Lithium-sulfur batteries (LSBs) are considered to be one of the most promising alternatives to the current lithium ion batteries (LIBs) to meet the increasing demand of energy storage due to their high energy density, natural abundance, low cost and environmental-friendliness. Despite great success, LSBs are still suffering from several problems including undermined capacity arising from low utilization of sulfur, unsatisfactory rate performance and poor cycling life due to shuttle effect of polysulfides and poor electrical conductivity of sulfur. Under such circumstances, design/fabrication of porous carbon-sulfur composite cathodes is regarded as an effective solution to overcome the above problems. In this review, we summarize different synthetic methods of porous carbon hosts and corresponding integration ways of carbon-sulfur cathodes. We also address the pore formation mechanism of porous carbon hosts. The pore size effect on electrochemical performance is highlighted and compared. The enhanced mechanism of porous carbon host on the sulfur cathode is systematically reviewed and revealed. Finally, we demonstrate the combination of porous carbon hosts and high-profile solid-state electrolytes nowadays, and discuss the challenges to realize large-scale commercial application of porous carbon-sulfur cathodes and propose their developing trend in the future.

SnO2 has been extensively studied as an anode material for sodium-ion batteries, which, however, has long been subjected to poor conductivity and large volume expansion accompanied with an unsatisfactory electrochemical performance. Here, novel interlaced SnO2 nanoflakes are synthesized directly on a carbon cloth collector via hydrothermal and annealing treatment and then coated with polypyrrole (PPy) via electrodeposition. The as-prepared flexible SnO2@PPy on the carbon cloth exhibits a high initial capacity of 1172.1 mAh g–1 and an outstanding cycling stability with 85% capacity retention after 300 cycles at 0.1 A g–1, which can be contributed to the interlaced SnO2 nanoflakes as well as the coating of PPy. This result shows promising potential for construction of an electrode in high-performance energy storage fields.

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