Bio-inspired construction of electrocatalyst decorated hierarchical porous carbon nanoreactors with enhanced mass transfer ability towards rapid polysulfide redox reactions

• Published in: Nano research Vol. 14; no. 11; pp. 3942 - 3951
• Main Authors: Zhang, Shijie, Zhang, Yongshang, Shao, Guosheng, Zhang, Peng
• Format: Journal Article
• Language: English
• Published: Beijing Tsinghua University Press 01.11.2021
• Subjects: Atomic/Molecular Structure and Spectra; Batteries; Biomedicine; Biotechnology; Carbon; Chemistry and Materials Science; Cobalt; Condensed Matter Physics; Electrocatalysts; Electrolytic cells; Energy storage; Flux density; Lithium; Lithium sulfur batteries; Mass transfer; Materials Science; Nanoparticles; Nanotechnology; Nucleation; Polysulfides; Rechargeable batteries; Redox reactions; Research Article; Sodium chloride; Specific capacity; Sulfur; electrocatalyst; sulfur species reactor; high sulfur loading; low electrolyte/sulfur ratio; hierarchical porous carbon network
• ISSN: 1998-0124; 1998-0000
• DOI: 10.1007/s12274-021-3319-x

Li-S batteries are considered as a highly promising candidate for the next-generation energy storage system, attributing to their tremendous energy density. However, the two-dimensional island nucleation-growth process of lithium sulfide leads to a thick insulating film covering the electrode, inducing slow electrons transfer and mass-transfer of ions and liquid sulfur species in working Li-S cells. Here, we demonstrate a bio-inspired strategy of constructing ant-nest-like hierarchical porous ultrathin carbon nanosheet networks with the implants of metallic nanoparticles electrocatalysts (HPC-MEC) as efficient nanoreactors enabling rapid mass transfer, via a simple and green NaCl template. Such nanoreactors with a large active surface area could effectively anchor polysulfides for mitigating the shuttle effect, facilitating uniformly thin Li 2 S film, and promoting the mass transfer for fast sulfur species conversions. This helps contribute to a continuously high sulfur utilization in Li-S batteries with the HPC-MEC reactors. As a typical exhibition, cobalt embedded hierarchical porous carbon (HPC-Co) could realize to deliver a remarkably high specific capacity of 1,540.6 mAh·g −1 , an excellent rate performance of 878.8 mAh·g −1 at 2 C, and high area capacity of 11.6 mAh·cm −2 at a high sulfur load of 10 mg·cm −2 and low electrolyte/sulfur ratio of 5 µL·mg −1 .