氢氧化镧涂层改性锌负极及其在水系锌离子电池中的应用

Lanthanum hydroxide coating-modified zinc anode for aqueous zinc ion batteries

通过刮刀涂布法把氢氧化镧浆料涂布到锌负极表面,构建了一种用于水系锌离子电池锌负极保护的氢氧化镧涂层。氢氧化镧涂层紧密地粘附在锌负极表面,能够抑制枝晶生长和析氢反应的发生,在循环过程中实现均匀的锌沉积。使用该涂层修饰锌负极组装的对称电池,在0.25 mAh·cm^(-2)的电流密度和0.05 mAh·cm^(-2)的沉积量下可以稳定循环3000 h。在以NH_(4)V_(4)O_(10)(理论比容量为491 mAh·g^(-1))为正极的全电池充放电测试中,使用涂层修饰锌负极的全电池在5 A·g^(-1)的电流密度下稳定循环600圈后,仍具有114 mAh·g^(-1)的放电比容量和高达99.99%的库伦效率。实验结果说明氢氧化镧作为锌负极保护层,可显著提升锌负极的稳定性并提升水系锌离子电池的电化学性能。

A lanthanum hydroxide(La(OH)3)protect-coating layer on zinc anode(La(OH)3@Zn)for rechargeable aqueous zinc ion batteries(AZIBs)was constructed via a simple blade coating method.La(OH)3 layer was closely connected to the surface of the zinc anode.The Zn dendrite growth and side reactions was effectively inhibited,and then the uniform Zn deposition during the cycling process was realized.As a result,the Zn‖Zn cell modified by La(OH)3 layer stably cycled over 3000 h at the current density of 0.25 mAh·cm^(-2) with a specific capacity of 0.05 mAh·cm^(-2).In Zn‖NH_(4)V_(4)O_(10) full cells,the La(OH)3@Zn anode stably cycled 600 cycles at the current density of 5 A·g^(-1).Moreover,the cell exhibits a high discharge capacity of 114 mAh·g^(-1) and a high Coulombic efficiency of 99.99%.These results indicate that La(OH)3 coating layer can significantly improve the stability of Zn anode and further enhance the electrochemical performance of AZIBs.