| 摘要 |
PURPOSE:To prevent the reduction of adhesion between graphite powders by soaking an artificial graphite powder in the mixing solution of an undiluted sulfuric acid and an undiluted nitric acid, and making the volume dilatation of the produced compound when it is heated rapidly up to a high temperature, less than 5 times of the original volume. CONSTITUTION:An artificial graphite used for a negative electrode is formed by making carbonized needle coke as a filler, and mixing a pitch to it as a binder, and then it is made into a graphite by heating. The graphite powder is soaked in a mixing solution of an undiluted sulfuric acid and an undiluted nitric acid, so as to make a compound between graphite layers including sulfuric acid. And the volume dilatation when the compound is heated rapidly up to a high temperature is made less than 5 times of the original volume. Furthermore, the artificial graphite is crushed, and a binder of an acrylic resin, and a water solution of carboxymethylcellulose are added to make into a paste. The paste is applied to both sides of a specific thickness of copper foil, and dried to form a specific size of negative electrode. As a result, the reduction of the adhesion between graphite powders is prevented, the collecting efficiency is improved, and the charge and discharge property is also improved. |
