RAYOVAC®'s 9-volt battery is designed for safe operation under a wide range of usage and environmental conditions. A key design feature is the use of Safety Shutdown Separator.
RAYOVAC®'s 9-volt battery is constructed using a safety shutdown separator, which upon either an internal or external short circuit, or current overload condition, will prevent thermal runaway within the cell. The cell electrodes, consisting of a lithium anode and manganese dioxide cathode, are separated by a safety shutdown separator, which is a microporous tri-layer membrane with a single layer of polyethylene membrane between two layers of polypropylene membrane. When a cell is overloaded or short circuited, the polyethylene membrane layer melts upon reaching a temperature of 134° C, significantly reducing ion flow (i.e., current). The reduction in current permits the cell to accept a short circuit or overload condition and shutdown without venting. The safety shutdown is a non-reversible process; once the cell has shutdown it is no longer usable.