this invention relates to rechargeable manganese dioxide cells , and particularly to the cathodes therefore . in keeping with the present invention , the cathodes are essentially unconstrained -- that is , no cage is used in the cell between the cathodes and the anodes . the cathode is restricted from significantly changing its dimensions during discharge of the cell , when it is inclined to swell -- as opposed to the tendency of the cathode to contract during a charge cycle . the cathode substantially fills the entire space allotted for it within the cell , with a light accommodation for height - wise or longitudinal expansion or growth of the cathode of bobbin - type cells , or crosswise expansion or growth of button - type cells . there may be additives in the cathode mix , including particularly conductive fibres of graphite or other conductive materials ; and other materials may also be added to the cathode mix , including metallic additives . methods of manufacture are also provided by the present invention , including compaction and recompaction of the cathode pellet , and a range of compaction pressures is suggested . cells in keeping with the present invention are capable of exhibiting high current drain rates , and long cycle life .