New battery technology

The need for better batteries is a recurring theme in the effort to reduce energy consumption and in the effort to make electricity increasingly portable. As the world depends more and more on portable devices and turns to electric vehicles to reduce pollution, it becomes important that lightweight, long-hved batteries be developed. Additional desirable features of batteries include safety, dependabihty, environmental friendliness, and cost. This article considers battery technology currendy used in transportation, including in electric vehicles and spacecraft. 

A battery is a collection of one or more electrochemical cells that convert chemical energy into electrical energy via electrochemical reactions (oxidation-reduction reactions). These reactions take place at the battery s anode and cathode. The electrochemical cells are connected in series or in parallel depending on the desired voltage and capacity. Series connections provide a higher voltage, whereas parallel connections provide a higher capacity, compared with one cell. 

Battery performance is measured in terms of voltage and capacity. The voltage is determined by the chemistry of the metals and electrolytes used in the battery. The capacity is the number of electrons that can be obtained from a battery. Since current is the number of electrons released per imit time, cell capacity is the current supplied by a cell over time and is normally measure in ampere-hours. Battery specialists experiment with many different redox combinations and try to balance the energy output with the costs of manufacturing the battery. Other factors, such as battery weight, shelf life, and environmental impact also factor into the battery s design. 

Lead-acid batteries are used in gasoline-driven automobiles and in electric and hybrid vehicles. They have the best discharge rate of secondary battery technology, they are the cheapest to produce, and they are rechargeable. The chemical reactions are  

The positive electrode is made of lead dioxide (Pb02) and is reduced to lead sulfate (PbS04), while sponge metallic lead (Pb) is oxidized to lead sulfate at the negative electrode. The electrolyte is sulfuric acid (H2SO4), which provides the sulfete ion (S04 ) for the discharge reactions. 

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The rechargeable lithium-ion battery is one of a number of new battery technologies which have been developed in the last ten years. TTiis battery system, operating at room temperature, offers several advantages compared to conventional aqueous battery technologies, for example,... 

Modeling has become an important tool in developing new battery technology as well as for improving the performance of existing commercial systems. Models based on engineering principles of current distribution and fundamental electrochemical reaction parameters can predict the behavior of porous... 

S. Kawauchi, T. Iijima and T. Kawase, New Battery Technologies, Matsushita Battery Industrial Co. Ltd, Osaka, 1994. 

New civilian markets for batteries appear to be substantial. In the United States, the electric utility industry is estimating a market by the year 2000 of 0.3 billion per year for battery off-peak energy storage systems, provided new battery technology is available (11). This corresponds to a total installed battery capability of 40,000 MW by the year 2000. The U.S. market for batteries for over-the-road consumer electric vehicles is projected to be 4 billion per year if only 10 percent of new vehicles would be battery-powered. More research is needed to enter this potential market. Realization of that market requires that battery prices be reduced to about 100/kWh and lifetimes be extended to more than 3 years. Multibillion-dollar annual markets for associated equipment such as electric drive motors, microprocessor controls, and related electronics would be created by the successful penetration of the market by electric automobiles. 

Under low-temperature conditions, the battery will rarely achieve a full SoC. In fact, the specifications laid down in the various standards do not represent the duty the SLI battery has to serve in a modern automobile. For advanced vehicle electrical systems, which may be a motivation for new battery technologies like the VRLA, it is essential to know the expected operating condition in order to evaluate alternative energy-storage technologies. 

Realization of the great societal benefits to be derived from the new battery technologies has galvanized an extensive research activity that promises continued development. 

There is an (uigoing need to treat various heart conditions, hearing loss, and chronic pain. Improvements to electronic circuit components and designs, along with the batteries that make them function, will continue. New therapies and device features wiU be enabled by new battery technologies. 

Recommended battery seminars are the Power Conference, Annual Battery Conference, The International Seminar on Primary and Secondary Battery Technology and Application, andthe Power Source Conference, Mobile Communications magazine frequently feature articles addressing new battery technologies. This information is commonly user-oriented and provides hints on how to get the most out of rechargeable batteries. Additional battery information can be found on the Web under NiCd, NiMH, Battery Analyzer, or Battery, in general. 

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