Improving Cyclability of All-Solid-State Batteries via Stabilized Electrolyte-Electrode Interface with Additive in...

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Solid polymer electrolytes (SPEs) are crucial for next-generation batteries, but often suffer from poor ionic conductivity and interfacial instability.
• Poly(propylene carbonate) (PPC) is a promising polymer electrolyte material, yet requires modification to overcome its limitations.
• Achieving stable and efficient solid-state electrolytes is vital for the development of safer and more powerful batteries.

Purpose of the Study:

• To investigate the role of tetraethylene glycol dimethyl ether (TEGDME) as an additive in poly(propylene carbonate) (PPC) based solid polymer electrolytes (SPEs).
• To enhance the ionic conductivity and interfacial stability of PPC-based SPEs for improved battery performance.
• To evaluate the electrochemical properties and cycling stability of the optimized SPEs in lithium battery configurations.

Main Methods:

• Incorporation of TEGDME as an additive into PPC polymer matrix, utilizing a tissue membrane for mechanical support.
• Characterization of the resulting SPEs for ionic conductivity, potential stability, and Li-ion transference number at elevated temperatures.
• Fabrication and testing of Li/SPE/Li symmetric cells and Li/SPE/LFP full cells to assess cycling stability and capacity retention.

Main Results:

• Optimized TEGDME content in PPC resulted in an ionic conductivity of 0.89 mS cm⁻¹ and a high Li-ion transference number of 0.81 at 60 °C.
• The SPE demonstrated excellent potential stability up to 4.89 V and suppressed the formation of a protrusion-type cathode electrolyte interface (CEI).
• Li/SPE/Li cells showed remarkable cycling stability for 1650 hours, and Li/SPE/LFP full cells maintained good capacity over 500 cycles at 1 C.

Conclusions:

• TEGDME effectively improves the ionic conductivity and interfacial properties of PPC-based SPEs.
• The addition of TEGDME promotes the formation of a stable and uniform CEI layer, crucial for battery longevity.
• The developed SPEs show significant potential for application in advanced solid-state lithium-ion batteries (ASSLIBs).