Developing Dynamic Ion Transport Channels in Polymer Solid Electrolytes for High-Performance Lithium Metal Batteries.

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Solid polymer electrolytes (SPEs) offer enhanced safety and electrochemical stability for lithium metal batteries.
• Key challenges include limited ionic conductivity and poor interfacial stability, hindering practical applications.
• Developing advanced SPEs is crucial for next-generation energy storage.

Purpose of the Study:

• To enhance ionic conductivity and interfacial stability in polyacrylic-based SPEs.
• To investigate the effect of incorporating sulfone (SL) for creating dynamic ion transport channels.
• To enable the development of high-performance, long-lifetime lithium metal batteries.

Main Methods:

• Incorporation of trace amounts of sulfone (SL) into polyacrylic-based SPEs.
• Molecular dynamics simulations to analyze ion transport mechanisms.
• Experimental validation including electrochemical performance and interfacial analysis.
• Fabrication and testing of LFP|In situ-SL2|Li battery cells.

Main Results:

• Optimal SL incorporation (in situ-SL2) created dynamic ion transport channels via gradient ion-dipole interactions.
• Enhanced Li+ solvation and reduced energy barriers for ion hopping, boosting ionic conductivity and transference numbers.
• Formation of a stable, inorganic-rich solid electrolyte interphase (SEI), suppressing dendrite growth.
• Achieved over 91.7% capacity retention after 2000 cycles in LFP|In situ-SL2|Li cells.

Conclusions:

• The novel in situ-SL2 SPE effectively addresses limitations of traditional SPEs.
• This approach significantly improves ionic conductivity and interfacial stability for lithium metal batteries.
• Provides valuable insights for designing safer, high-performance SPEs for long-lifetime applications.