The decay of lithium–sulfur (Li–S) batteries is mainly due to the shuttle effect caused by intermediate polysulfides (LiPSs). Herein, a multiple confined cathode architecture is prepared by filling graphitized Pinus sylvestris with carbon nanotubes and defective LaNiO3−x (LNO‐V) nanoparticles. The composite electrode with high areal sulfur loading of 11.6 mg cm−2 shows a high areal specific capacity of 8.5 mAh cm−2 at 1 mA cm−2 (0.05 C). Both experimental results and theoretical calculations reveal that this unique structure not only provides physical restriction on LiPSs within microchannels but also offers strong chemical immobilization and catalytic conversion of LiPSs attributed to the spin density around oxygen vacancies of LaNiO3−x. These oxygen vacancies elongate the SS and LiS bonds and make them easy to break. Furthermore, the lengthwise channels derived from cytoderm restrict the transverse diffusion of polysulfides, leading to a uniform areal current and thus homogeneous lithium infiltration. This suppresses the corrosion of the lithium anode due to polysulfides confinement. The discovery of the multiple confined structure that provides chemical adsorption, fast diffusion, and catalytic conversion for polysulfides can broaden the application of biomass materials and offer a new strategy to achieve robust Li–S batteries.
Although the lithium−sulfur battery has been developed for many years, how to restrain the intrinsic polysulfide shuttle is still a hot topic. Recently, it has been found that adding a multifunctional interlayer between cathode and separator can effectively inhibit the shuttle of polysulfides, while the lightweight factor of the interlayer commonly is ignored. In this work, a kind of lightly freestanding interlayer (0.16−0.4 mg cm −3 ) consisting of CeF 3 nanorod (prepared by in situ fluorination of CeO 2 nanorod in carbonization at 700 °C) and carbon nanotubes film (CF) is prepared. In this network structure, the CF network displays high electronic conduction and enhances the reaction kinetics for sulfur; CeF 3 can effectively adsorb polysulfides and enhance the cycle performance. Especially, the battery exhibits an initial specific capacity of 1505 mAh g −1 at 0.05 C, and the capacity decay after 100 cycles is only 0.063% per cycle. In addition, it retains a discharge capacity of 951 mAh g −1 over 100 cycles at 0.2 C and 542 mAh g −1 over 500 cycles at 1 C. Lightly freestanding CeF 3 /CNTs interlayer show a high application potential in the lithium−sulfur batteries.
High energy density and long cycle life of lithium–sulfur (Li–S) batteries suffer from the shuttle/expansion effect. Sufficient sulfur storage space, local fixation of polysulfides, and outstanding electrical conductivity are crucial for a robust cathode host. Herein, a modified template method is proposed to synthesize a highly regular and uniform nitrogen/oxygen dual‐doped honeycomb‐like carbon as sulfur host (N/O‐HC‐S). The unique structure not only offers physical entrapment for polysulfides (LiPSs) but also provides chemical adsorption and catalytic conversion sites of polysulfides. In addition, this structure offers enough space for loading sulfur, and a regular space of nanometer size can effectively prevent sulfur particles from accumulating. As expected, the as‐prepared N/O‐HC900‐S with high areal sulfur loading (7.4 mg cm−2) shows a high areal specific capacity of 7.35 mAh cm−2 at 0.2 C. Theoretical calculations also reveal that the strong chemical immobilization and catalytic conversion of LiPSs attributed to the spin density and charge distribution of carbon atoms will be influenced by the neighbor nitrogen/oxygen dopants. This structure that provides cooperative chemical adsorption, high lithium ions flux, and catalytic conversion for LiPSs can offer a new strategy for constructing a polysulfide confinement structure to achieve robust Li–S batteries.
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