Department of Electrical and Computer Engineering and Materials Science and Engineering Program, University of Houston, Houston, Texas 77204, United States.
Texas Center for Superconductivity at the University of Houston, Houston, Texas 77204, United States.
Nano Lett. 2021 Dec 22;21(24):10446-10452. doi: 10.1021/acs.nanolett.1c03792. Epub 2021 Dec 6.
Uncontrolled zinc electrodeposition is an obstacle to long-cycling zinc batteries. Much has been researched on regulating zinc electrodeposition, but rarely are the studies performed in the presence of a separator, as in practical cells. Here, we show that the microstructure of separators determines the electrodeposition behavior of zinc. Porous separators direct zinc to deposit into their pores and leave "dead zinc" upon stripping. In contrast, a nonporous separator prevents zinc penetration. Such a difference between the two types of separators is distinguished only if caution is taken to preserve the attachment of the separator to the zinc-deposited substrate during the entire electrodeposition-morphological observation process. Failure to adopt such a practice could lead to misinformed conclusions. Our work reveals the mere use of porous separators as a universal yet overlooked challenge for metal anode-based rechargeable batteries. Countermeasures to prevent direct exposure of the metal growth front to a porous structure are suggested.
锌的无控制沉积是长循环锌电池的一个障碍。人们已经对调节锌沉积进行了大量研究，但很少在分离器存在的情况下进行研究，因为在实际电池中就是如此。在这里，我们表明分离器的微观结构决定了锌的沉积行为。多孔分离器将锌引导到其孔中，并在剥离时留下“死锌”。相比之下，无孔分离器阻止锌渗透。只有在整个电沉积形态观察过程中小心地保持分离器与锌沉积基底的附着的情况下，才能区分这两种类型的分离器之间的这种差异。如果不采用这种做法，可能会得出错误的结论。我们的工作揭示了仅仅使用多孔分离器作为基于金属阳极的可充电电池的一个普遍但被忽视的挑战。建议采取对策以防止金属生长前沿直接暴露于多孔结构。
