Implanting Niobium Carbide into Trichoderma Spore Carbon: a New Advanced Host for Sulfur Cathodes

Abstract

Tailored construction of advanced carbon hosts is playing a great role in the development of high-performance lithium-sulfur batteries (LSBs). Herein, a novel N,P-codoped trichoderma spore carbon (TSC) with a bowl structure, prepared by a "trichoderma bioreactor" and annealing process is reported. Moreover, TSC shows excellent compatibility with conductive niobium carbide (NbC), which is in situ implanted into the TSC matrix in the form of nanoparticles forming a highly porous TSC/NbC host. Importantly, NbC plays a dual role in TSC for not only pore formation but also enhancement of conductivity. Excitingly, the sulfur can be well accommodated in the TSC/NbC host forming a high-performance TSC/NbC-S cathode, which exhibits greatly enhanced rate performance (810 mAh g^-1 at 5 C) and long cycling life (937.9 mAh g^-1 at 0.1 C after 500 cycles), superior to TSC-S and other carbon/S counterparts due to the larger porosity, higher conductivity, and better synergetic trapping effect for the soluble polysulfide intermediate. The synergetic work of porous the conductive architecture, heterodoped N&P polar sites in TSC and polar conductive NbC provides new opportunities for enhancing physisorption and chemisorption of polysulfides leading to higher capacity and better rate capability.