Abstract: A flow frame for a redox flow battery includes: a frame body having a plate-like shape and an electrode hole in its center where an electrode is to be disposed; four through holes disposed at corners of the frame body, respectively; a flow channel disposed at a front of the frame body above and below the electrode hole so that two of the through channels diagonal to each other as a pair are connected to each other via the electrode hole; through channels disposed at distal ends of the flow channel to cause electrolyte flows toward a rear of the frame body; and a distribution channel connecting the through channels with the electrode hole at the rear of the frame body. The flow channel has at least one branch point, and a change in cross sectional area of the flow channel before and after the branch point is 10% or less.

Abstract: A flow frame for a redox flow battery includes: a frame body having a plate-like shape and an electrode hole in its center where an electrode is to be disposed; four through holes disposed at corners of the frame body, respectively; a flow channel disposed at a front of the frame body above and below the electrode hole so that two of the through channels diagonal to each other as a pair are connected to each other via the electrode hole; through channels disposed at distal ends of the flow channel to cause electrolyte flows toward a rear of the frame body; and a distribution channel connecting the through channels with the electrode hole at the rear of the frame body. The flow channel has at least one branch point, and a change in cross sectional area of the flow channel before and after the branch point is 10% or less.

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 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: Disclosed herein are a redox flow battery and a cell frame. In a cell frame of a redox flow battery, the cell frame comprising: a pair of unit frames adhered to each other; a protection plate shared by the unit frames, wherein each unit frame includes an electrolyte channel formed on a contact region of the unit frame with the protection plate; and a bipolar plate on which an electrolyte flows, wherein the electrolyte is supplied through the electrolyte channel. The cell frame has an integration type structure in which the protection plate is positioned in the cell frame, such that leakage of the electrolyte may be effectively prevented.