N-doped interconnected carbon aerogels as an efficient SeS2 host for long life Na-SeS2 batteries

Selenium sulfide (SeS2) cathodes have attracted much concerns as an optimized choice comparing to sulfur and selenium for lithium and sodium storage. However, it also suffers from poor cycling stability due to the dissolution of reaction intermediate products. In this study, N-doped Interconnected carbon aerogels was applied as an efficient SeS2 host by infiltrating selenium sulfide into its microporous structure (denoted as SeS2@NCAs), which could effectively accommodate the volume change of SeS2 during cycling and alleviate the dissolution of reaction intermediate products. Therefore, as for Na storage, the SeS2@NCAs cathode delivers a superior long-term cycling performance of 536 mA·h·g−1 at a current density of 0.5 A·g−1 after 1,000 cycles with only 0.04% capacity decline per cycle and a high rate performance (524 mA·h·g−1 at 2 A·g−1 and 745 mA·h·g−1 at 0.1 A·g−1 retained), indicating the remarkable cycling stability of SeS2@NCAs cathodes.