Nitrogen and phosphorus dual-doped porous carbons for high-rate potassium ion batteries

Ultra-High Sulfur-Doped Hierarchical Porous Hollow Carbon Sphere Anodes Enabling Unprecedented Durable Potassium-Ion Hybrid Capacitors

“…Heteroatom doping (such as nitrogen and sulfur) has been confirmed to be one of the most effective strategies to improve the potassium storage performance of carbon-based anodes. − Sulfur with a large covalent radius can effectively expand the carbon layer spacing so that there is reversible intercalation/deintercalation of potassium ions in the carbon interlayers. ,, In addition, the reversible pseudocapacitive reaction between the sulfur-containing functional groups and potassium ions can contribute an additional reversible specific capacity. , Therefore, sulfur-doped carbon-based anodes are a sensible choice to enhance the kinetics of PIHCs. As for carbon hosts, the sulfur-doped carbons mainly have three configurations, including C–S–C, C–SO x –C ( x = 1, 2, and 3), and C–SH .…”

Optimizing the nitrogen configuration in interlayer-expanded carbon materials via sulfur-bridged bonds toward remarkable energy storage performances

“…2g, the N 1s spectrum for S/N-CMs can be tted into pyridinic-N (398.6 eV), pyrrolic-N (400.0 eV), and graphitic-N (401.8 eV), and the corresponding ratios are 39.4, 48.5 and 12.1%, suggesting that the edge-N doping (pyridinic-N and pyrrolic-N) ratio reaches 87.9%. 24,34 Compared to graphitic-N doping, edge-N doping facilitates the reversible adsorption of K + , providing extra potassium-storage capacity for N-doped carbon materials. 28 To investigate the effect of the doping order of S-doping and N-doping on the contents of N and S in the nal sample, we have also rst induced N atoms into CMs (denoted as N-CMs) followed by sulfuration, and the resulting sample was denoted as N/S-CMs.…”

Porous Carbon Tubes Constructing Freestanding Flexible Electrodes for Symmetric Potassium-Ion Hybrid Capacitors

“…Moreover, the adsorption isotherm of FS-CTs belongs to type IV, and the pore size distribution is more concentrated below 5 nm than that of FSF-PCTs. The abundant pore structure and the huge specific surface area are not only conducive to ion transport and electrolyte penetration but also promote a fast kinetic process. , …”

“…The abundant pore structure and the huge specific surface area are not only conducive to ion transport and electrolyte penetration but also promote a fast kinetic process. 40,41 Information on the surface functional groups of FSF-PCTs and FS-CTs is explored by X-ray photoelectron spectroscopy (XPS). The survey XPS spectra of samples demonstrate that the elemental composition of FSF-PCTs is mainly 88.2% C and 11.8% O, while FS-CTs are mainly composed of 86.05% C, 13.38% O, and 0.57% N (Figure S6).…”