Our long-term research goal is to gain fundamental understanding necessary to control the compositions, structures, and morphology over multiple length scales and over three dimensions (3D) in order to create functional materials with chemistries and structure tailored for energy and environmental technologies. In pursuit of this goal, the key research objective of our recent efforts is to obtain the relationship between processing parameters, the structure of the materials, microstructure, and the resultant properties to achieve the rational design of functional materials for next-generation batteries, fuel cells, and greenhouse gas capture.
1. Novel Processing of Functional Materials
When the dimension of materials, grains, or domains becomes comparable to (or less than) the characteristic length scale (e.g., mean free path) of phonons, photons, electrons, ions, or molecules, many physical phenomena involving them are strongly influenced. This often leads to new modes of transporting charge, mass, and energy and to new processes of chemical and energy transformation. In typical electrochemical systems, the length scales of mobile species (electrons, ions, and molecules) fall generally in the order of 0.1 to 100 nm, suggesting that some unique physicochemical properties of materials and novel reaction pathways may become operative in the nanoscale regime. Thus, my research group focuses on the rational design and novel materials processing of functional materials with proper nano-structures/architectures (i.e., reduced length scales and characteristic time scales of physical phenomena) to dramatically enhance the transport of electrons, ions, and molecules associated with the operation of functional systems. The following are specific examples of, but not limited to, my research interests.
- CO2-thermic Oxidation Process (CO-OP) for Dimension-Controllable Functional Materials
- Advanced Manufacturing of Metal-Organic Frameworks for CO2 Separation
- Scalable Processing of Nanoporous Materials for Electrochemical Desalination of Water
2. Electrochemical Principles of Next-Generation Energy Storage Systems
The performance of current lithium-ion batteries is not capable of meeting tomorrow’s energy storage requirements for advanced transportation and portable applications. For example, new energy storage systems with substantially higher specific energy and excellent cycle life must be developed if electric vehicles are to be widely adopted as replacements for gasoline-powered vehicles. In particular, the obtainable energy densities of current cathode materials remain insufficient to meet the ever-increasing requirements of the rapidly progressing emerging technologies. Therefore, my research group explores new materials and innovative chemistries to go beyond incremental improvements in the energy densities of existing batteries.
- Novel Materials for Li-ion Batteries
- Metal-Sulfur Batteries, Metal-Air Batteries
- All Solid-State Batteries
- Wearable/Foldable Energy Storage Devices
3. Bio-Inspired Materials and Process for Energy and Environment
In recent years, attempts to learn from nature’s way of assembling high-precision and robust materials have been reported by researchers including myself. Materials found in nature, evolved over time in structure and functionality in response to a variety of demands from environments, often exhibit remarkable properties. One of notable features of biological systems is their ability to assemble sophisticated, three-dimensionally porous, hierarchical structures with high-precision at different length scales (ranging from nanometers to millimeters) and complexity far exceeding those of artificial architectures created by human. My research group develops bio-inspired approach to design nanostructures and novel architectures to create electrodes with significantly improved performance for the development of future-generation energy storage and conversion devices.