A High‐Capacity Gradient Zn Powder Anode for Flexible Zn‐Ion Batteries

Abstract

Abstract Zn powder‐based anodes are promising for flexible Zn‐ion batteries with large‐scale production, but the drawbacks such as dendrite growth and side reactions strictly hinder their wide application. Herein, a free‐standing Zn powder‐based anode with gradient particle size and porosity is facilely constructed for flexible Zn‐ion batteries. The gradient design not only optimizes the electric field distribution and the Zn‐ion flux but also induces ideal bottom‐up deposition and top‐down stripping behaviors of Zn, thus suppressing dendrite growth. As a result, the flexible gradient Zn powder anode can be stably cycled for 1250 h at 1 mA cm −2 /1 mAh cm −2 , and even at high current/capacity of 5 mA cm −2 /5 mAh cm −2 , it still achieves a long lifespan of 130 h, which outperforms its non‐gradient counterparts and most previous results from Zn powder‐based anodes. The gradient strategy is expected to inspire the extensive utilization of Zn powder‐based anodes for flexible energy storage devices.