Large-Molecule Decomposition Products of Electrolytes and Additives Revealed by On-Electrode Chromatography and MALDI

•Large-molecule decomposition products in SEIs are revealed with MALDI-TOF-MS •On-electrode chromatography is employed to assist MALDI measurements •The molecular SEI components characterized directly on the electrode surfaces •This approach can be applied a variety of battery systems The solid-electrolyte interphase (SEI) produced by electrolyte has critical impact performance. However, precise makeup SEI, including composition organic and polymeric species, one least understood aspects lithium-ion batteries. Here, we probe using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) assisted on-electrode chromatography. On-electrode utilizes itself as stationary phase for fractionating molecules surfaces, thus realizing separation different species prior analysis. This strategy proven important effective surfaces. With chromatography, large-molecule carbonate electrolytes containing vinylene methacrylate additives unambiguously illustrated each case clear structure assignment. work provides simple, powerful, universal solution identification SEIs.