Eric G. Dow

Enhanced electrochemical performance in the development of the aluminum/hydrogen peroxide semi-fuel cell

Abstract Significant accomplishments from this research effort have defined and characterized the nature and rate of the chemical dynamics at the anode and cathode, thus allowing the development of the aluminum/hydrogen peroxide couple as an energy-dense semi-fuel cell system. This effort has included the investigation of new aluminum alloys, development of new electrocatalysts for the hydrogen peroxide, optimization of the operating parameters and modelling of the electrochemical performance of the couple. Furthermore, it has demonstrated a technique that will enhance the electrochemical properties of selected aluminum anodes, while controlling unwanted corrosion reactions at a tolerable level. The unique methodology described in this paper involves the use of additives to activate the surface of the aluminum anode-electrolyte, thus avoiding alloying, processing and heat treating. In addition to this anode development, we have identified a novel electrocatalyst that enhances effective and efficient electrochemical reduction of hydrogen peroxide, thus shifting the predilection of the peroxide from parasitic decomposition to desired high rate electrochemical reduction. The improved performance of this electrochemical couple has led to the attainment of current densities of 500 to 800 mA cm −2 , five to seven times that originally achievable at comparable cell voltages of 1.4 to 1.2. System-level modelling, based on the experimental evidence reported in this paper, indicates that the aluminum/hydrogen peroxide couple is a versatile and energetic electrochemical energy source.

A study of cathode catalysis for the aluminium/hydrogen peroxide semi-fuel cell

Abstract The characterization and use of a Pd and Ir catalyst combination on a C substrate in an Al/H2O2 semi-fuel cell is described. The Pd–Ir combination outperforms Pd alone or Ir alone on the same substrate. Scanning electron microscopy (SEM) and energy dispersive spectrophotometry (EDS) were used to establish the location of Pd, Ir and O in clusters on the cathode substrate surface. X-ray photoelectron spectroscopy (XPS) binding energy measurements indicate that Pd is in the metallic state and the Ir is in the +3 state. A configuration consisting of an Ir(III) oxide (Ir2O3) core and a Pd shell is proposed. The electrochemical, corrosion, direct and decomposition reactions which take place during cell discharge were evaluated. Improved initial and long term performance, at low current densities, of the Al/H2O2 semi-fuel cell incorporating a Pd–Ir on C cathode relative to a similarly catalyzed Ni substrate and a baseline silver foil catalyst is demonstrated.