Cost-efficient high energy density redox flow battery

Abstract

Methods and systems are provided for a redox flow battery system. In one example, the redox flow battery is adapted with an additive included in a battery electrolyte and an anion exchange membrane separator dividing positive electrolyte from negative electrolyte. An overall system cost of the battery system may be reduced while a storage capacity, energy density and performance may be increased.

1 . A redox flow battery system, comprising:
 a plurality of battery cells, wherein each battery cell comprises:
 a positive electrolyte and a negative electrolyte, the positive electrolyte in contact with a positive electrode and the negative electrolyte in contact with a negative electrode, wherein the negative electrolyte comprises stearic acid as a plating additive, and wherein the plating additive forms uniform and crack-free layers of metal at the negative electrode; and 
 a membrane separator arranged between the negative electrolyte and the positive electrolyte, the membrane separator formed from an anion exchange membrane (AEM). 
   
     
     
         2 . The redox flow battery system of  claim 1 , wherein the plurality of battery cells are connected in parallel. 
     
     
         3 . The redox flow battery system of  claim 1 , wherein the plurality of battery cells are connected in series. 
     
     
         4 . The redox flow battery system of  claim 1 , wherein electrolytes are stored in at least one tank external to the battery cell. 
     
     
         5 . The redox flow battery system of  claim 1 , wherein the AEM blocks passage of cations between the positive electrolyte and the negative electrolyte. 
     
     
         6 . The redox flow battery system of  claim 1 , wherein the AEM is formed from a polymer network configured with ion transport selectivity. 
     
     
         7 . A power module comprising:
 a first pressure plate arranged at a first end with a first picture frame arranged on an inner face of the first pressure plate;   a second pressure plate arranged at a second end with a second picture frame arranged on an inner face of the second pressure plate;   a negative spacer adjacent the first picture frame, wherein the negative spacer defines flow channels along a surface of a negative electrode;   a bipolar plate in face-sharing contact with the negative spacer;   a positive electrode arranged along a face of the bipolar plate opposite the negative spacer;   an anion exchange membrane adjacent the positive electrode, on a side of the positive electrode facing the second end of the power module;   a negative electrolyte contained between another membrane arranged on a side of the bipolar plate towards the first end of the power module, the negative electrolyte in contact with both the negative spacer and the negative electrode; and   a positive electrolyte contained between the bipolar plate and the anion exchange membrane, in contact with the positive electrode;   wherein the negative electrolyte comprises stearic acid as a plating additive, and wherein the plating additive forms uniform and crack-free layers of metal at the negative electrode.   
     
     
         8 . The power module of  claim 7 , wherein the anion exchange membrane transports anions between the positive electrolyte and the negative electrolyte. 
     
     
         9 . The power module of  claim 8 , wherein the anion exchange membrane blocks passage of cations between the positive electrolyte and the negative electrolyte. 
     
     
         10 . The power module of  claim 7 , wherein the anion exchange membrane is formed from a polymer network configured with ion transport selectivity. 
     
     
         11 . The power module of  claim 7 , wherein the anion exchange membrane is formed from a covalent organic framework. 
     
     
         12 . The power module of  claim 7 , wherein the negative spacer, the bipolar plate, the positive electrode, and the anion exchange membrane repeat within the power module from the first end to the second end, forming a battery stack. 
     
     
         13 . The power module of  claim 7 , wherein the negative spacer is surrounded by a bipolar plate frame plate. 
     
     
         14 . The power module of  claim 7 , wherein the positive electrode is graphite felt. 
     
     
         15 . The power module of  claim 7 , wherein the anion exchange membrane comprises pH resistant functional groups. 
     
     
         16 . The power module of  claim 7 , wherein the bipolar plate has an integrated negative electrode along a surface of the bipolar plate.