhibits a high reversible capacity of 190 mAh g−1 and stable cycle performance.