Synergistic Modification of Fe-Based Prussian Blue Cathode Material Based on Structural Regulation and Surface
Zhao-Yao Chen1,2, Lu-Lu Zhang1,2, Xin-Yuan Fu2
1Hubei Provincial Collaborative Innovation Center for New Energy Microgrid, College of Materials and Chemical Engineering, China Three Gorges University, Yichang, Hubei 443002, China.
ACS Applied Materials & Interfaces
|September 15, 2022
Summary
Copper doping and CuO coating enhance iron-based Prussian blue (Fe-PB) for sodium-ion batteries. This modification improves capacity and cycle stability, showing great potential for advanced battery materials.
Area of Science:
- Materials Science
- Electrochemistry
- Computational Chemistry
Background:
- Iron-based Prussian blue (Fe-PB) is a promising cathode material for sodium-ion batteries due to its low cost and high theoretical capacity.
- Structural defects like crystal water and vacancies in Fe-PB limit its electrochemical performance, particularly capacity and cycle stability.
- Developing effective strategies to overcome these limitations is crucial for practical applications of Fe-PB in energy storage.
Purpose of the Study:
- To enhance the electrochemical performance of Fe-PB by addressing structural limitations.
- To investigate the synergistic effects of copper (Cu) doping and copper oxide (CuO) surface coating on Fe-PB.
- To explore the potential of this modified material for high-performance sodium-ion batteries.
Main Methods:
- Synthesis of a Cu-modified Fe-PB composite (FeCu-PB@CuO) via Cu doping and CuO surface engineering.
- Density Functional Theory (DFT) calculations to understand the mechanism of Cu doping on the Fe-PB lattice.
- Electrochemical testing to evaluate the performance of FeCu-PB@CuO as a cathode material for sodium-ion batteries, including capacity, rate capability, and cycling stability.
Main Results:
- DFT calculations confirmed that Cu preferentially substitutes Fe ions (FeHS) and reduces the bandgap of Fe-PB.
- The CuO coating provided additional active sites, suppressed side reactions, and potentially boosted the activity of FeHS sites.
- The FeCu-PB@CuO composite exhibited a high initial discharge capacity of 123.5 mAh g-1 at 0.1 A g-1 and an impressive 84.3 mAh g-1 at 2 A g-1.
- The material demonstrated excellent cycle stability with a low capacity decay rate of 0.02% over 1500 cycles.
Conclusions:
- The synergistic strategy combining Cu doping and CuO coating effectively enhances the electrochemical properties of Fe-PB for sodium-ion batteries.
- This modification overcomes the intrinsic limitations of Fe-PB, leading to improved capacity and long-term stability.
- The developed approach offers a promising pathway for designing advanced electrode materials for next-generation energy storage systems.
