纳米铜修饰三维锌网电极的制备及锌离子电池负极的电化学性能

设计构建了纳米铜修饰的三维锌网电极(Nano Cu@3D Zn Mesh, 简称3D Cu-Zn电极), 并将其作为锌沉积的宿主材料用作锌离子电池的负极, 获得了稳定的、 具有长循环寿命的锌负极材料. 3D Cu-Zn电极的三维(3D)锌网骨架和表面均匀分布的3D树枝状纳米铜可以降低局部电流密度, 并为锌的沉积提供结构支撑和容纳空间. 锌网表面具有的较强锌结合能力的铜和后续原位形成的铜锌合金, 可以有效降低锌形核的过电势, 并作为均匀分布的形核位点引导锌的均匀成核和沉积. 这种3D Cu-Zn电极宿主材料表现出较低的形核过电势和界面阻抗, 并在对称电池中表现出优异的循环稳定性, 在0.5 mA/cm²的电流密度下可以稳定循环超过1100 h. 3D Cu-Zn电极与MnO₂组装的全电池表现出更小的极化、 良好的倍率性能和循环性能.

Preparation of Nano-copper Modified Three-dimensional Zinc Mesh Electrode and Its Performance as Anode for Zinc-ion Batteries

Nano-copper modified three-dimensional zinc mesh（nano Cu@3D Zn mesh， denoted as 3D Cu-Zn） electrode was designed and fabricated. The 3D Cu-Zn electrode was adopted as the host material of Zn deposition in zinc ion batteries. Stable Zn anode with long cycle life was achieved. The 3D Cu-Zn electrode with 3D zinc mesh skeleton and uniformly distributed Cu nanoparticles with 3D dendritic morphology can reduce the local current density and provide structural support and accommodation space for Zn deposition. In addition， the copper with strong zinc binding ability on the surface of the zinc mesh and subsequent in situ formed Cu-Zn alloy can effectively reduce the nucleation overpotential and act as uniformly distributed nucleation sites to guide the uniform nucleation and deposition of zinc. The 3D Cu-Zn electrode exhibits low nucleation overpotential and interfacial impedance， and shows excellent cycling stability（over 1100 h lifespan） in symmetric cells at a current density of 0.5 mA/cm². When combined with MnO₂ cathode， the full cell with 3D Cu-Zn electrode exhibits smaller polarization， superior rate performance and excellent cycling performance.