High energy density redox flow device

Abstract

Redox flow devices are described in which at least one of the positive electrode or negative electrode-active materials is a semi-solid or is a condensed ion-storing electroactive material, and in which at least one of the electrode-active materials is transported to and from an assembly at which the electrochemical reaction occurs, producing electrical energy. The electronic conductivity of the semi-solid is increased by the addition of conductive particles to suspensions and/or via the surface modification of the solid in semi-solids (e.g., by coating the solid with a more electron conductive coating material to increase the power of the device). High energy density and high power redox flow devices are disclosed. The redox flow devices described herein can also include one or more inventive design features. In addition, inventive chemistries for use in redox flow devices are also described.

What is claimed is: 
     
         1 . (canceled) 
     
     
         2 . A composition for an energy storage device, the composition comprising:
 ion-storing solid phase particles in a liquid electrolyte, the ion-storing solid phase particles (1) are capable of taking up or releasing said ions, and (2) remain substantially insoluble during operation of the energy storage device.   
     
     
         3 . The composition of  claim 2 , wherein the ion-storing solid phase particles remain substantially insoluble in all of its oxidation states. 
     
     
         4 . The composition of  claim 2 , wherein a volume percentage of the ion-storing solid phase particles is between 5% and 70%. 
     
     
         5 . The composition of  claim 2 , further comprising:
 a conductive additive in the liquid electrolyte.   
     
     
         6 . The composition of  claim 5 , wherein a volume percentage of total solids including the conductive additive is between 10% and 75%. 
     
     
         7 . The composition of  claim 5 , wherein the conductive additive forms a percolative continuously electronically conductive network in the liquid electrolyte. 
     
     
         8 . The composition of  claim 5 , wherein the conductive additive includes at least one of metal carbides, metal nitrides, carbon black, graphitic carbon powder, carbon fibers, carbon microfibers, vapor-grown carbon fibers (VGCF), fullerenes, carbon nanotubes (CNTs), multi-walled carbon nanotubes (MWNTs), single wall carbon nanotubes (SWNTs), graphene sheets, and materials comprising fullerenic fragments that are not predominantly a closed shell or tube of the graphene sheet, and mixtures thereof. 
     
     
         9 . The composition of  claim 2 , wherein the ion-storing solid phase particles store at least one of Li, Na, and H. 
     
     
         10 . An electrode for use in an energy storage device, the electrode comprising:
 a current collector;   an ion permeable membrane spaced apart from the current collector; and   an electrode disposed between the current collector and the ion permeable membrane, the electrode includes ion-storing solid phase particles in a liquid electrolyte, the ion-storing solid phase particles (1) are capable of taking up or releasing ions, and (2) remain substantially insoluble during operation of the energy storage device.   
     
     
         11 . The electrode of  claim 10 , wherein the electrode is a semi-solid. 
     
     
         12 . The electrode of  claim 11 , wherein the semi-solid is at least one of a slurry, a particle suspension, a colloidal suspension, an emulsion, a gel, and a micelle. 
     
     
         13 . The electrode of  claim 10 , wherein a volume percentage of the ion-storing solid phase particles is between 5% and 70%. 
     
     
         14 . The electrode of  claim 10 , further comprising:
 a conductive additive in the liquid electrolyte.   
     
     
         15 . The electrode of  claim 14 , wherein a volume percentage of total solids including the conductive additive is between 10% and 75%. 
     
     
         16 . The electrode of  claim 10 , wherein the electrode has a thickness of about 250 μm to about 800 μm. 
     
     
         17 . An energy storage device, comprising:
 a positive electrode;   a negative electrode; and   an ion-permeable membrane separating the positive electrode and the negative electrode,   wherein at least one of the positive electrode and the negative electrode includes ion-storing solid phase particles in a liquid electrolyte, the ion-storing solid phase particles (1) are capable of taking up or releasing ions, and (2) remain substantially insoluble during operation of the energy storage device.   
     
     
         18 . The energy storage device of  claim 17 , wherein the ion-storing solid phase particles remain substantially insoluble in all of its oxidation states. 
     
     
         19 . The energy storage device of  claim 17 , wherein a volume percentage of the ion-storing solid phase particles is between 5% and 70%. 
     
     
         20 . The energy storage device of  claim 17 , wherein a volume percentage of the ion-storing solid phase particles is greater than 25%. 
     
     
         21 . The energy storage device of  claim 20 , wherein a volume percentage of the ion-storing solid phase particles is greater than 40%. 
     
     
         22 . The energy storage device of  claim 17 , wherein the electrode containing the mixture of the ion-storing solid phase particles and the liquid electrolyte has a thickness of about 250 μm to about 800 μm.