The Study of the Binder Poly(acrylic acid) and Its Role in Concomitant Solid–Electrolyte Interphase Formation on Si Anodes

Journal Article · Sat Jan 25 00:00:00 EST 2020 · ACS Applied Materials and Interfaces

DOI:https://doi.org/10.1021/acsami.9b22382· OSTI ID:1606640

Browning, Katie L. ^[1]; Sacci, Robert L. ^[2]; Doucet, Mathieu ^[2]; Browning, James F. ^[2]; Kim, Joshua R. ^[2]; Veith, Gabriel M. ^[2]

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1. Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

In this work we use neutron reflectometry to study how the polymeric binder, poly(acrylic acid) (PAA), affects the in situ formation and chemical composition of the solid–electrolyte interphase (SEI) formation on a silicon anode at various states of charge. The reflectivity is correlated with electrochemical quartz crystal microbalance to better understand the viscoelastic effects of the polymer during cycling. The use of model thin films allows for a well-controlled interface between the amorphous Si surface and the PAA layer. If the PAA perfectly coats the Si surface and standard processing conditions are used, the binder will prevent the lithiation of the anode. The PAA suppresses the growth of a new layer formed at early states of discharge (open circuit voltage to 0.8 V vs Li/Li+), protecting the surface of the anode. At 0.15 V, the SEI layer underneath the PAA changes in chemical composition as indicated by an increase in the scattering length density and thickness as the layer incorporates components from the electrolyte, most likely the salt. At lithiated and delithiated states, the SEI layer changes in chemical composition and grows in thickness with delithiation and shrinks during lithiation.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Vehicle Technologies Office (EE-3V); USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Materials Sciences & Engineering Division; USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Scientific User Facilities Division
• Grant/Contract Number: AC05-00OR22725
• OSTI ID: 1606640
• Journal Information: ACS Applied Materials and Interfaces, Journal Name: ACS Applied Materials and Interfaces Journal Issue: 8 Vol. 12; ISSN 1944-8244
• Publisher: American Chemical Society (ACS)
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
Si anodes
neutron reflectometry
poly(acrylic acid) binder
quartz crystal microbalance
solid-electrolyte interphase