Polymers with Intrinsic Microporosity as Solid Ion Conductors for Solid-State Lithium Batteries.

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Chemistry

Background:

• Solid-state electrolytes (SSEs) are crucial for safe solid-state lithium batteries.
• Current SSEs often fall short of the conductivity and stability required for practical applications.

Purpose of the Study:

• To develop a general strategy for high-performance SSEs using polymers of intrinsic microporosity (PIMs).
• To enhance ionic conductivity, mechanical strength, and electrochemical stability of SSEs for advanced lithium batteries.

Main Methods:

• Engineering polymers of intrinsic microporosity (PIMs) to create interconnected ion pathways.
• Incorporating ionizable groups within the PIM structure to facilitate ion transport.
• Fabricating PIM-based SSEs for testing in lithium-metal and lithium-oxygen batteries.

Main Results:

• Achieved high ionic conductivity of 1.06×10⁻³ S/cm at 25°C in PIM-based SSEs.
• Demonstrated mechanically strong (50.0 MPa) and non-flammable SSEs with excellent electrochemical stability.
• PIM-based SSEs successfully suppressed dendrite growth and short-circuiting in Li symmetric batteries for over 2200 hours.
• PIM-based SSEs enabled high specific capacity (11307 mAh/g) and stable cycling (247 cycles) in solid-state Li-O₂ batteries.
• PIM-based SSEs exhibited robust performance under abuse tests (bending, cutting, penetration).

Conclusions:

• PIM-based SSEs offer a powerful strategy for developing safe, high-energy solid-state batteries.
• The engineered PIM structure provides a pathway to overcome limitations of current SSEs.
• This approach significantly advances the potential for practical solid-state lithium battery technology.