Nanofiber electrodes for batteries and methods of making nanofiber electrodes

Abstract

Provided herein is a battery and an electrode. The battery may include two electrodes; and an electrolyte, wherein at least one electrode further includes: a nano-scale coated network, which includes one or more first carbon nanotubes electrically connected to one or more second carbon nanotubes to form a nano-scale network, wherein at least one of the one or more second carbon nanotubes is in electrical contact with another of the one or more second carbon nanotubes. The battery may further include an active material coating distributed to cover portions of the one or more first carbon nanotubes and portions of the one or more second carbon nanotubes, wherein a plurality of the one or more second carbon nanotubes are in electrical communication with other second carbon nanotubes under the active material coating. Also provided herein is a method of making a battery and an electrode.

1 . An electrode, comprising:
 a nano-scale coated network, comprising:   first carbon nanotubes;   second carbon nanotubes; and   an active material coating,
 wherein the first carbon nanotubes are electrically connected to at least one of the second carbon nanotubes to form an underlying nano-scale network, 
 wherein the underlying nano-scale network comprises first carbon nanotubes, second carbon nanotubes, and at least one electrical contact connection between at least two of the second nanotubes; and 
 wherein the active material coating forms the nano-scale coated network by covering at least a portion of the first carbon nanotubes while not interfering with the at least one electrical contact connection between the second carbon nanotubes to form the nano-scale coated network. 
   
     
     
         2 . The electrode of  claim 1 , wherein the active material coating was redistributed from the at least a portion of the carbon nanotubes to at least a portion of the second carbon nanotubes to isolate the first carbon nanotubes and second carbon nanotubes from the electrolyte, and wherein the active material coating does not interfere with the electrical connection between at least two of the second carbon nanotubes. 
     
     
         3 - 11 . (canceled) 
     
     
         12 . A battery, comprising:
 two electrodes; and   an electrolyte, wherein at least one electrode comprises:   a nano-scale coated network, comprising:
 one or more first carbon nanotubes electrically connected to one or more second carbon nanotubes to form a nano-scale network, wherein at least one of the one or more second carbon nanotubes is in electrical contact with another of the one or more second carbon nanotubes; and 
 an active material coating distributed to cover portions of the one or more first carbon nanotubes and portions of the one or more second carbon nanotubes, wherein a plurality of the one or more second carbon nanotubes are in electrical communication with other second carbon nanotubes under the active material coating. 
   
     
     
         13 . The battery of  claim 12 , wherein the battery, when discharged at ambient conditions at a 1C rate, has a cell voltage greater than 80% of the theoretical voltage and/or a recharge efficiency, when recharged at a 2C rate, of greater than 95%. 
     
     
         14 - 18 . (canceled) 
     
     
         19 . A charge storage device comprising:
 a first electrode comprising:
 a nano-scale coated network, comprising:
 first carbon nanotubes 
 second carbon nanotubes; and 
 an active material coating,
 wherein the first carbon nanotubes are electrically connected to the second carbon nanotubes to form a nano-scale network, 
 wherein at least a first of the second carbon nanotubes is in electrical contact with a second of the second carbon nanotubes; 
 wherein the active material coating covers portions of the first carbon nanotubes and portions of the first of the second carbon nanotubes, and 
 wherein a the first of the second carbon nanotubes is in direct physical contact with a second of the second carbon nanotubes under the active material coating covering the portion of the first of the second carbon nanotubes; 
 
 
   a second electrode; and   an electrolyte, wherein the electrolyte is in contact with the first or the second electrode.   
     
     
         20 . The charged storage device of  claim 19 , wherein the active material coating is redistributed from a surface of the first multi-wall carbon nanotube to a surface of a second multi-wall carbon nanotube, and wherein the second multi-wall carbon nanotube is in direct contact with another second multi-wall carbon nanotube. 
     
     
         21 . The charge storage device of  claim 20 , wherein the active material coating is treated using electrical charge and discharge to form the first electrode, or recrystallization to form the first electrode. 
     
     
         22 . The charge storage device of  claim 19 , wherein the electrolyte comprises an aqueous solution with a pH below 12.5. 
     
     
         23 . The charge storage device of  claim 19 , wherein the active material coating includes a compound of Zn, Cd, Co, Ni, Fe, Pb, Al, Mn, or Ag. 
     
     
         24 . The charge storage device of  claim 19 , wherein the active material coating comprises a compound of Ni or Zn. 
     
     
         25 - 41 . (canceled) 
     
     
         42 . A method of forming a battery, comprising:
 providing a first electrode, wherein forming the first electrode comprises:
 providing first carbon nanotubes; 
 providing second carbon nanotubes; 
 coating the first carbon nanotubes with a nanoscale substance to form coated carbon nanotubes; 
 forming a network of the coated carbon nanotubes and the second carbon nanotubes; 
 providing a first electrolyte; and 
 redistributing the nanoscale substance onto the network in the first electrolyte to form the first electrode; 
   providing a second electrolyte;   providing a second electrode; and   providing the first and the second electrode in the second electrolyte to form a battery, wherein the first electrolyte and the second electrolyte are different electrolytes.   
     
     
         43 . The method of  claim 42 , wherein the coating the first carbon nanotubes with a nanoscale substance comprises coating the first carbon nanotubes with an electrochemically active nanoscale solid substance. 
     
     
         44 . The method of  claim 43 , wherein coating the first carbon nanotubes with an electrochemically active nanoscale solid substance comprises coating the first carbon nanotubes with a compound of Ni, Zn, Cd, Fe, Pb, Mn, Co, Ag, Al, or Mg. 
     
     
         45 . The method of  claim 43 , wherein coating the first carbon nanotubes with an electrochemically active nanoscale solid substance comprises coating the first carbon nanotubes with one or more of hydroxides, carbonates, fluorides, sulfates, oxalates, phosphates. 
     
     
         46 . The method of  claim 42 , wherein the coating the first carbon nanotubes with a nanoscale substance comprises depositing the nanoscale substance from a solution on to the first carbon nanotubes. 
     
     
         47 . The method of  claim 42 , wherein the providing the first electrolyte and/or the second electrolyte comprises providing an aqueous, ionically conductive electrolyte. 
     
     
         48 . The method of  claim 42 , wherein the providing the second electrolyte comprises providing an electrolyte with a pH level between 7 and 12.5. 
     
     
         49 . The method of  claim 42 , wherein the providing the second electrolyte comprises providing an electrolyte containing a carbonate, a fluoride, a phosphate, and/or a sulfate. 
     
     
         50 . The method of  claim 42 , wherein the providing the second electrolyte comprises providing an electrolyte containing K 2 CO 3 , K 2 SO 4 , KF, NaF, and/or K 3 PO 4 . 
     
     
         51 . The method of  claim 42 , further comprising providing one or more of an oxide, a hydroxide, or a carbonate in solid form to the step of providing first carbon nanotubes, to the step of providing second carbon nanotubes, or to the step of coating the first carbon nanotubes with a nanoscale substance to form coated carbon nanotubes. 
     
     
         52 - 102 . (canceled)