ABSTRACT
Research into battery materials has continued since Volta’s experiments on a variety of different metals to the present day when battery technologies, particularly lithium-ion, are continually updated by the discovery of new and better materials. The scope for discovery is enormous; new materials for these specialist applications need not even be new chemical compositions or crystal phases – even the most minor manipulations of structure or impurity content induced by processing, for example, can have profound effects on the performance and marketability of a new product. The scope of this chapter, by contrast, is limited and therefore we will concentrate on the desired properties of the three major components of a battery, i.e., the positive electrode, negative
electrode, the electrolyte-containing separator. Some figures of merit for these are shown in Table 15.1, which illustrates the state of the art in commercial lithium rechargeable batteries with some data on the materials used in the lithium carbon/cobalt oxide cell.1-5
The above figures combine to determine the two most important figures of merit for the complete cell, which are the energy and power per unit mass or volume. Also important are the number of cycles possible and the operational life, which depend not only on the individual materials but also on the interfaces between each electrode and the electrolyte. Thus we can already see a rapid expansion in the number of experiments required to characterize a system, calling for high-throughput techniques.
