The electrochemical behavior of poly 1-pyrenemethyl methacrylate binder and its effect on the interfacial chemistry of a silicon electrode
Document Type
Article
Date of Original Version
2-1-2018
Abstract
The physico-chemical properties of poly (1-pyrenemethyl methacrylate) (PPy) are presented with respect to its use as a binder in a Si composite anode for Li-ion batteries. PPy thin-films on Si(100) wafer and Cu model electrodes are shown to exhibit superior adhesion as compared to conventional polyvinylidene difluoride (PVdF) binder. Electrochemical testing of the model bi-layer PPy/Si(100) electrodes in a standard organic carbonate electrolyte reveal higher electrolyte reduction current and an overall irreversible cathodic charge consumption during initial cycling versus the uncoated Si electrode. The PPy thin-film is also shown to impede lithiation of the underlying Si. XAS, AFM, TGA and ATR-FTIR analysis indicated that PPy binder is both chemically and electrochemically stable in the cycling potential range however significant swelling is observed due to a selective uptake of diethyl carbonate (DEC) from the electrolyte. The increased concentration of DEC and depletion of ethylene carbonate (EC) at the Si/PPy interface leads to continuous decomposition of the electrolyte and results in non-passivating behavior of the Si(100)/PPy electrode as compared to pristine silicon. Consequently, PPy binder improves the mechanical integrity of composite Si anodes but it influences mass transport at the Si(100)/PPy interface and alters electrochemical response of silicon during cycling in an adverse manner.
Publication Title, e.g., Journal
Journal of Power Sources
Volume
376
Citation/Publisher Attribution
Haregewoin, Atetegeb M., Lydia Terborg, Liang Zhang, Sunhyung Jurng, Brett L. Lucht, Jinghua Guo, Philip N. Ross, and Robert Kostecki. "The electrochemical behavior of poly 1-pyrenemethyl methacrylate binder and its effect on the interfacial chemistry of a silicon electrode." Journal of Power Sources 376, (2018): 152-160. doi: 10.1016/j.jpowsour.2017.11.060.