B-site Fe/Co trade-off in single-phase PrFexCo1-xO3-δ oxygen electrodes for mechanically robust protonic ceramic cells - Junbiao Li; Shiyin Tang; Haojie Zhu; Zhipeng Liu; Zhaoqi Song; Yue Pang; Hangbin Lin; Ruiwei Ding; Kuiwu Lin; Hainan Sun; Yuan Zhang; Minhua Shao; et al. (Chemical Engineering Journal, 2026)