ZIF-67 decorated wood derived carbon host dual-stage-order microchannels for self-supporting cathode of high-performance lithium sulfur batteries

Although lithium-sulfur (Li-S) batteries have broad market prospects owing to their high theoretical energy density and potential cost-effectiveness, their practical application still faces serious shuttle effects of polysulfides (LiPSs) and sluggish redox kinetics. In this study, a cobalt-organic framework, ZIF-67, decorated balsa wood matrix (ZIF-67/BW) was utilized to prepare a cobalt-nitrogen-encapsulated carbon host (Co-N/CBW) with dual-stage-order microchannels for self-standing cathodes in high-performance Li-S batteries. The first-stage-order microchannels inherited from wood provided fast transmission paths for electrolyte. The ZIF-67 derived Co-N carbon particles with the second-stage-order microchannels provided strong chemical adsorption and enhanced conversion kinetics for LiPSs. Owing to these advantages, the Co-N/CBW/Li 2 S 8 cathode exhibited a high initial discharge specific capacity of 1213.1 mAh g −1 at 0.1 C and good cycling stability at 0.5 C (590 mAh g −1 after 200 cycles). By increasing the sulfur loading to 5.97 mg cm −2 , the cathode maintained a remarkable area-specific capacity (3.42 mAh cm −2 ) after 100 cycles. This work proposes a strategy for the cooperation of the catalyst and matrix, providing more possibilities for the development of Li-S batteries.