Highly crumpled nanocarbons as efficient metal-free electrocatalysts for zinc–air batteries

Abstract

The rational design of an efficient and robust oxygen reduction reaction (ORR) electrocatalyst is vital for energy conversion and storage systems, especially for metal–air batteries. Herein, we report a highly nanocrumpled and nitrogen, phosphorus-codoped nanocarbon (NC-NPC) synthesized by direct pyrolysis of melamine and triphenylphosphine. With the rich nano-crumpled structure and codoping of heteroatoms, this low-cost catalyst exhibits an excellent ORR performance, and possesses a half-wave potential of 0.84 V vs. RHE, a small Tafel slope of 70.2 mV dec⁻¹, and good electrocatalytic stability. More importantly, it can also be applied in zinc–air batteries as an efficient electrode which delivers an open-circle voltage of 1.38 V, a specific capacity of 782 mA h g_Zn⁻¹, and a long cycling life of 210 h, superior to the commercial Pt/C catalyst.