文摘
All-solid-state lithium–sulfur batteries (ASSLSBs) using highly conductive sulfide-based solid electrolytes suffer from low sulfur utilization, poor cycle life, and low rate performance due to the huge volume change of the electrode and the poor electronic and ionic conductivities of S and Li<sub>2sub>S. The most promising approach to mitigate these challenges lies in the fabrication of a sulfur nanocomposite electrode consisting of a homogeneous distribution of nanosized active material, solid electrolyte, and carbon. Here, we reported a novel bottom-up method to synthesize such a nanocomposite by dissolving Li<sub>2sub>S as the active material, polyvinylpyrrolidone (PVP) as the carbon precursor, and Li<sub>6sub>PS<sub>5sub>Cl as the solid electrolyte in ethanol, followed by a coprecipitation and high-temperature carbonization process. Li<sub>2sub>S active material and Li<sub>6sub>PS<sub>5sub>Cl solid electrolyte with a particle size of ∼4 nm were uniformly confined in a nanoscale carbon matrix. The homogeneous nanocomposite electrode consisting of different nanoparticles with distinct properties of lithium storage capability, mechanical reinforcement, and ionic and electronic conductivities enabled a mechanical robust and mixed conductive (ionic and electronic conductive) sulfur electrode for ASSLSB. A large reversible capacity of 830 mAh/g (71% utilization of Li<sub>2sub>S) at 50 mA/g for 60 cycles with a high rate performance was achieved at room temperature even at a high loading of Li<sub>2sub>S (∼3.6 mg/cm<sup>2sup>). This work provides a new strategy to design a mechanically robust, mixed conductive nanocomposite electrode for high-performance all-solid-state lithium sulfur batteries.