US 6,054,228 A · Fuel cell system for low pressure operation

Abstract

This invention is an improved fuel cell design for use at low pressure. The invention has a reduced number of component parts to reduce fabrication costs, as well as a simpler design that permits the size of the system to be reduced at the same time as performance is being improved. In the present design, an adjacent anode and cathode pair are fabricated using a common conductive element, with that conductive element serving to conduct the current from one cell to the adjacent one. This produces a small and simple system suitable for operating with gas fuels or alternatively directly with liquid fuels, such as methanol, dimethoxymethane, or trimethoxymethane. The use of these liquid fuels permits the storage of more energy in less volume while at the same time eliminating the need for handling compressed gases which further simplifies the fuel cell system. The electrical power output of the design of this invention can be further increased by adding a passage for cooling the stack through contact with a coolant.

Claims61

Dependent claims

An electrochemical apparatus comprising:

(a) an array of cells arranged edge to edge in sheet configuration, each cell comprising an ionically conducting membrane, an anode having an active area in contact with a first side of the membrane, and a cathode having an active area in contact with a second side of the membrane;
and
(b) a plurality of fluid permeable electronically conducting sheets providing electronic communication between adjacent cells in the array, the sheets having a first region extending across the active area of a cathode of one cell and a second region extending across the active area of an anode of an adjacent cell such that the cells are electronically connected in series and the anode of each cell is on the same side of the array.

An apparatus comprising an array of electrochemical cells arranged in sheet configuration, wherein the cells are spaced a distance apart from each other and electrically connected in series at least along one edge;

each electrochemical cell comprising:
(a) a separate ion exchange membrane;
(b) an anode active area in contact with at least a part of the first side of the ion exchange membrane;
(c) a cathode active area in contact with at least a part of the second side of the ion exchange membrane;
(d) a first continuous, fluid permeable, electronically conducting sheet having a first region extending across and in electronic communication with the active area of the cathode of a first electrochemical cell, a second region of the sheet defining a gas barrier in the space between the first cell and an adjacent second electrochemical cell on one side of the first electrochemical cell, and a third region of the sheet extending across and in electronic communication with the active area of the anode of the adjacent second electrochemical cell;
and
(e) a second continuous, fluid permeable, electronically conducting sheet having a first region extending across and in electronic communication with the active area of the anode of the first electrochemical cell, a second region of the sheet defining a gas barrier in the space between the first cell and an adjacent third electrochemical cell in a different direction from the second electrochemical cell, and a third region of the sheet extending across and in electronic communication with the active area of the cathode of the adjacent third electrochemical cell.

4 more elements

Dependencies are inferred from the claim text.

Fuel cell system for low pressure operation

Life of this patent

Fuel cell system for low pressure operation

Life of this patent

Abstract

Claims61