Lithium-sulfur (Li-S) batteries show great promise to serve as high-energy-density energy storage devices. Nevertheless, the practical applications of Li-S batteries are significantly limited by the shuttle effect and sluggish sulfur...

Ultrathin and air‐stable Li metal anodes hold great promise toward high‐energy and high‐safety Li metal batteries (LMBs). However, the application of LMBs is technically impeded by existing Li metal anodes with large thickness, high reactivity, and poor performance. Here, we developed a novel and scalable approach for the construction of a 10‐μm‐thick flexible and air‐stable Li metal anode by conformally encapsulating Li within a multifunctional VN film. Specifically, the highly lithiophilic VN layer guides a uniform deposition of Li, while abundant and multilevel pores arising from assembly of ultrathin nanosheets enable a spatially confined immersion of metallic Li, thus ensuring an ultrathin and sandwiched Li anode. More impressively, the strong hydrophobicity of VN surface can effectively improve the stability of anode to humid air, whereas the highly conductive framework greatly boosts charge transfer dynamics and enhances Li utilization and high‐rate capability. Benefiting from such fascinating features, the constructed Li‐VN anode exhibits ultrastable cycling stability in both ether (2500 h) and carbonate (900 h) electrolytes, respectively. Moreover, even exposed to ambient air for 12 h, the anode still can retain ~78% capacity, demonstrating excellent air‐defendable capability. This work affords a promising strategy for fabricating high‐performance, high‐safety, and low‐cost LMBs.

Despite lithium‐sulfur (Li‐S) batteries possessing ultrahigh energy density as great promising energy storage devices, the suppressing shuttle effect and improving sulfur redox reaction (SROR) are vital for their practical application. Developing high‐activity electrocatalysts for enhancing the SROR kinetics is a major challenge for the application of Li‐S batteries. Herein, single‐molecule iron phthalocyanine species are anchored on the N and P dual‐doped porous carbon nanosheets (Fe‐NPPC) via axial Fe‐N coordination to optimize the electronic structure of active centers. The Fe‐NPPC can promote the catalytic conversion of polysulfides by modulation of the electronic density in active moieties, endowing the Li‐S battery with a high reversible capacity of 1023 mAh g−1 at 1 C as well as an ultralow capacity decay of 0.035% per cycle over 1500 cycles. Even with a high sulfur loading of 7.1 mg cm−2, the Li‐S battery delivers a high areal capacity of 4.8 mAh cm−2 after 150 cycles at 0.2 C. With further increasing the sulfur loading to 9.2 mg cm−2, an excellent areal capacity of up to 9.3 mAh cm−2 is obtained at 0.1 C.

No abstract

No abstract