Three-Dimensional Porous Carbon Skeleton Synthesized by a Template-Free and No-Post-Activation Process Applied for High-Performance Lithium - Sulfur Batteries

In recent years, hierarchical porous carbonaceous material has aroused widespread interest as the sulfur carrier-buffer for lithium-sulfur batteries (LSBs), particularly for high-loading and high-energy LSBs. However, the complexity and high cost of fabrication prohibit their extensive promotion and application. In this study, a three-dimensional porous carbon skeleton (3DPCS) has been successfully synthesized from low-cost raw materials by a template-free method without any post-activation process. The 3DPCS/S-60 (60 wt % sulfur content) composite exhibits a high initial capacity of 1623 mA h g-1 (96.9% of theoretical value) at 0.1 C. Benefiting from the abundant hierarchical pores and highly conductive networks, the 3DPCS can be loaded with 90 wt % sulfur, which displays an initial capacity of 889.7 mA h g-1 at 1 C and a slow capacity attenuation ratio of 0.06% per cycle during 1000 charge/discharge tests. Besides, even at an areal sulfur loading of 3 mg cm-2, the 3DPCS/S-80 (80 wt % sulfur content) cathode exhibits an initial capacity of 1256.6 mA h g-1 at 0.1 C and retains 854.7 mA h g-1 after 200 cycles.