An electrolytic manganese dioxide improved for tool wear reduction, methods for preparing the improved electrolytic manganese dioxide and for preparing a positive-electrode precursor, and a primary battery are provided. One method includes displacement-washing neutralized electrolytic manganese dioxide with a solution including a corrosion inhibitor configured to be at a first predetermined concentration. The method further includes drying the washed electrolytic manganese dioxide to collect improved electrolytic manganese dioxide including the corrosion inhibitor configured to be at a second predetermined concentration within the improved electrolytic manganese dioxide to minimize corrosion of a metal material in contact with the improved electrolytic manganese dioxide. The corrosion inhibitor includes one of a benzoate salt, a phosphate salt, a carbonate salt, a metaborate salt, a tetraborate salt, a metaperiodate salt, and a meta-aluminate salt.