Addressing voltage hysteresis in Li-rich cathode materials via gas-solid interface modification.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Li-rich layered materials offer high capacity (>250 mA h g⁻¹) due to anion redox at high voltages.
• Commercialization is hindered by capacity decay and voltage hysteresis during cycling.
• Anion redox asymmetry and structural instability are key challenges.

Purpose of the Study:

• To improve the structural stability and electrochemical performance of Li-rich layered materials.
• To mitigate capacity decay and voltage hysteresis during battery cycling.
• To enable practical applications of high-capacity cathode materials.

Main Methods:

• Construction of an oxygen vacancy-accompanied spinel interface layer via gas-solid reaction.
• Treatment with 1 mol% Nickel Carbonate (NiCO₃) at 650 °C.
• Electrochemical characterization including cycling performance and voltage profiles.

Main Results:

• The NiCO₃-modified material exhibits significantly reduced voltage hysteresis (∼0.23 V) in the first cycle.
• Achieved a high discharge capacity of 275 mA h g⁻¹ at 0.1 C.
• Demonstrated excellent capacity retention of 90% over 200 cycles at 1 C.

Conclusions:

• The constructed spinel interface layer effectively stabilizes the material and reduces anion redox asymmetry.
• NiCO₃ modification provides a viable strategy to overcome key limitations in Li-rich layered materials.
• The enhanced material shows great promise for next-generation high-energy-density lithium-ion batteries.