Motivated by the increased demand for energy storage technologies with maximum power density and safety, zinc–air batteries have drawn extensive attention. However, developing a competent and robust bifunctional oxygen reduction and oxygen evolution reaction (ORR/OER) catalyst and studying the underlying active-site mechanisms with the aim of optimizing the electrochemical process remains challenging. In this work, defective/graphitic synergy in heteroatom-interlinked-triggered asphaltene (D/G-HASP) is explored via Raman spectroscopy, density functional theory (DFT), and other characterization approaches, in which reactions involving the oxygen-containing intermediates on the carbon substrate can be accelerated by the electron deficit triggered by heteroatoms, thus enhancing the oxygen reaction performance. As estimated, D/G-HASP reveals a superior half-wave potential (E_1/2 = 840 mV) and the lowest overpotential (η₁₀ = 310 mV) towards the ORR and OER compared to its other counterparts. Remarkably, zinc–air batteries primed with such an air-electrode show outstanding reversibility and stability. This effort hence delivers insightful understanding of the synergistic reaction principles of heteroatom-interlinked-triggering nanomaterials when used in zinc–air batteries.

Carbon materials have drawn remarkable attention as promising anode materials for high performance sodium-ion batteries (SIBs). Developing carbon-based anodes is important for the practical utilization of SIBs in energy storage technologies. Herein, hard carbon spheres encapsulated with graphene networks are prepared by a large-scalable and low-cost method, which deliver better electrochemical performance, such as rate capability and long-cycling life with respect to the ever reported hard carbon materials. The electrochemical test indicates that the as-prepared hard carbon anode exhibits a reversible capacity of 140 mA h g⁻¹ under a current density up to 10 A g⁻¹. Of special interest is that the capacity of 122 mA h g⁻¹ is maintained after 4000 cycles, corresponding to the high capacity retention of 87.1%. The robust and flexible structure of the G-HCS material could facilitate a fast electron and sodium ion transport rate, and sustain fast sodium storage at a high current rate owing to the construction of conductive graphene networks with outstanding electrical conductivity, enabling good contact between hard carbon sphere particles and graphene nanosheets. These results provide a rewarding avenue to design and optimize advanced carbon anode materials for next-generation SIBs.