An Ion-Channel-Reconstructed Water/Organic Amphiphilic Quasi-Solid-State Electrolyte for High-Voltage Energy Storage Devices

Abstract

Quasi-solid-state electrolytes (QSSE) have garnered significant attention due to combining the dynamic properties of liquid electrolytes and the high safety of solid-state electrolytes. However, the limited electrochemical stability window (ESW) of liquid electrolytes and the low conductivity of the polymer matrix seriously constrain practical application. Herein, an ant-nest electrospun amphiphilic polyurethane-based gel electrolyte (eAPG) with hydrophilic ion channels in an organic polyurethane matrix was synthesized by swelling electrospun amphiphilic polyurethane (eAP) membrane in NaClO₄-based trimethyl phosphate (TMP) aqueous solution. The dynamically reconstructed hydrophilic ion channels enhance the Na⁺ transport rate five times compared to that in the polymer hydrophobic regions, which leads to a remarkable ion conductivity of 23.6 mS cm^-1. The transport of free water in QSSEs via the Grotthuss mechanism is intimately associated with the ESW, where the eAP cross-linked network diminished the activity of free water, resulting in an increased ESW of 2.3V. Additionally, symmetric supercapacitors assembled by eAPG and activated carbon (AC) electrode exhibit 45.32 Wh kg^-1 at a power density of 0.933 kW kg^-1 with stable and long-term cycling. This rational electrolyte design strategy and remarkable electrochemical performance pave the way for the next generation of energy storage devices.

• Download figure
• Download PowerPoint