The practical uses of lithium–sulfur batteries are greatly restricted by the sluggish reaction kinetics of lithium polysulfides (LiPSs), leading to low sulfur utilization and poor cyclic stability. Using the heterostructure catalysts is an effective way to solve the above problems, but how to further enhance the conversion efficiency and avoid the surface passivation by the insulative Li2S has not been well investigated. Herein, a heterostructure catalyst with rich heterointerfaces was prepared by modifying Mo2N microbelt with SnO2 nanodots. The formed rich interfaces with high accessibility act as the profitable nucleation sites guiding the Li2S 3D growth, which avoids the catalyst surface passivation and facilitates the LiPS conversion. The introduction of SnO2 nanodots also enhances the LiPS adsorption. Thus, the assembled battery with the above catalyst as the cathode additive shows a high capacity of 738.3 mAh g–1 after 550 cycles at 0.5 C with an ultralow capacity decay of 0.025% per cycle. Even with high sulfur loading of 9.0 mg cm–2, good cyclic stability is also achieved at 0.5 C with a low E/S ratio of 5 μL mgs –1. This work shows an effective way to enhance the LiPS conversion kinetics and guide Li2S deposition in Li–S batteries.

Non-graphitic carbons are promising anode candidates for sodium-ion batteries, while their variable and complicated microstructure severely limits the rational design of high-energy carbon anodes that could accelerate the commercialization of sodium-ion batteries as is the case for graphite in lithium-ion batteries. Here, we propose sieving carbons, featuring highly tunable nanopores with the tightened pore entrances, as high-energy anodes with extensible and reversible low-potential plateaus (<0.1 V). It is shown that the tightened pore entrance blocks the formation of the solid electrolyte interphase inside the nanopores and enables sodium clustering to produce the plateau. Theoretical and spectroscopic studies also show that creating a larger area of sodiophilic pore surface leads to an almost linearly increased number of sodium clusters and controlling the pore body diameter guarantees the reversibility of sodium cluster formation, producing a sieving carbon anode with a record-high plateau capacity of 400 mAh g–1. More excitingly, this approach to preparing sieving carbons is potential to be scalable for modifying different commercial porous carbons.

Lithium metal is the most promising candidate anode material for high energy density batteries, but its high activity and severe dendrite growth lead to safety concerns and limit its practical use. Constructing a protective layer (PL) on the lithium surface to avoid the side reactions and stabilize the electrode‐electrolyte interface is an effective approach to solve these problems. In this review, the recent progress on PLs is summarized, and their desired properties and design principles are discussed from the aspects of materials selection and the corresponding fabrication methods. Advanced PLs with different properties are then highlighted, including a self‐adjusting feature to increase structural integrity, the synergistic effect of organic and inorganic hybrids to improve mechanical properties and ionic conductivity, the use of embedded groups and ion diffusion channels to regulate ion distribution and flux, and a protective barrier to suppress corrosion from humid air or water. Finally, the remaining challenges and the possible solutions for PL design in future studies are proposed.