IPC분류정보
국가/구분 |
United States(US) Patent
등록
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국제특허분류(IPC7판) |
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출원번호 |
US-0016482
(2001-12-10)
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발명자
/ 주소 |
- Andrews, Craig C.
- Murphy, Oliver J.
- Boyd, Brian
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출원인 / 주소 |
- Lynntech International, Ltd.
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대리인 / 주소 |
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인용정보 |
피인용 횟수 :
8 인용 특허 :
34 |
초록
▼
Electrochemical apparatus and methods that support periodic, non-steady state, or discontinuous operation without suffering degradation of materials or loss of efficiency. The invention provides a means for positioning one or more electrodes into contact with electrolyte and means for retracting the
Electrochemical apparatus and methods that support periodic, non-steady state, or discontinuous operation without suffering degradation of materials or loss of efficiency. The invention provides a means for positioning one or more electrodes into contact with electrolyte and means for retracting the one or more electrodes out of contact with the electrolyte. The means for positioning and means for retracting may be the same device or different devices. The means for positioning and means for retracting may be designed to provide automatic, passive, or fail-safe retraction of the electrode upon a given shutdown condition, such as a voltage of less than one Volt being applied between the first and second electrodes, expiration of a time period, an ozone concentration greater than a setpoint ozone concentration, contact pressure of less than 5 psig, and combinations thereof.
대표청구항
▼
1. An electrochemical apparatus, comprising:at least one electrochemical cell having first and second electrodes and an ion exchange membrane disposed between the first and second electrodes, a power source for applying a voltage between the first and second electrodes, and means for automatically r
1. An electrochemical apparatus, comprising:at least one electrochemical cell having first and second electrodes and an ion exchange membrane disposed between the first and second electrodes, a power source for applying a voltage between the first and second electrodes, and means for automatically retracting one or more of the first and second electrodes out of contact with the ion exchange membrane. 2. The electrochemical apparatus of claim 1, wherein the means for automatically retracting is passive.3. The electrochemical apparatus of claim 2, wherein the passive means for automatically retracting is a stored energy device.4. The electrochemical apparatus of claim 3, wherein the stored energy device is selected from a spring, gravity, hydraulic accumulator, pneumatic accumulator, or combinations thereof.5. The electrochemical apparatus of claim 1, wherein the one or more of the first and second electrodes includes material that is unstable or deactivates in the presence of the ion exchange membrane without applying a voltage.6. The electrochemical apparatus of claim 5, wherein the material is lead dioxide.7. The electrochemical apparatus of claim 6, characterized in that the lead dioxide maintains its activity during repetitive cycling of the power source.8. The electrochemical apparatus of claim 1, further comprising:a pump for delivering water to the at least one electrochemical cell, wherein the means for retracting is a hydraulic actuator in fluid communication with the water. 9. The electrochemical apparatus of claim 8, further comprising means for introducing ozone into a separate system.10. The electrochemical apparatus of claim 9, wherein the ozone comprises dissolved ozone in water, an ozone/oxygen gas stream, or combinations thereof.11. The electrochemical apparatus of claim 1, wherein the ion exchange membrane and one of the electrodes are stationary.12. The electrochemical apparatus of claim 11, wherein the stationary electrode is a cathode.13. The electrochemical apparatus of claim 1, wherein the at least one electrochemical cell is a plurality of electrochemical cells.14. The electrochemical apparatus of claim 13, wherein the plurality of electrochemical cells form a stack of electrochemical cells.15. The electrochemical apparatus of claim 1, further comprising:a lead-containing catalyst disposed on one or more of the first and second electrodes; and a lead removal device in fluid communication with the at least one electrochemical cell. 16. The electrochemical apparatus of claim 15, wherein the lead removal device contains a material known to bind or adsorb lead ions, particulates or colloidal species.17. The electrochemical apparatus of claim 16, wherein the material is selected from a zeolite, alumina, silica, or mixtures thereof.18. The electrochemical apparatus of claim 16, wherein the material is in powdered or granulated form.19. The electrochemical apparatus of claim 1, wherein the one or more of the first and second electrodes are retracted out of contact with the ion exchange membrane when no voltage is being applied between the first and second electrodes.20. The electrochemical apparatus of claim 1, wherein the means for retracting the one or more electrodes further comprises a guide member to align the electrodes.21. The electrochemical apparatus of claim 1, wherein the means for retracting the electrodes is coupled to the one or more of the first and second electrodes by a positioning rod.22. The electrochemical apparatus of claim 21, further comprising an electrode chamber having a liquid impermeable diaphragm sealing the chamber and moving along with the positioning rod.23. The electrochemical apparatus of claim 1, further comprising:means for positioning the first and second electrodes in contact with the ion exchange membrane. 24. The electrochemical apparatus of claim 23, wherein the first electrode is coupled to the means for positioning and the first electrode has an electrocatalyst formed only on surfaces of the first electrode that are disposed to make contact with the ion exchange membrane.25. The electrochemical apparatus of claim 24, wherein the second electrode is stationary.26. The electrochemical apparatus of claim 25, wherein the ion exchange membrane is secured onto the second electrode.27. The electrochemical apparatus of claim 23, wherein the means for positioning is selected from a hydraulic actuator, a pneumatic actuator, manual mechanical means, piezo-electric means, electric motor means, or combinations thereof.28. The electrochemical apparatus of claim 23, further comprising:a pump for delivering water to the at least one electrochemical cell, wherein the means for positioning is a hydraulic actuator in fluid communication with the water. 29. The electrochemical apparatus of claim 23, wherein the means for positioning provides a compressive force against the ion exchange membrane generally greater than 15 psig.30. The electrochemical apparatus of claim 23, wherein the compressive force is between 5 and 100 psig.31. The electrochemical apparatus of claim 23, wherein the means for retracting overcomes the means for positioning when the power source is off.32. The electrochemical apparatus of claim 23, wherein the means for positioning overcomes the means for retracting when the power source is on.33. The electrochemical apparatus of claim 23, wherein the means for positioning the electrodes further comprises a guide member to align the electrodes.34. The electrochemical apparatus of claim 23, wherein the means for positioning the electrodes is coupled to the one or more of the first and second electrodes by a positioning rod.35. The electrochemical apparatus of claim 34, further comprising an electrode chamber having a liquid impermeable diaphragm sealing the chamber and moving along with the positioning rod.36. The electrochemical apparatus of claim 34, wherein the positioning rod comprises an electronic conductor communicating between a voltage source and the one or more of the first and second electrodes.37. The electrochemical apparatus of claim 23, further comprising a water reservoir in fluid communication with an inlet to the pump and in fluid communication with an outlet from the at least one electrochemical cell.38. The electrochemical apparatus of claim 37, further comprising a recirculation conduit from an outlet of the pump back to the water reservoir.39. The electrochemical apparatus of claim 38, further comprising means for apportioning the amount of water pumped to the at least one electrochemical cell and the amount of water recirculated back to the water reservoir.40. The electrochemical apparatus of claim 23, further comprising an ion exchange bed disposed upstream of the at least one electrochemical cell.41. The electrochemical apparatus of claim 40, further comprising an ozone destruct catalyst upstream of the ion exchange bed.42. The electrochemical apparatus of claim 23, wherein the at least one electrochemical cell is a fuel cell.43. The electrochemical apparatus of claim 1, wherein the ion exchange membrane is a cation exchange membrane.44. An electrochemical apparatus, comprising:an electrochemical cell having first and second electrodes and electrolyte disposed between the first and second electrodes, a power source for applying a voltage between the first and second electrodes, means for selectively positioning one or more of the first and second electrodes into contact with the electrolyte; and means for retracting the one or more of the first and second electrodes out of contact with the electrolyte when the means for selectively positioning is turned off. 45. A method of operating an electrochemical cell having first and second electrodes and electrolyte disposed between the first and second electrodes, comprising:(a) automatically separating one or more of the first and second electrodes from the electrolyte upon one or more standby conditions, wherein the electrolyte is an ion exchange membrane. 46. THe method of claim 45, wherein the one or more standby conditions is selected from a voltage os less than one Volt being applied between the first and second electrodes, expiration of a time period, an ozone concentration greater than a setpoint ozone concentration, contact pressure of less than 10 psig, or combinations thereof.47. The method of claim 45, further comprising:(b) automatically positioning the one or more of the first and second electrodes into contact with the electrolyte upon one or more production conditions. 48. The method of claim 47, wherein the one or more production conditions is selected from a voltage greater than one Volt being applied between the first and second electrodes, expiration of a time period, an ozone concentration less than a setpoint ozone concentration, contact pressure greater than 10 psig, or combinations thereof.49. The method of claim 47, wherein the electrolyte is a polymer electrolyte membrane, and wherein the step of automatically positioning comprises compressing the one or more of the first and second electrodes against the polymer electrolyte membrane with a compressive force between 5 and 100 psig.50. The method of claim 49, wherein the compressive force is between 25 and 70 psig.51. The method of claim 47, further comprising:applying a voltage between the first and second electrodes. 52. The method of claim 51, further comprising:turning on a water pump. 53. THe method of claim 52, further comprising:automatically positioning the one or more of the first and second electrodes into contact with the electrolyte upon one or more production conditions. 54. At least one electrochemical coil including a cathode electrode, an anode electrode, an acidic electrolyte disposed between the anode electrode and the cathode electrode, and a power source for applying a voltage between the anode electrode and the cathode electrode, characterized in that the anode electrode has a layer of lead dioxide electrocatalyst facing the acidic electrolyte, a retractor mechanism being provided which is responsive to one or more predetermined standby conditions to retract the anode electrode from an initial position in which the lead dioxide electrocatalyst is in contact with the electrolyte to a retracted position in which the lead dioxide electrocatalyst is spaced from the electrolyte.55. The at least one electrochemical cell of claim 54 wherein the retractor mechanism is a passive retraction mechanism.56. The at least one electrochemical cell of claim 54 wherein the lead dioxide electrocatalyst is β-lead dioxide, α-lead dioxide, or a combination thereof.57. The at least one electrochemical cell of claim 54 wherein the acidic electrolyte is a proton exchange membrane.58. The at least one electrochemical cell of claim 57, wherein the one or more standby conditions includes a contact pressure of less than 10 psig of the anode electrode with the proton exchange membrane.59. The at least one electrochemical cell of claim 57 further comprising an actuator for moving the anode electrode from the retracted position back to the initial position in response to one or more production conditions including a contact pressure of greater than 10 psig of the anode electrode with the electrolyte.60. The at least one electrochemical cell of claim 54 wherein the acidic electrolyte is an aqueous solution of a dissolved inorganic acid, a dissolved organic acid, or a mixture thereof.61. The at least one electrochemical cell of claim 54, wherein the one or more standby conditions are selected from:a voltage of less than one volt being applied between the first and second electrodes, the expiration of a time period of operation of the cell, an ozone concentration greater than a set point ozone concentration within the cell, no anodic oxygen/ozone evolution reactions occurring, and no current flowing through the cell. 62. The at least one electrochemical cell of claim 54 further comprising an actuator for moving the anode electrode from the retracted position back to the initial position in response to one or more production conditions.63. The at least one electrochemical cell of claim 62 wherein the one or more production conditions are selected from:a voltage greater than one volt being applied between the first and second electrodes, the expiration of a time period from termination of operation of the cell, and an ozone concentration less than a set point ozone concentration within the cell. 64. The at least one electrochemical cell of claim 62 wherein the retractor mechanism and the actuator are constituted by a passive device biasing the anode electrode away from the electrolyte and an active mechanism which, in operation, overcomes the biasing effect of the passive device to move the anode electrode into contact with the electrolyte.65. The at least one electrochemical cell of claim 64 wherein the active mechanism receives power from the power source so that when the power source is connected to apply a voltage between the anode electrode and the cathode electrode the power source provides power to the active mechanism.66. The at least one electrochemical cell of claim 54 wherein the lead dioxide electrocatalyst retains its β-lead dioxide crystalline form.67. The at least one electrochemical cell of claim 66 further comprising an actuator for moving the anode electrode from the retracted position back to the initial position in response to one or more production conditions, wherein the acidic electrolyte is a proton exchange membrane, and wherein the one or mare production conditions includes a contact pressure of greater than 10 psig of the anode electrode with the proton exchange membrane.68. At least one electrochemical cell including a cathode electrode, an anode electrode, an acidic electrolyte disposed between the anode electrode and the cathode electrode, and a power source for applying a voltage between the anode electrode and the cathode electrode, characterized in that the apparatus further comprises a mechanism to retract the anode electrode out of contact with the electrolyte in response to the absence of a current flowing through the electrochemical cell.69. At least one electrochemical cell including a cathode electrode, an anode electrode, and an acidic electrolyte disposed between the anode electrode and the cathode electrode, and a power source for applying a voltage between the anode electrode and the cathode electrode, characterized in that the apparatus further comprises a passive mechanism biasing the anode electrode away from the electrolyte and an active mechanism which, when operative, overcomes the biasing effect of the passive mechanism to bring the anode electrode into contact with the electrolyte.70. The at least one electrochemical cell of claim 69 wherein the active mechanism is adapted to be actuated when the power source is connected to apply the voltage between the electrodes.71. The at least one electrochemical cell of claim 69, wherein the active mechanism is selected from electrical, hydraulic, pneumatic, piezoelectric, and combinations thereof.72. The at least one electrochemical cell of claim 69, wherein the passive means is selected from a spring, gravity, hydraulic accumulator, pneumatic accumulator, and combinations thereof.73. At least one electrochemical cell including a cathode electrode, an anode electrode, an acidic electrolyte disposed between the anode electrode and the cathode electrode, and a power source for applying a voltage between the anode electrode and the cathode electrode, characterized in that the apparatus further comprises a mechanism to retract the anode electrode out of contact with the electrolyte to interrupt a circuit incorporating the at least one electrochemical cell, thereby placing the at least one electrochemical cell in a standby condition.74. The at least one electrochemical cell of claim 73, wherein the electrolyte is an ion exchange membrane.75. The at least one electrochemical cell of claim 74, wherein the at least one electrochemical cell is a fuel cell.76. The at least one electrochemical cell of claim 74, wherein the ion exchange membrane is a cation exchange membrane.77. The at least one electrochemical cell of claim 73, wherein the mechanism to retract the anode is selected from a hydraulic actuator, a pneumatic actuator, manual mechanical means, piezo-electric means, electric motor means, or combinations thereof.78. An electrochemical apparatus, comprising:at least one electrochemical cell having first and second electrodes and electrolyte disposed between the first and second electrodes, wherein the one or more of the first and second electrodes includes material that is unstable or deactivates in the presence of the electrolyte without applying a voltage, a power source for applying a voltage between the first and second electrodes, and means for automatically retracting one or more of the first and second electrodes out of contact with the electrolyte. 79. The electrochemical apparatus of claim 78, wherein the means for automatically retracting is passive.80. The electrochemical apparatus of claim 79, wherein the passive means for automatically retracting is a stored energy device.81. The electrochemical apparatus of claim 80, wherein the stored energy device is selected from a spring, gravity, hydraulic accumulator, pneumatic accumulator, or combinations thereof.82. The electrochemical apparatus of claim 78, wherein the electrolyte is an ion exchange membrane.83. The electrochemical apparatus of claim 82, wherein the ion exchange membrane is a cation exchange membrane.84. The electrochemical apparatus of claim 78, wherein the material is lead dioxide.85. The electrochemical apparatus of claim 84, characterized in that the lead dioxide maintains its activity during repetitive cycling of the power source.86. The electrochemical apparatus of claim 78, further comprising:a pump for delivering water to the at least one electrochemical cell, wherein the means for retracting is a hydraulic actuator in fluid communication with the water. 87. The electrochemical apparatus of claim 86, further comprising means for introducing ozone into a separate system.88. The electrochemical apparatus of claim 87, wherein the ozone comprises dissolved ozone in water, an ozone/oxygen gas stream, or combinations thereof.89. The electrochemical apparatus of claim 78, wherein the electrolyte and one of the electrodes are stationary.90. The electrochemical apparatus of claim 89, wherein the electrolyte is an ion exchange membrane.91. The electrochemical apparatus of claim 90, wherein the stationary electrode is a cathode.92. The electrochemical apparatus of claim 78, wherein the at least one electrochemical is a plurality of electrochemical cells.93. The electrochemical apparatus of claim 92, wherein the plurality of electrochemical cells form a stack of electrochemical cells.94. The electrochemical apparatus of claim 78, further comprising:a lead-containing catalyst disposed on one or more of the first and second electrodes; and a lead removal device in fluid communication with the at least one electrochemical cell. 95. The electrochemical apparatus of claim 94, wherein the lead removal device contains a material known to bind or adsorb lead ions, particulates or colloidal species.96. The electrochemical apparatus of claim 95, wherein the material is selected from a zeolite, alumina, silica, or mixtures thereof.97. The electrochemical apparatus of claim 78, wherein the one or more of the first and second electrodes are retracted out of contact with the electrolyte when no voltage is being applied between the first and second electrodes.98. The electrochemical apparatus of claim 78, wherein the means for retracting the one or more electrodes further comprises a guide member to align the electrodes.99. The electrochemical apparatus of claim 78, wherein the means for retracting the electrodes is coupled to the one or more of the first and second electrodes by a positioning rod.100. The electrochemical apparatus of claim 99, further comprising an electrode chamber having a liquid impermeable diaphragm sealing the chamber and moving along with the positioning rod.101. The electrochemical apparatus of claim 78, further comprising:means for positioning the first and second electrodes in contact with the electrolyte. 102. The electrochemical apparatus of claim 101, wherein the electrolyte is an ion exchange membrane, and wherein the first electrode is coupled to the means for positioning and the first electrode has an electrocatalyst formed only on surfaces of the first electrode that are disposed to make contact with the ion exchange membrane.103. The electrochemical apparatus of claim 101, wherein the second electrode is stationary.104. The electrochemical apparatus of claim 103, wherein the ion exchange membrane is secured onto the second electrode.105. The electrochemical apparatus of claim 101, wherein the means for positioning is selected from a hydraulic actuator, a pneumatic actuator, manual mechanical means, piezo-electric means, electric motor means, or combinations thereof.106. The electrochemical apparatus of claim 101, further comprising:a pump for delivering water to the at least one electrochemical cell, wherein the means for positioning is a hydraulic actuator in fluid communication with the water. 107. The electrochemical apparatus of claim 101, wherein the means for positioning provides a compressive force against the ion exchange membrane generally greater than 15 psig.108. The electrochemical apparatus of claim 101, wherein the compressive force is between 5 and 10 psig.109. The electrochemical apparatus of claim 101, wherein the means for retracting overcomes the means for positioning when the power source is off.110. The electrochemical apparatus of claim 101, wherein the means for positioning overcomes the means for retracting when the power source is on.111. The electrochemical apparatus of claim 101, wherein the means for positioning the electrodes further comprises a guide member to align the electrodes.112. The electrochemical apparatus of claim 101, wherein the means for positioning the electrodes is coupled to the one or more of the first and second electrodes by a positioning rod.113. The electrochemical apparatus of claim 112, further comprising an electrode chamber having a liquid impermeable diaphragm sealing the chamber and moving along with the positioning rod.114. The electrochemical apparatus of claim 112, wherein the positioning rod comprises an electronic conductor communicating between a voltage source and the one or more of the first and second electrodes.115. The electrochemical apparatus of claim 101, further comprising a water reservoir in fluid communication with an inlet to the pump and in fluid communication with an outlet from the at least one electrochemical cell.116. The electrochemical apparatus of claim 115, further comprising a recirculation conduit from an outlet of the pump back to the water reservoir.117. The electrochemical apparatus of claim 116, further comprising means for apportioning the amount of water pumped to the at least one electrochemical cell and the amount of water recirculated back to the water reservoir.118. The electrochemical apparatus of claim 101, further comprising an ion exchange bed disposed upstream of the at least one electrochemical cell.119. The electrochemical apparatus of claim 118, further comprising an ozone destruct catalyst upstream of the ion exchange bed.120. The electrochemical apparatus of claim 101, wherein the at least one electrochemical cell is a fuel cell.121. An electrochemical apparatus, comprising:at least one electrochemical cell having first and second electrodes and electrolyte disposed between the first and second electrodes, a power source for applying a voltage between the first and second electrodes, a pump for delivering water to the at least one electrochemical cell, and means for automatically retracting one or more of the first and second electrodes out of contact with the electrolyte, and a hydraulic actuator in fluid communication with the water for positioning the one or more electrodes in contact with the electrolyte. 122. The electrochemical apparatus of claim 121, wherein the means for automatically retracting is passive.123. The electrochemical apparatus of claim 122, wherein the passive means for automatically retracting is a stored energy device.124. The electrochemical apparatus of claim 123, wherein the stored energy device is selected from a spring, gravity, hydraulic accumulator, pneumatic accumulator, or combinations thereof.125. The electrochemical apparatus of claim 121, wherein the electrolyte is an ion exchange membrane.126. The electrochemical apparatus of claim 125, wherein the ion exchange membrane is a cation exchange membrane.127. The electrochemical apparatus of claim 121, wherein the one or more of the first and second electrodes includes material that is unstable or deactivates in the presence of the electrolyte without applying a voltage.128. The electrochemical apparatus of claim 127, wherein the material is lead dioxide.129. The electrochemical apparatus of claim 128, characterized in that the lead dioxide maintains its activity during repetitive cycling of the power source.130. The electrochemical apparatus of claim 121, wherein the electrolyte and one of the electrodes are stationary.131. The electrochemical apparatus of claim 130, wherein the electrolyte is an ion exchange membrane.132. The electrochemical apparatus of claim 131, wherein the stationary electrode is a cathode.133. The electrochemical apparatus of claim 121, wherein the at least one electrochemical cell is a plurality of electrochemical cells.134. The electrochemical apparatus of claim 133, wherein the plurality of electrochemical cells forms a stack.135. The electrochemical apparatus of claim 121, wherein the one or more of the first and second electrodes are retracted out of contact with the electrolyte when no voltage is being applied between the first and second electrodes.136. The electrochemical apparatus of claim 121, wherein the means for retracting the one or more electrodes further comprises a guide member to align the electrodes.137. The electrochemical apparatus of claim 121, wherein the means for retracting the electrodes is coupled to the one or more of the first and second electrodes by a positioning rod.138. The electrochemical apparatus of claim 137, further comprising an electrode chamber having a liquid impermeable diaphragm sealing the chamber and moving along with the positioning rod.139. The electrochemical apparatus of claim 121, further comprising means for introducing ozone into a separate system.140. The electrochemical apparatus of claim 139, wherein the ozone comprises dissolved ozone in water, an ozone/oxygen gas stream, or combinations thereof.141. The electrochemical apparatus of claim 121, further comprising:means for positioning the first and second electrodes in contact with the electrolyte. 142. The electrochemical apparatus of claim 141, wherein the electrolyte is an ion exchange membrane, and wherein the first electrode is coupled to the means for positioning and the first electrode has an electrocatalyst formed only on surfaces of the first electrode that are disposed to make contact with the ion exchange membrane.143. The electrochemical apparatus of claim 142, wherein the second electrode is stationary.144. The electrochemical apparatus of claim 143, wherein the ion exchange membrane is secured onto the second electrode.145. The electrochemical apparatus of claim 141, wherein the means for positioning is selected from a hydraulic actuator, a pneumatic actuator, manual mechanical means, piezo-electric means, electric motor means, or combinations thereof.146. The electrochemical apparatus of claim 141, wherein the means for positioning provides a compressive force against the ion exchange membrane generally greater than 15 psig.147. The electrochemical apparatus of claim 141, wherein the compressive force is between 5 and 100 psig.148. The electrochemical apparatus of claim 141, wherein the means for retracting overcomes the means for positioning when the power source is off.149. The electrochemical apparatus of claim 141, wherein the means for positioning overcomes the means for retracting when the power source is on.150. The electrochemical apparatus of claim 141, wherein the means for positioning the electrodes further comprises a guide member to align the electrodes.151. The electrochemical apparatus of claim 141, wherein the means for positioning the electrodes is coupled to the one or more of the first and second electrodes by a positioning rod.152. The electrochemical apparatus of claim 151, further comprising an electrode chamber having a liquid impermeable diaphragm sealing the chamber and moving along with the positioning rod.153. The electrochemical apparatus of claim 151, wherein the positioning rod comprises an electronic conductor communicating between a voltage source and the one or more of the first and second electrodes.154. The electrochemical apparatus of claim 141, further comprising a water reservoir in fluid communication with an inlet to the pump and in fluid communication with an outlet from the at least one electrochemical cell.155. The electrochemical apparatus of claim 154, further comprising a recirculation conduit from an outlet of the pump back to the water reservoir.156. The electrochemical apparatus of claim 155, further comprising means for apportioning the amount of water pumped to the at least one electrochemical cell and the amount of water recirculated back to the water reservoir.157. The electrochemical apparatus of claim 141, wherein the at least one electrochemical cell is a fuel cell.158. An electrochemical apparatus, comprising:a plurality of electrochemical cells, each electrochemical cell having first and second electrodes and electrolyte disposed between the first and second electrodes, a power source for applying a voltage between the first and second electrodes, and means for automatically retracting one or more of the first and second electrodes out of contact with the electrolyte. 159. The electrochemical apparatus of claim 158, wherein the means for automatically retracting is passive.160. The electrochemical apparatus of claim 159, wherein the passive means for automatically retracting is a stored energy device.161. The electrochemical apparatus of claim 160, wherein the stored energy device is selected from a spring, gravity, hydraulic accumulator, pneumatic accumulator, or combinations thereof.162. The electrochemical apparatus of claim 158, wherein the one or more of the first and second electrodes includes material that is unstable or deactivates in the presence of the electrolyte without applying a voltage.163. The electrochemical apparatus of claim 162, wherein the material is lead dioxide.164. The electrochemical apparatus of claim 163, characterized in that the lead dioxide maintains its activity during repetitive cycling of the power source.165. The electrochemical apparatus of claim 158, wherein the electrolyte and one of the electrodes are stationary.166. The electrochemical apparatus of claim 165, wherein the electrolyte is an ion exchange membrane.167. The electrochemical apparatus of claim 166, wherein the stationary electrode is a cathode.168. The electrochemical apparatus of claim 166, wherein the ion exchange membrane is a cation exchange membrane.169. The electrochemical apparatus of claim 158, wherein the one or more of the first and second electrodes are retracted out of contact with the electrolyte when no voltage is being applied between the first and second electrodes.170. The electrochemical apparatus of claim 158, wherein the means for retracting the one or more electrodes further comprises a guide member to align the electrodes.171. The electrochemical apparatus of claim 158, wherein the means for retracting the electrodes is coupled to the one or more of the first and second electrodes by a positioning rod.172. The electrochemical apparatus of claim 171, further comprising an electrode chamber having a liquid impermeable diaphragm scaling the chamber and moving along with the positioning rod.173. The electrochemical apparatus of claim 158, further comprising:means for positioning the first and second electrodes in contact with the electrolyte. 174. The electrochemical apparatus of claim 173, wherein the electrolyte is an ion exchange membrane, and wherein the first electrode is coupled to the means for positioning and the first electrode has an electrocatalyst formed only on surfaces of the first electrode that are disposed to make contact with the ion exchange membrane.175. The electrochemical apparatus of claim 174, wherein the second electrode is stationary.176. The electrochemical apparatus of claim 174, wherein the ion exchange membrane is secured onto the second electrode.177. The electrochemical apparatus of claim 173, wherein the means for positioning is selected form a hydraulic actuator, a pneumatic actuator, manual mechanical means, piezo-electric means, electric motor means, or combinations thereof.178. The electrochemical apparatus of claim 173, further comprising:a pump for delivering water to the at least one electrochemical cell, wherein the means for positioning is a hydraulic actuator in fluid communication with the water. 179. The electrochemical apparatus of claim 173, wherein the means for positioning provides a compressive force against the ion exchange membrane generally greater than 15 psig.180. The electrochemical apparatus of claim 173, wherein the compressive force is between 5 and 100 psig.181. The electrochemical apparatus of claim 173, wherein the means for retracting overcomes the means for positioning when the power source is off.182. The electrochemical apparatus of claim 173, wherein the means for positioning overcomes the means for retracting when the power source is on.183. The electrochemical apparatus of claim 173, wherein the means for positioning the electrodes further comprises a guide member to align the electrodes.184. The electrochemical apparatus of claim 173, wherein the means for positioning the electrodes is coupled to the one or more of the first and second electrodes by a positioning rod.185. The electrochemical apparatus of claim 184, further comprising an electrode chamber having a liquid impermeable diaphragm sealing the chamber and moving along with the positioning rod.186. The electrochemical apparatus of claim 184, wherein the positioning rod comprises an electronic conductor communicating between a voltage source and the one or more of the first and second electrodes.187. The electrochemical apparatus of claim 173, further comprising a water reservoir in fluid communication with an inlet to the pump and in fluid communication with an outlet from the at least one electrochemical cell.188. The electrochemical apparatus of claim 187, further comprising a recirculation conduit from an outlet of the pump back to the water reservoir.189. The electrochemical apparatus of claim 188, further comprising means for apportioning the amount of water pumped to the at least one electrochemical cell and the amount of water recirculated back to the water reservoir.190. The electrochemical apparatus of claim 173, wherein the at least one electrochemical cell is a fuel cell.191. The electrochemical apparatus of claim 158, wherein the plurality of electrochemical cells form a stack of electrochemical cells.
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