Electrical Characteristics According to the Manufacturing Process of the Flexible Li/MnO2 Primary Cell

Abstract

Manganese dioxide (MnO 2 ) is one of the most important cathode materials used in both aqueous and non-aqueous batteries. The MnO 2 polymorph that is used for lithium primary batteries is synthesized either by electrolytic (EMD-MnO 2 ) or chemical methods (CMD-MnO 2 ). Commonly, electrolytic manganese dioxide (EMD) is used as a cathode mixture material for dry-cell batteries, such as a alkaline batteries, zinc-carbon batteries, rechargeable alkaline batteries, etc. The characteristics of lithium/manganese-dioxide primary cells fabricated with EMD-MnO 2 powders as cathode were compared as a function of the parameters of a manufacturing process. The flexible primary cells were prepared with EMD-MnO 2 , active carbon, and poly vinylidene fluoride (PVDF) binder (10 wt.%) coated on an Al foil substrate. A cathode sheet with micro-porous showed a higher discharge capacity than a cathode sheet compacted by a press process. As the amount of EMD-MnO 2 increased, the electrical conductivity decreased and the electrical capacity increased. The cell subjected to heat-treatment at 200 o C for 1 hr showed a high discharge capacity. The flexible primary cell made using the optimum conditions showed a capacity and an average voltage of 220 mAh/g and 2.8 V, respectively, at 437.5 µA.