Cycling Performance and Interfacial Phenomena of High-Energy Li-Ion Battery with Sulfur-Based Cathode and Silicon-Based Anode

Abstract

Li-ion battery market is currently expanding from small, portable batteries to electric vehicles and energy storage systems. To meet the demands, more than doubled energy density than that of currently used batteries is required. The energy density of current batteries, which consist of lithium metal oxide cathode and graphite anode materials, is however limited. A general approach to increase the energy density of a battery is the replacement of current cathode and anode active materials to higher capacity materials, and electrolyte that is interfacially compatible to them. Recently, sulfur-based cathode and silicon-based anode materials are considered as one of the most promising active materials for high-energy batteries. Earlier reports on sulfur-based cathode and silicon composite anode in half-cells showed a good cycling performance.1,2 However, there are just a few reports on the full-cell with those materials.3,4 To date, the best performance of full-cell was obtained when being assembled with carbon composite of elemental sulfur cathode, lithiated nanosphere Si/SiOx anode and a polysulfide-containing electrolyte, showing the capacity of 750 mAhg-1 and capacity retention of 85 % at the 500th cycle.3 However, the combination of sulfur-based cathode and silicon-based composite anode in a full-cell face several common issues such as the lack of Li+ source of sulfur cathode, solvent intercalation into graphite anode, and possible interfacial reaction between anode and soluble polysulfide formed during cycling. To overcome those issues, researchers have used Li2S instead of sulfur, fabricated anode with functional binder to prevent solvent intercalation, and modified electrolyte with polysulfide additive.3-5 However, interfacial reaction behavior in full-cells is unknown. In this study, we demonstrate good cycling performance of a full-cell composed of a new micron-sized sulfur-based cathode material and submicron-sized lithiated silicon-based anode material. Correlation between the cycling performance and interfacial phenomena would be discussed in the meeting. Acknowledgements This work was supported under the framework of international cooperation program managed by National Research Foundation of Korea (2015K2A5A3000068) and German Academic Exchange Service (57141898), and by the Ministry of Trade, Industry & Energy (10049609) of Korea, and Nano-Material Technology Development Program by the Ministry of Science, ICT and Future Planning (2009-0082580) of Korea.