Boosting the Ion Mobility in Solid Polymer Electrolytes Using Hollow Polymer Nanospheres as an Additive

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Solid polymer electrolytes (SPEs) offer enhanced safety and stability for energy storage.
• Limitations include low ion mobility and poor electrochemical stability, hindering industrial adoption.

Purpose of the Study:

• To develop a novel SPE design for improved lithium-ion transport and electrochemical stability.
• To create a composite material using polydopamine hollow nanospheres within a poly(ethylene oxide) and LiTFSI matrix.

Main Methods:

• Incorporation of polydopamine hollow nanospheres, templated by silica, into a poly(ethylene oxide)/LiTFSI SPE.
• Utilizing theoretical calculations to understand ion transport mechanisms.
• Fabricating and testing all-solid-state Li/LiFePO4 batteries.

Main Results:

• Achieved an ionic conductivity of 0.189 mS cm⁻¹ at 60 °C, significantly higher than the base SPE (0.105 mS cm⁻¹).
• Demonstrated enhanced Li+ mobility and an enlarged electrochemical window.
• The composite electrolyte enabled a Li/LiFePO4 battery with high reversible capacity (134.9 mAh g⁻¹) and excellent capacity retention (97.2% after 205 cycles).

Conclusions:

• The novel SPE design effectively enhances ionic conductivity and electrochemical stability.
• The polydopamine hollow nanospheres act as efficient ion transport channels and anion traps.
• This composite material shows great promise for high-performance, safe all-solid-state batteries.