Water-Superstructured Solid Fuel Cells

TL;DR

This paper introduces a novel water-superstructured protonic superconductor using Al2O3 that significantly enhances proton conductivity, enabling high-performance low-temperature solid fuel cells with record power density.

Contribution

It presents a new strategy to turn Al2O3 into a protonic superconductor via in-situ water structuring, leading to advanced solid fuel cell performance.

Findings

Achieved ultrahigh proton conductivity of 0.13 S/cm at 550°C.

Demonstrated a water-superstructured solid fuel cell with 1036 mW/cm2 power density.

Maintained high open circuit voltage above 1.1 V at 550°C.

Abstract

Protonic ceramic fuel cells can be operated at low temperatures, but their performances relying on bulk ion transfer in solid electrolytes are usually limited by much lower proton conductivity than 0.1 S/cm below 600 {\deg}C. Herein, however, we report a strategy for Al2O3 insulator to become a protonic superconductor, namely, in-situ generation of superstructured-water in porous Al2O3 layer could realize the unprecedented water-mediated proton transfer on Al2O3 surface, attaining ultrahigh proton conductivity of 0.13 S/cm at 550 {\deg}C. With such a water-superstructured proton-superconductor, we created water-superstructured solid fuel cell, achieving very high power density of 1036 mW/cm2 and high open circuit voltage above 1.1 V at 550 {\deg}C with H2 fuel. This provides a general approach to develop protonic superconductors and solid fuel cells.