Nitrogen‐rich porous carbons (NPCs) are the leading cathode materials for next‐generation Zn–air and Li–S batteries. However, most existing NPC suffers from insufficient exposure and harnessing of nitrogen‐dopants (NDs), constraining the electrochemical performance. Herein, by combining silica templating with in situ texturing of metal–organic frameworks, a new bifunctional 3D nitrogen‐rich carbon photonic crystal architecture of simultaneously record‐high total pore volume (13.42 cm3 g−1), ultralarge surface area (2546 m2 g−1), and permeable hierarchical macro‐meso‐microporosity is designed, enabling sufficient exposure and accessibility of NDs. Thus, when used as cathode catalysts, the Zn–air battery delivers a fantastic capacity of 770 mAh gZn−1 at an unprecedentedly high rate of 120 mA cm−2, with an ultrahigh power density of 197 mW cm−2. When hosting 78 wt% sulfur, the Li–S battery affords a high‐rate capacity of 967 mAh g−1 at 2 C, with superb stability over 1000 cycles at 0.5 C (0.054% decay rate per cycle), comparable to the best literature value. The results prove the dominant role of highly exposed graphitic‐N in boosting both cathode performances.

An in situ strategy to simultaneously boost oxygen reduction and oxygen evolution (ORR/OER) activities of commercial carbon textiles is reported and the direct use of such ubiquitous raw material as low‐cost, efficient, robust, self‐supporting, and bifunctional air electrodes in rechargeable Zn‐air batteries is demonstrated. This strategy not only furnishes carbon textiles with a large surface area and hierarchical meso‐microporosity, but also enables efficient dual‐doping of N and S into carbon skeletons while retaining high conductivity and stable monolithic structures. Thus, although original carbon textile has rather poor catalytic activity, the activated textiles without loading other active materials yield effective ORR/OER bifunctionality and stability with a much lower reversible overpotential (0.87 V) than those of Pt/C (1.10 V) and RuO2 (1.02 V) and many reported metal‐free bifunctional catalysts. Importantly, they can concurrently function as current collectors and as ORR/OER catalysts for rechargeable aqueous and flexible solid‐state Zn‐air batteries, showing excellent cell performance, long lifetime, and high flexibility.

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At actile,U V-and solar-light multi-sensing smart rechargeable Zn-air battery (SRZAB) with excellent cell performance,s elf-conditioned charge/discharge,a nd reliable environmental responsivity is made by using multi-scale conjugated block-copolymer-carbon nanotube-polyurethane foam assemblies as both as elf-standing air electrode and as ensing unit. Multiscale engineering fully exploits the multisynergy among components to endow the newly designed metal-free multi-sensing air electrode (MSAE) with bifunctional oxygen reduction and evolution activities,p ressure sensitivity,a nd photothermal and photoelectric conversion functions in asingle electrode,enabling effective regulation of interface properties,e lectronic/ionic transport, or redox reactions in SRZAB upon various stimulations and establishing multiple working principles.M SAE-driven SRZAB can be used as compressible power sources,self-powered pressure and optical sensors and light-to-electrochemical energy systems.

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C2N has emerged as a new family of promising two-dimensional (2D) layered frameworks in both fundamental studies and potential applications. Transforming bulk C2N into zero-dimensional quantum dots (QDs) could induce unique quantum confinement and edge effects that produce improved or new properties. Despite their appealing potential, C2NQDs remain unexplored, and their intriguing properties and a fundamental understanding of their prominent edge effects are still not well understood. Here, we report the first synthesis of water-soluble C2NQDs via a top-down approach without any foreign stabilizer and exploit their linear/nonlinear optical properties and unique edge-preferential electrocatalytic activity toward polysulfides for versatile applications. The resultant dispersant-free C2NQDs with an average size of less than 5 nm feature rich oxygen-carrying groups and active edges, not only enabling excellent dispersion in water but also creating interesting multifunctionality. They can emit not only blue one-photon luminescence (OPL) under ultraviolet (UV) excitation but also green two-photon luminescence (TPL) with a wide near-infrared (NIR) excitation range of 750-900 nm, enabling their use as a new fluorescent ink. Interestingly, when C2NQDs are introduced to modify commercial separators, they can function as new metal-free catalysts to boost polysulfide redox kinetics and endow Li-S batteries with excellent cycling stability, high rate capability, and large areal capacity (7.0 mA h cm–2) at a high sulfur loading of 8.0 mg cm–2. Detailed theoretical and experimental results indicate that the edge of C2N is more favorable for trapping and catalyzing the polysulfide conversion than the terrace and that the synergy between the active edges and oxygenated groups enriched in C2NQDs remarkably improves polysulfide immobilization and catalytic conversion.

responsive batteries that enable the effective combination of solar harvesting and energy conversion/storage functionalities render a potential solution to achieve the large-scale utilization of unlimited and cost-effective solar energy and alleviate the limits of conventional energy storage devices. The internal integration of photo-responsive electrodes into rechargeable batteries with the simplest two-electrode configuration is regarded as a reliable and appealing strategy for highly-efficient and low-cost utilization of solar energy by simplifying the device architecture and improving the energy efficiency. This progress report provides a brief review on photo-responsive batteries with integrated two-electrode configuration that can achieve solar energy conversion/storage in one single device. The basic device architecture, operating principles and practical performance of various photo-responsive systems based on solar energy harvesting in various batteries including Li ion batteries, LiÀ S batteries, LiÀ I batteries, dual-liquid redox batteries, LiÀ O 2 batteries, non-Li anode-O 2 /air batteries are summarized and discussed. Finally, the future opportunities and challenges regarding the two-electrode photo-responsive batteries are proposed.[a] Dr.

2D π-d conjugated metal-organic frameworks (c-MOFs) are promising anode candidates for sodium-ion batteries (SIBs) due to their high intrinsic conductivity and stability in organic electrolytes. However, the development of c-MOFs with multi-redox sites to improve the overall performance of SIBs is highly desired but remains a great challenge. Herein, this work reports the electrochemically active hexaazatrinaphthylene-based 2D π-d c-MOFs (HATN-XCu, X = O or S) as advanced anode materials with dual-redox sites for SIBs. The ordered porous and layer-stacked structure can provide fast transmission and diffusion channels for ions along the stacking directions. Ex situ Fourier transformed infrared spectra together with X-ray photoelectron spectroscopy reveal the dual-redox site storage mechanism of HATN-XCu, namely, the continuous multi-electron reactions occurring on the redox-active CN group and [CuX 4 ]unit, respectively. Based on the synergistic effect of dual-redox sites, HATN-OCu anode exhibits impressive reversible capacity (500 mAh g −1 at 0.1 A g −1 ) and high-rate performance (151 mAh g −1 at 5 A g −1 ). Significantly, a sodium-ion full battery assembled using a HATN-OCu anode and Na 3 V 2 (PO 4 ) 2 O 2 F cathode also displays high-rate performance (117 mAh g −1 at 5 A g −1 ) and stable long-cycle life (the capacity retention of 80% after 500 cycles at 2 A g −1 ).