Sloping discharge curve. Powdered carbon is used in the cathode mix, usually in the form of carbon black to improve conductivity of the mix and for moisture retention. Cathodes are a mixture of manganese dioxide, carbon conductor and electrolyte. Anodes are zinc alloy can. The can also confines the active materials in the battery.
Carbon electrode serves as the cathode current collector.
Top and bottom covers provide contact surfaces of plated steel. The outside of the battery is covered with plastic film, Kraft paper and a printed plastic label. Asphalt or plastic closure acts as the battery seal. Venting mechanisms are incorporated in the battery either through the carbon electrode or plastic seal. Flat cells used in the construction of 9 volt batteries are of the LeClanche system.