Development of Nanoporous Carbide-Derived Carbon Electrodes for High- Performance Lithium-Ion Batteries

摘要

Lithium ion batteries are the state-of-the-art power sources for portable electronic devices and, due to their superior energy and power densities, are promising candidates for the demanding energy storage applications of the U.S. Navy and other branches of the military. While graphitic carbon is currently the most common anode material in lithium ion batteries, it suffers from low specific capacity (approx. 372 mAh/g) and poor power characteristics. In contrast, amorphous carbons allow for faster charge/discharge kinetics and were found to exhibit specific capacities of up to 1000 mAh/g due to a different, and still unknown storage mechanism. This work examines the suitability of amorphous carbide-derived carbon (CDC) anodes for high-power and high-energy density lithium ion batteries. Using different material characterization techniques, such as Raman Spectroscopy, X-Ray Diffraction (XRD), and Scanning Electron Microscope (SEM), we aim to determine the relationship between the structural features of CDC to its electrochemical performance. Studies were conducted on three titanium carbide (TiC)-based CDC powders, synthesized at 600, 1000, and 1200 C. Custom-made CDC anodes were fabricated, tested and cycled against commercial LiCoO2 and lithium metal cathodes in button-type coin cell enclosures. Electrochemical testing revealed specific capacities approaching 300 mAh/g. While the observed specific energy is lower than that of a conventional graphite anodes, the results are promising and may provide deeper insights into the relatively unknown charge storage mechanism in amorphous carbons. Our results also indicate that CDCs allow for substantial improvements in power characteristics, but additional research is needed to verify the obtained results and further optimize the electrode fabrication process.