[1] Nagasaki Univ, Grad Sch Engn, 1-14 Bunkyo Machi, Nagasaki 8528521, Japan
[2] MIT, Dept Mat Sci & Engn, 77 Massachusetts Ave, Cambridge, MA 02139 USA
[3] Kyushu Univ, Int Inst Carbon Neutral Energy Res, Nishi Ku, 744 Motooka, Fukuoka 8190395, Japan
[4] Redox Power Syst, College Pk, MD 20742 USA