title: Silver-Copper Nanoalloy Catalyst Layer for Bifunctional Air Electrodes in Alkaline Media.
abstract: A carbon-free and binder-free catalyst layer composed of a Ag-Cu nanoalloy on Ni foam was used as the air cathode in a zinc-air battery for the first time. The Ag-Cu catalyst was prepared using pulsed laser deposition. The structures of the catalysts were found to consist of crystalline Ag-Cu nanoalloy particles with an average size of 2.58 nm embedded in amorphous Cu films. As observed in the X-ray photoelectron spectra, the Ag 3d core levels shifted to higher binding energies, whereas the Cu 2p core levels shifted to lower binding energies, indicating alloying of the silver and copper. Rotating disk electrode measurements indicated that the oxygen reduction reaction (ORR) proceeded through a four-electron pathway on the Ag50Cu50 and Ag90Cu10 nanoalloy catalysts in alkaline solution. Moreover, the catalytic activity of Ag50Cu50 in the ORR is more efficient than that of Ag90Cu10. By performing charge and discharge cycling measurements, the Ag50Cu50 catalyst layer was confirmed to have a maximum power density of approximately 86.3 mW cm(-2) and an acceptable cell voltage at 0.863 V for current densities up to 100 mA cm(-2) in primary zinc-air batteries. In addition, a round-trip efficiency of approximately 50% at a current density of 20 mA cm(-2) was also obtained in the test.
authors.affiliation: †State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xian 710072, China.
authors.forename: Xiaoqiang
authors.initials: X
authors.lastname: Wu
authors.affiliation: †State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xian 710072, China.
authors.forename: Fuyi
authors.initials: F
authors.lastname: Chen
authors.affiliation: †State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xian 710072, China.
authors.forename: Yachao
authors.initials: Y
authors.lastname: Jin
authors.affiliation: †State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xian 710072, China.
authors.forename: Nan
authors.initials: N
authors.lastname: Zhang
authors.affiliation: ‡Department of Chemistry, University of Birmingham, Birmingham B15 2TT, United Kingdom.
authors.forename: Roy L
authors.initials: RL
authors.lastname: Johnston
keywords: nanoalloy; oxygen reduction reaction; primary zinc−air battery; pulsed laser deposition; rechargeable zinc−air battery