一种用于吸附和催化转化多硫化物的锶铁氧体改性隔膜，用于优异的锂硫电池。

A strontium ferrite modified separator for adsorption and catalytic conversion of polysulfides for excellent lithium-sulfur batteries.

机构信息

School of Chemistry, South China Normal University, Guangzhou 510006, P. R. China.

出版信息

Dalton Trans. 2023 Jul 4;52(26):9032-9041. doi: 10.1039/d3dt01126g.

Abstract

Lithium-sulfur batteries (LSBs) have emerged as one of the ideal contenders for the upcoming generation of high energy storage devices due to their superb energy density. Nonetheless, the shuttle effect generated by intermediate lithium polysulfides (LiPSs) during cell cycling brings about capacity degradation and poor cycling stability of LSBs. Here, a versatile SrFeO (FSO) and acetylene black (AB) modified PP separator is first presented to inhibit the shuttle effect. Thanks to the strong chemical interaction of Fe and Sr with polysulphides in FSO, it can trap LiPSs and provide catalytic sites for their conversion. Therefore, the cell using the FSO/AB@PP separator has a high initial discharge specific capacity (930 mA h g) at 2 C and lasts for 1000 cycles with a remarkably low fading rate (0.036% per cycle), while those using PE and AB@PP separators have inferior initial specific capacities (255 mA h g and 652 mA h g, respectively) and fail within 600 cycles. This work proposes a novel approach for addressing the shuttle of LiPSs from a bimetallic oxide modified separator.

摘要

锂硫电池（LSBs）因其超高的能量密度，已成为下一代高储能设备的理想竞争者之一。然而，电池循环过程中中间态多硫化锂（LiPSs）的穿梭效应导致了 LSBs 的容量衰减和较差的循环稳定性。在此，我们首次提出了一种多功能的 SrFeO（FSO）和乙炔黑（AB）修饰的 PP 隔膜来抑制穿梭效应。得益于 FSO 中 Fe 和 Sr 与多硫化物之间的强化学相互作用，它可以捕获 LiPSs 并提供其转化的催化位点。因此，使用 FSO/AB@PP 隔膜的电池在 2C 时具有较高的初始放电比容量（930 mA h g），并能持续 1000 个循环，且具有极低的衰减率（0.036%/循环），而使用 PE 和 AB@PP 隔膜的电池初始比容量较低（分别为 255 mA h g 和 652 mA h g），并在 600 个循环内失效。本工作提出了一种通过双金属氧化物修饰隔膜来解决 LiPSs 穿梭问题的新方法。