Ultrathin 2D Graphitic Carbon Nitride on Metal Films: Underpotential Sodium Deposition in Adlayers for Sodium-Ion Batteries.

Lu Chen,Martin Oschatz,Lei Jiang,Markus Antonietti,Runyu Yan,Kai Xiao

doi:10.1002/anie.202000314

Abstract

Efficient and low‐cost anode materials for the sodium‐ion battery are highly desired to enable more economic energy storage. Effects on an ultrathin carbon nitride film deposited on a copper metal electrode are presented. The combination of effects show an unusually high capacity to store sodium metal. The g‐C3N4 film is as thin as 10 nm and can be fabricated by an efficient, facile, and general chemical‐vapor deposition method. A high reversible capacity of formally up to 51 Ah g−1 indicates that the Na is not only stored in the carbon nitride as such, but that carbon nitride activates also the metal for reversible Na‐deposition, while forming at the same time an solid electrolyte interface layer avoiding direct contact of the metallic phase with the liquid electrolyte.

Highlights

In view of the virtually inexhaustible and ubiquitous sodium resources around the world, sodium-ion batteries (SIBs) are considered as an attractive alternative to lithiumion batteries and have received a great deal of attention in the last ten years.[1]
The fabrication process was based on chemical vapor deposition (CVD) and is illustrated in Figure 1 a
Ultrathin and ordered carbon nitride films were grown on metallic substrates, here copper, via an easy, efficient, and facile deposition method

Summary

Introduction

In view of the virtually inexhaustible and ubiquitous sodium resources around the world, sodium-ion batteries (SIBs) are considered as an attractive alternative to lithiumion batteries and have received a great deal of attention in the last ten years.[1]. Graphitic carbon nitride materials have aroused much interests because of their intrinsic features, such as being a metal-free catalyst and a polymer semiconductor.[11] They have been used in photocatalysis,[10c] electrocatalysis,[12] novel solar energy devices,[13] ionic-type photodetectors,[14] and carbon nitride based actuators.[15] Previous work has shown that even 500 nm thick layers of oriented carbon nitride are rather good ion conductors,[16] for example, for Na+, while being essentially impermeable for most organic solvents This property makes such thin carbon nitride layers ideal candidates as a solid electrolyte interface (SEI) for metal anodes in batteries. The concept was that owing to the electric resistance of the carbon nitride film, Na0 is only deposited on the copper surface after permeating the g-C3N4 film, the carbon nitride is moved up as an SEI layer on top of the growing sodium layer

Results and Discussion

Conclusion

Conflict of interest