Abstract: According to one embodiment of the present invention, the method for controlling the pump speed of a redox flow battery for transferring an electrolyte stored in an electrolyte tank to a cell stack comprises the steps of: measuring the input power and/or the output power of the redox flow battery; measuring the charging power and/or the discharging power of the redox flow battery; calculating the power loss of the redox flow battery by using the difference between the input power and the charging power, or the difference between the output power and the discharging power; and adjusting the pump speed according to the power loss.

Abstract: The present invention relates to a redox flow battery, and more particularly, to a redox flow battery which is charged and discharged by supplying a positive electrolyte and a negative electrolyte to a battery cell using an active material containing vanadium and a cation exchange membrane, in which the positive electrolyte and the negative electrolyte contain vanadium ions as active ions, the difference in volume between the positive electrolyte and the negative electrolyte is maintained at 10% or less, and the total concentration of anions in the negative electrolyte is higher than the total concentration of anions in the positive electrolyte, whereby the transfer of water in the battery is controlled and a change in the volume of the electrolytes is minimized.

Abstract: According to one embodiment of the present invention, the method for controlling the pump speed of a redox flow battery for transferring an electrolyte stored in an electrolyte tank to a cell stack comprises the steps of: measuring the input power and/or the output power of the redox flow battery; measuring the charging power and/or the discharging power of the redox flow battery; calculating the power loss of the redox flow battery by using the difference between the input power and the charging power, or the difference between the output power and the discharging power; and adjusting the pump speed according to the power loss.

Abstract: A method for measuring an electrolyte balance of a redox flow battery may include: charging the redox flow battery by applying a current to a stack; measuring temperatures of an anode electrolyte solution and a cathode electrolyte solution while the redox flow battery is charged; calculating a temperature change rate of the anode electrolyte solution over time and a temperature change rate of the cathode electrolyte solution over time; deciding a first change time corresponding to an inflection point of the temperature change rate of the anode electrolyte solution over time and a second change time corresponding to an inflection point of the temperature change rate of the cathode electrolyte solution over time; and calculating an average electrolyte oxidation number of the redox flow battery, using the first change time, the second change time, an oxidation number of the anode electrolyte and an oxidation number of the cathode electrolyte.

Abstract: The present invention relates to a redox flow battery, and more particularly, to a redox flow battery which is charged and discharged by supplying a positive electrolyte and a negative electrolyte to a battery cell using an active material containing vanadium and a cation exchange membrane, in which the positive electrolyte and the negative electrolyte contain vanadium ions as active ions, the difference in volume between the positive electrolyte and the negative electrolyte is maintained at 10% or less, and the total concentration of anions in the negative electrolyte is higher than the total concentration of anions in the positive electrolyte, whereby the transfer of water in the battery is controlled and a change in the volume of the electrolytes is minimized.

Abstract: A method and apparatus for controlling operation of a redox flow battery. The method of controlling operation of a redox flow battery includes obtaining a diffusivity of anolyte ions with respect to a separator, obtaining a diffusivity of catholyte ions with respect to the separator, determining electrolyte diffusivities depending upon a state of charge value of the redox flow battery based on the diffusivity of the anolyte ions and the diffusivity of the catholyte ions, determining a minimum state of charge value and a maximum state of charge value of the redox flow battery based on the electrolyte diffusivities, and setting operating conditions of the redox flow battery based on the minimum state of charge value and the maximum state of charge value. The method and apparatus for controlling operation of a redox flow battery can prevent reduction in capacity of the redox flow battery.

Abstract: A system for evaluating a redox flow battery according to an embodiment of the present disclosure includes: a control unit configured to control the path of a flow channel connected between a detection cell and the redox flow battery or a flow channel connected between the detection cell and an agitator; and an evaluation unit configured to evaluate any one of the state of charge, capacity fade and oxidation number balance of an electrolyte, which is used in the redox flow battery, by measuring a current or voltage of the detection cell based on the controlling of the path by the control unit. According to the present disclosure, the capacity fade problem of a redox flow battery can be quickly coped with by evaluating the information of the positive and negative electrode electrolytes on battery capacity fade and information about the valence balance of the electrolytes in situ.

Abstract: A method and apparatus for controlling operation of a redox flow battery. The method of controlling operation of a redox flow battery includes obtaining a diffusivity of anolyte ions with respect to a separator, obtaining a diffusivity of catholyte ions with respect to the separator, determining electrolyte diffusivities depending upon a state of charge value of the redox flow battery based on the diffusivity of the anolyte ions and the diffusivity of the catholyte ions, determining a minimum state of charge value and a maximum state of charge value of the redox flow battery based on the electrolyte diffusivities, and setting operating conditions of the redox flow battery based on the minimum state of charge value and the maximum state of charge value. The method and apparatus for controlling operation of a redox flow battery can prevent reduction in capacity of the redox flow battery.

Abstract: Disclosed are a method and apparatus for analyzing an electrolyte of a redox flow battery. The method includes passing a first electrolyte solution or a second electrolyte solution through each of a first auxiliary cell and a second auxiliary cell connected to a main cell and a storage tank, closing at least one of the first auxiliary cell and the second auxiliary cell, applying current to the first auxiliary cell and the second auxiliary cell; creating data by measuring a voltage between the first auxiliary cell and the second auxiliary cell, and analyzing an electrolyte contained in the electrolyte solution in the first auxiliary cell or the second auxiliary cell based on variation in the voltage between the first auxiliary cell and the second auxiliary cell according to time. According to the present invention, information on an electrolyte can be obtained more efficiently and easily.