Nanostructure-Based Plasmon-Enhanced Raman Spectroscopic Strategies for Characterization of the Solid–Electrolyte Interphase: Opportunities and Challenges

The physicochemical properties of the solid–electrolyte interphase (SEI) at anodes of lithium-based batteries are crucial for achieving the highest performance, and therefore, accurate characterizations are necessary to reveal the molecular structure and chemical properties of SEI. Nanostructure-based plasmon-enhanced Raman spectroscopy (PERS) techniques rely on localized surface plasmonic enhancement mechanism and have offered significant opportunities, albeit with challenges, for nondestructive and real-time studies of SEI over the past two decades. In this Perspective, we highlight the recent progress in PERS, including surface-enhanced Raman spectroscopy (SERS), tip-enhanced Raman spectroscopy (TERS), and shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS) as a class of highly sensitive chemical fingerprint techniques for investigating the structure and chemistry of SEI. We also discuss the advantages and limitations of PERS for characterizing SEI and related interfacial processes. Lastly, we provide possible directions on how PERS can be further effectively leveraged to advance the characterization of interfaces and interphases of Li-based batteries, which could also be challenges for physical chemistry and energy chemistry.