Open AccessA Direct Ammonia Fuel Cell with a KOH-Free Anode Feed Generating 180 mW cm−2 at 120 °C
Author(s) -
Ben Achrai,
Yun Zhao,
Teng Wang,
Gal Tamir,
Reza Abbasi,
Brian P. Setzler,
Miles Page,
Yushan Yan,
S. Gottesfeld
Publication year - 2020
Publication title -
journal of the electrochemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.258
H-Index - 271
eISSN - 1945-7111
pISSN - 0013-4651
DOI - 10.1149/1945-7111/abbdd1
Subject(s) - anode , ammonia , electrolyte , aqueous solution , stack (abstract data type) , materials science , analytical chemistry (journal) , fuel cells , chemistry , chemical engineering , chromatography , electrode , organic chemistry , computer science , engineering , programming language
The motivations to operate the direct ammonia fuel cell (DAFC) with no addition of aqueous base, include facilitated fuel management and prevention of corrosion and shunt currents in the DAFC stack. We describe here a polymer electrolyte DAFC, operating at a cell temperature (T cell ) of 120 °C on ammonia and water alone as anode feed, that demonstrated peak power of 180 mW cm −2 —a record for this type of fuel cell. We offer a detailed analysis of polarization curves recorded for PE-DAFCs in the T cell range of 60 °C–120 °C, allowing to estimate the effects of KOH-free operation on the ionic and faradaic resistances, R i and R F , that determine together the value of R app , CL – an , the apparent resistance of the anode catalyst layer. The latter resistance drops ten times between 60 °C and 120 °C as result mainly of the drop in R F . Consequently, DAFC performance at T cell > 100 °C improves substantially, including the cell performance on a KOH-free anode feed. The demsontrated performance levels reported here for KOH-free DAFCs support further development of this type of ammonia/air fuel cells.