Currently available Li-ion batteries do not meet Department of Energy targets for electric vehicle (EV) or hybrid electric vehicle (HEV) applications. The problem is that today's cathode materials do not allow the specific energy and power density targets to be achieved while simultaneously being low cost, safe under abusive conditions, and environmentally benign. This project will develop electronically conductive lithium cathode materials, which have low raw- materials and manufacturing costs, high energy and power densities, and are electrochemically stable under extreme conditions, and environmentally benign. In Phase I, compositions and synthesis procedures were developed for a class of doped, lithium-transition-metal-phosphate cathodes having electronic conductivities exceeding 10-3 S/cm at room temperature as well as novel nanoparticulate morphologies enabling high utilization at high rates. Cathodes of conventional formulations were fabricated and tested, and exhibited high charge capacities of 155 mAh/g at low rates (C/5) while also retaining capacities as high as 75 mAh/g for 50C rate deep discharge. These properties suggest exceptional continuous discharge and pulse-power capabilities in full cells. In Phase II, a pilot-scale process will be developed for cathodes that can meet DOE cost targets in full-scale production. Cells with greater than 0.2Ah capacity will be developed using these cathodes. Pulse-power, cycle life, and accelerated-calendar-life tests will be conducted according to DOE protocols.
Commercial Applications and Other Benefits as described by the awardee: The new cathode material should allow for the development of high power density, low cost batteries that are safe at larger cell sizes. Potential applications include the growing HEV market, future fuel cell hybrids, and backup power systems.
