Ballard Power Systems Corporation

Other

Jens M&uuml;ller

Kevin M Colbow

Jiujun Zhang

David P Wilkinson

Peter Urban

Regina Wezel

Norbert Wiesheu

Arnold Lamm

Joy A Roberts

Jean St-Pierre

Cindy J Longley

Marian E Van Der Geest

Low temperature fuel cells, e.g. solid polymer fuel cells, can operate directly on a fuel comprising dimethyl ether with dimethyl ether being oxidized at the fuel cell anode. Being highly soluble in water, dimethyl ether can be supplied as a liquid aqueous fuel solution. As a fuel, dimethyl ether provides similar power characteristics as methanol but typically with a greater Faradaic efficiency in liquid feed solid polymer fuel cells.

Direct dimethyl ether fuel cells

Fuel cell system comprising at least one fuel cell which includes an anode compartment and a cathode compartment which are separated from one another by a proton-conducting membrane, further comprising a cathode feeder for delivering oxygen-containing gas to the cathode compartment, an anode feeder for delivering a liquid coolant/fuel mixture to the anode compartment, the anode compartment being disposed in an anode circuit which comprises a gas separator and a pump, and cooling of the coolant/fuel mixture circulating in the anode circuit is effected by the fuel cell which is designed for operation involving water break-through from the anode compartment into the cathode compartment. The evaporation cooling thus achieved in the fuel cell results in cooling of the coolant/fuel mixture at a steady-state operating temperature which is established in the fuel cell as a function of the membrane properties and the speed of the pump, thus obviating the need for any additional cooler in the anode circuit itself.

Liquid fuel cell system

The measuring range of a fuel cell based concentration sensor can be extended by decreasing the load across the fuel cell terminals and by increasing the amount of oxidant supplied to the fuel cell. In this way, such a sensor avoids saturation, for example, when measuring methanol concentrations from 0 M to over 4 M in liquid aqueous solution. Such a sensor is suitable for use in measuring fuel concentrations in the recirculating fuel stream of certain fuel cell stacks (for example, direct methanol fuel cell stacks).

Fuel cell concentration sensor

An electrochemical fuel cell is operated with periodic reactant starvation at either or both electrodes. Periodic reactant starvation conditions cause a change in the potential of the starved electrode and may result in the removal of electrocatalyst poisons and in improved fuel cell performance. This technique may have other beneficial effects at the electrodes, including performance improvements due to water management effects or localized heating effects at the starved electrode. In a preferred method, while successive localized portions of a fuel cell electrode are periodically reactant starved, the remainder of the fuel cell electrode remains electrochemically active and saturated with reactant such that the fuel cell is able to continue to generate power.

Method and apparatus for operating an electrochemical fuel cell with periodic reactant starvation

Growing community of inventors

Blaustein, Germany

Jens Müller

Growing community of inventors

Blaustein, Germany

Jens M&uuml;ller

Jens Müller