With the development of high-performance electrode materials, sodium-ion batteries have been extensively studied and could potentially be applied in various fields to replace the lithium-ion cells, owing to the low cost and natural abundance. As the key anode materials of sodium-ion batteries, hard carbons still face problems, such as poor cycling performance and low initial Coulombic efficiency. Owning to the low synthesis cost and the natural presence of heteroatoms of biomasses, biomasses have positive implications for synthesizing the hard carbons for sodium-ion batteries. This minireview mainly explains the research progress of biomasses used as the precursors to prepare the hard-carbon materials. The storage mechanism of hard carbons, comparisons of the structural properties of hard carbons prepared from different biomasses, and the influence of the preparation conditions on the electrochemical properties of hard carbons are introduced. In addition, the effect of doping atoms is also summarized to provide an in-depth understanding and guidance for the design of high-performance hard carbons for sodium-ion batteries.

New hierarchical Fe(III)-doped Cu-MOFs (Fe-HK) were developed via introduction of Fe³⁺ ions during HKUST-1 synthesis. The obtained products were characterized by N₂ adsorption, X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, FTIR spectroscopy, and thermal analysis. The adsorption isotherms and kinetics of benzene vapor were measured and consecutive adsorption–desorption cycles were performed. It was found that the hierarchical-pore Fe-HK-2 exhibited optimal textural properties with high BET surface area of 1,707 m²/g and total pore volume of 0.93 cm³/g, which were higher than those of the unmodified HKUST-1. Significantly, the hierarchical-pore Fe-HK-2 possessed outstanding benzene adsorption capacity, which was 1.5 times greater than the value on HKUST-1. Benzene diffusivity of Fe-HK-2 was 1.7 times faster than that of parent HKUST-1. Furthermore, the benzene adsorption on Fe-HK-2 was highly reversible. The hierarchical-pore Fe-HK-2 with high porosity, outstanding adsorption capacity, enhanced diffusion rate, and excellent reversibility might be an attractive candidate for VOCs adsorption. This may offer a simple and effective strategy to synthesize hierarchical-pore MOFs by doping with other metal ions.

Low‐temperature lithium‐sulfur batteries (LSBs) face challenges such as Li₂S accumulation and the slow conversion of lithium polysulfides (LiPSs), significantly affecting their capacity and cycling life. While functionalizing cathode shows potential to overcome these problems, there has been little focus on understanding the deposition behavior of Li₂S at low temperatures and the specific catalysis processes of newly identified platforms. Here we report an island‐like Bi₂O₃ uniformly distributed on reduced graphene oxide (IBG) as a sulfur host material. This unique island‐like structure increases the contact area between the electrolyte and electrode, thus enhancing Li⁺ transport efficiency. More importantly, the IBG structure exhibits a targeted catalytic ability toward LiPSs at low temperatures, significantly accelerating the conversion of Li₂S₈ to Li₂S₄ and subsequently to Li₂S. Moreover, the nucleation of Li₂S on the IBG cathode follows a progressive mode with fewer nuclei, effectively preventing Li₂S accumulation and enhancing the battery's charge–discharge efficiency. As a result, LSBs using IBG as the sulfur host can operate reliably at extremely low temperatures, down to −60 °C. This remarkable performance broadens the operating temperature range of LSBs and offers valuable insights for selecting high‐performance cathode modification materials in the future.