(Invited) Protonic Ceramic Electrochemical Cells for Energy Conversion and Storage

Abstract

The rapid growth in solar and wind-based intermittent renewable electricity generation and the spectacular drop in renewable energy cost necessitates the development of highly efficient, long-term energy storage to levelize seasonal wind/PV generation output variations. While batteries are well suited for short-term (e.g. hourly or daily) energy storage, they are less suited for longer term (e.g. seasonal) energy storage due to self-discharge challenges and economic constraints caused by a linear cost/stored-energy scaling relationship. While significant progress has been made on developing reversible electrochemical cells based on proton exchange membrane fuel cells (PEMFCs) and solid oxide fuel cells (SOFCs), major challenges remain. In particular, high PGM catalyst cost and low energy efficiency due to sluggish kinetics still limit the commercialization of low-temperature reversible PEMFCs. Intermediate-temperature reversible electrochemical cells can potentially mitigate the challenges associated with both low-temperature reversible PEMFCs and high-temperature reversible SOFCs. Protonic ceramic electrochemical cells (PCECs) are an emerging and potentially promising energy storage technology which can electrochemically convert chemical energy to electricity in fuel cell mode and convert renewable electricity to fuel in electrolysis mode with high round-trip efficiency. In this presentation, we will discuss applications of PCECs for energy conversion and storage, how to achieve high round-trip efficiency, and efficient conversion of electrons to chemicals in PCECs.