Proton-conductive coordination polymer glass for solid-state anhydrous proton batteries

Area of Science:

• Materials Science
• Electrochemistry
• Solid-State Chemistry

Background:

• Designing solid-state electrolytes for proton batteries at moderate temperatures is challenging due to poor moldability and thermal stability of conventional conductors.
• Crystal-glass transformation of coordination polymers (CPs) and metal-organic frameworks (MOFs) via melt-quenching presents a promising route to overcome these limitations.

Purpose of the Study:

• To synthesize and characterize a novel glassy-state coordination polymer for solid-state proton battery applications.
• To investigate the proton conductivity and thermal properties of the new material.
• To demonstrate the feasibility of using this glassy CP in a rechargeable all-solid-state proton battery.

Main Methods:

• Synthesis of a glassy-state CP, [Zn3(H2PO4)6(H2O)3](1,2,3-benzotriazole), through melt-quenching of its crystalline counterpart.
• Characterization of the material's structure, thermal properties (low melting point of 114 °C), and anhydrous proton conductivity.
• Fabrication and testing of a rechargeable all-solid-state proton battery utilizing the glassy CP as the solid electrolyte.

Main Results:

• The synthesized glassy CP exhibited a low melting temperature (114 °C) and high anhydrous single-ion proton conductivity (8.0 × 10^-3 S cm^-1 at 120 °C).
• Melt-quenching induced an isotropic disordered domain, enhancing proton (H+) dynamics and creating an immersive interface beneficial for solid electrolyte applications.
• The all-solid-state H+ battery demonstrated a wide operating-temperature range (25 to 110 °C).

Conclusions:

• Glassy-state coordination polymers offer a viable strategy for developing moldable and thermally stable solid-state proton electrolytes.
• The new glassy CP exhibits excellent proton conductivity and enables the construction of efficient rechargeable all-solid-state proton batteries.
• This work opens new avenues for designing advanced solid-state energy storage devices.