The cathode–electrolyte interphase plays a pivotal role in determining the usable capacity and cycling stability of electrochemical cells, yet it is overshadowed by its counterpart, the solid–electrolyte interphase. This is primarily due to the prevalence of side reactions, particularly at low potentials on the negative electrode, especially in state-of-the-art Li-ion batteries where the charge cutoff voltage is limited. However, as the quest for high-energy battery technologies intensifies, there is a pressing need to advance the study of cathode–electrolyte interphase properties. Here, we present a comprehensive approach to analyse the cathode–electrolyte interphase in battery systems. We underscore the importance of employing model cathode materials and coin cell protocols to establish baseline performance. Additionally, we delve into the factors behind the inconsistent and occasionally controversial findings related to the cathode–electrolyte interphase. We also address the challenges and opportunities in characterizing and simulating the cathode–electrolyte interphase, offering potential solutions to enhance its relevance to real-world applications.

阴极-电解质界面在确定电化学电池的可用容量和循环稳定性方面发挥着关键作用，但它被其对应物固体-电解质界面所掩盖。这主要是由于副反应的普遍存在，特别是在负极电势较低的情况下，尤其是在充电截止电压有限的最先进的锂离子电池中。然而，随着对高能电池技术的追求不断加强，迫切需要推进阴极电解质界面特性的研究。在这里，我们提出了一种分析电池系统中阴极电解质界面的综合方法。我们强调采用模型阴极材料和纽扣电池协议来建立基准性能的重要性。此外，我们还深入研究了与阴极电解质界面相关的不一致且偶尔有争议的发现背后的因素。我们还解决了表征和模拟阴极电解质界面方面的挑战和机遇，提供潜在的解决方案以增强其与实际应用的相关性。