Brodersenhave0122

Thermoelectric material tetrahedrite Cu12Sb4S13 has attracted much attention because of its intrinsic low lattice thermal conductivity, excellent electrical transport property, and environment-friendly constituents. However, its thermoelectric figure merit, ZT, is limited because of the low Seebeck coefficient (S) and power factor (PF). Hence, it is indispensable to enhance its S and PF to increase its ZT. Here, we show that when Sb deviation from its stoichiometric ratio in the Cu12Sb4S13 band structure is modulated, it gives rise to increased density of states and enhancement of the Seebeck coefficient. Moreover, carrier concentration is tuned by changing sulfur and copper vacancies through controlling the Cu3SbS4 phase with an atomic ratio of Sb, leading to increased electrical conductivity. In addition, as large as ∼60% reduction of lattice thermal conductivity is obtained by intensified phonon scattering using an impurity phase/element and vacancy-like defects induced by different Sb contents. As a result, a high ZT = 0.86 is achieved at 723 K for the Cu12Sb4+δS13 sample with δ = 0.2, which is ∼50% larger than that of stoichiometric Cu12Sb4S13 studied here, indicating that ZT of Cu12Sb4S13 can be improved through simple modulation of the Sb stoichiometric ratio.Ni-rich cathode materials LiNixCoyMn1-x-yO2 (x ≥ 0.6) have attracted much attention due to their high capacity and low cost. However, they usually suffer from rapid capacity decay and short cycle life due to their surface/interface instability, accompanied by the high Ni content. In this work, with the Ni0.9Co0.05Mn0.05(OH)2 precursor serving as a coating target, a Li-ion conductor Li2SiO3 layer was uniformly coated on Ni-rich cathode material LiNi0.9Co0.05Mn0.05O2 by a precoating and syn-lithiation method. The uniform Li2SiO3 coating layer not only improves the Li-ion diffusion kinetics of the electrode but also reduces mechanical microstrain and stabilizes the surface chemistry and structure with a strong Si-O covalent bond. These results will provide further in-depth understanding on the surface chemistry and structure stabilization mechanisms of Ni-rich cathode materials and help to develop high-capacity cathode materials for next-generation high-energy-density Li-ion batteries.Loose nanofiltration (NF) membranes with diverse selectivity can meet the great demands in various bioseparation applications. Thus, a facile strategy to tune the properties such as pore size, surface charge, and hydrophilicity of the NF membrane is required to produce tailor-made loose NF membranes without changing the existing production line. Herein, we systematically investigated the post-treatment of the nascent poly(piperazine amide) NF membranes using different reagents (organic acids, weak bases, organic solvents and ionic liquid (IL)). Various characterizations revealed that the skin/separation layer became looser and permeance was promoted with the decrease of salt rejection in varying degrees. It was found that the O/N ratio did not rigorously represent the cross-linking degree of the skin layer, because besides the hydrolysis of the residual acyl chloride impeding the amido bond formation, the breaking of existing amido bonds and the grafting of free trimesoyl chloride molecules on the nascent membranes could also increase the O/N ratio during post-treatments. BiP Inducer X price Then three mechanisms including hydrolysis, swelling rearrangement and capping reaction effects were proposed to better understand the membrane properties variations. All these effects resulted in larger pore size of the NF membrane, and the hydrolysis/capping effect might increase negative charge and hydrophilicity on the membrane, while the swelling rearrangement could produce less defective skin structure. These three effects might be involved together during a single treatment. Finally, the NF membrane post-treated by N-hexane could efficiently separate antibiotics and NaCl with the highest permeate flux, whereas the one post-treated by ionic liquid outperformed others for the decoloration of cane molasses (much more efficient than NF270, DL, and NTR7450 membranes). The long-term operating stability of the post-treated membranes selected was also confirmed by a continuous crossflow filtration for 15 h with regular alkaline cleaning.In this study, we synthesize glass-ceramics of the new Na1+xGe2(SiO4)x(PO4)3-x NASICON (Na super-ionic conductor) series to evaluate the effect of Si4+/P5+ substitution on the structural, microstructural, and electrical properties of the NaGe2(PO4)3 system. From X-ray diffraction, the presence of the NASICON phase is confirmed in all glass-ceramics. An expansion of the unit cell volume suggesting an increase in the bottleneck of the NASICON structure is also observed. Impedance spectroscopy allowed the separation of grain and grain boundary contributions. We observe that the grain conductivity is higher than the specific grain boundary conductivity in all of the investigated compositions (0 ≤ x ≤ 0.8). The Si4+/P5+ substitution causes an enhancement of about 2 and 3 orders of magnitude in the grain and specific grain boundary conductivities, respectively. This behavior is attributable to the introduction of new charge carriers (Na+) in the NASICON structure and a decrease in the activation energy. Finally, the lowest activation energy for grain (0.586 eV) is observed in the x = 0.6 sample, which indicates the easiest displacement of ions in the investigated series, suggesting that this composition presents the most suitable bottleneck size for (Na+) sodium ion conduction.Herein, we report a straigthforward procedure to prepare an excellent intertwined nanosponge solid-state polymer electrolyte (INSPE) for highly bendable, rollable, and foldable lithium-ion batteries (LIBs). The mechanically reliable and electrochemically superior INSPE is conjugated with intertwined nanosponge (IN) poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-co-HFP) and ion-conducting polymer electrolyte (PE) containing poly(ethylene glycol) diacrylate (PEGDA), succinonitrile (SCN) plasticizer, and lithium bis(trifluoromethanesilfonyl)imide (LiTFSI). The conjugated INSPE has both high strength with great flexibility (tensile strength of 2.1 MPa, elongation of 36.7%), and excellent ionic conductivity (1.04 × 10-3 S·cm-1, similar to the values of liquid electrolytes). As a result of such special combination, the as-prepared INSPE retains almost 100% of its ionic conductivity when subjected to many types of severe mechanical deformations. Therefore, the INSPE is successfully applied to bendable, rollable, and foldable LIBs that show excellent energy storage performance despite the intense mechanical deformations.