High‐Performance Li–O₂ Batteries Based on All‐Graphene Backbone

Abstract The Li–O₂ battery is one of the most captivating energy storage forms due to its extraordinarily high energy density and the readily its the ready availability of oxygen. However, significant challenges lie ahead on both the anode and cathode sides before the technology can be finally deployed to benefit human life. Herein, a two‐birds‐one‐stone tactic is implemented to fabricate high‐performance and flexible Li–O₂ batteries utilizing only one structural backbone composed of graphene oxide aerogel embedding hollow NiCo₂O₄ microspheres for both the anode and cathode. While the composite Li anode fabricated through lithium infusion exhibits an ultrahigh capacity of 3398.4 mAh g⁻¹ and significantly inhibits dendrite growth and volume expansion, the freestanding oxygen cathode demonstrates great capability in promoting energy efficiency by catalyzing reversible Li₂O₂ formation. When coupled together, the resultant Li–O₂ batteries manifest a superb long‐term cycling stability with highly reversible discharge/charge for more than 400 cycles, apart from the remarkable mechanical deformability demonstrated by flexible pouch cells. By employing a full spectrum of ex situ and operando spectroscopic and microscopic tools, mechanistic insights into the remarkable Li–O₂ performance are given.