context: Aiming to achieve higher energy batteries, researchers have started to revisit the LiNiO2 chemistry with hopes that knowledge obtained from NMC and NCA studies could be applied to LiNiO2 and resolve the issues that were identified decades ago. Furthermore, eliminating the use of cobalt can circumvent the issues surrounding Co such as high toxicity, high cost, and child labor abuse in mining. At the material level, the most popular strategy is the bulk cationic doping to enhance the electrochemical reversibility. With doping strategies, Co-free Ni-rich layered cathode materials are expected to deliver comparable battery performance to NMCs and NCAs. In addition, many studies have been performed on modulating the electrolyte composition to improve the electrode–electrolyte interphase for stabilizing the battery performance. The surface of LiNiO2-based materials is much more reactive than NMC and NCA materials owing to the extreme Ni3+/Ni4+ redox couple. Thus, revealing the origins of surface changes can better inform the advanced design of promising LiNiO2-based materials. At present, most studies rely on ex situ characterization methods to understand the surface degradation of cathode materials, for example, transition electron microscopy (TEM) based techniques for atomic scale structural and chemical analysis, as well as surface sensitive X-ray spectroscopy for ensemble-averaged measurements to probe surface chemical information. The surface sensitive probing techniques typically have low penetrating depths, which makes it difficult to study surface chemistry under practical battery operating environments. Noticeably, the chemical and structural information on the particle surface may be influenced by a range of experimental conditions, including but not limited to, human exhalation, sample storage, and sample preparation during material surface analysis. This can skew observations found in characterization analysis, surface doping, and electrochemical protocol. Therefore, to characterize the surface of LiNiO2 properly, one must understand how the experimental conditions influence overall surface and interfacial chemistries.