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:
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:
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.
Abstract:
Disclosed herein is a redox flow battery, and more particularly, a cell frame channel design capable of efficiently distributing an electrolyte.The present invention provides a cell frame of a redox flow battery providing an electrolyte to an electrode, the cell frame of a redox flow battery including: an electrolyte inlet part and an electrolyte outlet part disposed at both side surfaces of the electrode, respectively; a distribution channel connected to the electrolyte inlet part and dividing the electrolyte into a plurality of channels; a buffer channel formed in a shape in which the buffer channel is connected to an end of each distribution channel and a channel width thereof is increased toward the electrode; a mixing zone formed between the buffer channel and the electrode to mix electrolytes flowed from the buffer channels with each other.
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:
Disclosed is a carbon structure electrode for redox flow batteries, which includes a plurality of spherical macropores formed on a surface of a polymer-derived carbon structure and inside the polymer-derived carbon structure so as to allow electrolyte migration. The carbon structure electrode for redox flow batteries has excellent electrical conductivity and enables cost reduction through a simplified preparation process.
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:
Disclosed are a redox flow battery system and a control method for the same. In the redox flow battery system, an oxidation number is controlled by injecting at least one of an oxidant and a reducer into at least one of a cathode side and an anode side using a measured oxidation number of the electrolyte. Therefore, even though an oxidation number balance is inevitably broken, since an initial concentration of vanadium ion, that is, an average oxidation number is maintained without a large change in the concentration, efficiency and stability of a battery may be promoted, and the oxidation number balance may be monitored in real time and the oxidation number balance may be recovered without a separate process of separating electrolytes to entirely mixing the electrolytes, or the like, that is, without stopping a function of the battery, thereby facilitating maintenance and control of performance of the battery.
Abstract:
The present invention relates to a redox flow battery and, more specifically, to a redox flow battery comprising an anolyte, a catholyte, and an ion exchange membrane, wherein the anolyte and the catholyte respectively comprise an electrolyte containing a Cl− ion and an active material containing a vanadium ion, and the electrolyte comprises at least one side reaction inhibitor selected from the group consisting of a metal phosphate, a metal hydrochloride and a metal sulfate.
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.