Research

Support from the following sponsors is gratefully acknowledged:

Lithium Ion Batteries

Energy storage is a key need for vehicle electrification, with the Li-ion battery (LIB) considered as the primary candidate for vehicular energy storage. Increased automobile electrification will require development of battery technologies with improved power density and energy density capabilities while also improving durability. A stronger understanding of microstructure-transport interactions in LIB electrodes will support deterministic nano- and microscale design of battery electrodes to meet these diverse objectives. We are studying the effects of transport and microstructure on LIB performance and reliability using 3D imaging and microstructural modeling. Current efforts include investigation of of high capacity nanostructured anodes and high power nanostructured cathodes.

This work is supported by a 2015 NSF CAREER Award (CBET-1454437) and an NSF Collaborative Research Grant (CBET-1438683).

Solid Oxide Cells

Solid oxide fuel cells (SOFCs) and electrolyzers (SOEs) are high temperature electrochemical energy conversion devices that may be used for power generation and fuel production. A key component of these solid oxide cells is the porous, composite electrode made of an ion conductor and an electron conductor. High temperature operation permits use of carbon tolerant nickel catalyst that permits fuel flexibility. However, rigorous operating conditions, including elevated temperatures and exposure to reducing and oxidizing environments, cause changes in the microstructural geometry and composition of solid oxide cell electrodes. These microstructural changes lead to performance degradation through loss of chemical reaction sites, breakdown of charge conducting networks, increased stress, and cell failure. We are studying the impact of macroscopic solid oxide cell geometry on microstructural evolution within composite electrode materials using analytical, numerical, and experimental methods. It is expected that cell geometry will create reactant and charge distributions that drive localized microstructural evolution in SOE electrodes.

This work is supported by the NASA EPSCoR program through a Research Infrastructure Grant made by the Alabama Space Grant Consortium.

Thermoelectric Materials

Thermoelectrics provide the capability to convert thermal energy directly to electricity and open several routes to more efficient energy use. The performance of thermoelectric materials may be enhanced by incorporating microstructural features including grain boundaries, porosity, and precipitate phases. Our current work on thermoelectrics focuses on the effects of microstructural geometry on the transport properties that govern thermoelectric device performance. For example, the arrangement of bulk grains and relative properties of distinct phases may impact current flow within the microstructure, affecting bulk electrical resisitivity. Understanding such interactions can lead to tailored structures that improve thermoelectric device performance and reliability.

This w
ork was supported by an ORAU Ralph E. Powe Junior Faculty Enhancement Award.

Facilities

Our primary lab facility is the Transport, Reaction, and Energy Conversion Lab at UAH is a 1,500 ft2 laboratory (Shelby Center 309). This lab is led by Prof. George Nelson (MAE) and Prof. Yu Lei (ChE) and houses equipment for materials processing and characterization, electrochemical testing, and catalyst testing. This facility supports research on electrochemical and catalytic material systems relevant to sustainable energy.

Materials processing and handling equipment includes a controlled atmosphere glove box and a fume hood for materials handling, two furnaces (1000 °C and 1200 °C), and a vacuum oven for materials processing. A multichannel potentiostat/galvanostat (Bio-Logic) with 5 A boosters is available for electrochemical testing. A 600 W Rigaku Miniflex X-ray Diffraction (XRD) system is available for characterization of powder and thin film materials. The potentiostat/galavnostat and XRD system were purchased with awards from the UAH Research Infrastructure Fund.

With respect to computational modeling and microstructural analysis, we have several desktop workstations that are available for finite element simulations in COMSOL Multiphysics, image processing, and microstructural analysis. These systems include four Dell Precision workstations: T7810 (Dual 8 Core Intel XEON, 2.4 GHz, 64 GB RAM), T5600 (Dual Six Core Intel XEON, 2.0 GHz, 64 GB RAM), a Dell Precision T7500 (Quad Core Intel XEON, 2.8 GHz, 24 GB RAM), T1700 (Quad Core Intel XEON, 3.1 GHz, 8 GB RAM). These workstations employ Nvidia GPUs with CUDA capabilities.