Highly mesoporous carbon foams synthesized by a facile, cost-effective and template-free Pechini method for advanced lithium–sulfur batteries

Abstract

Highly mesoporous carbon foam (MCF) with a high specific surface area has been successfully synthesized via a facile, cost-effective and template-free Pechini method. The as-prepared MCF exhibits a high specific surface area of 1478.55 m² g⁻¹ and a commendable pore size distribution for impregnating sulfur. After sulfur loaded in MCF, the relationship between pore size distribution of mesoporous carbon foam/sulfur nanocomposite (MCF/S) and the content of loaded sulfur is investigated in detail, which impacts on subtle variation of lithium storage performance. MCF/S (57.22 wt%) delivers an initial discharge of 1285 mA h g⁻¹ and retains 878 mA h g⁻¹ after 50 cycles. Compared with pristine sulfur, MCF/S cathodes display enhanced electrochemical performances, which can be attributed to the cross-linked hierarchical structure of MCF conductive matrix. Based on the advantages of the template-free Pechini method such as low cost, relative simplicity and atomic-scaled mixing, the MCF with hierarchical porous structure can be generalized to other practical applications including electrochemical double-layer capacitors, adsorption, separation, catalyst supports, etc. In addition, we believe that this modified Pechini method is general and can be extended to the fabrication of other types of mesoporous carbon by changing metal salts and organic reagents.