LiFePO4 Cathode Material Designed for Use in Lithium-Ion Batteries with Application to Electric and Hybrid-Electric Vehicles

72170 One of the factors limiting rapid development of electric and hybrid-electric vehicles is the cost and performance of battery technologies. Lithium-ion battery technology represents the state-of-the-art for portable electronics, but in order to meet the demands of hybrid electric vehicle, further development is required, especially in the area of cathode materials. LiMn2O4 and LiFePO4 are candidate cathode materials for application in lithium-ion batteries designed for hybrid electric vehicle, having suitably low cost. However, demonstrations to date show LiMn2O4 suffers from Mn dissolution into the electrolyte and possesses low capacity, both of which presently limit its use for application into hybrid electric vehicle. LiFePO4 has sufficiently high energy density but low conductivity, which limits high power capabilities. Solving these issues are a key requirement for hybrid electric vehicle applications. Contractor has identified a path towards development of a LiFePO4 material that allows lithium-ion technology to meet the demands of hybrid electric vehicle application. The contractor approach combines molecular modeling, materials synthesis and electrode fabrication. Molecular modeling will identify chemical dopants which, when synthesized under appropriate conditions, lead to improved material conductivity. Careful control of synthetic parameters will be used to allow optimization of particle size and morphology. Synthesized materials will then be formulated into electrodes optimized for the specific material and these electrodes will be tested in lithium-ion battery systems. The desired final product will be a LiFePO4 cathode material that can be incorporated into large-scale lithium-ion batteries for application into hybrid electric vehicle. Contractor's goal for Phase I was to demonstrate a LiFePO4-based material having power capability which is similar to the current industry standard, LiCoO2, thereby allowing LiFePO4 material commercialization into lithium-ion batteries. This was accomplished in the contractor laboratories using proprietary doping and surface treatments identified through molecular modeling and synthetic efforts. Particular attention was given to optimizing performance for supporting the requirements of lithium-ion batteries used for hybrid electric vehicle application. In phase II contractor is planning to optimize and demonstrate high conductivity (and hence high power ability) for LiFePO4 samples produced using a low cost synthetic strategy. Demonstration of this chemical manufacturing method will bring the prodcut closer to commercialization. An electrode formulation study will allow incorporation of the new material in 1Ah Li-ion cells with high specific power. Commercial Applications and Other Benefits as described by awardee: The hybrid electric vehicle business represents a sizable market for battery technology and contractor's goal is to develop a cathode material that allows lithium-ion battery technology to meet the requirements for the hybrid electric vehicle market. The contractor LiFePO4 technology has the potential to advance hybrid electric vehicle development efforts hastening widespread use of hybrid electric vehicle¿s, decreasing the US dependency on petroleum imports and improving the environment through reduction of automobile emissions. LiFePO4 can also serve as an environmentally friendly replacement of the LiCoO2 material, which is too costly for hybrid electric vehicle applications, used in today¿s lithium-ion batteries.