Semiconducting Zn_xMo₃S₁₃-GO Chalcocarbogel: A High-Capacity and Stable Sulfur-Equivalent Conversion-Based Electrode for Lithium-Ion Batteries

Lithium–sulfur batteries with a sulfur electrode offer a theoretical capacity of ∼1672 mAh g^–1, but rapid capacity loss mainly constrains their practical application. This work introduces a semiconducting and amorphous Zn_xMo₃S₁₃-GO (x = 0.5) chalcocarbogel sulfur-equivalent electrode with superior capacity and stability for lithium-ion batteries (LIBs). The Zn_xMo₃S₁₃-GO is synthesized in solution under ambient conditions, and its local structure contains S–S, M-Q (M = Mo, Zn; Q = S, O), C–S, and Mo–Mo bonding motifs with Mo coordination environment closely related to Mo₃S₁₃anions, as determined by X-ray photoelectron spectroscopy, synchrotron X-ray scattering, X-ray absorption spectroscopy, and ab initio molecular dynamics simulations. The Li/Zn_xMo₃S₁₃-GO cell offers an initial discharge capacity of 1019 mAh g^–1at a rate of C/3. After the activation cycles, the Li/Zn_xMo₃S₁₃-GO cell demonstrates good cycling stability, retaining a discharge capacity of 519.4 mAh g^–1after 250 cycles with ∼99.98% Coulombic efficiency and excellent rate capabilities. Moreover, it provides an initial discharge capacity of ∼574 mAh g^–1and maintains a retention capacity of 279 mAh g^–1at 1C after 625 cycles. The Lewis acidic Zn²⁺ion enhances the Lewis basic polysulfide anchoring ability and reduces the dissolution of polysulfides produced during the redox process through Zn–S covalent interaction, while the semiconducting and amorphous structure of the chalcocarbogel increases the electrical and ionic conductivity. This work highlights chalcocarbogels’ potential for developing high-capacity and stable electrodes for LIBs.