La₄NiLiO₈-Shielded Layered Cathode Materials for Emerging High-Performance Safe Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Commercial cathode materials like olivine and spinel have limited theoretical capacities.
• Nickel-rich (NCM) materials offer higher theoretical capacity but suffer from low conductivity and electrolyte degradation at elevated temperatures.
• Developing stable, high-energy-density cathode materials is crucial for advanced battery technologies.

Purpose of the Study:

• To address the limitations of nickel-rich (NCM) cathode materials by enhancing their conductivity and stability.
• To investigate the efficacy of novel "La4NiLiO8 shields" in improving the electrochemical performance and safety of NCM cathodes.
• To enable the commercialization of high-performance NCM batteries through improved charge conduction and resistance to degradation.

Main Methods:

• Coating LiNi0.5Co0.2Mn0.3O2 (LSN5) with La4NiLiO8 shields.
• Electrochemical testing of shielded and non-shielded NCM cathodes at various temperatures (25 °C and 60 °C).
• Analysis of charge transfer resistance, discharge capacity, and capacity retention over extended cycling.

Main Results:

• La4NiLiO8-shielded LSN5 exhibited a 4.1× lower charge transfer resistance compared to non-shielded NCM.
• Shielded LSN5 achieved a significantly higher discharge capacity (219.7 mA h g⁻¹) than non-shielded NCM (187 mA h g⁻¹).
• Exceptional capacity retention was observed for shielded NCM: 91.7% at 25 °C (500 cycles) and 84.2% at 60 °C (200 cycles), far exceeding non-shielded NCM (58.9% and 45.5%, respectively).

Conclusions:

• The novel La4NiLiO8 shields effectively enhance charge conduction and prevent electrolyte-induced degradation in NCM cathode materials.
• Shielded NCM demonstrates superior electrochemical performance and remarkable stability, particularly at elevated temperatures.
• This shielding strategy holds significant promise for the development of safe, high-performance secondary batteries.