Self-Reconstruction of ultralow-Pt-loading Co3O4 nanoneedle array cathode for high-performance Li-O2 battery

The practical implementation of Li-O 2 batteries remains constrained by three persistent challenges: sluggish oxygen redox kinetics, prohibitive costs of noble metal catalysts, and insufficient activity of non-precious alternatives. Herein, we present a novel ultralow Pt (0.25 wt%) single-atom loading Co 3 O 4 nanoneedle array catalyst (Pt 1 -Co 3 O 4 ) grown on carbon cloth via an ionic substitution strategy. This material functions as an advanced self-supporting cathode for aprotic Li-O 2 batteries. Benefiting from the surface self-reconstruction induced by Pt single-atom occupied the tetrahedral central sites of Co 3 O 4 , the electronic structure of Co 3 O 4 is modified, significantly enhancing the kinetics of both the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). As a result, the Pt 1 -Co 3 O 4 cathode demonstrates excellent cycling stability and a remarkably low discharge–charge overpotential of just 0.86 V. Furthermore, the Li-O 2 battery with this cathode exhibits a high discharge-specific capacity (8.20mAh cm −2 ) and long cycling life (220 cycles, >1100 h at 0.1 mA cm −2 ), outperforming all reported Co 3 O 4 -based ORR/OER catalysts, as well as many non-noble metal catalysts, even those with significant noble metal loading. Crucially, the thin-film-like layers of discharge product Li 2 O 2 are uniformly dispersed on the Pt 1 -Co 3 O 4 nanoneedles. This reduces the adsorption energy between LiO 2 /Li 2 O 2 and Pt 1 -Co 3 O 4 compared to Co 3 O 4 , ensuring good structural stability during discharge/charge cycles and facilitating the decomposition of discharge products during recharge, thus reducing overvoltage and enhancing battery efficiency. These findings position Pt 1 -Co 3 O 4 as a promising catalyst for Li-O 2 batteries and open new avenues for the development of oxide-based single-atom catalysis.