Co-construction of advanced sulfur host by implanting titanium carbide into Aspergillus niger spore carbon

Abstract It is of great importance to directionally construct advanced carbon host to achieve high-performance carbon/sulfur cathodes for lithium sulfur batteries (LSBs). Herein, we report a unique hollow pumpkin-like carbon with notable rich-wrinkle microstructure and intrinsically dual doping with N&P elements via a facile annealing process of Aspergillus niger spore. Furthermore, highly conductive polar absorbents, TiC nanoparticles, are in situ implanted into the above Aspergillus niger spore carbon (ANSC) by carbothermal reaction, accordingly forming high-performance ANSC/TiC composite host for sulfur. Impressively, TiC nanoparticles play dual roles of not only pore formation in ANSC matrix but also enhancement of chemical absorption with polysulfides. With the positive synergistic effect between N&P co-doped ANSC matrix and TiC polar absorbent, the designed ANSC/TiC-S cathodes show unique advantages including larger accommodation space for sulfur, higher surface area, enhanced conductivity and better chemical absorption with soluble polysulfide intermediates. Consequently, the ANSC/TiC-S cathodes are endowed with good rate performance (496 mAh/g at 0.5 C) and enhanced long-term cycling stability (736 mAh/g with a capacity retention of 78.8% at 0.1 C after 100 cycles). Our research opens a new door to controllably design advanced composite cathodes from microorganisms for application in lithium sulfur batteries.