Study on Electrochemical Characteristics of CuS/FeS2 Heterostructure Derived from Prussian Blue Analogues as Anode Materials for Sodium-Ion Batteries
초록/요약
In recent years, research on next-generation battery systems has been actively conducted to meet low-cost, eco-friendly, and scale-up feasibility. Among these batteries, sodium ion batteries (SIBs) have received remarkable attention as a promising candidate to replace lithium ion batteries (LIBs) due to their inexpensive sodium-containing resources and abundant reserves. Unfortunately, graphite, a commercial anode in LIBs, cannot undergo stable electrochemical reactions with sodium, and thus various attempts are being made to apply new anode materials. In this work, we design and synthesize a heterostructured nanocube anode composed of CuS/FeS2 embedded in porous nitrogen-doped carbon (CuS/FeS2@NC). Size- and shape-controlled porous carbon nanocubes containing metallic nanoparticles are realized by the two-step pyrolysis of a bimetallic (Cu/Fe) Prussian blue analog (PBA) precursor. When the composites were applied to the anode for SIBs, the electrode exhibits enhanced rate capability showing a ~540 mAh g-1 even at a high current density of 5A g-1. The improved electrochemical performance is due to the synergistic effects of high conductive CuS and high capacity FeS2, which contribute to structural stability and fast Na+ diffusion kinetics. The simple, facile synthetic route combined with the rational design of bimetallic PBA nanostructures can be widely utilized in the development of conversion-reaction-based metal sulfides and other high-capacity anode materials for high-performance SIBs.
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Abstract Ⅰ
List of Figures Ⅱ
List of Tables Ⅲ
Chapter Ⅰ. Introduction 1
1.1 Rechargeable battery systems 1
1.1.1 Sodium-ion batteries 4
1.2 Anode materials for SIBs 5
1.2.1 Transition metal sulfides-based anode materials 6
1.3 Improvement strategies 7
1.3.1 Construction of heterostructured anode materials 8
1.3.2 Anode materials derived from prussian blue analogues 9
Chapter Ⅱ. Experimental 11
2.1 Materials Preparation 11
2.1.1 Synthesis of Cu/Fe-PBAs and Cu/Fe-based nanocubes 11
2.1.2 Synthesis of CuS/FeS2@NC and FeS2@NC nanocubes 12
2.2 Material characterization 13
2.3 Electrochemical characterization 14
Chapter Ⅲ. Results and Discussion 15
3.1 Characterization of CuS/FeS2@NC nanocubes 15
3.2 Electrochemical Performance 34
3.3 Post-Mortem analysis 56
Chapter Ⅳ. Conclusion 58
Reference 60
