Zn-Ion Batteries: Boosting the Rate Capability and Low-temperature Performance by Combining Structure and Morphology...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Prussian blue analogues (PBAs) are promising cathode materials for zinc-ion batteries (ZIBs) due to cost, safety, and abundance.
• Challenges include low conductivity and single-electron reactions, limiting reversible capacity, rate capability, and temperature adaptability.

Purpose of the Study:

• To design and synthesize a novel PBA cathode material with enhanced electrochemical performance for ZIBs.
• To overcome the limitations of low conductivity and single-electron reactions in traditional PBAs.

Main Methods:

• Combined structure and morphology engineering to create K1.14(VO)3.33[Fe(CN)6]2·6.8H2O (KVHCF) integrated with a double conductive carbon framework (DCCF).
• Utilized in situ X-ray diffraction (XRD) and ex situ X-ray photoelectron spectroscopy (XPS) to investigate the reaction mechanism.

Main Results:

• The KVHCF@DCCF cathode exhibited a high specific capacity of 180 mAh·g⁻¹ at 400 mA·g⁻¹ and excellent rate performance (116 mAh·g⁻¹ at 8000 mA·g⁻¹).
• Demonstrated strong low-temperature performance with 132 mAh·g⁻¹ at 0 °C and 127 mAh·g⁻¹ at -10 °C (40 mA·g⁻¹).
• Achieved 86% capacity retention after 700 cycles at -10 °C, indicating remarkable stability.

Conclusions:

• The developed KVHCF@DCCF material offers a multielectron reaction and high electronic conductivity, significantly improving ZIB cathode performance.
• This material shows excellent temperature adaptability and cycling stability, making it a viable candidate for advanced energy storage applications.