Nanoporous electrodes and related devices and methods

Abstract

High surface area electrodes formed using sol-gel derived monoliths as electrode substrates or electrode templates, and methods for making high surface area electrodes are described. The high surface area electrodes may have tunable pore sizes and well-controlled pore size distributions. The high surface area electrodes may be used as electrodes in a variety of energy storage devices and systems such as capacitors, electric double layer capacitors, batteries, and fuel cells.

1 - 33 . (canceled) 
     
     
         34 . A method of making an electrode, the method comprising:
 a) providing a sol-gel derived silica monolith comprising an open network of pores;   b) coating a surface of the open network of pores or at least partially filling the open network of pores with a conductive material; and   c) selectively removing the silica material in the monolith to provide a conductive network.   
     
     
         35 . The method of  claim 34 , wherein the open network of pores are substantially filled with the conductive material. 
     
     
         36 . The method of  claim 34 , wherein at least partially filling the open network of pores comprises impregnating the open network of pores with a colloidal solution of metal and/or metal oxide particles. 
     
     
         37 . The method of  claim 34 , wherein at least partially filling the open network of pores comprises impregnating the open network of pores with one or more precursor to a conducting polymer, and reacting the one or more precursors to form the conductive network. 
     
     
         38 . The method of  claim 37 , wherein at least partially filling the open network of pores comprises impregnating the open network of pores with one or more carbon precursor materials selected from the group consisting of furfural, furfuryl alcohol, polyfurfuryl alcohol, resorcinol formaldehyde, sucrose and glucose, and converting the one or more carbon precursor materials into carbon by polymerization and carbonization. 
     
     
         39 . The method of  claim 34 , adapted for making a conductive network having a conductive surface area of at least about 500 m 2 /g. 
     
     
         40 . The method of  claim 34 , wherein the sol-gel derived silica monolith has an average pore diameter between about 0.3 nm and about 10 nm. 
     
     
         41 . The method of  claim 34 , wherein the sol-gel derived silica monolith has a pore size distribution wherein at least about 50% of pores are within about 20% of an average pore size. 
     
     
         42 . An electrode made by the method of  claim 34 . 
     
     
         43 . The electrode of  claim 42 , configured for use in a capacitor, an electric double layer capacitor, a battery, or a fuel cell. 
     
     
         44 . A method of making an electrode material, the method comprising:
 a) providing a silica sol-gel derived monolith comprising an open network of pores;   b) coating a surface of the open network of pores or at least partially filling the open network of pores with a conductive material to form a conductive network;   c) selectively removing the silica material in the monolith to provide a conductive network; and   d) making the resulting material from step c) into a conductive powder.   
     
     
         45 . The method of  claim 44 , wherein at least partially filling the open network of pores comprises impregnating the open network of pores with one or more carbon precursor materials selected from the group consisting of furfural, furfuryl alcohol, polyfurfuryl alcohol, resorcinol formaldehyde, sucrose and glucose, and converting the one or more carbon precursor materials into carbon by polymerization and carbonization. 
     
     
         46 . The method of  claim 44 , wherein the silica sol-gel derived monolith has an average pore diameter between about 0.3 nm and about 10 nm, and/or has a pore size distribution wherein at least about 50% of the pores are within about 20% of the average pore size. 
     
     
         47 . The method of  claim 44 , adapted for making a conductive network having a conductive surface area of at least about 500 m 2 /g. 
     
     
         48 . An electrode material made by the method of  claim 44 . 
     
     
         49 . A method of making an electrode, the method comprising:
 a) mixing an electrode material made by the method of  claim 44  with a binder; and   b) drying the mixture formed in step a) on a surface to form a thin film.   
     
     
         50 . An electrode made by the method of  claim 49 . 
     
     
         51 . The electrode of  claim 50 , configured for use in a capacitor, an electric double layer capacitor, a battery, or a fuel cell. 
     
     
         52 . An energy storage device comprising:
 first and second electrodes;   an electrolyte disposed between the first and second electrodes; and   a separator disposed between the first and second electrodes;   wherein the first electrode and/or the second electrode comprise a conductive network formed from a sol-gel derived monolith by coating a surface of an open pore network of the monolith or at least partially filling an open pore network of the monolith with a conductive material.   
     
     
         53 . (canceled) 
     
     
         54 . The energy storage device of  claim 52 , wherein the conductive network in the first electrode and/or the second electrode is formed by using the silica sol-gel derived monolith as a template and subsequently removing at least part of the material of the monolith so that the conductive network is substantially a stand-alone conductive network. 
     
     
         55 - 73 . (canceled)