Sulfur is one of the most promising cathode candidates for lithium batteries for emerging advanced energy storage technology, portable electronics, electric vehicles, and grid-scale energy station. Its overwhelming advantages include abundance, low cost, environmentally friendly and most importantly, high theoretical capacity (1675 mAh g^-1) and energy density (2600 vs 387 Wh kg^-1 of traditional Li-ion batteries) [1-3]. However, there are major issues which hindered the practical application of lithium-sulfur (Li-S) batteries such as rapid fading of specific capacity, low columbic efficiency and low cycle life due to the “shuttle effect” during charge/discharge process. Here, we present a study using acid treated carbon nanotubes (CNT) as a nano-confinement material for sulfur to develop high areal loading and areal capacity sulfur/CNT composite as cathode for Li-S batteries with a goal to achieve high performance with high specific capacity and long cycle life [4]. During the synthesis process, CNT is segmented to relatively short length followed by chemical reaction deposition and heat treatment to encapsulate sulfur. Morphology of the electrode is characterized by SEM. Crystal structures and mapping results of the sample are determined by XRD and EDS. The sulfur loading in the composition is determined by TGA. Surface characterization is investigated by FTIR. Electrochemical testing is further performed in half-cells using lithium foil as counter and reference electrode and evaluated by cyclic-voltammetry (CV), galvanostatic charge/discharge cycle test and electrochemical impedance spectroscopy (EIS). The detailed results of specific capacity, rate capability, and cyclability will be presented and discussed during the conference.

References:

1. Melot, B.C. and Tarascon, J.M., 2013. Design and preparation of materials for advanced electrochemical storage. Accounts of chemical research, 46(5), pp.1226-1238.
2. Evers, S. and Nazar, L.F., New approaches for high energy density lithium–sulfur battery cathodes. Accounts of chemical research, 46(5), 2012. pp.1135-1143.
3. Manthiram, A., Fu, Y. and Su, Y.S., Challenges and prospects of lithium–sulfur batteries. Accounts of chemical research, 46(5), 2012. pp.1125-1134.
4. Li, M., Carter, R., Douglas, A., Oakes, L. and Pint, C.L., 2017. Sulfur Vapor-Infiltrated 3D Carbon Nanotube Foam for Binder-Free High Areal Capacity Lithium–Sulfur Battery Composite Cathodes. ACS nano, 11(5), pp.4877-4884.