Self-sustainable protonic ceramic electrochemical cells using a triple conducting electrode for hydrogen and power production

Hanping Ding,Yong Ding,Dong Ding,Christopher J Orme,Wenjuan Bian,Chao Jiang,Prabhakar Singh,Yunya Zhang,Wei Wu,Boxun Hu,Lucun Wang

doi:10.1038/s41467-020-15677-z

Abstract

The protonic ceramic electrochemical cell (PCEC) is an emerging and attractive technology that converts energy between power and hydrogen using solid oxide proton conductors at intermediate temperatures. To achieve efficient electrochemical hydrogen and power production with stable operation, highly robust and durable electrodes are urgently desired to facilitate water oxidation and oxygen reduction reactions, which are the critical steps for both electrolysis and fuel cell operation, especially at reduced temperatures. In this study, a triple conducting oxide of PrNi0.5Co0.5O3-δ perovskite is developed as an oxygen electrode, presenting superior electrochemical performance at 400~600 °C. More importantly, the self-sustainable and reversible operation is successfully demonstrated by converting the generated hydrogen in electrolysis mode to electricity without any hydrogen addition. The excellent electrocatalytic activity is attributed to the considerable proton conduction, as confirmed by hydrogen permeation experiment, remarkable hydration behavior and computations.

Highlights

The protonic ceramic electrochemical cell (PCEC) is an emerging and attractive technology that converts energy between power and hydrogen using solid oxide proton conductors at intermediate temperatures
As significant advances have been made in solid state proton conductors and related electrochemical cells in the past decade[5,6], PCEC represents a promising technology for the purpose of achieving low-cost energy storage and conversion at reduced temperatures by offering attracting advantages such as high efficiency[7,8], longer system durability[9,10,11], and less expensive materials[12,13]
Both the water oxidation reaction (WOR) and the oxygen reduction reaction (ORR) in the mixed ion and electronic conducting (MIEC) electrodes are strictly confined to the triple phase boundaries (TPBs) where ion, electron, and gas meet (Fig. 1a)

Summary

Introduction

The protonic ceramic electrochemical cell (PCEC) is an emerging and attractive technology that converts energy between power and hydrogen using solid oxide proton conductors at intermediate temperatures. The protonic ceramic electrochemical cell (PCEC) is a proton-conductor-based solid oxide cell that can serve in a reversible operation manner to store renewable energies using water electrolysis to produce hydrogen and convert it back to electricity in fuel cell mode[2,3,4]. One early technical opportunity is the development of oxygen electrode materials to mitigate these problems that contribute the most to performance degradation and efficiency loss in the existing PCECs16 Both the water oxidation reaction (WOR) and the oxygen reduction reaction (ORR) in the mixed ion and electronic conducting (MIEC) electrodes are strictly confined to the triple phase boundaries (TPBs) where ion, electron, and gas meet (Fig. 1a). The demonstrated triple conduction of this material facilitates WOR and ORR and promoted electrochemical performance of the cell in a self-sustainable and reversible operation at reduced temperatures

Methods

Results

Conclusion