Unraveling battery interface chemistry and architecture with TOF-SIMS: Recent advances, unique advantages and future trends

Battery interface behavior is a critical factor determining battery performance, but the complex chemical composition and nanoscale dynamic evolution impose extremely high demands on the precision of characterization techniques. Time-of-flight secondary ion mass spectrometry (TOF-SIMS) has emerged as a core technique in battery interface research, with its unique advantages such as ultra-high sensitivity, nanoscale spatial resolution, and three-dimensional chemical imaging capabilities. This review systematically introduces the technical principles and development process and functional characteristics of TOF-SIMS, focusing on summarizing its advances and strengths in studying electrode interface evolution, electrolyte decomposition, and ion migration. Using representative interface components as examples, it provides an in-depth discussion on the analytical strategies and principles for accurate identification through cluster ions, providing crucial support for enhancing the reliability of data interpretation. Furthermore, this review explores emerging trends, including the development of in-situ TOF-SIMS and its integration with multi-modal characterization techniques. Finally, proposing development directions including standard database construction, machine learning-assisted data analysis, and wide-temperature-range in-situ characterization to advance TOF-SIMS as a standardized and synergistic technology for battery interface research.