Zinc Anode for Direct Borohydride Fuel Cells

• Type: Article in International Scientific Journal
• Date: 2010

Authors

Sequeira, CAC (Author) Other

Journal

Title: Journal of the Electrochemical Society

Vol. 157 No. 5

Pages: B13-B19

ISSN: 0013-4651

Publisher: Electrochemical Society, Inc.

Indexing

ISI Web of Knowledge - 54 Citations

Scopus - 63 Citations

Other information

Authenticus ID: P-003-BS7

DOI: 10.1149/1.3247540

Abstract (EN): Zinc is evaluated as a negative electrode for the direct electrochemical oxidation of sodium borohydride (NaBH4). Open-circuit potential measurements, cyclic voltammetry, chronoamperometry, and chronopotentiometry are used to characterize the electrode behavior, namely, the oxidation reaction at the Zn/borohydride interface. Two consecutive oxidation steps are identified, and a possible working mechanism is proposed. A relatively low electrocatalytic activity of Zn for borohydride oxidation is indicated. A laboratory direct sodium borohydride/hydrogen peroxide (NaBH4/H2O2) fuel cell using a Zn anode is studied at room temperature. Cell voltages of 2.14 V and short-circuit currents of 1.05 A cm(-2) are reported but cell stability is limited to 6 h operation. Energy densities and maximum specific capacities of 2799 Wh kg(-1) and 1577 Ah kg(-1), respectively, are obtained. A power density of about 470 mW cm(-2) at a cell voltage of 1.10 V and a current density of 426 mA cm(-2) is reported but it cannot be sustained for appreciable operation times.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7