PTCDA/CuS cathode enabling stable sulfide-based all-solid-state batteries

Organic cathode materials have garnered significant attention for their potential application in lithium-ion batteries due to their lightweight nature, tunable structures, high energy density, and environmental friendliness. However, the dissolution of organic cathodes in liquid electrolytes often leads to poor cycling stability, which limits their practical application. In this study, a composite cathode was prepared by ball milling the PTCDA/CuS (perylene-3,4,9,10-tetracarboxylic dianhydride, PTCDA) with a sulfide-based electrolyte and carbon nanotubes. By optimizing the component ratios, the assembled all-solid-state batteries (ASSBs) show a high discharge capacity of 210 mA·h/g after 200 cycles without any capacity degradation at a current density of 33.0 mA/g. Through comprehensive characterization techniques including X-ray diffraction (XRD), Raman spectroscopy, Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS), the coordination of Cu²⁺ and the formation of sulfur-linked polymers during the charge-discharge processes are elucidated, and the reversibility of the electrochemical reactions has been confirmed. This work highlights the excellent compatibility between organic cathodes and sulfide-based electrolytes, providing a new way for the development of high-performance ASSBs with high energy density and extended lifespan.