Flame-assisted synthesis of Li ion battery materials

点击翻译按钮获取中文摘要

0928964AxelbaumThis award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).Research under this award aims to develop the needed science for a flame-synthesis process to synthesize nanoparticles of lithium manganese spinel (LiMn2O4) and to extend this process to produce olivine-type lithium iron phosphate (LiFePO4) nanoparticles. Scientific understanding is crucially needed to be able to control particle size, doping and carbon coating. If successful, this work will lead to a low-cost, high-production method for producing high-performance Li-ion battery materials. With the rising need to reduce our dependence on foreign oil and greenhouse gas emissions, this research will enable the use of hybrid electric vehicles and renewable energy.The basic approach is to introduce a fine aerosol of precursors into a premixed or diffusion flame, where temperature and flame chemistry produce the nanoparticles. The technical steps to be followed in this research will be guided by previous work in the Li-Mn-O system and by new equilibrium calculations on that system and the Li-Fe-P-O system. Size distribution of precursor aerosol was previously shown to be an important factor for achieving nanoscale particles, so a new precursor-generation and size-refinement system will be devised. In addition, doping of the LiMn2O4 with Co, Mg, Ni, Al in a hydrogen/oxygen diffusion flame particles will be studied, optimizing the synthesis conditions to remove impurities and post-processing the as-prepared powders to optimize the electrochemical performance (cyclability, discharge capacity). In a related part of the study, LiFePO4 particles nanoparticles will be carbon-coated in the flame by condensation and pyrolysis of polycyclic aromatic hydrocarbons on the surface of the particle. Electrochemical performance in test cells will be performed with particle sizes segregated by a differential mass analyzer.The research could lead to new battery technology that will complement fuel cell efforts toward remote power generation and automotive use for the next ten to twenty years. Students conducting the research will have a unique entry with the area of ion battery technologies, which are poised to be the storage technologies of the future. Likewise, high school and undergraduate students will be engaged through an outreach program.