An amorphous niobium polysulfide based nanocomposite enables ultrastable all-solid-state lithium batteries

Transition metal sulfide cathodes have attracted much attention in all-solid-state lithium batteries due to their high theoretical specific capacity. However, the low ionic/electronic conductivities and volume expansion of sulfide cathodes are great challenges for their practical application. In this work, an amorphous NbS4.5 (a-NbS4.5) based nanocomposite cathode is designed for all-solid-state lithium batteries. Combining with Super P, the electronic conductivity of a-NbS4.5 is improved and volume changes are suppressed. Further coupling with Li7P3S11 solid electrolyte, both interfacial contact and ionic conductivity are enhanced. As a result, the all-solid-state batteries using the a-NbS4.5/20%Super P@15%Li7P3S11 cathode exhibit high reversible capacity and excellent cycling stability, delivering an initial discharge capacity of 975.7 mA h g(-1) at a current density of 0.1 A g(-1) and a reversible capacity of 464.8 mA h g(-1) after 2500 cycles at 0.5 A g(-1). These results demonstrated that the a-NbS4.5/20%Super P@15%Li7P3S11 nanocomposite is a promising potential cathode for all-solid-state batteries.

Automated summary

In this study, an amorphous NbS4.5 (a-NbS4.5) based nanocomposite cathode was developed for all-solid-state lithium batteries. By combining with Super P, the electronic conductivity of a-NbS4.5 was improved and volume changes were suppressed. Coupled with Li7P3S11 solid electrolyte, both interfacial contact and ionic conductivity were enhanced. The a-NbS4.5/20%Super P@15%Li7P3S11 nanocomposite exhibited high reversible capacity and excellent cycling stability, showing promising potential as a cathode for all-solid-state batteries.