PDF Publication Title:
Text from PDF Page: 014
metal sulfides and polysulfides are not completely clearly yet and need to be deeply investigated. 2.2.3 MXene phase material Hosts The MXene phase is a family of transition metal carbides or carbonitrides that was first reported by Gogotsi’s group,[84] which are well known for high conductivity in the core and abundant functional groups on the surface. The MXenes are produced by selectively etching A atoms from layered MAX phases (Mn+1AXn, where M is transition metal, A is one of a group of IIIA/IVA elements, and X is C or N), and then delaminating the sheets in polar solvent. The delaminated 2D MXene phases possess high conductivity and abundant functional groups on the surface. Several TixCy-type MXenes have been explored as sulfur hosts for Li-S batteries. Ti2C was first reported to be a highly effective cathode host material by Liang et al,[85] which was prepared by corroding Al atoms from Ti2AlC. It was found that the unoccupied orbitals of Ti atoms in the surfaces of Ti2C nanosheets were bound with either -OH or sulfides after exfoliation and delamination treatment (Figure 6a). Although Ti2C nanosheet has neither porous structure nor high specific surface area, unexpectedly superior properties still were obtained when it was employed as a sulfur host material. This indicates that the chemical bonding with polysulfides effectively suppressed the dissolution and diffusion of the polysulfides, which is supported by XPS analysis (Figure 6b). The Ti 2p XPS spectrum of 70S/Ti2C sample exhibited an additional peak at 457.6 eV assigned to the S-Ti-C bonds, which is also found in Li2S4-Ti2C and fully discharged 70S/Ti2C electrode. This implies that the -OH functional groups were substituted by sulfur species. Therefore, the analysis mentioned above proves that there exists a strong chemical interaction between the polysulfides and the nanosheets, enhancing the electrochemical stability of the Ti2C/S composite. After that, Liang et al. further investigated the MXene phases Ti3C2 and Ti3CN as sulfur hosts, with XPS and DFT calculations results also demonstrating the strong interaction 12PDF Image | Advances in Polar Materials for Lithium-Sulfur Batteries
PDF Search Title:
Advances in Polar Materials for Lithium-Sulfur BatteriesOriginal File Name Searched:
212718644.pdfDIY PDF Search: Google It | Yahoo | Bing
Sulfur Deposition on Carbon Nanofibers using Supercritical CO2 Sulfur Deposition on Carbon Nanofibers using Supercritical CO2. Gamma sulfur also known as mother of pearl sulfur and nacreous sulfur... More Info
CO2 Organic Rankine Cycle Experimenter Platform The supercritical CO2 phase change system is both a heat pump and organic rankine cycle which can be used for those purposes and as a supercritical extractor for advanced subcritical and supercritical extraction technology. Uses include producing nanoparticles, precious metal CO2 extraction, lithium battery recycling, and other applications... More Info
| CONTACT TEL: 608-238-6001 Email: greg@infinityturbine.com | RSS | AMP |