Design and synthesis of novel structured electrode materials for next generation lithium-ion batteries

Abstract

Owing to the continuous growth of the electronic industry in recent years and the call for miniaturiza-tion and high performance, much effort has been focused on improving the operation of lithium-ion batteries (LIBs). Moreover, as they are increasingly applied in fields from the portable devices such as portable phones and notebooks to the large devices such as electrical vehicles (EVs) and hybrid electrical vehicles (HEVs), further the development of LIBs is required to obtain high rechargeable capacities and cycle stabilities. To date, carbonaceous materials including graphite are widely used as anode materials in commercial LIBs; they have attracted considerable attention because of their low and flat lithium-ion intercalation potential and superior stability. The use of graphite as an anode material is still restricted, however, because they can accommodate only one lithium atom for every six carbon atoms, which results in capacity limitations. Therefore, new electrode materials with high capacities for next-generation LIBs need to be developed. Since the Tarascon group reported the application potential of transition-metal oxides as LIB electrode materials, many new materials have been explored, including metal oxides and alloys that can alter the capacity limitation of graphite. Although these metal oxides and alloys are known to possess high capacities, their large volume change during lithium-ion insertion and extraction, which leads to electrode pulverization and rapid capacity fade, hinder their use in practical applications. As a result, there have been various approaches to improve the electrochemical properties of LIBs by developing novel nanostructured electrode materials. The research for this thesis consists of a study on the design and synthesis of novel structured elec-trode materials using spray pyrolysis for next-generation LIBs. During spray pyrolysis, a large number of droplets, which are generated from the spray solution by an ultra...