沙特阿卜杜拉国王科技大学Husam N. Alshareef团队报道了稳定无阳极锌金属电池的共溶剂电解质工程。相关研究成果于2022年4月18日发表在国际顶尖学术期刊《美国化学会杂志》。
无阳极金属电池原则上可以提供更高的能量密度，但这要求它们具有非凡的库仑效率（>99.7%）。虽然锌基金属电池有望用于固定储能，但寄生副反应使无阳极电池难以在实践中实现。
该文中，研究人员提出了一种盐析效应诱导的混合电解质作为一种有效的策略，既能实现高度可逆的锌阳极，又能实现对各种阴极的良好稳定性和兼容性。所制备的电解液也可以在较宽的温度范围（即20至50°C）下正常工作。研究表明，在碳酸丙烯酯存在下，即使在低盐浓度（2.14M）下，三氟磺酸根阴离子也参与了Zn2+溶剂化鞘层结构。独特的溶剂化结构导致阴离子的还原，从而形成疏水性固体电解质界面。混合电解质中的防水界面以及水活性的降低有效地防止了副反应，从而确保锌阳极具有前所未有的库仑效率（在1 mA cm–2的条件下，500次循环中99.93%）。
更重要的是，研究人员设计了一种无阳极锌金属电池，具有优异的循环稳定性（在0.5 mA cm–2下进行275次循环后，容量保持率为80%）。
该工作为无阳极锌金属电池共溶剂电解质的设计提供了一种通用策略。
附：英文原文
Title: Co-Solvent Electrolyte Engineering for Stable Anode-Free Zinc Metal Batteries
Author: Fangwang Ming, Yunpei Zhu, Gang Huang, Abdul-Hamid Emwas, Hanfeng Liang, Yi Cui, Husam N. Alshareef
Issue&Volume: April 18, 2022
Abstract: Anode-free metal batteries can in principle offer higher energy density, but this requires them to have extraordinary Coulombic efficiency (>99.7%). Although Zn-based metal batteries are promising for stationary storage, the parasitic side reactions make anode-free batteries difficult to achieve in practice. In this work, a salting-in-effect-induced hybrid electrolyte is proposed as an effective strategy that enables both a highly reversible Zn anode and good stability and compatibility toward various cathodes. The as-prepared electrolyte can also work well under a wide temperature range (i.e., from 20 to 50 °C). It is demonstrated that in the presence of propylene carbonate, triflate anions are involved in the Zn2+ solvation sheath structure, even at a low salt concentration (2.14 M). The unique solvation structure results in the reduction of anions, thus forming a hydrophobic solid electrolyte interphase. The waterproof interphase along with the decreased water activity in the hybrid electrolyte effectively prevents side reactions, thus ensuring a stable Zn anode with an unprecedented Coulombic efficiency (99.93% over 500 cycles at 1 mA cm–2). More importantly, we design an anode-free Zn metal battery that exhibits excellent cycling stability (80% capacity retention after 275 cycles at 0.5 mA cm–2). This work provides a universal strategy to design co-solvent electrolytes for anode-free Zn metal batteries.
DOI: 10.1021/jacs.1c12764
Source: https://pubs.acs.org/doi/10.1021/jacs.1c12764
