Although noble metal-based materials are known as favorable catalysts for electrocatalytic oxygen reduction, their scarcity and expensive prices are unsatisfactory. Hence, developing earth-abundant and efficient bifunctional oxygen electrocatalysts for rechargeable ZABs is demanded and remains grand challenging.Carbon materials with unique surface properties and high structural flexibility have been used to prepare advanced electrocatalysts by heteroatom doing and/or loading of various transition metals from nanoparticles to single atoms. [3] Currently, the strategy to improve the electrocatalytic activity of bifunctional ORR/OER electrocatalysts is proposed by the synergistic effect via the integration of multiple active components. Alternatively, the modulation of the geometric and porous structure would facilitate mass transfer and enhance the number of accessible active sites. Obviously, the uniform loading of additional metal active sites is of importance in improving electrocatalytic activity. [4] Specifically, the cobalt species were anchored on the conductive carbon supports via the thermal treatment of organic precursors with the good capability to disperse metal species (such as ZIF-67). [5,6] However, the sintering and aggregation of cobalt species during the annealing process would result in poor electrocatalytic performance. Alternatively, molecular assembly is an efficient strategy for preparing the controllable architectures of catalysts. [7] Therefore, it is highly desirable to integrate the wellshaped 3D porous carbons with cobalt active sites for high-performing electrocatalysis.Inspired by the affinity of receptors and ligands for directly targeting cancer cells, the mini biomimetic coordination of chitosan and folic acid (FA) provides a reaction platform to facilitate the anchoring of metal ions. Herein, the pre-coordination of chitosan with folic acid led to the formation of hierarchical aggregates composed of nanosheets. Their surface functional groups (e.g., carboxylic groups, amino groups) provide the anchoring sites for metal ions via the metal-nitrogen coordination and can avoid the agglomeration of excessive metal ions. During the carbonization, the presence of cobalt species promotes the selfcatalytic growth of carbon nanotubes on the carbon nanosheets of 3D hierarchical porous nanoflowers (CoCNTs/PNAs). With a low boiling point of 732 °C, the thermal release of ZnCl 2The strategy of heteroatom doping and metal active sites can synergistically promote oxygen electrocatalysis. Especially, the combination of theoretical simulations with experimental results provides new opportunities to understand the electrocatalytic mechanism. Herein, the 3D carbon nanosheets aggregate with highly branched carbon nanotubes and cobalt active sites (CoCNTs/PNAs) is prepared via the facile self-assembly-pyrolysis strategy. The CoCNTs/PNAs electrocatalysts exhibit superior bifunctional activities to oxygen reduction (E 1/2 = 0.925 V) and evolution (E j = 10 = 1.54 V) reactions, surpassing those of Pt/C-...

The compelling demand for higher energy performance, flexibility, and miniaturization is the main driving force of the energy storage and conversion industry's quest for flexible devices based on new integration and fabrication process. Herein, the recent advances on the development of flexible zinc–air batteries based on self‐supported air electrodes are summarized, focusing on the multiscale and systematic design principles for the design of flexible air electrodes. With the electrocatalytic activity regulation and structural engineering strategies, the rational design of self‐supported air electrodes is discussed in integrated devices to underpin the good flexibility for wearable requirement. The perspectives on promising developments of flexible zinc–air batteries and the accumulated knowledge from other flexible devices are also addressed for promoting the advances on flexible zinc–air batteries.

Carbon-based catalysts are widely regarded as one of the most promising materials for energy storage and conversion technologies due to their high electrical conductivity as well as the tunable micro-...

Explore cost‐effective and efficient carbon‐based electrocatalysts toward oxygen reduction reaction is highly desired to replace high‐cost platinum group metal (PGM) catalysts. Herein we synthesized a N, P co‐doped carbon foam by direct blowing of glucose in the presence of phytic acid (blowing catalyst) and urea (self‐sacrificing template). This template‐free one‐step approach achieved high surface heteroatom content of N (5 at.%) and P (2.33 at.%), large surface area (1026 m2 g−1) and high ID/IG ratio. It was found that the edges‐rich activated carbon scaffold as well as the active N‐sites work synthetically to guarantee its efficient ORR performance with the half‐wave potential of 0.84 VRHE. Besides, the well‐balanced porous structure facilitates its practical application as an air cathode in zinc‐air cell, reaching power density of 145 mW cm−2 at the current density of 169 mA cm−2.

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