title: 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.
authors.affiliation: 1] Department of Mechanical Engineering, Vanderbilt University, Nashville, TN 37235, USA [2] Interdisciplinary Materials Science Program, Vanderbilt University, Nashville, TN 37235.
authors.forename: Landon
authors.initials: L
authors.lastname: Oakes
authors.forename: Andrew
authors.initials: A
authors.lastname: Westover
authors.forename: Jeremy W
authors.initials: JW
authors.lastname: Mares
authors.forename: Shahana
authors.initials: S
authors.lastname: Chatterjee
authors.forename: William R
authors.initials: WR
authors.lastname: Erwin
authors.forename: Rizia
authors.initials: R
authors.lastname: Bardhan
authors.forename: Sharon M
authors.initials: SM
authors.lastname: Weiss
authors.forename: Cary L
authors.initials: CL
authors.lastname: Pint