Surface engineered porous silicon for stable, high performance electrochemical supercapacitors
Abstract
Silicon materials remain unused for supercapacitors due to extreme reactivity of silicon with electrolytes. However, doped silicon materials boast a low mass density, excellent conductivity, a controllably etched nanoporous structure and combined earth abundance and technological presence appealing to diverse energy storage frameworks. Here, we demonstrate a universal route to transform porous silicon (P-Si) into stable electrodes for electrochemical devices through growth of an ultra-thin, conformal graphene coating on the P-Si surface. This graphene coating simultaneously passivates surface charge traps and provides an ideal electrode-electrolyte electrochemical interface. This leads to 10–40X improvement in energy density and a 2X wider electrochemical window compared to identically-structured unpassivated P-Si. This work demonstrates a technique generalizable to mesoporous and nanoporous materials that decouples the engineering of electrode structure and electrochemical surface stability to engineer performance in electrochemical environments. Specifically, we demonstrate P-Si as a promising new platform for grid-scale and integrated electrochemical energy storage.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Oct 22, 2013
- Source ID
- 10.1038/srep03020
Entities
People
- Andrew Westover
- Cary L Pint
- Jeremy W. Mares
- Landon Oakes
- Rizia Bardhan
- Shahana Chatterjee
- Sharon M Weiss
- William R. Erwin