This work focuses on understanding the role of various binders, including sodium alginate (SA), Nafion, and polyvinylidene fluoride (PVDF), on the mechanical behavior and cracking resistance of silicon composite electrodes during electrochemical cycling. In situ curvature measurement of bilayer electrodes, consisting of a silicon-binder-carbon black composite layer on a copper foil, is used to determine the effects of binders on bending deformation, elastic modulus, and stress on the composite electrodes. It is found that the lithiation induced curvature and the modulus of the silicon/SA electrodes are larger than those of electrodes with Nafion and PVDF as binders. Although the modulus of Nafion is smaller than that of PVDF, the curvature and the modulus of silicon/Nafion composite are larger than those of silicon/PVDF electrodes. The moduli of all three composites decrease not only during lithiation but also during delithiation. Based on the measured stress and scanning electron microscopy observations of cracking in the composite electrodes, we conclude that the stress required to crack the composite electrodes with SA and Nafion binders is considerably higher than that of the silicon/PVDF electrode during electrochemical cycling. Thus, the cracking resistance of silicon/SA and silicon/Nafion composite electrodes is higher than that of silicon/PVDF electrodes.
|Number of pages||7|
|Journal||Journal of Power Sources|
|State||Published - May 31 2018|
Bibliographical noteFunding Information:
The authors gratefully acknowledge the financial supports of the National Science Foundation of China under Grant No. 11332005 . Dawei Li would like to acknowledge the support of China Scholarship Council . Yikai Wang, Jiazhi Hu, Dingying Dang, and Y.-T. Cheng would like to acknowledge the support by US National Science Foundation Award 1355438 (Powering the Kentucky Bioeconomy for a Sustainable Future), the Assistant Secretary for Energy Efficiency and Renewable Energy , Vehicle Technologies Office of the U.S. Department of Energy under Contract No. Award Number DE-EE0007787 under the Battery Materials Research (BMR) Program and the financial support from the Alliance for Sustainable Energy , LLC , Managing and Operating Contractor for the National Renewable Energy Laboratory for the U.S. Department of Energy .
© 2018 Elsevier B.V.
- Cracking resistance
- Elastic modulus
- Polymer binder
- Stress evolution
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Energy Engineering and Power Technology
- Physical and Theoretical Chemistry
- Electrical and Electronic Engineering