燕麦肽电解液添加剂实现高性能水系锌负极

Oat Peptide Electrolyte Additives Enable High-Performance Aqueous Zinc Anodes

摘要: 水系锌离子电池以其高的理论容量、安全性、低成本和环境友好性在未来储能设备中显示出巨大的应用前景。然而，锌负极易发生析氢、自腐蚀与枝晶生长，导致极化加剧和寿命衰减。本文在常规2 M ZnSO₄电解液中引入微量天然燕麦肽(OP)作为添加剂，比较不同浓度对锌界面稳定性的影响，并通过组装锌锌对称电池(Zn||Zn)、锌铜半电池(Zn||Cu)与锌碘(Zn-I₂)全电池进行验证。结果表明，1% OP可显著降低锌腐蚀与界面阻抗，同时提高析氢相关反应过电位，有效抑制副反应。Zn||Zn对称电池在1 mA∙cm⁻²/1mAh∙cm⁻²下稳定运行超过2400 h；Zn-I₂电池表现出更优倍率与耐久性，在1 A∙g⁻¹下实现30,000圈超长稳定循环，即使在5 A∙g⁻¹的大电流下也能保持20,000圈长循环。以上结果表明OP是一种极具可行性的锌离子电池电解液添加剂，该策略为长寿命锌离子电池提供了富有前景的实现途径。

Abstract: Aqueous zinc-ion batteries have demonstrated significant application potential in future energy-storage devices owing to their high theoretical capacity, safety, low cost, and environmental friendliness. Nevertheless, the zinc anode is susceptible to hydrogen evolution, self-corrosion, and dendrite growth, which result in increased polarization and a shortened lifespan. In this research, a minute quantity of natural oat peptide (OP) was introduced as an additive into the conventional 2 M ZnSO₄ electrolyte, and the impacts of different concentrations on the stability of the zinc interface were examined. The outcomes were verified by assembling Zn||Zn symmetric cells, Zn||Cu half-cells, and Zn-I₂ full-cells. The results indicate that 1% OP can notably reduce zinc corrosion and interface impedance, while augmenting the overpotential of hydrogen-evolution-related reactions, effectively suppressing side reactions. The Zn||Zn symmetric cell can operate stably for over 2400 h at 1 mA∙cm⁻²/1mAh∙cm⁻²; the Zn-I₂ battery exhibits excellent rate performance and durability, achieving an ultra-long stable cycle of 30,000 cycles at 1 A∙g⁻¹, and maintaining a long cycle of 20,000 cycles even at a high current of 5 A∙g⁻¹. These findings suggest that OP is a highly viable additive for zinc-ion battery electrolytes, and this strategy offers a promising solution for long-life zinc-ion batteries.