Methods and system for manufacturing a redox flow battery system by roll-to-roll processing

Abstract

Methods and systems are provided for manufacturing a membrane separator for a redox flow battery. In one example, the membrane separator is fabricate by a calendering process. The membrane separator may be configured with a polymer network to provide selectivity for ion transport across the membrane separator. The membrane separator may be further adapted with an integrated spacer in contact with a negative electrolyte.

1 . A separator for a redox flow battery, comprising:
 a fluid-impermeable, ionically conductive membrane; and   ribs molded into a surface of the fluid-impermeable, ionically conductive membrane.   
     
     
         2 . The separator of  claim 1 , wherein the fluid-impermeable, ionically conductive membrane is a solid barrier between a negative electrolyte and a positive electrolyte and allows transport of selected ions between the negative electrolyte and the positive electrolyte. 
     
     
         3 . The separator of  claim 2 , wherein the fluid-impermeable, ionically conductive membrane blocks flow of ferrous and ferric ions between the negative electrolyte and the positive electrolyte. 
     
     
         4 . The separator of  claim 2 , wherein the ribs are configured to increase turbulent flow of the negative electrolyte. 
     
     
         5 . The separator of  claim 1 , wherein the fluid-impermeable, ionically conductive membrane is formed from a mixture of an ultrahigh molecular weight polyethylene, a silica with high oil absorptivity, and a plasticizer. 
     
     
         6 . The separator of  claim 1 , wherein a porosity of the fluid-impermeable, ionically conductive membrane is greater than 75%. 
     
     
         7 . The separator of  claim 1 , wherein the ribs are formed from a same material as the fluid-impermeable, ionically conductive membrane and protrude outwards from the surface of the fluid-impermeable, ionically conductive membrane. 
     
     
         8 . The separator of  claim 1 , wherein the fluid-impermeable, ionically conductive membrane includes a cross-linked polymer network within pores of the fluid-impermeable, ionically conductive membrane. 
     
     
         9 . The separator of  claim 8 , wherein the cross-linked polymer network is adapted with one or more of carbon, nitrogen and sulfur-based functional groups that interact with selected ions. 
     
     
         10 . The separator of  claim 8 , wherein the cross-linked polymer network is formed of monomers, the monomers including one of 2-acrylamido-2-methylpropane sulfonic acid or a sodium 4-vinyl benzene sulfonate salt. 
     
     
         11 . The separator of  claim 1 , wherein the ribs extend along a vertical axis of the separator, at an angle to the vertical axis of the separator, or sinuously across the separator. 
     
     
         12 . The separator of  claim 1 , wherein the separator is positioned within a chamber of a battery cell of the redox flow battery. 
     
     
         13 . The separator of  claim 12 , wherein the ribs of the separator are in face-sharing contact with a negative electrode of the battery cell. 
     
     
         14 . A redox flow battery, comprising:
 a first battery cell storing a positive electrolyte and a negative electrolyte within a chamber of the first battery cell;   a first positive electrode submerged in the positive electrolyte and a first negative electrode submerged in the negative electrolyte of the chamber of the first battery cell, wherein the first positive electrode is bonded to a side of a bipolar plate, the bipolar plate being a roll-to-roll calendered bipolar plate; and   a membrane separator arranged in the chamber of the first battery cell between the positive electrolyte and the negative electrolyte and in contact with the first negative electrode, the membrane separator adapted with an ion selective polymer network disposed in pores of the membrane separator, a surface of the membrane separator forming an integrated negative spacer in contact with the negative electrolyte.   
     
     
         15 . The redox flow battery of  claim 14 , wherein the bipolar plate is positioned between the first positive electrode and a second negative electrode of a second battery cell adjacent to the first battery cell, the bipolar plate separating a negative electrolyte in the second battery cell from the positive electrolyte in the first battery cell. 
     
     
         16 . The redox flow battery of  claim 14 , wherein the integrated negative spacer includes a plurality of ribs and a plurality of valleys, the plurality of ribs and the plurality of valleys formed from a same material as the membrane separator and continuous with the membrane separator, each rib of the plurality of ribs spaced apart by a valley of the plurality of valleys, the pluralities of ribs and the plurality of valleys defining flow paths for the negative electrolyte along a surface of the first negative electrode. 
     
     
         17 . The redox flow battery of  claim 16 , wherein the plurality of ribs extends along a vertical axis of the integrated negative spacer, at an angle to the vertical axis of the integrated negative spacer, or sinuously across the integrated negative spacer. 
     
     
         18 . The redox flow battery of  claim 16 , wherein the plurality of ribs are configured to increase a turbulent flow of the negative electrolyte. 
     
     
         19 . The redox flow battery of  claim 14 , wherein the ion selective polymer network is formed of monomers, the monomers including one of 2-acrylamido-2-methylpropane sulfonic acid or a sodium 4-vinyl benzene sulfonate salt. 
     
     
         20 . The redox flow battery of  claim 14 , wherein the bipolar plate is formed of sewn together layers.