全固态氟离子电池(ASSFIB)由于其低成本而显示出作为储能设备的巨大潜力,优越的安全性,和高能量密度。然而,F-导体的离子导电性差,大体积膨胀,缺乏合适的阳极会抑制它们的发展。在这项工作中,成功合成并表征了不同相(β-和γ-PbSnF4)的PbSnF4固体电解质。由β-PbSnF4电解质组成的ASSFIB,BiF3阴极,和微米/纳米尺寸(µ-/n-)Sn阳极,表现出巨大的能力。与μ-Sn阳极相比,具有纳米结构的n-Sn阳极在BiF3/β-PbSnF4/Sn电池中表现出优异的电池性能。优化的电池在8mAg-1时提供了181.3mAhg-1的高初始放电容量,并且可以在40mAg-1时可逆地循环,在120次循环后具有超过100.0mAhg-1的高放电容量在室温下。此外,它显示了超过90.0mAhg-1的高放电容量,在-20°C下超过100次循环具有优异的循环性。详细的表征已经证实,减小Sn颗粒尺寸和提高外部压力对于在Sn阳极中实现良好的脱氟/氟化行为至关重要。这些发现为在不同工作温度下设计具有高容量和优异循环性能的ASSFIB铺平了道路。
All-solid-state fluoride ion batteries (ASSFIBs) show remarkable potential as energy storage devices due to their low cost, superior safety, and high energy density. However, the poor ionic conductivity of F- conductor, large volume expansion, and the lack of a suitable anode inhibit their development. In this work, PbSnF4 solid electrolytes in different phases (β- and γ-PbSnF4) are successfully synthesized and characterized. The ASSFIBs composed of β-PbSnF4 electrolytes, a BiF3 cathode, and micrometer/nanometer size (µ-/n-) Sn anodes, exhibit substantial capacities. Compared to the μ-Sn anode, the n-Sn anode with nanostructure exhibits superior battery performance in the BiF3/β-PbSnF4/Sn battery. The optimized battery delivers a high initial discharge capacity of 181.3 mAh g-1 at 8 mA g-1 and can be reversibly cycled at 40 mA g-1 with a high discharge capacity of over 100.0 mAh g-1 after 120 cycles at room temperature. Additionally, it displays high discharge capacities over 90.0 mAh g-1 with excellent cyclability over 100 cycles under -20 °C. Detailed characterization has confirmed that reducing Sn particle size and boosting external pressure are crucial for achieving good defluorination/fluorination behaviors in the Sn anode. These findings pave the way to designing ASSFIBs with high capacities and superior cyclability under different operating temperatures.