Engineering Commons^™

Innovative Electrode Nanocomposites For Energy Storage And Conversion Systems, Yiran Wang

Doctoral Dissertations

Nanocomposites emerged as suitable alternatives for electrode materials, are defined as “two or more materials with different properties remain separate and distinct on a macroscopic level within one unity and with any dimension in any phase less than 100 nm”. Recently, polymer/carbon based nanocomposites have attracted significant research interests for energy applications due to their multi-functionalities, improved structure stability and ease of production. This dissertation work focusing on the development of innovative electrode nanocomposites for proton exchange membrane fuel cell, supercapacitor and electrochromic applications.

Chapter 1 is an introduction. Chapter 2 & 3 focus on the synthesis of Pd-based nanocatalysts …

Impedance-Resolved Performance And Durability In Redox Flow Batteries, Alan Michael Pezeshki

Doctoral Dissertations

The realization of redox flow batteries (RFBs) as a grid-scale energy solution depends on improving the performance and lifetime of the technology to decrease the high capital costs. The electrodes are a key component in the RFB; performance enhancement is often achieved through chemical or thermal treatments of commercially available porous carbon materials.

This dissertation uses impedance spectroscopy-based methods to gain insight into performance and durability in RFBs, enabling intelligent cell design. Initial work focused on understanding the impact of improved electrode and membrane properties on system performance. An accelerated stress test was then developed that can be used to …

Lignin Maximization: Analyzing The Impact Of Different Feedstocks And Feedstock Ratios Using Organosolv Fractionation, Marc Banholzer

Masters Theses

Over-exploitation of fossil fuels coupled with increasing pressure to reduce carbon emissions are prompting a transition from conventional petrochemical feedstocks to sustainable and renewable sourced carbon. The use of lignocellulosic biomass as a feedstock for integrated biorefining is of current high interest, as separation into its component parts affords process streams of cellulose, hemicellulose and lignin, each of which can serve as a starting point for the production of biobased chemicals and fuels. Given the large number of potential sources of lignocellulosic feedstocks, the biorefinery will need to adapt to the supplies available over a normal growing season. Of particular …

Effects Of Ultrasonic Transducers On Heat Transfer In Packed Particle Beds, David Patrick Moseley

Masters Theses

The objective of this study was to determine the effects of ultrasonic transducers on heat transfer in a packed particle bed heat exchanger. Although substantial research has been devoted to ultrasound, and the associated improvements in heat transfer, data regarding the effects on packed particle beds is non-existent. This is of particular interest given the potential to improve heat transfer in a wide variety of packed particle bed systems. A 42.9% increase in the heat transfer rate was demonstrated as the result of improved fluid convection throughout the packed particle bed. Secondary effects, including acoustic cavitation, acoustic streaming and local …

Tandem Laser Ablation Synthesis In Solution-Galvanic Replacement Reaction (Lasis-Grr): A Facile Route For The Synthesis Of Complex Intermetallic Nanomaterials With Engineered Functionalities, Sheng Hu

Doctoral Dissertations

Tailoring the heteronanostructures of nanoscale materials to tune their structure-property relations for desirable interfacial energetics is imperative for their catalytic, optoelectronic and electrochemical applications. Current PhD thesis develops a facile, yet “green” synthesis route that uses laser ablation synthesis in solution in tandem with galvanic replacement reaction (tandem LASiS-GRR) as a one-pot, one-step technique for manufacturing diverse and complex heteronanostructures of metal oxides, hydroxides, nanocomposites (NCs), and nanoalloys (NAs). The scientific concept here is that the non-equilibrium thermodynamics and kinetics of high-energy LASiS-GRR can be tuned by laser parameters and solvent chemistry to form complex NCs/NAs of tailored sizes/shapes, metastable …

Synthesis Of Ptcuco Ternary Alloy Using Laser Ablation Synthesis In Solution-Galvanic Replacement Reaction (Lasis-Grr), Kangmin Cheng

EURēCA: Exhibition of Undergraduate Research and Creative Achievement

Laser ablation synthesis in solution in tandem with galvanic replacement reaction (LASiS-GRR) is a newly-developed, facile and environmental friendly synthesis technique for manufacturing a variety of complex nanostructures including hydroxides, metal/metal oxides nanocomposites (NCs), metal-metal nanoalloys (NAs), core-shell nanostructures, etc. This synthetic technique incorporates both “top-down” pulsed laser ablation synthesis in solution approach (LASiS) and the “bottom-up” chemical reduction method (CRM). The setup houses a Q-switched Nd:YAG pulsed laser (1064 nm) with the laser beam focused at a metal target in liquid medium inside a sealed stainless steel reactor cell. The cell is mounted with a gas inlet/outlet, viewing windows, …