An Air-Stable High-Nickel Cathode with Reinforced Electrochemical Performance Enabled by Convertible Amorphous Li₂...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• High-nickel cathodes offer high specific capacity for next-generation lithium-ion batteries (LIBs).
• Their application is limited by high interfacial reactivity with air and electrolytes.
• Developing stable interfaces is crucial for practical LIBs.

Purpose of the Study:

• To design a stable high-nickel cathode by in situ inducing a dense amorphous Li2CO3 coating.
• To investigate the protective mechanism of the Li2CO3 coating against air erosion and electrolyte assault.
• To evaluate the electrochemical performance and interfacial stability of the modified cathode.

Main Methods:

• In situ induction of amorphous Li2CO3 coating on high-nickel cathode particles via preemptive atmosphere control.
• Characterization of the coating layer and its evolution during cycling.
• Electrochemical performance testing using assembled coin cells (discharge capacity, Coulombic efficiency, capacity retention).

Main Results:

• A dense amorphous Li2CO3 coating was successfully formed on the cathode surface.
• The Li2CO3 coating acted as a physical barrier against air and transformed into a robust F-rich cathode electrolyte interphase (CEI).
• The modified cathode achieved a high discharge capacity of 232.4 mAh g-1, initial Coulombic efficiency of 95.1%, and 90.4% capacity retention after 100 cycles.

Conclusions:

• Amorphous Li2CO3 coating effectively enhances the interfacial stability of high-nickel cathodes.
• The coating strategy provides a valuable perspective on protecting unstable high-capacity cathodes.
• This approach offers guidance for developing advanced energy-storage devices.