Layered Organic Molecular Crystal with One-Dimensional Ion Migration Channel for Durable Magnesium-Based Dual-Ion Batteries

Abstract

Mg-based dual-ion batteries (DIBs) represent promising battery technologies for next-generation sustainable energy storage; however, their advancement is strongly hindered by sluggish Mg²⁺ diffusion and structural instability of anode materials. Herein, fast and reversible storage of Mg²⁺ in nonaqueous and aqueous electrolyte is shown for a layered organic crystal, 5,7,12,14-pentacenetetrone (PT). The enolization redox chemistry of PT and its weakly stacked layered structure with rich 1D molecular channels promote Mg²⁺ storage kinetics, providing a high diffusion coefficient on the order of 10^–8–10^–9 cm² S^–1. As expected, the nonaqueous Mg-DIBs exhibit a reversible capacity of 95 mAh g^–1 at 0.1 A g^–1, wide-temperature operating capability (−20 to 50 °C), and good cycling stability over 2000 cycles. Interestingly, the applicability of PT as Mg²⁺-hosting materials extends to aqueous systems, enabling the construction of high-safety aqueous Mg-DIBs. This study provides crucial insights into the structural design of organic molecular crystal for multivalent ion-based DIBs.