A High-Capacity Polyethylene Oxide-Based All-Solid-State Battery Using a Metal-Organic Framework Hosted Silicon Anode

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Polyethylene oxide (PEO)-based solid electrolytes are promising for solid-state lithium batteries due to cost and fabrication ease.
• However, PEO electrolytes struggle with lithium dendrite suppression, limiting anode capacity.
• Existing solid-state batteries often face challenges with interfacial stability and dendrite formation.

Purpose of the Study:

• To develop a high-capacity all-solid-state battery with improved lithium dendrite suppression.
• To investigate the performance of a novel silicon-metal-organic framework (Si@MOF) anode.
• To evaluate a fiber-supported PEO/garnet composite electrolyte for enhanced interfacial contact and stability.

Main Methods:

• Embedding silicon nanoparticles within a MOF-derived carbon host (Si@MOF) to manage silicon's volume changes.
• Fabricating a fiber-supported PEO/garnet composite electrolyte.
• Assembling and testing full cells with LiFePO4 (LFP) cathodes and the Si@MOF anode.

Main Results:

• The Si@MOF anode demonstrated excellent interfacial stability with the composite electrolyte (>1000 h) and a high reversible areal capacity (3 mAh cm⁻²).
• Full cells achieved an initial capacity of 135 mAh g⁻¹ and retained 73.1% after 500 cycles at 60 °C.
• Cells with high LFP loadings exceeded 2 mAh cm⁻² areal capacity, surpassing many PEO-based solid-state batteries.

Conclusions:

• The developed Si@MOF anode and composite electrolyte system offers a viable pathway for high-capacity, stable all-solid-state lithium batteries.
• This approach overcomes limitations of PEO-based electrolytes in dendrite suppression and anode capacity.
• The pouch cell demonstrated practical potential with good electrochemical performance and safety.