College of Chemistry and Materials Science, Jinan University, Guangzhou, 511443, China.
Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China.
Adv Mater. 2023 May;35(18):e2300019. doi: 10.1002/adma.202300019. Epub 2023 Mar 22.
Ultrathin separators are indispensable to high-energy-density zinc-ion batteries (ZIBs), but their easy failure caused by zinc dendrites poses a great challenge. Herein, 23 µm-thick functional ultrathin separators (FUSs), realizing superb electrochemical stability of zinc anodes and outstanding long-term durability of ultrathin separators, are reported. In the FUSs, an ultrathin but mechanically strong nanoporous membrane substrate benefits fast and flux-homogenized Zn transport, while a metal-organic framework (MOF)-derived C/Cu nanocomposite decoration layer provides rich low-barrier zinc nucleation sites, thereby synergistically stabilizing zinc anodes to inhibit zinc dendrites and dendrite-caused separator failure. Investigation of the zinc affinity of the MOF-derived C/Cu nanocomposites unravels the high zincophilicity of heteroatom-containing C/Cu interfaces. Zinc anodes coupled with the FUSs present superior electrochemical stability, whose operation lifetime exceeds 2000 h at 1 mA cm and 600 h at 10 mA cm , 40-50 times longer than that of the zinc anodes using glass-fiber separators. The reliability of the FUSs in ZIBs and zinc-ion hybrid supercapacitors is also validated. This work proposes a new strategy to stabilize zinc anodes and provides theoretical guidance in developing ultrathin separators for high-energy-density zinc-based energy storage.
超薄分离器对于高能量密度锌离子电池（ZIBs）是不可或缺的，但由于锌枝晶的易失效性，这给它们的应用带来了巨大的挑战。在此，报告了 23μm 厚的功能性超薄分离器（FUS），其实现了锌阳极的优异电化学稳定性和超薄分离器的长期耐久性。在 FUS 中，超薄但机械强度高的纳米多孔膜基底有利于快速和通量均匀化的 Zn 传输，而金属-有机骨架（MOF）衍生的 C/Cu 纳米复合材料修饰层提供了丰富的低势垒锌成核位点，从而协同稳定锌阳极以抑制锌枝晶和枝晶引起的分离器失效。对 MOF 衍生的 C/Cu 纳米复合材料的锌亲和力的研究揭示了含杂原子的 C/Cu 界面的高锌亲合性。与 FUS 结合的锌阳极表现出优异的电化学稳定性，其工作寿命在 1 mA cm 下超过 2000 小时，在 10 mA cm 下超过 600 小时，是使用玻璃纤维分离器的锌阳极的 40-50 倍。FUS 在 ZIBs 和锌离子混合超级电容器中的可靠性也得到了验证。这项工作提出了一种稳定锌阳极的新策略，为开发用于高能量密度锌基储能的超薄分离器提供了理论指导。
