High-Capacity Molecular Scale Conversion Anode Enabled by Hybridizing Cluster-Type Framework of High Loading with...

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• High-capacity anodes are crucial for advanced lithium-ion batteries (LIBs).
• Existing materials often face limitations like limited electron transfer or volume expansion.
• Open framework materials offer potential for multielectron reactions and structural stability.

Purpose of the Study:

• To develop novel open framework anodes for high-performance LIBs.
• To investigate polyoxometalates (POMs) as stable, high-capacity anode materials.
• To enhance the electrochemical performance of POMs through structural modification.

Main Methods:

• Synthesized Al- or Si-based polyoxometalates (POMs).
• Hybridized POMs with positively charged graphene to improve solubility and conductivity.
• Fabricated an Al-based POM composite (NAM-EDAG) for lithium storage.
• Conducted electrochemical testing including cycling stability and rate capability.

Main Results:

• The Al-based POM composite (NAM-EDAG) achieved a reversible capacity over 1000 mAh g⁻¹.
• The material demonstrated excellent long-term cycling stability (>1100 cycles) at high current densities (20 A g⁻¹).
• A six-electron conversion reaction at the molecular scale was identified as key to high electroactivity.

Conclusions:

• Cluster-like POMs function as effective open framework anodes for Li-storage.
• Graphene hybridization successfully addresses POM solubility and conductivity issues.
• POM-based open frameworks provide a promising strategy for developing next-generation energy storage materials.