Despite their promising potential, the real performance of lithium-sulfur batteries is still heavily impeded by the notorious shuttle behavior and sluggish conversion of polysulfides. Complex structures with multiple components have been widely employed to address these issues by virtue of their strong polarity and abundant surface catalytic sites. Nevertheless, the tedious constructing procedures and high cost of these materials make the exploration of alternative high-performance sulfur hosts increasingly important. Herein, we report an intrinsic defect-rich hierarchically porous carbon architecture with strong affinity and high conversion activity toward polysulfides even at high sulfur loading. Such an architecture can be prepared using a widely available nitrogen-containing precursor through a simple yet effective in situ templating strategy and subsequent nitrogen removal procedure. The hierarchical structure secures a high sulfur loading, while the intrinsic defects strongly anchor the active species and boost their chemical conversion because of the strong polarity and accelerated electron transfer at the defective sites. As a result, the lithium-sulfur batteries with this carbon material as the sulfur host deliver a high specific capacity of 1182 mAh g–1 at 0.5 C, excellent cycling stability with a capacity retention of 70% after 500 cycles, and outstanding rate capability, one of the best results among pure carbon hosts. The strategy suggested here may rekindle interest in exploring the potential of pure carbon materials for lithium-sulfur batteries as well as other energy storage devices.

Inhibiting the shuttle effect of polysulfides is one key factor to develop a practically applicable Li−S battery. To overcome the shuttle effect, we developed here an ultrastable Li−S battery with amorphous Al 2 O 3 nanohybrid separator for the first time. Through molecular design of the ligands, the material of the separator from carbonized MOF−Al at elevated temperature is composed of amorphous Al 2 O 3 and N-doped porous carbon, which shows higher electrical conductivity, faster lithium diffusion and charge transfer capability, and stronger interaction with lithium polysulfides through the synergistic effect (MOF, metal−organic framework). The fabricated Li−S battery proposed here corresponds to the lowest capacity decay (only 0.054% of capacity decay in each cycle) as far as we know, which may open up new avenues for developing the next-generation lithium-ion battery.

Oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) play significant role on the practical applications of water splitting for producing clean fuel. Although some low‐cost metal oxides are active on catalyzing OER and HER, the instinct drawback of sluggish charges carriers transfer mobility decrease the reactions kinetic and hinder their application. To overcome the issue, CoV oxide is successfully built‐up with a CoOV structure to eliminate energy barrier during carriers transfer by the spin‐flip hopping process, which can be coated on various substrate to stimulate OER and HER. Moreover, the V “bridge” between CoO bonds stimulates the OER through more effective lattice oxygen oxidation mechanism, which can directly format OO bond in more effective pathway. The protocol could be spread on rational design of such OER electrocatalysts on various electrode to lower‐cost water splitting.

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Lithium–sulfur (Li–S) batteries are facing a significant barrier due to the diffusion of intermediate redox species. Although some S doped covalent framework cathodes have been reported with outstanding reversibility, the low content of sulfur (less than 30%) limits the practical applications. To overcome the issue, the sulfur and nitrogen co‐doped covalent compounds (S‐NC) as a host‐type cathode have been developed through the radical transfer process during thermal cracking amino groups on the precursor, and then plentiful positively charged sulfur radicals can be controllably introduced. The experimental characterization and DFT theoretical calculation certificate that the sulfur radicals in S‐NC/S can expedite redox reactions of intermediate polysulfides to impede their dissolution. Moreover, the energy barriers during ions transfer also obviously decreased after introducing S radicals, which lead to improved rate performance.