Intermetallic niobium boride toward efficient adsorption and catalysis of polysulfides in Lithium-Sulfur batteries

The shuttling and sluggish conversion kinetics of lithium polysulfides (LPSs) seriously hinder the cycling performance of Li-S batteries. To address this issue, a NbB 2 @CC cathode/separator interlayer is designed by dispersing NbB 2 nanoparticles in a textile carbon cloth (CC). NbB 2 has stronger adsorption ability than CC, which can effectively capture the dissolved LPSs in the electrolyte. Then, under the catalysis of NbB 2 , the reaction kinetics of LPSs is greatly facilitated. Benefiting from these advantages, the Li-S cell can offer a high discharge capacity of 735.2 mA·h·g −1 at 1C, with very small capacity fading in 800 cycles. It also shows excellent low-temperature performance, which can deliver a stable discharge capacity of 802 mA·h·g −1 at −10 °C. Moreover, a high areal capacity of 7.34 mA·h·cm −2 is achieved for the Li-S cell with a high sulfur loading of 9.45 mg·cm −2 and low electrolyte/sulfur ratio of 6.34 µL·mg −1 .