AB5-type Hydrogen Storage Alloy Modified with Carbon Used as Anodic Materials in Borohydride Fuel Cells

• Published in: International journal of electrochemical science Vol. 9; no. 2; pp. 659 - 669
• Main Authors: Lota, Grzegorz, Sierczynska, Agnieszka, Acznik, Ilona, Lota, Katarzyna
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.02.2014
• Subjects: AB5 alloy; anode material; carbon modification; Direct borohydride fuel cell; anode material; AB5 alloy; carbon modification; Direct borohydride fuel cell
• ISSN: 1452-3981; 1452-3981
• DOI: 10.1016/S1452-3981(23)07747-7

This paper describes anodic materials for fuel cells using borohydride as a fuel (DBFC). A fuel cell is an electrochemical device which converts chemical energy stored in borohydride ion and in an oxidant, directly into electricity by redox processes. In this work the electrochemical properties of multicomponent hydrogen storage alloy of the AB5-type: LaMmNi3.55Al0.30Mn0.40Co0.75 modified with carbon used as anodic materials in a borohydride fuel half-cell are discussed. Composites with a small amount of carbon were obtained by pyrolysis directly on a hydrogen storage alloy or by carbonization of conducting polymers. It was done in order to improve the hydrogen electrosorption properties of anode material. The electrochemical properties were examined in 6 M KOH solution with the addition of a different amount of KBH4, using cyclic voltammetry and galvanostatic methods. It has been proved that only particular forms of carbon are able to promote the electrocatalytic activity of an AB5 alloy type anode and remarkably enlarge the surface area of the working electrode. Additionally, tubular morphology of nanocarbons makes fuel diffusion easier, in comparison to pores in a carbon layer obtained by carbonization of conducting polymers composites.