Current Issues and Market Trends of Li-Ion Batteries for Consumer Applications

The focus of this chapter is Li-Ion batteries in consumer applications. There is a long history and a large market of non Li-Ion batteries-many of them primary lithium batteries—but this other field is too extensive for inclusion here except to mention the recent apparent success to commercialize, after a long gestation period, the lithium metal-polymer electrolyte technology in the telecommunications backup application. The reader should also note that Li-Ion batteries are now finding their way into many non-consumer applications. This, too, is outside the scope of the present chapter.The subject begins with the lithium metal/molybdenum disulfide system introduced by Moli Energy in the late 1970, early 1980 period. Other rechargeable lithium systems were introduced for consumer applications about this same time but the Moli cell was the first to reach wide spread use. As is very well known, the product encountered a safety issue. Was it just faulty construction or was the lithium metal-liquid electrolyte system so unstable as to be unacceptable for consumer applications? (And does the “dry” polymer electrolyte solve this problem?) Whatever the technical explanation, the technology gained a perceived image as unsafe and there was a need to move on. Sony researchers (and others) saw the opportunity and developed a high capacity carbon based anode. (Research into lithium intercalation in graphite has a much longer history but the capacities needed for practical use had generally not been observed.) This anode, along with a high voltage metal oxide cathode was key to what came to be called the Li-Ion battery, first officially described in 1991. The name was intended to dissociate the new system from the “unsafe” lithium battery. It is, of course, also to imply a “rocking chair” type battery (or the physicist's battery as early on mentioned). The researchers, themselves, cannot be blamed for the ensuing confusion from the unfortunate use of “anode” and “cathode” in a rechargeable system. Not incidental to Sony's development of Li-Ion technology was a need to leapfrog the nickel-metal hydride technology in the growing portable electronics market.