Recent advances in electrochemical performance of Mg-based electrochemical energy storage materials in supercapacitors: Enhancement and mechanism

The application of Mg-based electrochemical energy storage materials in high performance supercapacitors is an essential step to promote the exploitation and utilization of magnesium resources in the field of energy storage. Unfortunately, the inherent chemical properties of magnesium lead to poor cycling stability and electrochemical reactivity, which seriously limit the application of Mg-based materials in supercapacitors. Herein, in this review, more than 70 research papers published in recent 10 years were collected and analyzed. Some representative research works were selected, and the results of various regulative strategies to improve the electrochemical performance of Mg-based materials were discussed. The effects of various regulative strategies (such as constructing nanostructures, synthesizing composites, defect engineering, and binder-free synthesis, etc.) on the electrochemical performance and their mechanism are demonstrated using spinel-structured MgX2O4 and layered structured Mg-X-LDHs as examples. In addition, the application of magnesium oxide and magnesium hydroxide in electrode materials, MXene's solid spacers and hard templates are introduced. Finally, the challenges and outlooks of Mg-based electrochemical energy storage materials in high performance supercapacitors are also discussed.