Formulation strongly influences the structure, properties, and electrochemical performance in composite electrodes. The role of polymeric binders is especially critical for electrodes containing high volume change active materials, such as silicon. In this study, we investigated the impact of polyimide binder in silicon microparticle electrodes. The impact of binder content on electrode adhesion to the current collector, cohesion, porosity, electrical resistivity, local electrical connectivity, and silicon utilization was characterized in pristine and cycled electrodes to elucidate the mechanisms driving the electrochemical performance during rate and cycle life tests of Si-NMC622 full cells. We observed that capacity retention improved with increasing binder content, but rate performance suffered with excess binder content, indicating that there is an optimal binder weight fraction to balance the trade-off between these two metrics. Our research reveals important design principles for the optimization of binder content in silicon electrode formulations and can be applied to the development of electrodes containing other active materials and conductive additives.
|Journal||Journal of the Electrochemical Society|
|State||Published - Jan 2023|
Bibliographical noteFunding Information:
The authors are especially indebted to Nicole Ellison, who provided the cathode electrodes and developed the baseline formulation used in our study, to Matthew Keast, who performed the scratch test experiments, to Bradley Frieberg and Srikanth Arisetty for helpful discussions, and to Robert S. Conell, who worked diligently to maintain the cyclers and taught us to repair the glove boxes that were used for this work. We are very thankful for their kindness and contributions to this work.
© 2023 The Author(s). Published on behalf of The Electrochemical Society by IOP Publishing Limited.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Renewable Energy, Sustainability and the Environment
- Surfaces, Coatings and Films
- Materials Chemistry