Centre for Clean Energy Technology, School of Mathematical and Physical Sciences, Faculty of Science, University of Technology Sydney, Sydney, NSW, 2007, Australia.
Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China.
Nat Commun. 2023 Feb 18;14(1):925. doi: 10.1038/s41467-023-36622-w.
Rechargeable halide-ion batteries (HIBs) are good candidates for large-scale due to their appealing energy density, low cost, and dendrite-free features. However, state-of-the-art electrolytes limit the HIBs' performance and cycle life. Here, via experimental measurements and modelling approach, we demonstrate that the dissolutions in the electrolyte of transition metal and elemental halogen from the positive electrode and discharge products from the negative electrode cause the HIBs failure. To circumvent these issues, we propose the combination of fluorinated low-polarity solvents with a gelation treatment to prevent dissolutions at the interphase, thus, improving the HIBs' performance. Using this approach, we develop a quasi-solid-state Cl-ion-conducting gel polymer electrolyte. This electrolyte is tested in a single-layer pouch cell configuration with an iron oxychloride-based positive electrode and a lithium metal negative electrode at 25 °C and 125 mA g. The pouch delivers an initial discharge capacity of 210 mAh g and a discharge capacity retention of almost 80% after 100 cycles. We also report assembly and testing of fluoride-ion and bromide-ion cells using quasi-solid-state halide-ion-conducting gel polymer electrolyte.
可充电卤化物离子电池 (HIB) 由于其吸引人的能量密度、低成本和无枝晶的特点，是大规模应用的理想选择。然而，最先进的电解质限制了 HIB 的性能和循环寿命。在这里，我们通过实验测量和建模方法，证明了来自正极的过渡金属和元素卤素以及来自负极的放电产物在电解质中的溶解会导致 HIB 失效。为了规避这些问题，我们提出了将氟化低极性溶剂与凝胶处理相结合的方法，以防止在界面处溶解，从而提高 HIB 的性能。使用这种方法，我们开发了一种准固态 Cl-离子传导凝胶聚合物电解质。该电解质在 25°C 和 125mA g 下，以基于氧化铁氯的正极和锂金属负极的单层袋式电池结构进行了测试。该袋式电池的初始放电容量为 210 mAh g，经过 100 次循环后，放电容量保持率接近 80%。我们还报告了使用准固态卤化物离子传导凝胶聚合物电解质组装和测试氟化物离子和溴化物离子电池的情况。
