Electrode assembly and flow battery with improved electrolyte distribution

Abstract

An electrode assembly for a flow battery is disclosed comprising a porous electrode material, a frame surrounding the porous electrode material, at least a distributor tube embedded in the porous electrode material having an inlet for supplying electrolyte to the porous electrode material and at least another distributor tube embedded in the porous electrode material having an outlet for discharging electrolyte out of the porous material. The walls of the distributor tubes are preferably provided with holes or pores for allowing a uniform distribution of the electrolyte within the electrode material. The distributor tubes provide the required electrolyte flow path length within the electrode material to minimize shunt current flowing between the flow cells in the battery stack.

Description

TECHNICAL FIELD[0001]The present invention relates to an electrode assembly for a flow battery having a construction that allows an improved electrolyte distribution within the electrode material and to a flow battery comprising such electrode assemblies.BACKGROUND[0002]Flow batteries, also known as redox flow batteries, convert electrical energy into chemical energy that can be stored and then converted into electrical energy which is released when there is a demand.[0003]Flow batteries are distinguished from other electrochemical devices, for example from fuel cells, by the use of liquid electrolytes that participate in a reversible electro-chemical reaction. Fuel cells use gaseous fuels to produce energy, they do not store energy whereas flow batteries do not generate any energy, they store and release energy. This is a basic difference between fuel cells and flow batteries, but there are many other differences between these two types of electrochemical cells, some of which are f...

AI Technical Summary

Benefits of technology

The present invention is an improved electrode assembly for batteries that allows for better distribution of electrolyte through the electrodes, lower pressure drop, and better control of shunt current without needing extra space or materials. The electrodes are easier to manufacture, use lower cost materials, and have a higher energy efficiency and current density than current solutions. Additionally, the design allows for increased electrolyte flow rate and reaction rate.

Problems solved by technology

This type of design provides less of a pressure drop because the electrolytes flow unrestricted through the flow channels, but the performance is relatively low because of the non-uniform distribution of the electrolytes into the electrodes.

The design disclosed in this prior art document is complicated involving electrodes comprising several parts, plastic protective plates covering the electrolyte circulation grooves cut or formed into the bipolar plates and arrangements that require the proper positioning of the electrode parts such that they do not interfere with the electrolyte circulation channels.

Another problem characteristic to flow batteries in general is that the electrolyte feed ports into the flow cells are conductive paths for current leakage from one cell to the next cell in the stack.

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