LAUSR

A novel three-dimensional (3D) bifunctional electrocatalyst, CoNi alloy nanoparticles and carbon nanotubes decorated N-doped carbon nanosheet arrays on carbon cloth (CoNi alloy/NCNSAs/CC) derived from polymetallic organic frameworks, is firstly prepared. The CoNi alloy/NCNSAs/CC-800 fabricated by pyrolyzing at 800 °C exhibits oxygen reduction reaction (ORR) (limiting current density) of 6.5 mA cm-2 and superior oxygen evolution reaction (OER, at 10 mA cm-2) of 1.51 V, as well as smaller potential difference of 0.676 V between OER and ORR half-wave potential, outperforming previous self-supporting cathodes. The flexible Zn-air batteries (FZABs) assembled with the CoNi alloy/NCNSAs/CC-800 exhibit higher energy density (98.8 mW cm-2) and higher capacity (879 mAh g-1), excellent mechanical cycle ability (lower voltage gap of 0.66 V during the charge/discharge cycles at flat and folded state), significantly outstripping all of FZABs with self-supporting electrodes reported. Such remarkable performances are ascribed to the 3D hierarchical nanostructure promoting mass transport, higher graphitization facilitating electronic mobility, and evenly dispersed active sites accelerating kinetic reaction. So CoNi alloy/NCNSAs/CC-800 is a promising cathode candidate for ideal wearable energy and has greatly potential application in the field of electrochemical energy storage and conversion.