Patent ID: 8778552

Claim:
A method of operating a portable device comprising a power system housed within the device, comprising: providing: (a) a plurality of secondary 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; and wherein the flowable redox composition comprises a redox-active solid which is capable of taking up or releasing a working ion of the cell and which remains a solid in all of its oxidation states; or the flowable redox composition comprises a redox-active condensed liquid which is capable of taking up or releasing a working ion of the cell and which remains a condensed liquid in all of its oxidation states; (b) 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 (c) 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; and 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.