Hydrogen-bonded organic framework-sulfur composite for high performance lithium–sulfur batteries

Abstract

With the rapid development of energy storage devices, lithium–sulfur batteries are considered as one of the promising candidates due to their high energy density (2600 Wh Kg−1) and low cost of sulfur. Despite these advantages, the application of lithium–sulfur batteries is limited by many issues, such as the shuttle effect of polysulfide and slow redox reactions. In this paper, hydrogen-bonded organic frameworks (HOFs) materials are chosen for the first time to improve the performance of sulfur cathodes by exploiting their unique properties. Thanks to the abundant hydrogen bond of HOFs materials, which can interact with lithium polysulfide, this S-HOF composite can inhibit the shuttle of polysulfide and enhance the transformation of polysulfide. As a result, the HOF-S composite has a high initial capacity of 1100 mAh g−1 at 0.1 C and 530 mAh g−1 at 1 C. In this paper, hydrogen-bonded organic frameworks (HOFs) materials are chosen for the first time to improve the performance of sulfur cathodes. In the S-HOF, abundant hydrogen bond sites can interact with lithium polysulfide to inhibit the shuttle of polysulfide and accelerate the redox conversion of polysulfide. Therefore, the S-HOF composite has higher capacity and cycle stability. The initial capacity of the S-HOF composite is 1100 mAh g–1 at 0.1 C and 530 mAh g–1 at 1 C.