(14bi) Energy Solutions through Electrochemical Processing: Electronic Devices,Energy Storage Devices, and Extractive Metallurgy

Grid scale electrochemical energy storage devices

Multi-valent batteries for automobile propulsion

Electrochemical fabrication for future electronics and optoelectronics

Metal extraction processes and production processes of semiconductor materials

Corrosion for prolonging the life of devices and processes

Research Experience:

In my graduate work at Waseda University, I developed an electrochemical fabrication process for bit patterned magnetic recording media for future hard disk drives. Bit patterned magnetic recording media consist of an ordered highly crystalline and uniform ferromagnetic nanodot array. To fabricate these arrays, I developed a combined process using nano-patterning (nano-imprinting lithography) and electrochemical depositions â?? electrodeposition, electroless deposition. The process enabled deposition of magnetic materials onto nano-patterned substrates at the single nano-meter scale. I designed deposition conditions by characterizing the crystal structure, magnetic properties, and morphology (nucleation and growth) of the deposits. To better understand the electrochemical deposition reactions, I developed an in-situ technique for characterizing catalytic reactions on substrates at the molecule scale (1-2 nm) using Surface Enhanced Raman Scattering effects. Through this work, I demonstrated the feasibility of electrochemical deposition processes to fabricate nano-structures with both well-controlled crystallinity and uniformity at the single nano-meter scale. I also applied these processes to fabricate Si nano-pillars from ionic liquids.

Currently at MIT, I am leading the research project of liquid metal batteries, which consist of liquid electrodes and a molten salt electrolyte, to address the need for a grid-scale energy storage device. Large-scale electrochemical energy storage devices are valuable for the future grid, enabling intermittent renewable energy technologies to be integrated into the base load and creating a variety of economic benefits via off-peak shifting, load leveling, and frequency regulation. The liquid metal battery is, in principle, a reversible electrorefining cell. In this work, I have investigated the thermodynamics and kinetics of the electrochemical charge/discharge processes at the interfaces of the molten salt electrolytes and liquid metal electrodes. As a result, the applicability of calcium metal and its molten salts for electrochemical energy storage devices was demonstrated (the first calcium metal battery). Furthermore, I identified why and how corrosion occurs in the batteries and developed a solution to prolong their lifetime. These efforts have been the basis for the practical use.

My work contributes new knowledge of the electrochemical behaviors at the interfaces of electrodes and electrolytes (nucleation and growth, alloying and dealloying) at a wide range of scales (atom ~ meter) and temperatures (room temperature ~ high temperature). Tailoring these processes to specific applications is an enduring challenge in electrochemical processes as well as in the operation of the electrochemical devices. The backgrounds behind these topics are multi-disciplinary fields, such as surface science, electrochemistry, electrometallurgy, and multi-scale fabrication processes.

Postdoctoral Project: â??Liquid metal battery for grid scale energy storageâ?

Adviser: Donald R. Sadoway, Materials Science and Engineering, Massachusetts Institute of Technology

PhD Dissertation: â??Electrochemical Fabrication of Ordered Ferromagnetic Nanostructures and Control of Initial Deposition Processâ?

Adviser: Takayuki Homma, Applied Chemistry, Waseda University

Teaching Interests:

As for teaching, I feel competent to handle most any course at the undergraduate and graduate levels based on my multidisciplinary research experiences and extensive teaching experience. I have taught in the Department of Applied Chemistry at Waseda University and in the Department of Materials Science and Engineering at MIT. At both Waseda and MIT, I applied hands-on and heads-on training. At Waseda, I supported several professors in the department as an instructor of undergraduate courses in physical chemistry, inorganic chemistry, and lab courses. I managed teaching assistants and was also responsible for grading exams and reports. At MIT, I worked as an instructor for an undergraduate lab course (3.014 Materials Laboratory) by designing a syllabus, creating modules, giving short lectures, and preparing exam. Furthermore, I completed teaching certificate program at MIT in 2014. In Professor Hommaâ??s research group at Waseda, I mentored several undergraduate and masterâ??s students in writing their theses while pursuing my own thesis work. In the research group of Professor Sadoway at MIT, I also mentored six undergraduates for their research projects, two visiting students for their short-term projects, and two graduate students for their PhD research.

Future Research Direction:

As a faculty I will aim to contribute to energy research program and materials research program with the success of developing energy storage devices, electronic devices, materials synthesis processes, coating technology, and metal extraction and recycling processes. To do this, I will use the following features of electrochemical processes: precisely control over the composition, crystal structure, and phases; formation of complicated 3D structures by area-selective deposition and etching; rapid production from atom to meter scale. I have the advantage of being able to set the goal of the project from the broader perspectives like in metal extraction and approach the individual issues from understanding and designing basic chemistries at the atomic and molecular levels.

Selected Publications:

1. T. Ouchi, H. Kim, B. L. Spatocco, D. R. Sadoway, â??Calcium-based multi-element chemistry for grid-scale electrochemical energy storage,â? Nature communication, 7:10999, doi: 10.1038/ncomms10999 (2016).
2. K. Wang, K. Jiang, B. Chung, T. Ouchi, P. J. Burke, D. A. Boysen, D. J. Bradwell, H. Kim, U. Muecke, D. R. Sadoway, â??Lithiumâ??antimonyâ??lead liquid metal battery for grid-level energy storage,â? Nature, 514, 348â??350 (2014).
3. 3. T. Ouchi, H. Kim, X. Ning, D. R. Sadoway, â??Calcium-Antimony Alloys as Electrodes for Liquid Metal Batteries,â? J. Electrochem. Soc., 161(12) A1898-A1904 (2014).
4. T. Ouchi, N. Shimano, T. Homma, â??CoNiP Electroless Deposition Process for Fabricating Ferromagnetic Nanodot Arrays,â? Electrochimica Acta, 56, 9575-9580 (2011).
5. T. Ouchi, Y. Arikawa, T. Homma, â??Fabrication of CoPt Magnetic Nanodot Arrays by Electrodeposition Process,â? Journal of Magnetism and Magnetic Materials, 320, (22), 3104-3107 (2008).