Feng Rongfang, Chi Xiaowei, Qiu Qiliang, Wu Jing, Huang Jiaqi, Liu Jianjun, Liu Yu
Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 201899, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
ACS Appl Mater Interfaces. 2021 Sep 1;13(34):40638-40647. doi: 10.1021/acsami.1c11106. Epub 2021 Aug 18.
The serious zinc dendrites and poor cyclability at high cathode loading owing to the strong solvation effect of traditional aqueous electrolytes are the main bottlenecks to the development of aqueous rechargeable zinc-ion batteries (ARZIBs). Here, we design an ether-water hybrid zinc-ion electrolyte with bifunctional roles of not only unplugging the dendrites bottleneck at the Zn anode but also extending the cycle life at high cathode loading. A cyclic ether (1,4-dioxane (DX)) is incorporated into traditional ZnSO-based electrolytes to finely tune the solvation sheath of Zn. DX is found to guide the deposition orientation of zinc along the (002) plane, leading to not a dendritic structure but distinctively dense lamellar deposition due to the stronger affinity of the cyclic DX molecules toward Zn(002) than that of water, which is proven by density functional theory calculations. The cycling lifespan of the Zn anode extends up to over 600 h at 5.0 mA cm and maintains extremely high Coulombic efficiency of 99.8%, thereby further enabling the Zn-MnO full cells to stably cycle at an ultrahigh mass loading of 9.4 mg cm, paving the way to their practical applications. This work also provides a novel electrolyte regulating solution for other aqueous multivalent metal-ion batteries.
由于传统水系电解质的强溶剂化效应，严重的锌枝晶以及在高阴极负载下较差的循环稳定性是水系可充电锌离子电池（ARZIBs）发展的主要瓶颈。在此，我们设计了一种醚 - 水混合锌离子电解质，它不仅能消除锌阳极处的枝晶瓶颈，还能在高阴极负载下延长循环寿命，具有双重功能。将环状醚（1,4 - 二氧六环（DX））加入到传统的基于ZnSO的电解质中，以精细调节锌的溶剂化鞘层。发现DX能引导锌沿（002）平面的沉积取向，由于环状DX分子对Zn(002)的亲和力比水更强，从而导致形成的不是枝晶结构，而是独特的致密层状沉积，这一点通过密度泛函理论计算得到了证实。在5.0 mA cm下，锌阳极的循环寿命延长至600多小时，并保持99.8%的极高库仑效率，进而使Zn - MnO全电池能够在9.4 mg cm的超高质量负载下稳定循环，为其实际应用铺平了道路。这项工作还为其他水系多价金属离子电池提供了一种新型的电解质调控解决方案。
