Suppressing Manganese Dissolution via Exposing Stable {111} Facets for High-Performance Lithium-Ion Oxide Cathode

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Spinel-type lithium manganese oxide (LiMn2O4) cathode materials face challenges with manganese dissolution, especially at elevated temperatures, limiting their performance in lithium-ion batteries (LIBs).
• Interfacial side reactions are a primary cause of degradation in conventional LiMn2O4 cathodes.

Purpose of the Study:

• To design and synthesize a novel 3D hollow fusiform LiMn2O4 cathode material with enhanced structural stability.
• To investigate the mechanism for suppressing manganese dissolution and improve the electrochemical performance of LiMn2O4 cathodes.

Main Methods:

• Advanced electron microscopy techniques including microfocused ion beam scanning electron microscopy (FIB-SEM), high-resolution transmission electron microscopy (HRTEM), and scanning transmission electron microscopy (STEM) were used for structural characterization.
• Electrochemical performance was evaluated through rate capability tests, cycling stability tests, and high-temperature performance assessments.
• In situ X-ray diffraction (XRD) and ex situ X-ray photoelectron spectroscopy (XPS) were employed to elucidate the working mechanism.

Main Results:

• The synthesized 3D hollow fusiform LiMn2O4 exhibited preferentially exposed stable {111} facets and a seamless outer structure.
• The material demonstrated excellent rate capability (107.6 mAh g-1 at 10 C) and remarkable cycling stability (83.3% capacity retention after 1000 cycles at 1 C).
• Outstanding high-temperature performance was achieved, attributed to the suppression of manganese dissolution.

Conclusions:

• The unique geometrical structure and exposed {111} facets effectively suppress manganese dissolution, leading to improved electrochemical performance.
• The findings provide significant insights and guidelines for designing highly stable cathode materials for advanced LIBs.
• This work highlights the potential of precisely engineered nanostructures for next-generation energy storage solutions.