Ultrafast Li-Rich Transport in Composite Solid-State Electrolytes

Area of Science:

• Materials Science
• Electrochemistry
• Solid-State Batteries

Background:

• Solid-state lithium metal batteries (SSLMBs) offer high energy density and safety advantages.
• Low ionic conductivity in solid-state electrolytes remains a key challenge for SSLMB development.

Purpose of the Study:

• To propose a novel Li-rich transport mechanism for ultrafast Li-ion conduction in composite solid-state electrolytes.
• To enhance the ionic conductivity and performance of SSLMBs.

Main Methods:

• Incorporation of cation-deficient dielectric nanofillers into polymer matrices.
• Investigation of Li-ion adsorption and transport phenomena on nanofiller surfaces.
• Fabrication and electrochemical testing of composite solid-state electrolytes and full cells.

Main Results:

• A novel Li-rich transport mechanism was identified, leading to high Li-ion concentration enrichment on nanofiller surfaces.
• Interconnected Li-rich layers formed continuous ultrafast Li-ion transport networks.
• Achieved ionic conductivity of ~1 × 10⁻³ S cm⁻¹ at room temperature with low activation energy (0.17 eV).
• Demonstrated extended cycling life (>200 cycles) with 70.7% capacity retention in Li||LiNi₀.₈Co₀.₁Mo₀.₁O₂ full cells.

Conclusions:

• Constructing interconnected Li-rich transport networks is an effective strategy to improve Li-ion transport in solid-state electrolytes.
• The developed composite electrolyte shows significant potential for high-performance SSLMB applications.
• This work offers new insights for advancing SSLMB technology.