Performance advanced battery systems

Another conventional battery technology that has been considered for EVs is Ni/Cd. Although capable of somewhat better performance than lead-acid in some respects, this battery is also more costly and does not equal the performance levels possible with advanced battery systems. It is unlikely to see widespread use in EV applications in the U.S. although there are reported to be more than 10,000 EVs using Ni/Cd batteries presently on the road in Europe [23]. Because of the toxicity of cadmium, which precludes disposal, and the value of the nickel, there are well-developed processes for recycling of Ni/Cd batteries. Most of the facilities in Europe are dedicated Ni/Cd battery recycling plants. 

At present batteries worth more than 30 billion USD are produced every year and the demand is still increasing rapidly as more and more mobile electronic end electric devices ranging from mobile phones to electric vehicles are entering into our life. The various materials required to manufacture these batteries are mostly supplied by the chemical industry. Ten thousands of chemists, physicists and material scientists are focusing on the development of new materials for energy storage and conversion. As the performance of the battery system is in many cases a key issue deciding the market success of a cordless product there is in fact a kind of worldwide race for advanced batteries. 

The basic thermodynamic and electrochemical kinetic concepts involved in batteries and the parameters used to evaluate their performance are summarized in Section 2.2. The most widespread primary and rechargeable systems are described by highlighting the most recent advances in Section 2.3. Supercapacitors and fuel cells, whose importance in the field of energy conversion is growing, are also briefly treated in this section. The lithium-based rechargeable systems, the most advanced batteries with the highest performance, are discussed in detail in Section 2.4, with particular emphasis on the new materials on which these batteries are based. 

Lithium-ion batteries have been commercially available for over 2 decades and currently represent state-of-the-art power source for all modem consumer electronic devices. Due to its advanced chemistry, Li-ion cells exhibit superior performance characteristics over most other rechargeable battery systems. The lithium-ion technology offers a high energy and power density, long life, and reliability that makes it attractive for electric drive vehicle (EDV), military, and aerospace fields, and large format Li-ion cells and battery packs are currently under development for such applications. 

The calculating function provides advanced features for a Li-ion battery system since calculations, either performed locally or remotely, can provide significant insight into the performance of the battery system. 

Increases in the energy density of primary hatteries has tapered off during the past decade as the existing battery systems have matured and the development of new higher energy batteries is limited by the lack of new and/or untried battery materials and chemistries. Nevertheless, advances have been made in other important performance characteristics, such as power density, shelf life and safety. Examples of these recent developments are the high power zinc/alkaline/manganese dioxide batteries for portable consumer electronics, the improvement of the zinc/air battery and the introduction of new lithium batteries. 

As with the primary battery systems, significant performance improvements have been made with the older secondary battery systems, and a number of newer types, such as the silver-zinc, the nickel-zinc, nickel-hydrogen, and lithium ion batteries, and the high-temperature system, have been introduced into commercial use or are under advanced development. Much of the development work on new systems has been supported by the need for high-performance batteries for portable consumer electronic applications and electric vehicles. Figure 22.1 illustrates the advances achieved in and the projections of the performance of rechargeable batteries for portable applications. 

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