Materials Characterization for Three-Dimensional Electrochemical Energy Storage Devices
- Author(s): Lau, Jonathan Sai Jet
- Advisor(s): Dunn, Bruce S
- et al.
Three-dimensional electrochemical energy storage devices are a promising solution for decoupling the energy and power densities of micro-scale devices. The use of the third-dimension allows for increased active material loading and surface area, leading to higher energy and power densities for a given footprint area compared to thin-film devices. Towards the realization of this technology, novel materials must be developed for these applications including conformal solid or pseudo-solid electrolytes, conformal redox-active material, and three-dimensional scaffolds. In this dissertation electrochemical impedance spectroscopy and redox probe analysis are adapted to obtain unique insights into the properties of these materials and evaluate their potential use in three- dimensional energy storage devices. Electrochemical impedance spectroscopy is used to characterize electrochemical phenomena including the ionic and electronic conductivities of iCVD/ALD solid electrolytes and MOFs for pseudo-solid electrolytes, the charge-transfer resistances of oCVD PEDOT active material, and the electrolyte pore resistances of a porous graphene scaffold. Redox probe characterization is used to characterize film morphologies including the microdefect density of iCVD thin films and the porosity of MOF thin films. Finally, the fabrication of full cells is used to demonstrate the potential of oCVD PEDOT for high-rate applications, and EDLC and hybrid devices are used validate computational models and demonstrate the conversion of low-grade heat to electrochemical energy, respectively.