# Constructing Li-O-Vacancy Configuration Coupling with a Layered/Spinel Mixed Structure in Li-Deficient Li-Rich Layered Oxides to Realize Stable Oxygen Redox

## TL;DR

Researchers designed a new structure for lithium-rich battery materials that improves stability and performance by controlling oxygen and lithium vacancies.

## Contribution

A layered/spinel mixed structure with a Li-O-vacancy configuration is constructed to enable stable oxygen redox in Li-rich oxides.

## Key findings

- The Li-O-vacancy configuration was visualized using advanced STEM-iDPC.
- The layered/spinel-like structure achieved high Coulombic efficiency and structural stability.
- The design retains 86.5% of its capacity after 100 cycles.

## Abstract

A Li-O-vacancy configuration is constructed in Li-rich layered oxides.Advanced STEM-iDPC is used to visualize structures.Anions achieve stable oxidation–reduction.The layered/spinel-like composite structure achieved superior structural and electrochemical stability.Ultra-high Coulombic efficiency is obtained during initial cycling.

A Li-O-vacancy configuration is constructed in Li-rich layered oxides.

Advanced STEM-iDPC is used to visualize structures.

Anions achieve stable oxidation–reduction.

The layered/spinel-like composite structure achieved superior structural and electrochemical stability.

Ultra-high Coulombic efficiency is obtained during initial cycling.

What are the main findings?
We visualized the Li-O-V configuration in lithium-rich layered oxides.We have verified the stability of the spinel/layered mixed structure.We have demonstrated that the Li-O-V configuration can achieve available anionic capacity.

We visualized the Li-O-V configuration in lithium-rich layered oxides.

We have verified the stability of the spinel/layered mixed structure.

We have demonstrated that the Li-O-V configuration can achieve available anionic capacity.

What are the implications of the main findings?
They provide structural design strategy for achieving stable lattice oxygen capacity.They develop a lithium-rich material that can achieve high initial Coulombic efficiency.They provide ideas for designing lithium defect materials.

They provide structural design strategy for achieving stable lattice oxygen capacity.

They develop a lithium-rich material that can achieve high initial Coulombic efficiency.

They provide ideas for designing lithium defect materials.

Owing to the synergistic effect of cationic and anionic charge compensation, Li-rich layered oxide cathodes stand as the most promising candidates for next-generation high-energy-density Li-ion batteries. However, the unstable oxygen redox process triggers irreversible oxygen release and structural degradation of the layered framework, which further destabilizes the Li-O-Li configuration and leads to severe performance decay. In this work, a layered/spinel heterostructure coupled with a stabilized Li-O-vacancy configuration is successfully constructed in a Li-rich layered oxide cathode. This design enables outstanding structural and electrochemical stability, delivering an initial discharge capacity of 232 mAh g−1 with a Coulombic efficiency of 90.5%. Moreover, the cathode retains 86.5% of its capacity after 100 cycles. The proposed structural design strategy offers a new pathway toward high-performance Li-rich layered oxide cathodes.