Rational Design of Prussian Blue Analogs Cathodes With "Dual-Channel" Structure for Wide-Temperature-Range Sodium-Ion...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Sodium-ion batteries (SIBs) face challenges in wide-temperature (WT) performance due to sluggish kinetics and transition metal dissolution.
• Developing stable and efficient cathode materials is critical for advancing SIB technology.

Purpose of the Study:

• To design and synthesize a novel Prussian blue analog (PBA) cathode material with enhanced WT electrochemical performance for SIBs.
• To investigate the role of carbon-nitrogen vacancies (V_CN) in improving ion diffusion and structural stability.

Main Methods:

• A "one-step" in situ etching strategy was employed to create a channel-structured PBA (MnANP-channel, MAC) with V_CN.
• Theoretical calculations and experimental characterization were used to analyze the material's properties.
• Electrochemical testing was performed across a wide temperature range, including rate capability and cycling stability assessments.

Main Results:

• The V_CN in MAC significantly enhanced sodium ion diffusion kinetics and transition metal affinity.
• The channel microstructure facilitated efficient mass and charge transport, leading to excellent WT adaptability (103.9, 151.4, 162.1 mAh/g at -50°C, 25°C, 50°C).
• The MAC//HC full cell achieved high energy density (≈ 309 Wh/kg) and remarkable cycling stability (≈ 6800 cycles).

Conclusions:

• The developed MAC material exhibits superior wide-temperature electrochemical performance and long-term stability for SIBs.
• The V_CN and channel microstructure synergistically improve electrochemical properties.
• The versatile synthesis strategy offers a promising route for designing advanced PBA materials for energy storage.