Multiphase Functional Regulation of the Interface between Sulfide Solid-State Electrolyte and Nickel-Rich Cathode

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• High-energy-density sulfide-based solid-state batteries require integrating nickel-rich cathodes with sulfide solid-state electrolytes.
• Interfacial degradation between oxide cathodes and sulfide electrolytes limits battery performance.

Purpose of the Study:

• To engineer a hybrid coating layer to address interfacial degradation between nickel-rich cathodes and sulfide solid-state electrolytes.
• To enhance the stability and electrochemical performance of solid-state batteries.

Main Methods:

• A hybrid coating incorporating polyvinylpyrrolidone (organic) and Li_xBO_y (inorganic) was designed.
• The coating was applied to polycrystalline and single-crystal nickel-rich cathodes.
• Electrochemical performance was evaluated, including specific discharge capacity and cycle life.

Main Results:

• The hybrid coating improved structural and chemical stability by filling surface depressions and mitigating space charge layer formation.
• Polycrystalline cathodes achieved 174.2 mAh g^-1 at 1 C and 76.8% retention after 2000 cycles at 5 C.
• Single-crystal cathodes maintained 80% retention for up to 4778 cycles at 5 C.

Conclusions:

• The multiphase coating paradigm effectively addresses interfacial challenges between sulfide solid-state electrolytes and nickel-rich layered oxide cathodes.
• This approach significantly enhances the cycle life and performance of solid-state batteries.
• The engineered hybrid coating offers a promising strategy for developing advanced energy storage solutions.