FUEL SYSTEM USING REDOX FLOW BATTERY

• US 20100323264A1
• Filed: 04/06/2010
• Published: 12/23/2010
• Est. Priority Date: 04/06/2009
• Status: Active Grant

• Current Assignee: 24M Technologies, Inc.
• Original Assignee: A123 Systems Incorporated
• Inventors: Bazzarella, Ricardo, Chiang, Yet-Ming
• Granted Patent: US 8,778,552 B2
• Time in Patent Office: Days
• US Class Current: 429/449
• CPC Class Codes: B60L 50/64 Constructional details of batteries specially adapted for electric vehicles
• CPC Class Codes: B60L 53/14 Conductive energy transfer
• CPC Class Codes: B60L 53/80 Exchanging energy storage elements, e.g. removable batteries
• CPC Class Codes: B60L 58/26 by cooling
• CPC Class Codes: H01M 2004/8694 Bipolar electrodes
• CPC Class Codes: H01M 2250/20 Fuel cells in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H01M 2250/30 Fuel cells in portable systems, e.g. mobile phone, laptop
• CPC Class Codes: H01M 4/8626 characterised by the form
• CPC Class Codes: H01M 4/8631 Bipolar electrodes
• CPC Class Codes: H01M 4/94 Non-porous diffusion electrodes, e.g. palladium membranes, ion exchange membranes
• CPC Class Codes: H01M 8/04208 Cartridges, cryogenic media or cryogenic reservoirs
• CPC Class Codes: H01M 8/0432 Temperature; Ambient temperature
• CPC Class Codes: H01M 8/0438 Pressure; Ambient pressure; Flow
• CPC Class Codes: H01M 8/04604 Power, energy, capacity or load
• CPC Class Codes: H01M 8/04626 of auxiliary devices, e.g. batteries, capacitors
• CPC Class Codes: H01M 8/04753 of fuel cell reactants
• CPC Class Codes: H01M 8/188 by recharging of redox couples containing fluids; Redox flow type batteries
• CPC Class Codes: H01M 8/20 Indirect fuel cells, e.g. fuel cells with redox couple being irreversible H01M8/18 takes precedence
• CPC Class Codes: H01M 8/225 Fuel cells in which the fuel is based on materials comprising particulate active material in the form of a suspension, a dispersion, a fluidised bed or a paste
• CPC Class Codes: Y02B 90/10 Applications of fuel cells in buildings
• CPC Class Codes: Y02E 60/50 : Fuel cells
• CPC Class Codes: Y02P 70/50 : Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 90/12 : Electric charging stations
• CPC Class Codes: Y02T 90/14 : Plug-in electric vehicles
• CPC Class Codes: Y02T 90/40 : Application of hydrogen technology to transportation, e.g. using fuel cells

Abstract

An automotive or other power system including a flow cell, in which the stack that provides power is readily isolated from the storage vessels holding the cathode slurry and anode slurry (alternatively called “fuel”) is described. A method of use is also provided, in which the “fuel” tanks are removable and are separately charged in a charging station, and the charged fuel, plus tanks, are placed back in the vehicle or other power system, allowing fast refueling. The technology also provides a charging system in which discharged fuel is charged. The charged fuel can be placed into storage tanks at the power source or returned to the vehicle. In some embodiments, the charged fuel in the storage tanks can be used at a later date. The charged fuel can be transported or stored for use in a different place or time.

Claims

1. A method of operating a portable device comprising a power system housed within the device, comprising:

providing a plurality of flow cells, each flow cell comprising;

a positive electrode current collector,

a negative electrode current collector,

an ion-permeable membrane separating said positive and negative current collectors;

wherein said positive electrode current collector and said ion-permeable membrane define a positive electroactive zone for accommodating a positive electroactive material;

wherein said negative electrode current collector and said ion-permeable membrane define a negative electroactive zone for accommodating a negative electroactive material;

wherein at least one of said positive and negative electroactive materials comprises a flowable redox composition in said electroactive zone;

at least one dispensing vessel for dispensing a flowable redox composition into one of the positive or negative electroactive zone;

wherein said dispensing vessel is connected with said plurality of flow cells and in fluidic communication with said electroactive zone and the dispensing vessel is capable of being connected and disconnected from said flow cell; and

at least one receiving vessel for receiving flowable redox composition from one of the positive or negative electroactive zone, wherein said receiving vessel is connected with said flow cell and in fluidic communication with said electroactive zone and the receiving vessel is capable of being connected and disconnected from said flow cell;

introducing said flowable redox composition from said dispensing vessel into at least one of the electroactive zones to cause the flow cell to discharge to provide electric energy to operate the device; and

receiving the discharged redox composition in the receiving vessel.

2. The method of claim 1, further comprising refueling said power system by replacing said dispensing vessel with a new dispensing vessel containing fresh flowable redox composition.

3. The method of claim 1, further comprising replacing said receiving vessel with a new empty receiving vessel.

4. The method of claim 1, wherein said portable device is a vehicle.

5. The method of claim 1, wherein said portable device is a portable power generator.

6. The method of claim 5, wherein said vehicle is a land, air, or water vehicle.

7. The method of claim 1, wherein said redox composition comprises a flowable semi-solid or condensed liquid ion-storing redox composition capable of taking up and releasing said ions during operation of the cell.

8. The method of claim 7, further comprising refueling said power system by replacing said dispensing vessel containing said redox composition with a new dispensing vessel containing a fresh flowable redox composition.

9. The method of claim 8, wherein said fresh redox composition has at least one different characteristic from said redox composition.

10. The method of claim 9, wherein said fresh redox composition and said redox composition has different power densities.

11. The method of claim 9, wherein said fresh redox composition and said redox composition has different energy densities.

12. The method of claim 9, wherein said fresh redox composition and said redox composition has different semi-solid particle sizes.

13. The method of claim 9, wherein said fresh redox composition and said redox composition has different electroactive material concentrations.

14. The method of claim 9, wherein said fresh redox composition has smaller semi-solid particle size and higher power density than said redox composition.

15. The method of claim 9, wherein said fresh redox composition has higher electroactive material concentration and higher energy density than said redox composition.

16. The method of claim 1, wherein the dispensing vessel and receiving vessel form a unitary body.

17. The method of claim 1, wherein said plurality of flow cells form a stack of flow cells, and said dispensing and receiving vessels are reversibly connected with the flow cell stack.

18. The method of claim 17, wherein said flow cells are connected in parallel.

19. The method of claim 17, wherein said flow cells are connected in series.

20. The method of claim 17, further comprising providing a pump disposed between one or both of said dispensing and receiving vessels and said flow cell stack.

21. The method of claim 17, wherein said pump is a reversible flow pump that is operable for flow in both directions.

22. The method of claim 1, wherein the dispensing or receiving vessels comprise a flexible bladder.

23. The method of claim 17, further comprising valves positioned at the entrance of each fuel cell to control the flow of redox composition into the respective flow cell and minimize shunt current between adjacent flow cells.

24. The method of claim 17, further comprising providing a multiport injection system configured and arranged to control the amount of redox composition delivered to each electroactive zone of each flow cell.

25. The method of claim 24, wherein the multiport injection system comprises a plurality of compartments, each compartment in flow communication with a subset of the flow cells in the flow cell stack and injectors for introducing redox composition into each compartment.

26. The method of claim 25, wherein pressure in the plurality of compartment is greater than the pressure in the electroactive zone pressure.

27. The method of claim 17, further comprising a cooling system for circulating a coolant in said flow cell stack.

28. The method of claim 1, further comprising providing a monitoring meter connected to one or both of the dispensing and receiving vessels for monitoring the volume or content of the redox composition in one or both of the dispensing or receiving vessel.

29. The method of claim 1, further comprising replenishing the dispensing vessel with fresh redox composition.

30. The method of claim 29, wherein replenishing the dispensing vessel comprises introducing new redox composition into the dispensing vessel.

31. The method of claim 1, further comprising removing the discharged redox composition from the receiving vessel.

32. The method of claim 31, wherein removing the discharged redox composition from the receiving vessel comprises emptying the receiving vessel of discharged redox composition.

33. The method of claim 1, wherein the dispensing and receiving vessel form a unitary body, said unitary body having a movable membrane between said receiving and dispensing compartments and the method further comprises replacing said unitary body with a new unitary body comprising a power storage vessel containing fresh flowable semi-solid or condensed liquid ion-storing redox compositions and an empty spent redox composition storage vessel.

34. The method of claim 1, further comprising monitoring the levels of said flowable redox compositions in said dispensing or receiving vessels.

35. The method of claim 1, further comprising

reversing the direction of flow of the redox composition so that the spent redox composition flows from said receiving vessel to said electroactive zone;

and

applying a reverse voltage to said power system to recharge said discharged redox composition.

36. The method of claim 35, further comprising advancing the recharged redox composition from said electroactive zone to said dispensing vessel for storage.

37. The method of claim 35, wherein said flow of the spent redox composition is controlled by a reversible pump.

38. The method of claim 7, wherein the particle size of the flowable semi-solid ion-storing redox composition being discharged is selected to provide a preselected power density.

39. The method of claim 1, wherein the load in wt percent of the flowable semi-solid ion-storing redox composition being discharged is selected to provide a preselected energy capacity of the redox composition.

40. The method of claim 1, further comprising monitoring the condition of the redox composition before during or after discharge.

41. The method of claim 18, wherein the condition monitored comprises the temperature, flow rates, or the relative amounts of the cathode or anode redox compositions.

42. The method of claim 41, further comprising modifying a property of the redox composition based on the results of the monitoring.

43. The method of claim 1, further comprising increasing the flow rate of the redox composition along the electroactive zone to increase the power of the flow cell.

44. The method of claim 7, further comprising reconditioning said flowable semi-solid or condensed liquid ion-storing redox composition.

45. The method of claim 44, wherein said reconditioning comprises

sequesting residual water from the said redox composition;

adding additional salt to improve ion conductivity;

adding solvents or electrolyte additives;

adding additional solid phases including active materials used for ion storage, or conductive additives;

separating solid phases from the liquid electrolyte;

adding coagulation aids;

replacing the liquid electrolyte;

or

any combination thereof.

46. The method of claim 7, wherein at least one of said flow cells comprises:

an electrode comprising a flowable semi-solid or condensed liquid ion-storing redox composition capable of taking up and releasing said ions during operation of the cell; and

a stationary electrode.

47. A method of operating a stationary device comprising a power system housed within the device, comprising:

providing a plurality of flow cells, each flow cell comprising;

a positive electrode current collector,

a negative electrode current collector,

an ion-permeable membrane separating said positive and negative current collectors;

wherein said positive electrode current collector and said ion-permeable membrane define a positive electroactive zone for accommodating a positive electroactive material;

wherein said negative electrode current collector and said ion-permeable membrane define a negative electroactive zone for accommodating a negative electroactive material;

wherein at least one of said positive and negative electroactive materials comprises a flowable redox composition in said electroactive zone;

at least one dispensing vessel for dispensing a flowable redox composition into one of the positive or negative electroactive zone;

wherein said dispensing vessel is connected with said plurality of flow cells and in fluidic communication with said electroactive zone and the vessel is capable of being connected and disconnected from said flow cell; and

at least one receiving vessel for receiving flowable redox composition from one of the positive or negative electroactive zone, wherein said receiving vessel is connected with said flow cell and in fluidic communication with said electroactive zone and the vessel is capable of being connected and disconnected from said flow cell;

introducing said flowable redox composition from said dispensing vessel into at least one of the electroactive zones to cause the flow cell to discharge to provide electric energy to operate the device; and

receiving the discharged redox composition in the receiving vessel.

48. The method of claim 47, further comprising refueling said power system by replacing said dispensing vessel with a new dispensing vessel containing fresh flowable redox composition.

49. The method of claim 47, further comprising replacing said receiving vessel with a new empty receiving vessel.

50. The method of claim 47, wherein said stationary device is a stationary power generator.

51. The method of claim 47, wherein said redox composition comprises a flowable semi-solid or condensed liquid ion-storing redox composition capable of taking up and releasing said ions during operation of the cell.

52. The method of claim 51, further comprising refueling said power system by replacing said dispensing vessel containing said redox composition with a new dispensing vessel containing a fresh flowable redox composition.

53. The method of claim 52, wherein said fresh redox composition has at least one different characteristics from said redox composition.

54. The method of claim 53, wherein said fresh redox composition and said redox composition has different power densities.

55. The method of claim 53, wherein said fresh redox composition and said redox composition has different energy densities.

56. The method of claim 53, wherein said plurality of flow cells form a stack of flow cells, and said dispensing and receiving vessels are reversibly connected with the flow cell stack.

57. The method of claim 47, further comprising providing a monitoring meter connected to one or both of the dispensing and receiving vessels for monitoring the volume or content of the redox composition in one or both of the dispensing or receiving vessel.

58. The method of claim 47, wherein the dispensing and receiving vessel form a unitary body, said unitary body having a movable membrane between said receiving and dispensing compartments and the method further comprises replacing said unitary body with a new unitary body comprising a power storage vessel containing fresh flowable semi-solid or condensed liquid ion-storing redox compositions and an empty spent redox composition storage vessel.

59. The method of claim 47, further comprising

reversing the direction of flow of the redox composition so that the spent redox composition flows from said receiving vessel to said electroactive zone;

and

applying a reverse voltage to said power system to recharge said discharged redox composition.

60. A vehicle comprising a power system housed within the vehicle, wherein said power system comprising:

a plurality of flow cells, each flow cell comprising;

a positive electrode current collector,

a negative electrode current collector,

an ion-permeable membrane separating said positive and negative current collectors;

wherein said positive electrode current collector and said ion-permeable membrane define a positive electroactive zone for accommodating a positive electroactive material;

wherein said negative electrode current collector and said ion-permeable membrane define a negative electroactive zone for accommodating a negative electroactive material;

wherein at least one of said positive and negative electroactive materials comprises a flowable redox composition in said electroactive zone;

at least one dispensing vessel for dispensing a flowable redox composition into one of the positive or negative electroactive zone;

wherein said dispensing vessel is connected with said plurality of flow cells and in fluidic communication with said electroactive zone and the vessel is capable of being connected and disconnected from said flow cell; and

at least one receiving vessel for receiving flowable redox composition from one of the positive or negative electroactive zone, wherein said receiving vessel is connected with said flow cell and in fluidic communication with said electroactive zone and the vessel is capable of being connected and disconnected from said flow cell;

wherein said dispensing vessel and are located to provide access for removal and replacing.

61. The vehicle of claim 60, wherein said power system is capable of being refueled by replacing said dispensing vessel containing said flowable redox composition with a new dispensing vessel containing fresh flowable redox composition.

62. The vehicle of claim 60, wherein said receiving vessel is capable of being replaced with a new empty receiving vessel.

63. The vehicle of claim 60, wherein said redox composition comprises a flowable semi-solid or condensed liquid ion-storing redox composition capable of taking up and releasing said ions during operation of the cell.

64. The vehicle of claim 63, wherein said power system is capable of being refueled by replacing said dispensing vessel containing said flowable redox composition with a new dispensing vessel containing fresh flowable redox composition.

65. The vehicle of claim 64, wherein said fresh redox composition has at least one different characteristic from said redox composition.

66. The vehicle of claim 65, wherein said fresh redox composition and said redox composition has different power densities.

67. The vehicle of claim 65, wherein said fresh redox composition and said redox composition has different energy densities.

68. The vehicle of claim 65, wherein said fresh redox composition and said redox composition has different semi-solid particle sizes.

69. The vehicle of claim 65, wherein said fresh redox composition and said redox composition has different electroactive material concentrations.

70. The vehicle of claim 60, wherein the dispensing vessel and receiving vessel form a unitary body.

71. The vehicle of claim 60, wherein said plurality of flow cells form a stack of flow cells, and said dispensing and receiving vessels are reversibly connected with the flow cell stack.

72. The vehicle of claim 71, wherein said power system further comprising a pump disposed between one or both of said dispensing and receiving vessels and said flow cell stack.

73. The vehicle of claim 72, wherein said pump is a reversible flow pump that is operable for flow in both directions.

74. The vehicle of claim 60, wherein the dispensing and receiving vessels comprise a flexible bladder.

75. The vehicle of claim 71, further comprising valves positioned at the entrance of each fuel cell to control the flow of redox composition into the respective flow cell and minimize shunt current between adjacent fuel cells.

76. The vehicle of claim 75, further comprising a multiport injection system configured and arranged to control the amount of redox composition delivered to each electroactive zone of each flow cell.

77. The vehicle of claim 60, further comprising a monitoring meter connected to one or both of the dispensing and receiving vessels for monitoring the volume or content of the redox composition in one or both of the dispensing or receiving vessel.

78. The vehicle of claim 60, wherein the dispensing and receiving vessel form a unitary body, said unitary body having a movable membrane between said receiving and dispensing compartments and the method further comprises replacing said unitary body with a new unitary body comprising a power storage vessel containing fresh flowable semi-solid or condensed liquid ion-storing redox compositions and an empty spent redox composition storage vessel.

79. A power system, comprising:

a plurality of flow cells, each flow cell comprising;

a positive electrode current collector,

a negative electrode current collector,

an ion-permeable membrane separating said positive and negative current collectors;

wherein said positive electrode current collector and said ion-permeable membrane define a positive electroactive zone for accommodating said positive electrode;

wherein said negative electrode current collector and said ion-permeable membrane define a negative electroactive zone for accommodating said negative electrode;

wherein at least one of said positive and negative electrode comprises a flowable semi-solid or condensed liquid ion-storing redox composition in said electroactive zone which is capable of taking up and releasing said ions during operation of the cell;

at least one dispensing storage vessel for dispensing said flowable semi-solid or condensed liquid ion-storing redox composition into one of the positive or negative electroactive zone;

wherein said dispensing storage vessel is connected with said plurality of flow cells and in fluidic communication with said electroactive zone and the dispensing vessel is capable of being connected and disconnected from said flow cell; and

at least one receiving storage vessel for receiving flowable redox composition from one of the positive or negative electroactive zone, wherein said receiving vessel is connected with said flow cell and in fluidic communication with said electroactive zone and the receiving vessel is capable of being connected and disconnected from said flow cell.

80. The power system of claim 79, wherein said positive electrode comprises a cathode slurry comprising said flowable semi-solid or condensed liquid ion-storing redox compositions and said negative electrode comprises an anode slurry comprising said flowable semi-solid or condensed liquid ion-storing redox compositions and said

81. The power system of claim 79, wherein said power storage vessel and said spent redox composition storage vessel form a unitary body.

82. The power system of claim 79, wherein said plurality of flow cells form a stack of flow cells, wherein each flow cell comprises at least one electrode comprising a flowable semi-solid or condensed liquid ion-storing redox composition which is capable of taking up or releasing said ions during operation of the cell;

and said dispensing and receiving vessels are reversibly connected with the flow cell stack.

83. The power system of claim 82, wherein said flow cells are connected in parallel.

84. The power system of claim 82, wherein said flow cells are connected in series.

85. The power system of claim 79, further comprising a pump disposed between one or both of said dispensing and receiving vessels and said flow cell.

86. The power system of claim 85, wherein said pump is a reversible flow pump.

87. The power system of claim 79, wherein the dispensing and receiving vessels comprise a flexible bladder.

88. The power system of claim 82, further comprising valves positioned at the entrance of each fuel cell to control the flow of redox composition into the respective flow cell and minimize shunt current between adjacent fuel cells.

89. The power system of claim 82, further comprising a multiport injection system configured and arranged to control the amount of redox composition delivered to each electroactive zone of each flow cell.

90. The power system of claim 89, wherein the multiport injection system comprises injectors for introducing redox composition into a compartment supplying redox composition to a sub-portion of the total flow cells.

91. The power system of claim 89, wherein the multiport injection system provides a greater compartment pressure than electroactive zone pressure to minimize shunt current between each flow cell.

92. The power system of claim 79, further comprising a cooling system for circulating a coolant in said flow cell.

93. The power system of claim 79, further comprising a level meter connected to said power storage vessel for monitoring the state of charge of the flowable semi-solid or condensed liquid ion-storing redox composition.

94. A method of operating the power system of claim 79, comprising:

providing power system of claim 79;

introducing said flowable redox composition from said dispensing vessel into at least one of the electroactive zones to cause the flow cell to discharge to provide electric energy to operate the device; and

receiving the discharged redox composition in the receiving vessel.

95. The method of claim 94, further comprising refueling said power system by replacing said dispensing vessel containing said redox composition with a new dispensing vessel containing fresh flowable redox composition.

96. The method of claim 94, further comprising replacing said receiving vessel with a new empty receiving vessel.

97. The method of claim 95, wherein said fresh redox composition has at least one different characteristic from said redox composition.

98. The method of claim 97, wherein said fresh redox composition and said redox composition has different power densities.

99. The method of claim 97, wherein said fresh redox composition and said redox composition has different energy densities.

100. The method of claim 97, wherein said fresh redox composition and said redox composition has different semi-solid particle sizes.

101. The method of claim 97, wherein said fresh redox composition and said redox composition has different electroactive material concentrations.

102. The method of claim 97, wherein said fresh redox composition has smaller semi-solid particle size and higher power density than said redox composition.

103. The method of claim 97, wherein said fresh redox composition has higher electroactive material concentration and higher energy density than said redox composition.

104. The method of claim 94, wherein the dispensing vessel and receiving vessel form a unitary body.

105. The method of claim 94, wherein said plurality of flow cells form a stack of flow cells, and said dispensing and receiving vessels are reversibly connected with the flow cell stack.

106. The method of claim 94, wherein said flow cells are connected in parallel.

107. The method of claim 94, wherein said flow cells are connected in series.

108. The method of claim 94, wherein said power system further comprises a pump disposed between one or both of said dispensing and receiving vessels and said flow cell stack.

109. The method of claim 108, wherein said pump is a reversible flow pump that is operable for flow in both directions.

110. The method of claim 94, wherein the dispensing or receiving vessels comprise a flexible bladder.

111. The method of claim 94, further comprising valves positioned at the entrance of each fuel cell to control the flow of redox composition into the respective flow cell and minimize shunt current between adjacent flow cells.

112. The method of claim 111, further comprising providing a multiport injection system configured and arranged to control the amount of redox composition delivered to each electroactive zone of each flow cell.

113. The method of claim 112, wherein the multiport injection system comprises a plurality of compartments, each compartment in flow communication with a subset of the flow cells in the flow cell stack and injectors for introducing redox composition into each compartment.

114. The method of claim 113, wherein pressure in the plurality of compartment is greater than the pressure in the electroactive zone pressure.

115. The method of claim 108, further comprising a cooling system for circulating a coolant in said flow cell stack.

116. The method of claim 94, further comprising providing a monitoring meter connected to one or both of the dispensing and receiving vessels for monitoring the volume or content of the redox composition in one or both of the dispensing or receiving vessel.

117. The method of claim 94, further comprising replenishing the dispensing vessel with fresh redox composition.

118. The method of claim 117, wherein replenishing the dispensing vessel comprises introducing new redox composition into the dispensing vessel.

119. The method of claim 94, further comprising removing the discharged redox composition from the receiving vessel.

120. The method of claim 119, wherein removing the discharged redox composition from the receiving vessel comprises emptying the receiving vessel of discharged redox composition.

121. The method of claim 94, wherein the dispensing and receiving vessel form a unitary body, said unitary body having a movable membrane between said receiving and dispensing compartments and the method further comprises replacing said unitary body with a new unitary body comprising a power storage vessel containing fresh flowable semi-solid or condensed liquid ion-storing redox compositions and an empty spent redox composition storage vessel.

122. The method of claim 94, further comprising monitoring the levels of said flowable redox compositions in said dispensing or receiving vessels.

123. The method of claim 94, further comprising

reversing the direction of flow of the redox composition so that the spent redox composition flows from said receiving vessel to said electroactive zone;

and

applying a reverse voltage to said power system to recharge said discharged redox composition.

124. The method of claim 123, further comprising advancing the recharged redox composition from said electroactive zone to said dispensing vessel for storage.

125. The method of claim 123, wherein said flow of the spent redox composition is controlled by a reversible pump.

126. The method of claim 94, wherein the particle size of the flowable semi-solid ion-storing redox composition being discharged is selected to provide a preselected power density.

127. The method of claim 94, wherein the load in wt percent of the flowable semi-solid ion-storing redox composition being discharged is selected to provide a preselected energy capacity of the redox composition.

128. The method of claim 94, further comprising monitoring the condition of the redox composition before during or after discharge.

129. The method of claim 128, wherein the condition monitored comprises the temperature, flow rates, or the relative amounts of the cathode or anode redox compositions.

130. The method of claim 128, further comprising modifying a property of the redox composition based on the results of the monitoring.

131. The method of claim 94, further comprising increasing the flow rate of the redox composition along the electroactive zone to increase the power of the flow cell.

132. The method of claim 94, further comprising reconditioning said flowable semi-solid or condensed liquid ion-storing redox composition.

134. The power system of claim 94, wherein at least one of said flow cells comprises:

an electrode comprising a flowable semi-solid or condensed liquid ion-storing redox composition capable of taking up and releasing said ions during operation of the cell; and

a stationary electrode.

133. The method of claim 133, wherein said reconditioning comprises

sequesting residual water from the said redox composition;

adding additional salt to improve ion conductivity;

adding solvents or electrolyte additives;

adding additional solid phases including active materials used for ion storage, or conductive additives;

separating solid phases from the liquid electrolyte;

adding coagulation aids;

replacing the liquid electrolyte;

or

any combination thereof.