Revitalizing interphase in all-solid-state Li metal batteries by electrophile reduction

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• All-solid-state lithium metal batteries offer enhanced safety and energy density but face challenges like low Li reversibility, limited cell loading, and dendrite growth.
• Solid-state electrolyte (SSE) instability at low voltages and high voltages, coupled with lithium dendrite formation, hinders practical application.

Purpose of the Study:

• To address the limitations of solid-state lithium metal batteries by developing a novel interphase layer.
• To improve Li reversibility, suppress dendrite growth, and enable high-voltage cathode operation.

Main Methods:

• A family of reductive electrophiles were used to form protective interphase layers on SSE surfaces.
• The formation and properties of the solid reductive-electrophile interphase were investigated.
• All-solid-state lithium metal batteries utilizing the treated SSE were fabricated and tested.

Main Results:

• The solid reductive-electrophile interphase was found to be electron-blocking and lithiophobic, preventing SSE reduction and suppressing lithium dendrites.
• Treated SSEs demonstrated high critical capacity and Li reversibility.
• Batteries achieved high coulombic efficiency (>99.9%), long cycle life (~10,000 hours), and high loading (>7 mAh cm⁻²) at 30°C and 2.5 MPa.

Conclusions:

• The solid reductive-electrophile interphase effectively enhances the performance and stability of all-solid-state lithium metal batteries.
• This approach enables high-voltage operation and extends the cycle life of high-nickel cathodes.
• Surface modification with solid reductive-electrophile interphases offers a promising strategy for commercializing advanced solid-state batteries.