Synergistic Etching-Complexation Surface Reconstruction Induced by Dual Organic Acids toward High-Performance...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium-rich manganese-based cathode materials (LRMs) face challenges like voltage fade and poor rate capability.
• These limitations hinder the practical application of LRMs in energy storage devices.

Purpose of the Study:

• To develop a dual organic acid etching-complexation strategy to improve LRM performance.
• To enhance capacity, rate capability, and structural robustness of LRMs.

Main Methods:

• A dual organic acid (oxalic and citric acid) treatment was applied to LRMs.
• Characterization included electrochemical testing and in situ differential electrochemical mass spectrometry (DEMS).
• Theoretical calculations were used to understand vacancy formation and binding energies.

Main Results:

• The optimized LRM sample showed high initial capacity (287.8 mAh g⁻¹ at 0.1 C) and good rate performance (236.9 mAh g⁻¹ at 3 C).
• The material exhibited excellent stability with low voltage decay (2.81 mV per cycle) and high initial Coulombic efficiency (91.5%).
• The dual-acid strategy created cation-anion dual vacancies, stabilizing oxygen redox and accelerating lithium-ion diffusion.

Conclusions:

• The dual organic acid strategy effectively addresses intrinsic limitations of LRMs.
• This approach offers an eco-friendly method for developing advanced cathode materials for batteries.
• The generated vacancies significantly improve structural stability and ion transport.