3300 mAh zinc-air batteries for portable consumer products

Abstract

Summary form only given, as follows. Electric Fuel has introduced its line of Instant Power/sup TM/ brand batteries, configured as disposable replacement batteries for cellular telephones, and as portable chargers for rechargeable cellphones, personal digital assistants (PDAs) and other portable consumer products. All of the products to date are built using the company's 3300 mAh, 1.4 V zinc-air cell. The cells are assembled in series to provide the required voltage. Generally, four cells are used to provide voltage sufficient for emulating or charging a 3.6 V lithium-ion battery, although some models are comprised of five, or even six, cells, in order to obtain a higher total voltage. Electric Fuel's patented cell is a prismatic cell constructed from two roughly rectangular metal case components, an oxygen reduction cathode, and a zinc gel anode. The metal casing is perforated on the cathode side to allow air access to the cathode. Cells are fabricated on automated equipment capable of producing more than one million cells per month. The Instant Power batteries are optimized for all modes of cellular operation, including digital modes such as GSM which require pulses of up to 2 A, and analog modes which require continuous current draw of up to 500 mA. Batteries used as chargers can support simultaneously charging and operating the device. The batteries deliver at least 3300 mAh in all of these modes, although in the charger some energy is lost due to the relative inefficiency of the power electronics and of the rechargeable battery itself. The paper discusses additional details of the cell and battery construction, applications and performance.