TABLE OF CONTENTS Today, the most promising batteries are based on the lithium ion (Li-ion), lithium ion polymer (Li-ion-P), nickel metal hydride (NiMH), and nickel cadmium (NiCd) batteries, all being of the rechargeable type.
The lithium ion battery system (Pistoia, 1994; Scrosati, 1995), commonly used in high energy density applications, is the fastest growing technology. Despite the fact that it is the latest to emerge from the laboratory into the real-world applications, this revolution in battery technology is targeted to fulfil the requirements for future applications like electric vehicles and biomedical devices such as an artificial heart (Owens, et al., 1984). The pioneering work for research on lithium batteries was started by G. N. Lewis in 1912, but it was not until the seventies that the first non-rechargeable lithium batteries became commercially available. Lithium (Bach, 1985), being the lightest of all metals, has the greatest electrochemical potential and provides the largest energy content. However, it was found that occasional shorts from lithium dendrites developed in lithium electrodes could cause thermal runaway. The temperature would approach the melting temperature of metallic lithium which could result in violent explosions (Wilkinson, et al., 1990). Due to this inherent instability, especially during the charging process, attempts to develop rechargeable lithium batteries failed and research has since shifted to a non-metallic lithium battery. The concept of shuttling lithium ions between insertion electrodes was first proposed in the 1980s (Lazzari and Scrosati, 1980;
