Emerging Poorly Crystalline Molybdenum–Sulfur–Oxygen Ternary Compound for Aqueous Zinc-Ion Batteries

This study reports a novel poorly crystalline molybdenum–sulfur–oxygen ternary compound (PMoSO) synthesized via a simple solution-based approach, exhibiting exceptional zinc-ion storage performance across a wide temperature range from 25 to −60 °C. At room temperature (25 °C), PMoSO exhibits an initial charge capacity of 78.3 mAh g^–1 while maintaining 75.5% capacity retention after 1000 cycles at 30 A g^–1; further, the PMoSO-based zinc metal-free cell delivers charge/discharge capacities of 117.2/126.1 mAh g^–1 (second cycle), retaining 94.4/94.2 mAh g^–1 after 500 cycles. Remarkably, PMoSO retains stable electrochemical activity under subzero conditions, delivering initial discharge–charge capacities of 154.9/121.8 mAh g^–1 (0 °C), 95.0/68.6 mAh g^–1 (−40 °C), and 86.0/64.8 mAh g^–1 (−60 °C) at 0.1 A g^–1. Upon prolonged cycling, the capacities are 89.0/89.2 mAh g^–1 (40th cycle, 0 °C), 73.4/73.3 mAh g^–1 (170th cycle, −40 °C), and 46.0/46.1 mAh g^–1 (230th cycle, −60 °C).