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TECHNOLOGY
University Team discovers new class of fuel cells
Anew class of fuel cells based on a newly discovered cell technologies can signi?cantly bene?t the nation's
polymer-based material could bridge the gap between energy security, the environment and economy through
the operating temperature ranges of two existing types reduced oil consumption, greenhouse gas emissions,
of polymer fuel cells, a breakthrough with the potential and air pollution. The current research work supports
to accelerate the commercialization of low-cost fuel cells the Laboratory's missions related to energy security and
for automotive and stationary applications. A Los Alamos materials for the future. Currently, two main classes of
National Laboratory team, in collaboration with Yoong- polymer-based fuel cells exist. One is the class of low-
Kee Choe at the National Institute of Advanced Industrial temperature fuel cells that require water for proton
Science and Technology in Japan and Cy Fujimoto of conduction and cannot operate above 100°C. The other
type is high-temperature fuel cells that can operate
up to 180°C without water; however, the performance
degrades under water-absorbing conditions below 140°C.
The research team found that a phosphate-quaternary
ammonium ion-pair has much stronger interaction, which
allows the transport of protons effectively even under
water-condensing conditions.
Sandia National Laboratories, has discovered that fuel "The discovery happened when we were investigating
cells made from phosphate-quaternary ammonium ion- alkaline hydroxide conducting membranes, which have
pair can be operated between 80°C and 200°C with and quaternary ammonium groups," said Kim. "While the
without water, enhancing the fuel cells usability in a range alkaline membranes work only under high pH conditions,
of conditions. The research is published in the journal the idea came across that alkaline membranes can
Nature Energy. "Polymer-based fuel cells are regarded be used under low pH conditions by combining with
as the key technology of the future for both vehicle and phosphoric acid" said Kim. "This was a breathtaking
stationary energy systems," said Yu Seung Kim, the project moment, when Choe brought the calculation data that
leader at Los Alamos. showed the interaction between quaternary ammonium
and biphosphate is 8.7 times stronger than conventional
"There's a huge bene?t to running fuel cells at the widest acid-base interaction." The Los Alamos team collaborated
possible operating temperature with water tolerance. But with Fujimoto at Sandia to prepare quaternary ammonium
current fuel-cell vehicles need humidi?ed inlet streams functionalized polymers.
and large radiators to dissipate waste heat, which can
increase the fuel-cell system cost substantially, so people The prototype fuel cells made from the ion-pair-
have looked for materials that can conduct protons coordinated membrane demonstrated excellent fuel-
under ?exible operating conditions. It is very exciting cell performance and durability at 80-200°C, which is
that we have now found such materials." Los Alamos has unattainable with existing fuel cell technology. What's
been a leader in fuel-cell research since the 1970s. Fuel next? "The performance and durability of this new class
of fuel cells could even be further improved by high-
performing electrode materials," said Kim, citing an
advance expected within ?ve to ten years that is another
critical step to replace current low-temperature fuel cells
used in vehicle and stationary applications.
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