Decoration on the inner surface of low-tortuosity microchannels derived from wood plate for highly stable lithium sulfur batteries

•Cellulose-derived carbon aerogel coated on the inner surface of the low-tortuosity microchannels of wood-based carbon plate.•The decorated wood-based carbon plates were utilized as free-standing cathodes for Li-S batteries.•The carbon aerogel coating provided a large specific surface area and abundant reaction sites.•The cellulose-derived carbon aerogel coating effectively improved the cycling stability of the decorated cathodes. The low-tortuosity microchannels of wood-based carbon matrix in free-standing cathodes for lithium sulfur batteries (LSBs) were a double-edged sword, which brought in both a high energy density due to a high sulfur loading and severe shuttle effect for poor cycling stability. Herein, a layer of cellulose aerogel extracted from the wood wall was coated on the inner surface of the low-tortuosity microchannels of the wood plate, which was further transformed into a hierarchical carbon matrix using in free-standing cathode for LSBs. The decorated cathode exhibited a maximal specific capacity of 1377.2 mAh g−1 due to the enhanced utilizing ratio of active materials and exceptional cycling stability even under a high current density (1 C) for more than 500 cycles. Furthermore, the decorated cathode maintained good cycling stability with a higher sulfur areal loading (6.3 mg cm−2). The cellulose-based carbon aerogel coated on the inner surface of low-tortuosity microchannels provided a large specific surface area. This decoration strategy not only provided physical restriction on polysulfides but also increased conversion sites for polysulfides, improving the cycling performance of the wood-based free-standing cathode of LSBs. This work provided a potential structural design strategy for the advanced free-standing cathode of LSBs. A layer of cellulose aerogel was regenerated from the wood wall and then coated on the inner surface of the low-tortuosity microchannels of the wood plate. After carbonization and sulfur loading, the fabricated free-standing cathode exhibited extraordinary cycling stability at 1 C even under a satisfactory sulfur loading of 6.3 mg cm−2. [Display omitted]