Single-Crystal, Highly Ni-Rich LiNi_0.9Co_0.055Mn_0.045O₂ Cathode Material: Spray Pyrolysis Synthesis and Grain Size...

Area of Science:

• Materials Science
• Electrochemistry
• Chemical Engineering

Background:

• Highly nickel-rich layered oxide cathode materials (LiNi_xCo_yMn_zO₂, x ≥ 0.9) offer high capacity and low cost for lithium-ion batteries (LIBs).
• Conventional synthesis methods (coprecipitation, sol-gel) are complex, environmentally unfriendly, and result in poor uniformity and performance instability.
• Challenges include difficulties in continuous production and achieving desired material properties for high-performance LIBs.

Purpose of the Study:

• To develop a novel, environmentally benign synthesis route for single-crystal, highly Ni-rich cathode materials.
• To optimize the spray pyrolysis method for producing LiNi_0.9Co_0.055Mn_0.045O₂ (NCM90) with enhanced properties.
• To investigate the impact of synthesis parameters on the morphology, structure, and electrochemical performance of NCM90.

Main Methods:

• Synthesis of single-crystal NCM90 cathode materials using a novel spray pyrolysis technique.
• Introduction of an annealing step post-sintering to control particle size, increasing it from 0.31 μm to 0.81 μm.
• Comprehensive analysis of material properties (morphology, structure, electrochemistry) under varied spray pyrolysis, sintering, and annealing conditions.

Main Results:

• Optimized spray pyrolysis at 800 °C, sintering at 800 °C, and annealing at 650 °C yielded high-performance NCM90.
• Achieved initial discharge capacity of 225.7 mAh g^-1.
• Demonstrated 50-cycle capacity retention of 84.5%, indicating improved stability.

Conclusions:

• Spray pyrolysis offers a viable, scalable alternative for synthesizing advanced cathode materials for LIBs.
• The annealing process is crucial for enhancing particle size and electrochemical performance.
• Optimized synthesis conditions provide a pathway for developing next-generation, high-performance lithium-ion batteries.