Regenerable battery electrode

Abstract

A binder-free, self-supporting electrode including an electrochemically active material in the absence of a binder and a current collector is claimed. The electrochemically active material is a self-supporting transition metal oxide. A method of regenerating the electrode to restore capacity of the electrode is also claimed.

We claim: 
     
         1 . A method of regenerating a cycled electrode comprising:
 removing the cycled electrode from a battery with capacity fade, where the cycled electrode comprises an electrochemically active material in the absence of a binder and a current collector;   regenerating the electrode by a thermal treatment under air; and   placing the regenerated electrode in the battery to restore capacity.   
     
     
         2 . The method of  claim 1 , wherein the battery has undergone at least 50 cycles prior to electrode regeneration. 
     
     
         3 . The method of  claim 1 , wherein the electrochemically active material is selected from the group consisting of Zn x O y , Mn x O y , V x O y , Fe x O y , Sn x O y , La x Mn y O z , Ni x Co y O z , and Mo x O y , wherein x, y, and z are numbers greater than 0. 
     
     
         4 . The method of  claim 1 , wherein electrochemically active material is a self-supporting transition metal oxide comprising nanofibers. 
     
     
         5 . The method of  claim 1 , further comprising no more than about 20% based upon the total weight of the electrode of a conductive additive selected from the group consisting of nanostructured carbon, graphitic carbon, conductive metal nanoparticles, and metal wire mesh. 
     
     
         6 . The method of  claim 1 , wherein the thermal treatment includes heating the electrode to a temperature greater than 200° C. and less than a thermal decomposition temperature of the electrode. 
     
     
         7 . A method of regenerating an electrode comprising:
 providing the electrode from a battery having a delivered capacity below 60 mAh/g, where the electrode has an electrochemically active material in the absence of a binder and a current collector, and where the electrochemically active material is a self-supporting transition metal oxide, and   regenerating the electrode by a thermal treatment under air, wherein the regenerated electrode in a battery has a capacity above 100 mAh/g.   
     
     
         8 . The method of  claim 7  , wherein the electrochemically active material is selected from the group consisting of Zn x O y , Mn x O y , V x O y , Fe x O y , Sn x O y , La x Mn y O z , Ni x Co y O z , and Mo x O y , wherein x, y, and z are numbers greater than 0. 
     
     
         9 . The method of  claim 7 , wherein the self-supporting transition metal oxide comprises nanofibers. 
     
     
         10 . The electrode of  claim 7 , further comprising no more than about 20% based upon the total weight of the electrode of a conductive additive selected from the group consisting of nanostructured carbon, graphitic carbon, conductive metal nanoparticles, and metal wire mesh. 
     
     
         11 . The method of  claim 7 , wherein the thermal treatment includes heating the electrode to a temperature greater than 200° C. and less than a thermal decomposition temperature of the electrode. 
     
     
         12 . A method of regenerating a self-supporting, binder-free electrode comprising:
 providing a battery with a self-supporting, binder-free electrode having an electrochemically active material in the absence of a binder and a current collector, wherein the electrochemically active material is a self-supporting transition metal oxide;   obtaining the electrode from the battery after capacity fade;   regenerating the electrode by a thermal treatment under air; and   placing the regenerated electrode in the battery or in a new battery, wherein the battery or the new battery has a capacity above 100 mAh/g.   
     
     
         13 . The method of  claim 12 , wherein the battery has undergone at least 50 cycles prior to electrode regeneration. 
     
     
         14 . The method of  claim 12 , wherein the battery has undergone at least 250 cycles prior to electrode regeneration. 
     
     
         15 . The method of  claim 12 , wherein the electrochemically active material is selected from the group consisting of Zn x O y , Mn x O y , V x O y , Fe x O y , Sn x O y , La x Mn y O z , Ni x Co y O z , and Mo x O y , wherein x, y, and z are numbers greater than 0. 
     
     
         16 . The method of  claim 12 , wherein the self-supporting transition metal oxide comprises nanofibers. 
     
     
         17 . The electrode of  claim 12 , further comprising no more than about 20% based upon the total weight of the electrode of a conductive additive selected from the group consisting of nanostructured carbon, graphitic carbon, conductive metal nanoparticles, and metal wire mesh. 
     
     
         18 . The method of  claim 17 , wherein the conductive additive is nanostructured carbon and the nanostructure carbon is multi-walled carbon nanotubes, fullerene, or graphene. 
     
     
         19 . The method of  claim 12 , wherein the thermal treatment includes heating the electrode to a temperature of between 200° C. and 400° C. 
     
     
         20 . The method of  claim 12 , wherein the thermal treatment includes heating the electrode to a temperature greater than 200° C. and less than a thermal decomposition temperature of the electrode.