For wide-scale use in small electronic devices and other equipment, coin type manganese dioxide lithium primary batteries are required to have high capacity and conductivity. Basically positive electrode material is composed of conductive material, such as carbon black, binder and manganese dioxide. Although reduction of binder amount may enhance conductivity, it causes chip and crack in the positive electrode. One possible way of reducing binder amount is to use expanded graphite with binding ability, instead of using carbon black. However, as expanded graphite shows low density, it is difficult to disperse expanded graphite into pellet. So far, optimization of the granulation conditions has not been well studied.
The aim of this study is to determine optimal granulation process for manufacturing coin type Li primary batteries. Also, coin type Li primary batteries were made by granules prepared under various granulation methods and their battery performance and conduction of positive electrode were evaluated. It was found that granules made by high shear mixer showed better performance of battery and positive electrode. It was because the conductive material received high shear force by the high shear mixer, and binding performance of expanded graphite fully appeared.
抄録全体を表示