Enhancement of LiMn₂O₄ Cathode Material Stability by LiB₃O₅ Coating and Synchronized B Doping

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Spinel manganese lithium oxide (LMO) is a cost-effective cathode material for lithium-ion batteries.
• LMO suffers from capacity fading, particularly at elevated temperatures, limiting its practical use.

Purpose of the Study:

• To enhance the cycling stability and high-temperature performance of LMO cathode materials.
• To investigate the effectiveness of lithium borate (LiB3O5) as a surface coating for LMO.

Main Methods:

• A straightforward surface coating method was used to apply LiB3O5 onto LMO particles.
• Electrochemical performance was evaluated through cycling tests at various temperatures (25 °C and 55 °C) and rates (1C).
• Material characterization was performed to understand the underlying mechanisms of performance enhancement.

Main Results:

• The 2% LiB3O5 coated LMO (2% LBO@LMO) exhibited superior capacity retention compared to uncoated LMO.
• At 25 °C after 300 cycles, 2% LBO@LMO retained 88.55% capacity vs. 58.47% for LMO.
• At 55 °C after 100 cycles, 2% LBO@LMO retained 77.38% capacity vs. 58.37% for LMO.

Conclusions:

• LiB3O5 coating effectively improves the cycling stability and thermal performance of LMO cathodes.
• The coating induces beneficial surface modifications, including boron doping and mitigation of particle cracking and Mn dissolution.
• This work highlights the potential of lithium borates for enhancing LMO battery applications.