Converting Li-Rich Layered Oxide Cathode into Non-Shrinking Sacrificial Prelithiation Agent

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Conventional prelithiation agents for lithium-ion batteries cause volumetric shrinkage, degrading electrode integrity and performance.
• Active lithium loss during battery operation limits energy density.

Purpose of the Study:

• To develop a novel prelithiation agent that overcomes the limitations of conventional methods.
• To improve the energy density and cycle life of lithium-ion batteries.

Main Methods:

• Conversion of a typical Li-rich layered oxide cathode into a Li-rich disordered rocksalt oxide (LRDO) prelithiation agent.
• Utilizing a fluorinated electrolyte additive to create a gradient cathode-electrolyte interphase.
• Testing a graphite||LiFePO4 pouch cell with the developed LRDO agent.

Main Results:

• The LRDO agent achieved a charge capacity of 330 mAh g⁻¹ and a reversible capacity of 130 mAh g⁻¹.
• The phase-transition-free nature of LRDO eliminated volume shrinkage during prelithiation.
• The pouch cell demonstrated a high discharge capacity of 150.02 mAh and maintained 91.33% capacity after 1800 cycles.

Conclusions:

• The developed LRDO prelithiation agent effectively enhances lithium-ion battery energy density and cycle life.
• The phase-transition-free property of LRDO prevents electrode architecture degradation.
• This approach offers a promising strategy for next-generation high-performance lithium-ion batteries.