基于有机溶剂原位制备的致密疏水铜金属层在保护锌负极中的应用

通过在 N-甲基吡咯烷酮(NMP)有机溶剂中锌电极与 CuI之间的置换反应，在锌电极上原位构建了一层致密且疏水的铜金属保护层(Cu@Zn)。铜金属保护层能有效地隔离锌电极与电解液的接触，减少锌电极-电解液界面的析氢和腐蚀等副反应。同时，铜金属保护层还具有较好的亲锌性，更小的界面电阻，更低的成核能垒，有利于锌离子均匀沉积，从而有效抑制了锌枝晶的生成。Cu@Zn对称电池实现了超过 1 700 h(1 mA·cm^-2)和 1 330 h(3 mA·cm^-2)的循环寿命。采用商用 MnO₂与之匹配得到的Cu@Zn||MnO₂全电池不仅在1 A·g^-1下具有168.5 mAh·g^-1的可逆比容量，还可稳定循环2 000次以上

Application of a densely hydrophobic copper metal layer in-situ prepared with organic solvents for protecting zinc anodes

Herein, a dense and hydrophobic Cu metal protective layer was constructed in-situ on the Zn electrode (Cu@Zn) through a displacement reaction in an organic solvent. Specifically, CuI powder was dissolved in N-methyl-2-pyrrolidone (NMP) and stirred for 12 h to obtain a uniform solution. Subsequently, the bare Zn was immersed in the solution at 80 ℃ for 6 h, and then washed with absolute ethanol three times to achieve the Cu@Zn electrode. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses confirm a dense Cu protective layer on the surface of the Cu@Zn electrode. Additionally, the better hydrophobicity of the Cu@Zn electrode was demonstrated through contact angle measurements with a 2 mol·L^-1 ZnSO₄ electrolyte. The dense and hydrophobic Cu metal protective layer can effectively isolate the direct contact between the Zn electrode and electrolyte, suppressing side reactions such as hydrogen evolution and corrosion at the electrode/electrolyte interface. Furthermore, the Cu layer possesses zincophilicity, reduced interfacial resistance, and a lower nucleation energy barrier, thereby promoting uniform Zn deposition and effectively inhibiting dendritic growth. As a result, Cu@Zn symmetric cells exhibited continuous stable performance for 1 700 and 1 330 h at 1 mA·cm^-2, 1 mAh·cm^-2 and 3 mA·cm^-2, 1 mAh·cm^-2, respectively, which were higher than those of bare Zn symmetric cells (204 and 120 h). Furthermore, the Cu@Zn||MnO₂ full cell delivered a specific capacity of 168.5 mAh·g^-1 at 1 A·g^-1 respectively, maintaining stability for over 2 000 cycles.