Sandwich cathode design for alkali metal electrochemical cells having circuit safety characteristics

摘要

A new sandwich cathode design having a first cathode active material of a relatively low energy density but of a relatively high rate capability sandwiched between two current collectors and with a second cathode active material having a relatively high energy density but of a relatively low rate capability in contact with the opposite sides of the two current collectors, is described. The present cathode design is relatively safer under short circuit and abuse conditions than cells having a cathode active material of a relatively high energy density but a relatively low rate capability alone. A preferred cathode is: CFx/current collector/SVO/current collector/CFx. The SVO provides the discharge end of life indication since CFx and SVO.cathode cells discharge under different voltage profiles. This is useful as an end-of-replacement indicator (ERI) for an implantable medical device, such as a cardiac pacemaker.