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Lithium–sulfur (Li–S) batteries have been regarded as promising next‐generation energy‐storage devices owing to their inherently high theoretical energy density. Unfortunately, the poor capacity and cycling life caused by severe polysulfide shuttle effect and sluggish redox kinetics in sulfur cathodes greatly impede the practical application of Li–S batteries. Herein, a new class of nanonetwork‐structured carbon decorated with oxygen‐vacancy‐containing cerium oxide nanoparticles (NSC–CeO2−x), in which carbon skeleton is composed of highly conductive carbon nanotube core welded by hybrid carbon shell, has been developed via one‐step heating treatment of hybrid molecular brush and further employed as functional interlayer to modify separator of Li–S battery. Owing to the synergistic effect of the highly active CeO2−x nanoparticles and the three‐dimensional carbon nanonetwork in enhancing the preservation of the soluble polysulfides and boosting the redox kinetics of sulfur species, the NSC–CeO2−x significantly promotes the electrochemical performance of sulfur cathode. As a result, the as‐constructed Li–S batteries exhibit an ultrahigh initial sulfur utilization of 92.9% and an extremely large capacity of 751 mA h g−1 at a high rate of 5 C. Remarkably, a stable capacity of 728 mA h g−1 over 300 cycles at 1 C is also achieved.

Carbon‐based nanomaterials have been regarded as promising non‐noble metal catalysts for renewable energy conversion system (e.g., fuel cells and metal–air batteries). In general, graphitic skeleton and porous structure are both critical for the performances of carbon‐based catalysts. However, the pursuit of high surface area while maintaining high graphitization degree remains an arduous challenge because of the trade‐off relationship between these two key characteristics. Herein, a simple yet efficient approach is demonstrated to fabricate a class of 2D N‐doped graphitized porous carbon nanosheets (GPCNSs) featuring both high crystallinity and high specific surface area by utilizing amine aromatic organoalkoxysilane as an all‐in‐one precursor and FeCl3·6H2O as an active salt template. The highly porous structure of the as‐obtained GPCNSs is mainly attributed to the alkoxysilane‐derived SiOx nanodomains that function as micro/mesopore templates; meanwhile, the highly crystalline graphitic skeleton is synergistically contributed by the aromatic nucleus of the precursor and FeCl3·6H2O. The unusual integration of graphitic skeleton with porous structure endows GPCNSs with superior catalytic activity and long‐term stability when used as electrocatalysts for oxygen reduction reaction and Zn–air batteries. These findings will shed new light on the facile fabrication of highly porous carbon materials with desired graphitic structure for numerous applications.

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Carbonaceous materials are widely investigated as anodes for potassium‐ion batteries (PIBs). However, the inferior rate capability, low areal capacity, and limited working temperature caused by sluggish K‐ions diffusion kinetics are still primary challenges for carbon‐based anodes. Herein, a simple temperature‐programmed co‐pyrolysis strategy is proposed for the efficient synthesis of topologically defective soft carbon (TDSC) based on inexpensive pitch and melamine. The skeletons of TDSC are optimized with shortened graphite‐like microcrystals, enlarged interlayer spacing, and abundant topological defects (e.g., pentagons, heptagons, and octagons), which endow TDSC with fast pseudocapacitive K‐ion intercalation behavior. Meanwhile, micrometer‐sized structure can reduce the electrolyte degradation over particle surface and avoid unnecessary voids, ensuring a high initial Coulombic efficiency as well as high energy density. These synergistic structural advantages contribute to excellent rate capability (116 mA h g−1 at 20 C), impressive areal capacity (1.83 mA h cm−2 with a mass loading of 8.32 mg cm−2), long‐term cycling stability (capacity retention of 91.8% after 1200 h cycling), and low working temperature (−10 °C) of TDSC anodes, demonstrating great potential for the practical application of PIBs.