Scientific Evaluation of Nanomaterials of TiO{sub 2} and Related Derivatives in a Variety of Applications

Abstract

Objective 1. Design, synthesis and testing of Li-ion hosts for cathode service in inherently safe, long calendar life, long cycle life, high power, fast charge, secondary Li-ion batteries (Subcontract to Rutgers University). Objective 2. Design Synthesis and Characterization of Nanosensors For ChemicalBiological, and Radiological Agents (Subcontract to Western Michigan University).Objective 3. Development, Testing and Demonstration of a High-Rate LowTemperature Lithium-Ion Battery Platform.Objective 4. Interactions of Engineered Nanoparticles with Environmentally-and Societally-Important Bacteria (Subcontract to The University of California -Santa Barbara). We generated a series of electrolytes, tested those electrolytes and found that a 40% Acetonitrile + 60vol% 3-methoxypropionitrile solvent system that contained 1M-LiTFSI + 0.5M-LiBF 4 as dissolved salts was an excellent power cell electrolyte between 45degC and -40degC. If the CAN is removed and the solvent is pure 3-MPN an electrolyte that works well between 60degC and -40degC can be generated with a closed cup flash point of 79degC promoting improved safety. Further, the test cell was redesigned in an attempt to produce a testing matrix which did not limit the cell life or at least vastly extends the cell life so that active material life effects produced by this research were not masked by Li-ion cell life issues that had nothing to do with the active materials. This work was not completed in that cells with very high surface 4V actives (~10m^2/g) that allowed cycling for 6 months at 60degC were not generated. We believe we are close but the cell budget and time allowed for the research were not sufficient. Nice improvements were made from our starting point which was a cell that ballooned at 60degC and did not cycle well at -40degCComparison of Goals/ Objectives Met with Planned:The established goals of Objective One as stated in our proposal follow. Table I in the Addendum).Though the overall objective of this program is to find a Cathode Active, a Li-Ion host, that will extend cell life of nLTO anode Li-ion cells, which are currently cathode active life limited, and improve the charge/discharge rate performance of nLTO anode Li-ion cells (leading to an anode rate limited design), which again are rate limited by the cathode active, our initial research in this Project is focused on generating a Li-ion cell, of the Bellcore type, which is not in itself limiting on cell rate and cell life. Material substitutions and improvements in the cell structure were limited to commercially available materials.During the first 6 months of this program, a commercially available high molecular weight Homopolymer of PVDF was found and substituted into the cell. This substitution was essential to allow high temperature testing without softening or dissolving of the polymer by the electrolyte within the cell. The initial polymer product used was Kynar 301F. Its molecular weight is >500. This polymer of polyvinyliden fluoride is barely soluble in Acetone and Propylene Car...