CARBONACEOUS MATERIAL FOR NEGATIVE ELECTRODES OF LITHIUM ION CAPACITORS AND METHOD FOR PRODUCING SAME

摘要

The objective of the present invention is to provide: a method for producing a carbonaceous material for negative electrodes of lithium ion capacitors, said carbonaceous material using a plant-derived char as a starting material and having a small average particle diameter, while having potassium element and iron element sufficiently removed therefrom by decalcification; and a carbonaceous material for negative electrodes of lithium ion capacitors. The above-mentioned objective can be achieved by a method for producing a carbonaceous material for negative electrodes of lithium ion capacitors having an average particle diameter of 3-30 mum, which comprises: (1) a gas-phase decalcification step wherein a plant-derived char having an average particle diameter of 100-10,000 mum is subjected to a heat treatment at 500-1,250°C in an inert gas atmosphere containing a halogen compound; (2) a step wherein a carbonaceous precursor obtained by gas-phase decalcification is pulverized; and (3) a step wherein the pulverized carbonaceous precursor is fired at a temperature less than 1,100°C in a non-oxidizing gas atmosphere.