Improved Electrochemical Performance of Al2O3 and ZrO2 Coated LiNi0.6Mn0.2Co0.2O2 Cathodes By Atomic Layer Deposition

Abstract

There has been an increasing demand on high-energy and low-cost lithium-ion batteries (LIBs) in order to power future transportation. In this context, LiNi1-x-yMnxCoyO2 (NMC) cathodes are particularly attractive, due to their higher capacity and lower cost compared to the traditional LiCoO2 cathodes [1]. Among the NMC cathodes, LiNi0.6Co0.2Mn0.2O2 (NMC622) is one of the most promising cathode materials undergoing extensive investigations, but it still suffers from a series of technical issues, such as dissolution of transition metal elements, and structural instability [2]. Aimed at addressing these issues, we recently applied Al2O3 and ZrO2 coatings on NMC622 using atomic layer deposition (ALD). We coated the composite electrode directly and it revealed that the ALD Al2O3 and ZrO2 coatings can improve the cyclability and sustainable capacity of the NMC622 cathodes at different cutoff voltages. In the study, we investigated the effects of ALD Al2O3 and ZrO2 coatings using X-ray diffraction, X-ray photoelectron spectroscopy, impedance spectroscopy, scanning electron microscopy, and transmission electron microscopy. Our study demonstrated that ALD remains an important tool to tackle technical issues in LIBs [3]. 1. Manthiram, A., B. Song, and W. Li, A perspective on nickel-rich layered oxide cathodes for lithium-ion batteries. Energy Storage Materials, 2017. 6: p. 125-139.2. Hou, P., et al., Surface/Interfacial Structure and Chemistry of High-Energy Nickel-Rich Layered Oxide Cathodes: Advances and Perspectives. Small, 2017. 13(45): p. 1701802.3. Meng, X., X.-Q. Yang, and X. Sun, Emerging applications of atomic layer deposition for lithium-ion battery studies. Advanced Materials, 2012. 24(27): p. 3589-3615.