The aluminum-air reserve battery-a power supply for prolonged emergencies

An aluminum-air battery has been developed that can be stored for extended periods in the reserve condition and will provide over 360 Wh/Kg (>350 Wh/dm³) when discharged at a power output in the 1 kW range. Its rated power is developed within 30 minutes of activation. In combination with a sealed rechargeable lead-acid battery, the aluminum-air battery provides an emergency power supply that will function automatically for several days. The lead-acid battery supplies the power during mains outages lasting a few hours, with the aluminum-air battery taking over if the emergency is protracted. The exceptionally high energy density for this battery owes much to the development of a highly efficient aluminum anode alloy and to an electrolyte lifetime. A low-cost proprietary cathode makes this battery an economical attractive source of extended power supply. The described combination of rechargeable and reserve batteries is thought to be especially suitable as a source of emergency power for telecommunications systems to cover short or extended power failures