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

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 ZrO2ZrO2 coated NMC). The stable coating layers protect the reactive surface of the CAM from detrimental side reactions, preventing crack formation and particle disintegration. In‐depth analysis indicates an incorporation of lithium ions in the coating layers, contributing to the enhanced lithium transport across the CAM surface layer.