TiO₂-LiF composite coating for improving NCM622 cathode cycling stability: one-step construction.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Nickel-rich NCM622 is a promising cathode material for high energy lithium-ion batteries.
• Unstable electrochemical performance of NCM622 hinders its commercial application.
• Surface modification is a key strategy to improve cathode material stability.

Purpose of the Study:

• To enhance the cycling performance and electrochemical stability of NCM622 cathode materials.
• To develop a facile method for surface modification of NCM622.
• To investigate the effect of TiO2-LiF coating on NCM622.

Main Methods:

• A one-step approach using TiF4 was employed to create a TiO2-LiF coating on NCM622.
• Electrochemical performance was evaluated through cycling tests at 1C within a 2.7-4.3 V range for 200 cycles.
• Material characterization to validate the coating and its effects.

Main Results:

• The TiO2-LiF coated NCM622 exhibited 79.7% capacity retention after 200 cycles, compared to 68.9% for pristine NCM622.
• The uniform coating layer effectively alleviated structural degradation.
• The one-step modification approach proved to be efficient and easy to implement.

Conclusions:

• The TiO2-LiF coating significantly improves the electrochemical performance and cycling stability of NCM622 cathode materials.
• This surface modification strategy offers a viable pathway for commercializing high-energy lithium-ion batteries.
• The one-step synthesis method is practical for scalable production.