Bulk/Interfacial Structure Design of Li-Rich Mn-Based Cathodes for All-Solid-State Lithium Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Li-rich Mn-based cathode materials (LRMO) show potential for high-energy-density all-solid-state batteries (ASSBs).
• Poor electrical conductivity and interfacial instability hinder LRMO performance in ASSBs.

Purpose of the Study:

• To design in-situ bulk/interfacial structures for LRMO cathodes to create efficient Li+/e- pathways.
• To improve the conductivity and interfacial stability of LRMO cathodes for ASSBs.

Main Methods:

• Introduction of Li2WO4 into LRMO cathodes via in-situ structure design.
• Investigation of Li+ migration, surface oxygen structure stability, and oxygen redox reversibility.
• Fabrication and electrochemical testing of ASSBs with modified LRMO cathodes.

Main Results:

• Li2WO4 introduction reduced Li+ migration energy barriers and stabilized surface oxygen structure.
• Improved reversibility of oxygen redox and significantly addressed voltage decay in LRMO cathodes.
• Enhanced bulk structure and high-voltage interfacial stability, leading to high areal capacity (~3.15 mAh/cm2) and over 1200 cycles with 84.1% retention.

Conclusions:

• The in-situ bulk/interfacial structure design strategy effectively enhances LRMO cathode performance for ASSBs.
• Achieved ultrastable high-voltage interfaces and high-loading composite electrodes for advanced energy storage.
• This work provides insights for developing next-generation LRMO cathode materials for high-performance ASSBs.