Process for producing activated carbon for electrode of electric double-layer capacitor

Abstract

To produce activated carbon for an electrode of an electric double-layer capacitor, the following steps are carried out sequentially: a step of subjecting a massive mesophase pitch to a pulverizing treatment to provide a pulverized powder; a step of subjecting the pulverized powder to an infusibilizing treatment under conditions of a temperature in a range of 300° C. (inclusive) to 450° C. (inclusive) in the atmospheric air current, a step of subjecting the pulverized powder to a carbonizing treatment under conditions of a temperature in a range of 600° C. (inclusive) to 900° C. (inclusive) in an inert gas current to provide a carbonized powder, a step of subjecting the carbonized powder to an alkali activating treatment under conditions of a temperature in a range of 500° C. (inclusive) to 1,000° C. (inclusive) in an inert gas atmosphere, followed by the post treatments, thereby producing alkali-activated carbon, and a step of subjecting the alkali-activated carbon to a pulverizing treatment. If an electrode is produced using the activated carbon, the electrode density can be increased.

1 . A process for producing activated carbon for an electrode of an electric double-layer capacitor, comprising the steps of: 
 subjecting a massive mesophase pitch to a first pulverizing treatment to provide a pulverized powder, 
 subjecting said pulverized powder to an infusibilizing treatment under conditions of a temperature in a range of 300° C. (inclusive) to 450° C. (inclusive) in the atmospheric air current,  
 subjecting said pulverized powder to a carbonizing treatment under conditions of a temperature in a range of 600° C. (inclusive) to 900° C. (inclusive) in an inert gas current to provide a carbonized powder,  
 subjecting said carbonized powder to an alkali activating treatment under conditions of a temperature in a range of 500° C. (inclusive) to 1,000° C. (inclusive) in an inert gas atmosphere, followed by post treatments, thereby producing alkali-activated carbon, and  
 subjecting said alkali-activated carbon to a second pulverizing treatment,  
 wherein the above steps are carried out in the mentioned order, and wherein the electric double-layer capacitor has an electrode density of from greater than 0.9 q/cc to about 1 g/cc.  
   
   
   
       2 - 4 . (canceled)  
   
   
       5 . A process for producing activated carbon for an electrode of an electric double-layer capacitor according to  claim 1 , further comprising a step of subjecting a graphitizable carbon powder to an alkali activating treatment to produce activated carbon for an electrode of an electric double-layer capacitor, a mixed activating agent comprising KOH and NaOH being used as an alkali activating agent in said alkali activating treatment.  
   
   
       6 . A process for producing activated carbon for an electrode of an electric double-layer capacitor according to  claim 5 , wherein the content of NaOH in said mixed activating agent is in a range of 10% by weight≦NaOH≦90% by weight.  
   
   
       7 - 8 . (canceled)  
   
   
       9 . The process of  claim 1  wherein said post treatments are at least one of neutralization by hydrochloric acid, washing or drying.