In-situ patterned intra-anode triple phase boundary in SOFC electroless anode: An enhancement of electrochemical performance

Co-existence of intra-anode and conventional triple phase boundary (TPB) is reported for the first time in core (YSZ)–shell (Ni) electroless anode cermet. A mathematical model is proposed for determination of intra-anode TPB length and has been validated experimentally. Retention of longer intra-anode TPB even after repeated redox cycling is responsible for relatively lower conductivity degradation of such cermets. Existence of intra-anode TPB in electroless anode results in significant improvement of electrochemical performance. Single cells with electroless anode exhibit a current density of 2.5 A cm−2 compared to cells with conventional anode (1.7A cm−2) at 800 °C, 0.7 V.

► Patterned intra-anode TPB are generated in-situ within electroless anode.
► Unique core (YSZ)–shell (Ni) microstructure enhances TPB length of electroless anode.
► Intra-anode TPB for electroless anode are mathematically modeled and validated.
► Patterned intra-anode TPB lowers the conductivity degradation (7%/20 redox cycles).
► Existence of dual TPB enhances the cell performance (2.5 A cm−2 at 800 °C, 0.7 V).