Fuel cell system

Patent metadata

Field	Value
Publication number	US-10069159-B2
Application number	US-201415107656-A
Country	US
Kind code	B2
Filing date	Nov 4, 2014
Priority date	Dec 25, 2013
Publication date	Sep 4, 2018
Grant date	Sep 4, 2018

Abstract

In order to make a power generation quantity of a cell for fuel cell increase in a short time when a drop in moistness of the cell causes the power generation quantity of the cell to decrease, a cathode of the cell includes a conductive material, catalyst, and ionomer which covers the conductive material and catalyst. If an output voltage value of the cell is lower than a predetermined threshold voltage value and an electrical resistance value of the cell is higher than a predetermined threshold resistance value, control for increasing an oxidizing gas amount which increases an amount of oxidizing gas sent to the cell is performed.

First claim

What is claimed is:

1. A fuel cell system comprising:
a fuel cell having a membrane electrode assembly provided with an electrolyte and a cathode and anode respectively arranged at two sides of the electrolyte and an oxidizing gas passage configured to feed an oxidizing gas to the cathode, the cathode including a conductive material, catalyst, and ionomer which covers the conductive material and catalyst;
an oxidizing gas feed path connected to an inlet of the oxidizing gas passage;
an oxidizing gas feeder arranged in the oxidizing gas feed path and configured to feed oxidizing gas to the cathode; and
a system controller programmed to control the fuel cell system to make an output current value of the fuel cell equal to a target current value which is determined based on a target power generation quantity of the fuel cell, and programmed to, after an output voltage value of the fuel cell is becomes lower than a predetermined threshold voltage value and an electrical resistance value of the fuel cell is becomes higher than a predetermined threshold resistance value, control the oxidizing gas feeder to perform control for increasing an oxidizing gas amount which increases an amount of oxidizing gas sent to the fuel cell.

2. The fuel cell system according to claim 1 , wherein the system controller is programmed to stop the control for increasing the oxidizing gas amount if the output voltage value of the cell becomes higher than the threshold voltage value during the control for increasing the oxidizing gas amount.

3. The fuel cell system according to claim 1 , wherein the system controller is programmed to stop the control for increasing the oxidizing gas amount if the electrical resistance value of the cell becomes higher than a predetermined upper limit resistance value during the control for increasing the oxidizing gas amount.

4. The fuel cell system according to claim 3 , further comprising a fuel cell temperature controller configured to control a temperature of the cell, wherein the system controller is programmed to control the fuel cell temperature controller to perform control for lowering a fuel cell temperature which lowers the temperature of the cell if the control for increasing the oxidizing gas amount is stopped due to the electrical resistance value of the cell becoming higher than the upper limit resistance value.

5. The fuel cell system according to claim 4 , wherein the system controller is programmed to stop the control for lowering the fuel cell temperature if the electrical resistance value of the cell becomes lower than the threshold resistance value during the control for lowering the fuel cell temperature.

6. The fuel cell system according to claim 1 , further comprising a cathode off-gas passage connected to an outlet of the oxidizing gas passage of the cell and a back pressure control valve arranged in the cathode off-gas passage and configured to control a back pressure of the cell, wherein the system controller is programmed to perform the control for increasing the oxidizing gas amount and to control the back pressure control valve to perform control for raising a back pressure which rises the back pressure of the cell if the output voltage value of the cell is lower than the predetermined threshold voltage value and the electrical resistance value of the cell is higher than the predetermined threshold resistance value.

7. The fuel cell system according to claim 6 , wherein the system controller is programmed to, when performing the control for increasing the oxidizing gas amount and the control for raising the back pressure, perform first the control for increasing the oxidizing gas amount to increase and maintain an amount of the oxidizing gas up to a predetermined target amount, and then perform the control for raising the back pressure.

8. The fuel cell system according to claim 1 , wherein the system controller is programmed to increase the amount of oxidizing gas intermittently in the control for increasing the oxidizing gas amount.

9. The fuel cell system according to claim 1 , wherein the cell further has a fuel gas passage configured to feed fuel gas to the anode, wherein the fuel cell system further comprises a fuel gas feed path connected to an inlet of the fuel gas passage and an anode off-gas passage connected to an outlet of the fuel gas passage, and wherein an anode off-gas flows through the anode off-gas passage without being returned from the anode off-gas passage to the fuel gas feed path.

Assignees

• Toyota Motor Co Ltd

Inventors

• Kawahara Shuya
• Hasegawa Shigeki
• Yamaue Keita

Classifications

• H01M8/04634

  Other electric variables, e.g. resistance or impedance · CPC title

• H01M8/04544

  Voltage · CPC title

• H01M2008/1095

  Fuel cells with polymeric electrolytes · CPC title

• H01M8/04753 Primary

  of fuel cell reactants · CPC title

• H01M8/04559

  of fuel cell stacks · CPC title