In Situ Construction of Inorganics-Rich Cathode-Electrolyte Interface toward Long-Life Prussian White Cathode

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Prussian white (PW) is a promising cathode material for sodium-ion batteries (SIBs) due to its high theoretical capacity, excellent rate performance, and low cost.
• However, PW materials exhibit significant capacity decay during prolonged cycling, limiting their practical application.

Purpose of the Study:

• To enhance the cycling stability of Prussian white cathodes in sodium-ion batteries.
• To develop a robust cathode electrolyte interface (CEI) layer through electrolyte modification.

Main Methods:

• Employing cresyl diphenyl phosphate (CDP) and adiponitrile (ADN) as electrolyte additives.
• Utilizing the higher highest occupied molecular orbital (HOMO) energy levels of CDP and ADN for preferential decomposition.
• In situ formation of an inorganic-rich CEI layer on the PW cathode.

Main Results:

• The in situ formed CEI layer effectively inhibits the degradation of PW during cycling.
• The Na||PW cell demonstrated excellent cycling performance, retaining 85.62% of its capacity after 1400 cycles.
• Electrolyte modification with CDP and ADN significantly improved the long-term stability of PW cathodes.

Conclusions:

• A feasible strategy for improving the cycling performance of Prussian white cathodes in SIBs has been presented.
• The designed CEI layer effectively enhances the durability of PW, paving the way for its wider adoption in energy storage devices.