Heterostructured TiN/TiO2 on the hierarchical N-doped carbon for enhancing the polysulfide immobilization and sulfur reduction in lithium-sulfur battery

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2023-11, Vol.476, p.146581, Article 146581
• Main Authors: Bai, Yanqun, Nguyen, Thanh Tuan, Chu, Rongrong, Song, Hewei, Kim, Nam Hoon, Lee, Joong Hee
• Format: Article
• Language: English
• Subjects: Carbon matrix; Lithium-sulfur battery; Multi-scale porous framework; Reaction kinetic; Synergetic effect
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2023.146581

[Display omitted] •Heterostructured TiN/TiO2 on N-doped multi-scale porous carbon was synthesized.•Synergetic effects of polysulfide adsorption of TiO2 and catalytic activity of TiN were observed.•DFT indicates a great affinity to polysulfides and high conductivity of TiN/TiO2@NMPC.•The TiN/TiO2@NMPC-based cell presents high capacity and outstanding long-term stability. The commercialization of lithium-sulfur batteries (LSBs) is impeded by their low sulfur utilization and poor cycling stability. Herein, uniformly distributed TiN/TiO2 heterostructures on the hierarchical nitrogen-doped inter-connected multi-scale porous carbon matrix was developed as an effective polysulfide trapper and catalytic accelerator for sulfur reduction reaction. The performance of synthesized TiN/TiO2 heterostructures in LSBs are compared with those of TiN and TiO2. The synergetic effects of strong polysulfide adsorption of TiO2 and superior catalytical conversion ability of TiN draw rapid trap-diffusion-conversion process and enhance the reaction kinetics. This heterostructure-based LSBs exhibit a high specific capacity of 1458.5 mAhg−1 at 0.1 C and 684.9 mAhg−1 at 5 C. Over 1000 cycles, a high capacity of 576 mA h g−1 is retained with a low-capacity decay of 0.030 % per cycle at 2 C. Moreover, a high area capacity value of 6.65 mAh cm−2 is obtained at 0.5C with a high sulfur loading of 8.2 mg cm−2 and low electrolyte/sulfur ratio (E/S) of 4.7. This study provides a novel strategy to develop the transition metal nitride-oxide heterostructure on a three-dimensional porous carbon framework as efficient electrode materials for LSBs application.