The electrochemical behavior of poly 1-pyrenemethyl methacrylate binder and its effect on the interfacial chemistry of a silicon electrode

JOURNAL OF POWER SOURCES

卷:376

Article

Haregewoin, Atetegeb Meazah¹  Terborg, Lydia^1,4  Zhang, Liang²  Jurng, Sunhyung³  Lucht, Brett L.³  Guo, Jinghua²  Ross, Philip N.¹  Kostecki, Robert¹ 

[1] Lawrence Berkeley Natl Lab, Energy Storage & Distributed Resources Div, One Cyclotron Rd, Berkeley, CA 94720 USA

[2] Lawrence Berkeley Natl Lab, Adv Light Source, One Cyclotron Rd, Berkeley, CA 94720 USA

[3] Univ Rhode Isl, Dept Chem, Kingston, RI 02881 USA

[4] BMW AG, EA 461, Petuelring 130, D-80788 Munich, Germany

关键词: Li-ion battery;    Si anode;    PPy binder;    Surface film;   

DOI  :  10.1016/j.jpowsour.2017.11.060

来源: Elsevier

【 摘 要 】

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.

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