Element-Engineered Lithium Borate for High-Efficiency Prelithiation in Silicon-Based Lithium-Ion Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Enhancing energy density in lithium-ion batteries (LIBs) is crucial for next-generation energy storage.
• Silicon anodes offer high capacity but suffer from low initial coulombic efficiency (ICE), causing lithium loss and performance degradation.

Purpose of the Study:

• To develop a novel prelithiation agent for LIBs.
• To improve the initial coulombic efficiency and stability of silicon-based anodes.
• To enhance the overall energy density and cycle life of LIBs.

Main Methods:

• A novel lithium borate (LBO) prelithiation agent with a core-shell architecture (Li3BO3 core, Li2CO3 and amorphous carbon shell) was synthesized.
• The LBO agent's atmospheric stability and initial charge capacity were evaluated.
• LBO was applied in SiO(x)||LRLO (Li-rich layered oxide) pouch cells to assess its impact on energy density and degradation.

Main Results:

• The LBO agent demonstrated an exceptional initial charge capacity of 692 mAh g⁻¹.
• LBO exhibited superior atmospheric stability, retaining 70% capacity after 8 days of ambient exposure.
• In SiO(x)||LRLO pouch cells, LBO enhanced gravimetric and volumetric energy density by 14.7% and 21.8%, respectively.
• LBO effectively suppressed irreversible degradation in Li-rich layered oxides.

Conclusions:

• The developed lithium borate (LBO) agent is a promising solution for enhancing LIB performance.
• This work introduces an element-centric design approach for prelithiation agents.
• The findings pave the way for developing high-energy-density LIBs using advanced anode materials.