Abstract
Lithium ion batteries (LIB) are promising energy storage devices. They are a dominant power source for portable electronic devices and also show a promise for larger scale applications, such as Electric Vehicles. Significant research efforts are devoted to the development of novel electrode materials for LIBs with improved performance. Among various materials, metal oxide including transition-metal oxides (MxOy, M = Cu, Fe, Co, Ni, Mn, etc.) and some main group metal oxides (SnO2, SiO2, etc.) are of significant interest for LIB applications due to their high theoretical specific capacity. For example, SnO2 has the theoretical capacity about 790 mAh•g-1 and CuO has the theoretical capacity about 640 mAh•g-1, which is much higher than the specific capacity of currently widely used graphite anode (about 370 mAh•g-1). However, due to large volume change and poor conductivity of metal oxide, the lithium storage capacity of metal oxide anode drops significantly during the first few cycles.
In my research, several strategies will be tried to optimize the performance of a metal oxide anode: a) Composite anodes are synthesized to compensate the volume change during the lithiation/delithiation; b) Structures are designed to improve the electron and lithium-ion conductivity of the metal oxide anode by solution treatment and coating. c) Other strategies will also to be tried to address the severe volume change and poor conductivity, for instance, to relax strain stress in a hollow structure or along a one-dimensional (1D) direction by using “nanowire” or “nanorod” anodes; or to design and synthesize core-shell structures on SnO2 or silicon anode to compensate the volume change.