Abstract
Self-healing supramolecular binder was previously found to enhance the cycling stability of micron-sized silicon particles used as the active material in lithium-ion battery anodes. In this study, we systematically control the density of cross-linking junctions in a modified supramolecular polymer binder in order to better understand how viscoelastic materials properties affect cycling stability. We found that binders with relaxation times on the order of 0.1 s gave the best cycling stability with 80% capacity maintained for over 175 cycles using large silicon particles (∼0.9 um). We attributed this to an improved balance between the viscoelastic stress relaxation in the binder and the stiffness needed to maintain mechanical integrity of the electrode. The more cross-linked binder showed markedly worse performance confirming the need for liquid-like flow in order for our self-healing polymer electrode concept to be effective.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 2318-2324 |
| Number of pages | 7 |
| Journal | ACS Applied Materials and Interfaces |
| Volume | 8 |
| Issue number | 3 |
| DOIs | |
| State | Published - Jan 27 2016 |
Funding
This work was supported by the Global Climate and Energy Program at Stanford University. J.L. also acknowledges support by the National Science Foundation Graduate Research Fellowship Program under Grant No. (DGE-114747).
Keywords
- high capacity anode
- lithium-ion battery
- microparticles
- polymer binder
- self-healing
- silicon
- viscoelasticity
ASJC Scopus subject areas
- General Materials Science
