Nitrogen/sulfur dual-doped micro-mesoporous hierarchical porous carbon as host for Li-S batteries

Abstract

A simple hydrothermal process employing sucrose and glutathione as the source of carbon and nitrogen-sulfur, respectively, a porous carbon/sulfur composite material doped with nitrogen and sulfur (NSPCS) was synthesized. The detailed structure information of the material was characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. The morphology information was investigated through Scanning Electron Microscope (SEM) methods. Structure of the pores and pore size distribution were investigated employing N2 adsorption-desorption isotherm. The material was treated Thermogravimetric analysis (TGA) in order to know the weight ratio of sulfur. The synthesized NSPCS composite produced high specific capacity, excellent rate performance and exceptionally good cycle stability when used as the positive electrode in Li-S batteries.

Preparation of an N–S dual-doped black fungus porous carbon matrix and its application in high-performance Li–S batteries

“…This means that the conductivity of elemental sulfur was significantly increased after combined with the NS-FPC carbon matrix. Surprisingly, compared with previous published articles ( Zhao et al, 2019 ; Zhao et al, 2022a ; Zhao et al, 2022b ), the electrochemical performance of NS-FPC/S composite showed a considerable improvement.…”

“…From the high-resolution XPS spectra analysis of S2p ( Figure 2D ), it can be concluded that two characteristic peaks near 164.25 and 165.35 eV correspond to the C-S-C and C=S bonds, respectively. The dual-doping of N–S heteroatoms can effectively improve the conductivity of carbon materials and increase the active site, which is particularly important for enhancing the electrochemical performance of Li–S batteries ( Zhao et al, 2022b ; Yang et al, 2022 ; Qi et al, 2023 ). The XPS results show that nitrogen and sulfur atoms were both successfully doped into the carbon materials.…”

“…Cysteine (C 5 H 11 O 2 NS) is an amino acid containing both amino (-N 2 H) and mercapto (-SH) groups, which can be a rich source of nitrogen and sulfur. Compared to previous works ( Zhao et al, 2022a ; Zhao et al, 2022b ), the novelty of this article lies in introducing natural black fungus as the carbon source, which reduced the experiment cost. Furthermore, adopting cysteine as a reagent to introduce both nitrogen and phosphorus heterogeneous elements simplified the experimental steps.…”

Nitrogen-phosphorus dual-doped auricularia auricula porous carbon as host for Li-S battery

“…For the P2p spectra ( Fig 2D ), it contains two peaks of 133.45 eV (P-C) and 134.45 eV (P-O) [ 27 ]. The dual-doping of N-P heteroatoms in NP-PSC sample can effectively improve the conductivity and increase the active site, which is particularly important for enhancing the electrochemical performance of Li-S batteries [ 28 – 30 ]. The XPS results of NP-PSC/S sample was also displayed in Fig 2E .…”

“…For the P2p spectra (Fig 2D ), it contains two peaks of 133.45 eV (P-C) and 134.45 eV (P-O) [27]. The dual-doping of N-P heteroatoms in NP-PSC sample can effectively improve the conductivity and increase the active site, which is particularly important for enhancing the electrochemical performance of Li-S batteries [28][29][30]. The XPS results of NP-PSC/S sample was also displayed in Fig 2E . The XPS survey of NP-PSC/S (Fig 2E) exhibits six main characteristic peaks at 533, 395, 285, 230, 165 and 135 eV, which is attributed to the O1s, N1s, C1s, S2s, S2p and P2p peaks, respectively.…”