Batteries operational characteristics

The impedance behavior of a battery can reveal a significant amount of information about battery operation characteristics (34,44). The impedance of an electrode or battery is given by ... 

M.A. Fetcenko, K. Young, S.R. Ovshinsky, and T. Ouchi, Hydrogen storage alloys having improved cycle life and low temperature operating characteristics, US Patent 7393500, assigned to Ovonic Battery Company, Inc. (Rochester Hills, MI), July 1,2008. 

Although the hydrometallurgical process is more complicated than the thermal process, its principal virtue resides in the essential recovery of all of the materials in spent lead-acid batteries, including the plastic materials, and in the minimal generation of waste streams. As actufd data become available on the operational characteristics and the economics of full scale plants, it will be possible to make a meaningful assessment of this process and its merits relative to other processes for the recycling of lead-acid batteries. 

Two physical properties of separators, which are important to the operating characteristics of a battery, are electrolyte absorption and electrolyte retention. Any good separator should be able to absorb a significant amount of electrolyte and also. retain the absorbed electrolyte when the cell is in operation. These are more important in sealed cells where no free electrolyte is present A maximum amount of electrolyte in the separator is desirable to achieve minimum cell internal resistance. 

Two physical properties of separators, which are important to the operating characteristics of a battery, are electrolyte absorption and electrolyte retention. 

TABLE 10.16 Operating Characteristics of Common Battery Types... 

Energy and power density (ratio of energy and power deliverable by a battery to its volume) of batteries determine their suitability for most electrical devices. Other important criteria for use in medical devices are safety and reliability in operation during lifetime of the device (up to 10 years or longer), predictability of battery performance characteristics, and provision of device replacement indicators based on battery depletion and mechanical design features such as shape and size to allow efficient packaging in the device and for patient comfort. 

General electrochemical systems work optimally between 15 and 25 °C. Typical characteristics change at higher temperatures, for instance discharge behavior improves while others such as rechargeability and self-discharge deteriorate. Limit for economic battery operation is about 65 °C. Naturally batteries can be operated above this temperature if over-proportional reduction of lifetime can be accepted. 

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