Metal–Organic Framework‐Derived MnO/C Nanocomposite with Lamellar Porous Structure for High‐Performance Aqueous Zinc‐Ion Battery

Abstract

Manganese oxide (MnO) is a promising cathode for aqueous zinc‐ion batteries; however, issues such as low electrical conductivity, Mn2+ dissolution, and sluggish kinetics lead to poor electrochemical performance that block its commercialized application. Herein, the first utilization of Mn‐based metal–organic frameworks synthesized from manganese salt and 1,2,4,5‐benzenetetracarboxylic acid to fabricate MnO/C composite materials is presented. The analysis of electrochemical testing demonstrates that carbon‐coated MnO can effectively promote electrochemical properties compared to the pure MnO. Additionally, the Zn2+/Mn2+ concentration is optimized in order to maximize the electrode's potential in terms of electrochemical performance. The MnO/C‐600 electrode delivers a higher specific capacity of 322 mAh g−1 at 0.1 A g−1 and exhibits a capacity of 270 mAh g−1 after 360 cycles at 0.5 A g−1 in the 2.0 m ZnSO4 + 0.2 m MnSO4 system. The results also indicate that the MnO/C‐600 electrode has higher diffusion coefficients, and its unique structure improves structural stability and ion/electron transfer. Furthermore, the energy storage mechanism of the MnO/C‐600 electrode is investigated. Herein, a method is provided for preparing an inexpensive and convenient MnO/C cathode for high‐performance aqueous zinc‐ion batteries.