Micro-supercapacitors on Silicon with Superior Power Densities Based on Solid Source MXenes Growth
Abstract
Building further on the key knowledge developed during our 17IOA027, which allowed us to isolate the graphene from the SiC/Si substrate, we have established that we can obtain large -scale epitaxial graphene, and for the first time we have shown a thorough evaluation of the charge transport properties. This is a milestone for the pursuing applications of this graphene in electronics, photonics and energy. Specifically, in the supercapacitors area, we confirm that the solid state synthesis of MXenes has not led to notable results, indicating that this approach may be too challenging. However, we have: 1) Focused on the fundamental physical and chemical mechanisms behind the electrodes/gel electrolyte interface, which has led to the invention of an agent-free, fully in-situ functionalization of the graphene electrodes leading to greatly enhanced capacitance, Coulombic efficiency and cyclability, thanks to the addition of stable faradaic reactions sites. This work has earned a VIP mention, as well as front cover feature on Batteries and Supercaps, Wiley; 2) We have initiated an ongoing collaboration including AFRL and Sandia Nat Labs using the CINT/Sandia environmental TEM to study electrode/electrolyte interfaces; the Covid situation has slowed down this investigation, but Sandia is likely to extend the award; 3) We have shown an alternative 2D material stacking for enhanced capacitance, using a layer of MoS2 grown on the graphene on SiC/silicon. This research is about to be published and indicates that the combination of high-quality graphene and MoS2 as layered electrodes greatly enhances the capacitance of the supercapacitor cells. We argue that this is because the graphene offers high conductivity (unavailable in MoS2), while the TMD material allows for a high area available for storage.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 21, 2020
- Accession Number
- AD1189099
Entities
People
- Francesca Iacopi
Organizations
- University of Technology Sydney