Battery Electrode Material Formulation and Manufacturing Process

Abstract

An improved chemical composition and manufacturing process for a battery electrode are disclosed. This battery electrode may be later arranged in flowing electrolyte battery cells. Battery electrode material formulation may include a mixture of polypropylene, carbon black, graphite, bonding additives and other substances in different concentrations. The inclusion of graphite may reduce the amount of carbon black in the mixture, thereby reducing the swelling of the battery electrode in the presence of bromine. Moreover, material formulation may reduce warpage caused by the swelling of electrode material, and may additionally improve the performance and properties of flowing electrolyte batteries. An extrusion molding process may be employed in order to fabricate the disclosed battery electrode.

We claim: 
     
         1 . An electrode for use in an electrolyte flow battery, the electrode comprising:
 a. graphite;   b. carbon black; and   C. polypropylene.   
     
     
         2 . The electrode of  claim 1  wherein the graphite is present in an amount of between about 5% wt to about 15% wt. 
     
     
         3 . The electrode of  claim 1  wherein the carbon black is present in an amount of between about 7% wt to about 20% wt. 
     
     
         4 . The electrode of  claim 1  wherein the polypropylene is a combination of high melt flow index (MFI) polypropylene and low MFI polypropylene. 
     
     
         5 . The electrode of  claim 4  wherein the high MA polypropylene is present in an amount of between 5% wt to about 15% wt, and the low MA polypropylene is present in an amount of between about 35% wt to about 65% wt. 
     
     
         6 . The electrode of  claim 1  further comprising one or more of carbon nanotubes, carbon nanofibers, graphene, micro-graphites, insert molding adhesion promoters, glass beads, talc, mica, coupling agents, stabilizing fillers, crystallinity promoters and anti-oxidants. 
     
     
         7 . The electrode of  claim 1  further comprising a fibrous component. 
     
     
         8 . The electrode of  claim 7  wherein the fibrous component is selected from the groups consisting of glass fibers, carbon fibers and mixtures thereof. 
     
     
         9 . The electrode of  claim 1  further comprising a polyolefin elastomer. 
     
     
         10 . The electrode of  claim 9  wherein the polyolefin elastomer is ethylene octene copolymer. 
     
     
         11 . The electrode of  claim 1  further comprising an activation layer. 
     
     
         12 . A method for forming an electrode for use in an electrolyte flow battery, the method comprising the steps of:
 a. mixing polypropylene and carbon black to form a first mixture;   b. adding graphite to the first mixture;   c. extruding the first mixture into pellets; and   d. forming the electrode using the pellets.   
     
     
         13 . The method of  claim 12  further comprising the steps of:
 a. extruding the pellets into a film after extruding the first mixture into pellets; and 
 b. cooling the film. 
 
     
     
         14 . The method of  claim 13  further comprising the step of cutting the film into the desired configuration after cooling the film. 
     
     
         15 . The method of  claim 12  further comprising the step of placing an activation layer on the electrode after forming the electrode. 
     
     
         16 . The method of  claim 15  wherein the step of placing the activation layer on the electrode comprises attaching the activation layer to the electrode using an adhesive. 
     
     
         17 . The method of  claim 15  wherein the step of placing the activation layer on the electrode comprises laminating the activation layer onto the adhesive. 
     
     
         18 . A battery cell stack for an electrolyte flow battery comprising:
 a. a number of flow frames; and   b. a number of electrodes having the composition of  claim 1  secured to the flow frames.