Heterostructured MXene and g-C3N4 for high-rate lithium intercalation

Publication date: Available online 16 August 2019Source: Nano EnergyAuthor(s): Yun-Pei Zhu, Yongjiu Lei, Fangwang Ming, Edy Abou-Hamad, Abdul-Hamid Emwas, Mohamed N. Hedhili, Husam N. AlshareefAbstractA critical limitation to conventional electrochemical double-layer capacitors is their low energy densities. This has triggered significant interest in developing new pseudocapacitive materials, which utilize faradaic mechanisms to increase their energy densities. In this work, graphitic carbon nitride (g-C3N4) and Ti3C2Tx MXene are hybridized to form a unique two-dimensional (2D) heterostructure, which delivers remarkable pseudocapacitive characteristics and robust stability towards lithium storage. Interestingly, the improved kinetics is reflected by insignificant influence of (dis)charge rates on the pseudocapacitance even when testing at a 120C rate, and small peak potential offsets at high scan rates, revealing that there are no significant diffusion limitations in the heterostructure. This unexpected fast kinetics is related to the intrinsic chemical and electronic coupling effects between g-C3N4 and MXene, which can synergistically improve both electron transfer and lithium diffusion kinetics compared to MXene itself.Graphical abstractCouple makes double: The abundant surface terminations of MXene make it feasible to directly grow a thin layer of g-C3N4 on the surface of MXene, bringing strong coupling effect between these two 2D materials. The resultant charge redistribu...
Source: Nano Energy - Category: Nanotechnology Source Type: research