Metal Oxide Cathodes for Cost Effective Li-Ion Batteries : Investigations on LiFeO2 and LiFePO4 bulk and thin film cathodes for micro-power generation

The substantial development of lithium ion batteries with high energy density and capacity is originated from the identification of a good cathode host that can accommodate both Li+ ions and electrons with minimal structural changes. As a part of intensive search for alternative materials with cost effective and non-toxicity, lithium iron oxide (LiFeO2) and lithium iron phosphate (LiFePO4) are considered to be promising cathode materials for lithium rechargeable batteries. In the present investigation, LiFeO2 and LiFePO4 have been synthesized by using hydrothermal synthesis. Growth of these compounds especially in thin film form is of great interest as a positive electrode in the fabrication of all solid state rechargeable micro-batteries to power microelectronics. Hence, investigations are also aimed to deposit LiFeO2 and LiFePO4 films by rf magnetron sputtering. The microstructural, electrical and electrochemical properties of both bulk and thin film LiFeO2 and LiFePO4 cathode materials were studied systematically.