Synergic anchoring of Fe2N nanoclusters on porous carbon to enhance reversible conversion of iodine for high-temperature zinc-iodine battery

The coupling of zinc with iodine evokes the fabrication of advanced rechargeable batteries via redox conversion. However, the easy sublimation of iodine and high solubility of polyiodides restrict the application of the battery. Herein, the dispersion of iron nitride nanoclusters among three-dimensional porous carbon frameworks (PC@Fe2N) enables the efficient accumulation of iodine in combination with the promising electrocatalysis for reversible conversion. The experimental and theoretical results revealed that the Fe2N nanoclusters anchored on the carbon support is more efficient to inspire the ensemble effect for reversible redox reactions of iodine via suppressing the formation of polyiodide. Therefore, the zinc-iodine (Zn-I2) battery delivers excellent rate performance and ultralong cycling life for 20,000 cycles. Even at an elevated temperature of 60 °C, the pouch cell with a high iodine loading exhibited a reversible capacity 148 mAh g-1, which exemplifies rational fabrication of advanced Zn-I2 batteries for safe high-temperature energy storage.