Carbon‐Encapsulated CoNi Alloy Nanocrystal Derived From a Series of Ni‐Doped [Co(1‐MI) 6 ]·[B 5 O 6 (OH) 4 ] 2 ·DMF 2 for Ultralong‐Life Zinc–Air Batteries

The development of efficient and stable bifunctional catalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is crucial for advancing zinc–air batteries (ZABs). A series of Ni‐doped [Co(1‐MI) 6 ]·[B 5 O 6 (OH) 4 ] 2 ·DMF 2 ( 1 ) borates were designed and synthesized in this work. [B 5 O 6 (OH) 4 ] clusters and [Co(1‐MI) 6 ] 2+ cations are linked with each other through hydrogen bond interactions, which promote formation of supramolecular porous architectures, providing sufficient space for in situ metal nanocrystal (NC) formation. Through pyrolysis of doped 1 , CoNi alloy NC was produced and displayed neatly carbon‐encapsulated morphology, such encapsulated NC can preserve structural stability and expose more active sites for electron transfer. Notably, owing to electronic coupling between Co and Ni, alloy NC catalysts exhibited outstanding bifunctional activity with an ORR half‐wave potential of 0.88 V and an OER overpotential of 390 mV, surpassing commercial Pt/C and RuO 2 . When employed in ZAB, it delivered exceptional long‐term cycling stability (2000 h, 6000 cycles). Our findings provide new insights into the development of efficient borate‐based electrocatalysts.