Enhanced Nanostructuring Approach for Thermal Battery Cathode Materials

摘要

Understanding the potential and capabilities of nanoscale cathode materials can benefit the U.S. Army and the Armament Research, Development and Engineering Center (ARDEC) immensely. There is a growing concern over the power and energy needs of future munitions and military technologies. It is widely viewed that the current power and energy capabilities cannot meet the needs of future smart munitions, and improvements will need to be made at the materials level in order to make advancements. The use of Nanomaterials offers the potential to produce thermal batteries with performance improvements, such as higher voltages and increased current densities. In this study, nanoscale disulfide powders (iron, cobalt, and nickel) were synthesized using a fully scalable method, and characterized utilizing SEM, XRD, XRF, BET, EDS, and other techniques. High energy ball mills, which provide extremely high amounts of kinetic energy into the particles, were used to impart nanostructure into the FeS_2, CoS_2, and NiS_2 powders. All processing was carried out under an inert atmosphere to minimize oxygen pickup. The mechanical alloying process has multiple variables which were modified in order to create powders with tunable properties, and most importantly, to determine properties which are optimal for the disulfide cathode materials performance. Several processing variables were modified, such as rotational speed, milling time, and milling media type, in order to change the material properties. The nanoscale disulfide cathode powders were extensively characterized using the in-house U.S. Army ARDEC characterization facilities. This study successfully used powder processing technology to produce kilogram quantities of nanostructured disulfide powders for use as cathode materials in thermal battery systems, and this process can be applied to other potential cathode candidate materials.