Boosting Solid-State Reconversion Reactivity to Mitigate Lithium Trapping for High Initial Coulombic Efficiency.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Initial Coulombic efficiency (ICE) above 90% is vital for industrial lithium-ion batteries.
• Lithium trapping in high-capacity electrodes, caused by incomplete Li+ generation and diffusion, lowers ICE.
• Current methods like nanoscaling have drawbacks, including SEI formation and reduced energy density.

Purpose of the Study:

• To mitigate lithium trapping by enhancing the solid-state reaction kinetics for Li+ generation.
• To demonstrate a novel approach for improving ICE in advanced electrode materials.
• To validate the proposed method using ternary LiFeO2 anodes.

Main Methods:

• Investigated ternary LiFeO2 anodes as a proof-of-concept.
• Utilized synchrotron-based techniques and theoretical simulations.
• Assembled and tested pouch cells to demonstrate superior ICE.

Main Results:

• Ternary LiFeO2 anodes achieved an average ICE of ~92.77%, surpassing binary Fe2O3 anodes (~75.19%).
• The Fe-vacancy-rich environment in discharged products promotes the solid-state reconversion reaction.
• Demonstrated effective alleviation of lithium trapping and enhanced electrochemical performance.

Conclusions:

• Regulating intrinsic solid-state chemistry is a viable strategy to improve ICE.
• The findings offer a new paradigm for developing high-performance electrode materials for industrial applications.
• This approach effectively addresses lithium trapping, a key challenge in advanced battery technologies.