Poly(vinylene carbonate)-Based Composite Polymer Electrolyte with Enhanced Interfacial Stability To Realize...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Solid-state batteries offer enhanced safety and energy density over liquid-electrolyte counterparts.
• Commercialization of polymer electrolyte solid-state batteries is hindered by low ionic conductivity, poor mechanical properties, and interfacial issues.
• Room-temperature operation remains a significant challenge for solid-state rechargeable batteries.

Purpose of the Study:

• To develop a novel poly(vinylene carbonate)-based composite polymer electrolyte (PVC-CPE) for high-performance room-temperature solid-state sodium batteries.
• To address the limitations of low ionic conductivity, poor mechanical properties, and weak interfacial compatibility in existing polymer electrolytes.
• To demonstrate the efficacy of an in situ solidification method for enhancing electrode/electrolyte interfaces.

Main Methods:

• Synthesis and characterization of a poly(vinylene carbonate)-based composite polymer electrolyte (PVC-CPE).
• Design of a composite cathode (c-NFM) using in situ polymer electrolyte growth within the electrode structure.
• Assembly and electrochemical testing of solid-state sodium batteries using the developed PVC-CPE and c-NFM.
• Comparison of batteries assembled via in situ and ex situ methods to evaluate interfacial effects.

Main Results:

• The in situ solidified PVC-CPE exhibited superior ionic conductivity (0.12 mS cm^-1 at 25 °C) and a high Na⁺ transference number (t_Na = 0.60).
• Enhanced electrode/electrolyte interfacial stability was achieved through in situ polymer electrolyte growth within the composite cathode (c-NFM).
• The solid-state c-NFM/PVC-CPE/Na battery demonstrated excellent room-temperature performance: 104.2 mA h g^-1 at 0.2 C (86.8% retention over 250 cycles) and 80.2 mA h g^-1 at 1 C.

Conclusions:

• PVC-CPE is a highly promising electrolyte material for developing high-performance, safe, room-temperature solid-state sodium batteries.
• The in situ solidification method offers a viable strategy for improving interfacial properties and electrochemical performance in solid-state batteries.
• This research paves the way for designing advanced polymer electrolytes for various solid-state rechargeable battery applications demanding safety and efficiency.