MXenes for Zinc-Based Electrochemical Energy Storage Devices.

As an economical and safer alternative to lithium, zinc (Zn) is promising for realizing new high-performance electrochemical energy storage devices, such as Zn-ion batteries, Zn-ion hybrid capacitors, and Zn-air batteries. Well-designed electrodes are needed to enable efficient Zn electrochemistry for energy storage. Two-dimensional transition metal carbides and nitrides (MXenes) are emerging materials with unique electrical, mechanical, and electrochemical properties and versatile surface chemistry. They are potential material candidates for constructing high-performance electrodes of Zn-based energy storage devices. This review first briefly introduces the working mechanisms of the three Zn-based energy storage devices. Then, the recent progress on the synthesis, chemical functionalization, and structural design of MXene-based electrodes is summarized. Their performance in Zn-based devices is analyzed to establish relations between material properties, electrode structures, and device performance. Last, several research topics are proposed to be addressed for developing practical MXene-based electrodes for Zn-based energy storage devices to enable their commercialization and broad adoption in the near future.