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

The physicochemical properties of the solid-electrolyteinterphase (SEI) at anodes of lithium-based batteries are crucial for achieving the highest performance, and therefore, accurate characterizationsare necessary to reveal the molecular structure and chemical propertiesof SEI. Nanostructure-based plasmon-enhanced Raman spectroscopy (PERS)techniques rely on localized surface plasmonic enhancement mechanismand have offered significant opportunities, albeit with challenges,for nondestructive and real-time studies of SEI over the past twodecades. In this Perspective, we highlight the recent progress inPERS, including surface-enhanced Raman spectroscopy (SERS), tip-enhancedRaman spectroscopy (TERS), and shell-isolated nanoparticle-enhancedRaman spectroscopy (SHINERS) as a class of highly sensitive chemicalfingerprint techniques for investigating the structure and chemistryof SEI. We also discuss the advantages and limitations of PERS forcharacterizing SEI and related interfacial processes. Lastly, we providepossible directions on how PERS can be further effectively leveragedto advance the characterization of interfaces and interphases of Li-basedbatteries, which could also be challenges for physical chemistryand energy chemistry.