Sulfurized Two‐Dimensional Conductive Metal–Organic Framework as a High‐Performance Cathode Material for Rechargeable Mg Batteries
Yu Mu, James Nyakuchena, Yang Wang, James R. Wilkes, Tongtong Luo, Michael Goldstein, Brooke Elander, Udayan Mohanty, Junwei Lucas Bao, Jier Huang, Dunwei Wang
Abstract
Abstract Rechargeable Mg batteries are a promising energy storage technology to overcome the limitations inherent to Li ion batteries. A critical challenge in advancing Mg batteries is the lack of suitable cathode materials. In this work, we report a cathode design that incorporates S functionality into two‐dimensional metal‐organic‐frameworks (2D‐MOFs). This new cathode material enables good Mg 2+ storage capacity and outstanding cyclability. It was found that upon the initial Mg 2+ insertion and disinsertion, there is an apparent structural transformation that crumbles the layered 2D framework, leading to amorphization. The resulting material serves as the active material to host Mg 2+ through reduction and/or oxidation of S and, to a limited extent, O. The reversible nature of S and O redox chemistry was confirmed by spectroscopic characterizations and validated by density functional calculations. Importantly, during the Mg 2+ insertion and disinsertion process, the 2D nature of the framework was maintained, which plays a key role in enabling the high reversibility of the MOF cathode.