| 摘要 |
PURPOSE: To enhance the current output efficiency, suppress internal shortcircuiting, and increase the electric capacity by making the rate of voids of a positive electrode and a negative electrode black mix over a specified value. CONSTITUTION: A coin type secondary battery is structured so that the output current is over 5mA/cm<2> for the mating area of a positive 1 and a negative electrode, wherein the positive electrode black mix is prepared by mixing 0-20wt.% phosphorous graphite as electron leading agent and 2-10wt.% polytetra-fluoroethylene with a lithium-nickel oxide as positive electrode active material followed by a baking process, and the resultant is processed by pressure into a disc shape so that a positive electrode 1 is accomplished. A negative electrode black mix is prepared by mixing 95-50wt.% PVDF as binder with graphite followed by a baking process and the resultant is processed by pressure into a disc shape so that a negative electrode 2 is achieved. At this time, the rate of voids as the space share by apparent volume in the positive and negative electrode black mixes is made over 40%, and thereby the active material of the two electrodes are utilized effectively to lead to increase in the current, and also eduction of resin-form lithium metal at charging and discharging is dropped, which should lead to suppression of internal shortcircuiting of the battery. |
