Modelling 3D Zinc Anodes for Efficient Rechargeable Zinc-Ion Batteries

Abstract

Rechargeable Zn ion batteries have emerged as a promising candidate for energy storage owing to their advantages in low cost and high safety. Nevertheless, Zn anodes face the critical issues of Zn dendrite formation and undesired side reactions, which significantly limit their cycling stability and capacity. Constructing 3D Zn anodes with porous substrates has been proven to effectively inhibit the Zn dendrite growth via the enlarged surface area and homogenized electric field. However, some important structural parameters, including porosity, pore depth, etc. have been rarely studied for 3D Zn anodes. Exploring these parameters can provide valuable insights for the future design of 3D Zn anodes. In this work, previous research on 3D Zn anodes is firstly reviewed and critically compared. It is found that the current research mainly utilizes Zn anode composites with various 3D substrates (carbon, metal, Zn alloy), as well as 3D pure Zn structures. Following this, two different Zn anodes with varying porosity values are proposed and modelled, namely, 3D Zn pillar anode (porosity=0.3, 0.5, 0.7, 0.9) and 3D Zn concentric anode (porosity=0.1, 0.3, 0.5, 0.7). The electric field distributions of anodes are explored and simulated using Ansys Maxwell numerical analysis. Consequently, it is found that increasing porosity can disperse electric field distributions over anodes. In particular, the Zn pillar anode can accommodate Zn ions more effectively owing to its unique and open pillar channels, whereas the 3D Zn concentric anode can impose a weaker electric field across pores with its large volume of space. The studies of pore depth propose a low to moderate pore depth for effective Zn ion transport in 3D Zn anodes. These results pioneer the research on optimizing the performance of 3D Zn anodes by exploring their structural designs and parameters.