Improved Performance of Alkaline Membrane Fuel Cells

We have been developing materials for Alkaline membrane fuel cells(AMFCs) for about 10 years. AMFC is one of the polymer electrolyte fuel cells (PEFCs) which uses anion exchange membrane and anion conductive ionomer as polymer electrolyte materials. AMFC has some advantages over proton-exchange membrane fuel cells(PEMFC) ^1-2).

(1) The high pH environment of AMFC allows the use of non platinum catalysts.

(2) The kinetics of the ORR reaction is more facile in alkaline environment than in acidic environment.

  AMFC has been  attracting worldwide attentions, and the number of report is  increasing year by year.

  We have already demonstrated the relatively high AMFC performances with hydrogen fuel, and have confirmed several features specialized to AMFC, namely CO₂ self-purging phenomena³⁾, which could be a solution against serious CO₂ problem in AMFC^4-6), and the effective water transport from anode to cathode side, which prevent the lack of water needed for cathode reaction⁷⁾.

  To make the AMFC being popular FC, there are some issues to be resolved.

a) Few low-cost non-Pt or non-precious metal catalysts are known.

b) Low power density.

c) Low durability of electrolyte materials.

  The  absence of  good HOR catalysts with non precious metal is an big issues for the people in this field. But, with the considerable efforts for the development of  electrolyte materials, the operating conditions and so on, some researchers have achieved the power density of  1W/cm^{2 8)}.

  Now, we are focusing on the durability of electrolyte materials. The corsslinking between polymer chains  is one of  an effective way to improve the durability of electrolyte materials. We have  investigated some aspects of crosslinking reagents, and have achieved some improvement on the durability of  electrolyte materials for AMFC.

References

1. H. A. Gasteiger , FC-EXPO 2008, Technical conference fc-10.
2. J. R. Varcoe, R. C. T. Slade, E. Lam How Yee, S. D. Poynton, D. J. Driscoll, D. C. Apperley, Chem.  Mater., 19, 2686 (2007)
3. L. A. Adams, S. D. Poynton, C. Tamain, R. C. T. Slade, J. R. Varcoe, ChemSusChem, 1, 79 (2008).
4. H. Yanagi, K. Fukuta, ECS transactions, 16, 257 (2008).
5. K. Fukuta, H. Inoue, S. Watanabe, H. Yanagi, ECS transactions, 19, 23 (2009).
6. H. Yanagi, S. Watanabe, K. Sadasue, T. Isomura, H. Inoue, K. Fukuta, Abstract of 216^th ECS Meeting, #341 (2009).
7. T.Isomura, K.Fukuta, H.Yanagi, S.Ge and C.Y. Wang, Abstract of 219^th ECS Meeting, #221 (2011).
8. Y. Wang, G. Wang, G. Li, B. Huang, J. Pan, Q.Liu, J. Han, L. xiao, J. Lu, L. Zhuang, Enegy Environ. Sci. 8,177(2015)