A NbS₄-Based Nanocomposite Incorporating with Li₇P₃S₁₁ and Carbon for Stable All-Solid-State Lithium Batteries

Transition metal polysulfide cathodes exhibit promising potential applications in all-solid-state lithium batteries (ASSLBs) owing to their high theoretical specific capacity. However, the low ionic and electronic conductivities of transition metal polysulfide cathodes, along with their poor contact with solid electrolytes, remain critical issues. In this work, a nanocomposite cathode material NbS4/15%Li7P3S11@10%PAB-C (poly 1,3-diethynylbenzene derived carbon) for ASSLBs is synthesized. The in situ coated Li7P3S11 solid electrolyte on NbS4 enhances the interfacial contact between the active material and the electrolyte, realizing an increase in ionic conductivity from 2.10 × 10–6 S cm–1 for NbS4 to 9.76 × 10–4 S cm–1 for NbS4/15%Li7P3S11. After the carbonization of NbS4/Li7P3S11with PAB, the electronic conductivity of the material increases significantly from 2.80 × 10–8 S cm–1 for NbS4 to 5.90 × 10–2 S cm–1 for NbS4/15% Li7P3S11@10%PAB-C. The assembled ASSLBs with NbS4/15%Li7P3S11@10%PAB-C nanocomposite cathode deliver high reversible capacity and superior long-term cycling stability, showing an initial discharge specific capacity of 1061.2 mAh g–1 at 0.1 A g–1. After 500 cycles at 0.5 A g–1, the battery maintains a discharge specific capacity of 635 mAh g–1, highlighting the NbS4/15%Li7P3S11@10%PAB-C nanocomposite as a promising cathode material for ASSLBs.