Recently, Prof. WU Zhongshuai’s team and Prof. CHEN Jian’s team at Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) collaborated with Prof. WANG Xiaohui from Institute of Metal Research of CAS developed an all-MXene based integrated electrode for high-energy-density lithium-sulfur (Li-S) batteries. Their findings were published online in ACS Nano.

All-MXene-based integrated electrode constructed by Ti₃C₂ nanoribbon framework host and nanosheet interlayer for Li–S Batteries. (Image by DONG Yanfeng and ZHAO Xuejun) 

MXenes are a fascinating large family of 2D transition metal carbides/carbonitrides. And the most common MXene is Ti₃C₂ MXene with accordion-like layered structures.

However, several structural features of Ti₃C₂ MXene greatly prevent its application for high performance Li-S batteries, such as big particle sizes, and limited pore volume and surface area.

To overcome the above obstacles, researchers employed 3D alkalized Ti₃C₂ MXene nanoribbon (a-Ti₃C₂) frameworks as S/polysulfides host and 2D delaminated Ti₃C₂ MXene (d-Ti₃C₂) nanosheets as interlayer on polypropylene (PP) separator, respectively, resulting in an all-MXene based integrated cathode without metal current collector.

The a-Ti₃C₂ showed rich open macropores and large surface area, which could facilitate a high S loading and easy ionic diffusion. And the 2D d-Ti₃C₂ nanosheet-based interlayer could further physically and chemically hinder the shuttle effect of polysulfides.

Therefore, the integrated electrode exhibited an excellent electrochemical performance due to the synergistic combination of two different MXene nanostructures in the integrated electrode.

Since MXene could be synthesized from more than 60 kinds of MAX phases, this proposed strategy of constructing all-MXene-based electrode can be readily extended to assemble a large number of MXene based materials for various batteries and supercapacitors.

This work was supported by the National Natural Science Foundation of China, Ministry of Science and Technology of China, Thousand Youth Talents Plan of China, and DICP and China Postdoctoral Science Foundation.