Improved Cycling Performance of High-Nickel NMC by Dry Powder Coating with Nanostructured Fumed Al2O3, TiO2, and ZrO2: A Comparison

Abstract

Surface coating is an effective concept to protect layered cathode active materials (CAMs) in lithium ion batteries from detrimental side reactions. Dry powder coating is a fast and cost-effective coating process, and here we transfer this coating approach from Al2O3 to nanostructured fumed TiO2 and ZrO2 coatings on the same NMC (Li[Ni,Mn,Co]O2) material. Using similar processing, this allows a direct comparison of the characteristics of the achieved coating layers and their influence on the cycling performance of high-nickel NMC. The nanostructured small oxide aggregates result in a quite homogeneous coating layer with a certain porosity around each CAM particle. Significantly enhanced long-term cycling stability is observed, with a trend of increasing stability in the series ZrO2