Qifan Peng1 Yunling Ge1 Hongyuan Shao1 Yuepeng Guan1 Yaqin Huang1

1, Beijing University of Chemical Technology, Beijing, , China

Lithium-sulfur (Li-S) batteries have been considered as a promising candidate for next-generation energy storage devices, owing to the extremely high theoretical specific capacity and energy density of sulfur. However, the shuttle effect of lithium polysulfide hampered its commercial application. Trapping of polysulfides requires appropriate molecular functionalities built into a suitable nanostructure in the sulfur cathode. In this work, we present a scalable, room temperature, one-step approach to fabricate gelatin-encapsulated hollow sulfur nanospheres (GEHS) for sulfur cathode, allowing excellent control over electrode design from nanoscale to macroscale. The typical scanning electron microscopy (SEM) images of the gelatin-encapsulated hollow S nanospheres have been carried out. These SEM images show the particle size is highly monodispersed and particles are in the range of 170–220 nm. The stability was also checked for the different batteries by cycling at different rates. The GEHS cathode, cycling at 0.1, 0.2, 0.5, and 1.0 C rates, displayed reversible capacities of about 989, 893.7, 844.4 and 832 mA h g-1, respectively. When the rate was switched back to 0.1C, the electrode nearly regained its original capacity of about 967 mA h g-1. The rate capability of GEHS cathode is clearly superior to that of normal cathode, indicating that the GEHS cathode material is highly robust.

Financial support from the National Natural Science Foundation of China (No. 51672020) is gratefully appreciated.