Construction of MnO2 Artificial Leaf with Atomic Thickness as Highly Stable Battery Anodes

Abstract The leaf‐like structure is a classic and robust structure and its unique vein support can reduce structural instability. However, biomimetic leaf structures on the atomic scale are rarely reported due to the difficulty in achieving a stable vein‐like support in a mesophyll‐like substrate. A breathable 2D MnO 2 artificial leaf is first reported with atomic thickness by using a simple and mild one‐step wet chemical method. This homogeneous ultrathin leaf‐like structure comprises of vein‐like crystalline skeleton as support and amorphous microporous mesophyll‐like nanosheet as substrate. When used as an anode material for lithium ion batteries, it first solves the irreversible capacity loss and poor cycling issue of pure MnO 2 , which delivers high capacity of 1210 mAh g −1 at 0.1 A g −1 and extremely stable cycle life over 2500 cycles at 1.0 A g −1 . It exhibits the most outstanding cycle life of pure MnO 2 and even comparable to the most MnO 2 ‐based composite electrode materials. This biomimetic design provides important guidelines for precise control of 2D artificial systems and gives a new idea for solving poor electrochemical stability of pure metal oxide electrode materials.