High-Performance Protonic Ceramic Electrochemical Cells

Abstract

Protonic ceramic electrochemical cells (PCECs) have attracted considerable attention owing to their ability to reversibly convert chemical fuels into electricity at low temperatures below 600 °C. However, extreme sintering conditions during conventional convectionbased heating induce critical problems for PCECs such as nonstoichiometric electrolytes and microstructural coarsening of the electrodes, leading to performance deterioration. Therefore, we fabricated PCECs via a microwave-assisted sintering process (MW-PCEC). Owing to the ultrafast ramping rate (∼50 °C/min) with bipolar rotation and the resistive heating nature of microwave-assisted sintering, undesirable cation diffusion and grain growth were effectively suppressed, thus producing PCECs with stoichiometric electrolytes and nanostructured fuel electrodes. The MW-PCEC achieved electrochemical performance in both in fuel cell (0.85 W cm −2 ) and in electrolysis cell (1.88 A cm −2 ) modes at 600 °C (70% and 254% higher than the conventionally sintered PCEC, respectively) demonstrating the effectiveness of using an ultrafast sintering technique to fabricate high-performance PCECs.

Microstructure optimization of fuel electrodes for high‐efficiency reversible proton ceramic cells

“…From OCV to 0.5 A cm −2 , the increase is linearly and big, followed by a relatively flat increase in current density from 0.5 to 1.0 A cm −2 and a slower increase at currents higher than 1.0 A cm −2 , it suggests a complex interaction between bulk mass transport and surface electrocatalytic reaction. In fact, many reports exist on the variation of the I-V curves, 14,22,31,32 particularly in the studies focusing on the optimization of the electrode microstructure and improvement of TPBs. The Ni-BZCYYb-10 fuel-electrode sample shows the best improvement with regard to TPBs and thus the most pronounced change with temperature.…”

Advances in developing protonic ceramic cells

“…Ba evaporation and B-site dopant segregation at the surface a. and the cross-section after 1500 ℃ sintering. [72] Reproduced from Kim et al ACS Energy Lett. 2022;7:2393-2400, with permission of the American Chemical Society [72].…”

“…[72] Reproduced from Kim et al ACS Energy Lett. 2022;7:2393-2400, with permission of the American Chemical Society [72].…”

“…Schematic of the PCFC fabricated via PLD process and the SEM images of the cross-section and the surface. [83] Reprinted from [72] 추가적인 공정 없이도 Fig. 10 다.…”

Novel co-doped protonic conductors BaLa1.9Sr0.1In1.95M0.05O6.925 with layered perovskite structure

“…Electrochemical devices such as proton-conducting fuel cells [1][2][3] and electrolyzers [4,5] are in dire need of highly efficient materials with targeted properties including proton conductivity [6][7][8]. Active development and implementation of these devices as a part of the "hydrogen energy in everyday life" strategy should ensure sustainable environmental development [9][10][11][12][13][14][15][16].…”