Cobalt-Free LiNiO₂ with a Selenium Coating as a High-Energy Layered Cathode Material for Lithium-Ion Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Cobalt-free lithium nickel oxide (LiNiO2) offers high theoretical specific capacity but suffers from structural instability and poor cycling performance.
• Addressing these limitations is crucial for developing cost-effective, high-energy-density lithium-ion batteries.

Purpose of the Study:

• To enhance the electrochemical performance of LiNiO2 by applying a selenium (Se) coating.
• To investigate the effects of Se coating on the structural stability, interface properties, and rate capability of LiNiO2 cathodes.

Main Methods:

• Modification of LiNiO2 nanoparticles with an approximately 35 nm thick selenium coating.
• Utilized a combination of solid-phase mixing and low-temperature sintering for the coating process.
• Evaluated electrochemical performance through cycling tests and rate capability measurements.

Main Results:

• Selenium-coated LiNiO2 (Se-LNO) cathodes demonstrated 82.09% capacity retention after 300 cycles at 4.3 V.
• Improved rate performance was observed, with specific capacities of 168.7 mAh g-1 at 2 C and 149.6 mAh g-1 at 5 C.
• The Se coating effectively suppressed phase transitions, stabilized interfaces, and reduced particle pulverization.

Conclusions:

• Selenium coating is a viable strategy to enhance the structural and electrochemical stability of cobalt-free LiNiO2 cathodes.
• This approach offers a promising pathway towards lower-cost, higher-energy-density lithium-ion batteries.
• Further research into Se coating manipulation could unlock advanced battery technologies.