| 摘要 |
PURPOSE:To restrain the growth of dendrite taking place at the time of charging, and thereby lengthen the cyclic life of the secondary cell by making a negative electrode larger in size than a positive electrode, and weakening electric field strength in the edge section of the negative electrode. CONSTITUTION:Paste where 3% carbon powder of acetyleneblack by weight and 5% polyfluoridevinylidene by weight are mixed with positive electrode active material composed of lithium manganse oxide, and prepared while N- methylpyrrolidone is being added, is applied to an aluminum foil, dried and formed into a positive electrode 102. An aluminum foil larger than by 2mm in dismeter than the positive electrode 102 is etched with 5% potassium hydroxide solution by weight, and formed into a negative electrode 101. The positive electrode 102 and the negative electrode 101 are disposed face to face with each other while a separator 105 made out of fine porous polypropylene as thin as 25mum is being held in electrolyte 104 which comprises lithiumboratetetrafluoride dissolved by 1mol in equivalent mixed solution of propylenecarbonate and dimethoxyethane, and formed into a lithium secondary cell. |
