A Simple Dual-Ion Doping Method for Stabilizing Li-Rich Materials and Suppressing Voltage Decay

Area of Science:

• Materials Science
• Electrochemistry
• Solid-State Chemistry

Background:

• Developing advanced cathode materials is crucial for high-performance lithium-ion batteries.
• Structural instability and voltage decay limit the practical application of existing materials.

Purpose of the Study:

• To improve the electrochemical performance and structural stability of a precursor material.
• To investigate the effects of sulfate (SO₄^2-) and nickel (Ni²⁺) doping on material properties.

Main Methods:

• A gentle treatment method was employed to dope the precursor with SO₄^2- and Ni²⁺.
• Characterization of the modified material's structure and electrochemical properties.

Main Results:

• Doping induced oxygen vacancies and defects, enhancing structural stability and reducing voltage decay.
• Specific discharge capacity increased from 276.50 to 305.20 mAh g^-1, and Coulombic efficiency rose from 77.30% to 86.20%.
• Discharge midvoltage increased from 2.74 to 3.00 V after 350 cycles at 1C, demonstrating significantly improved cycle performance.

Conclusions:

• The dual-ion synergistic effect of SO₄^2- and Ni²⁺ doping leads to enhanced structural stability.
• The modified material exhibits superior electrochemical performance, including higher capacity, efficiency, and voltage stability, making it promising for battery applications.