The functionalization of semiconducting single-walled carbon nanotubes (SWNTs) with sp 3 defects that act as luminescent exciton traps is a powerful means to enhance their photoluminescence quantum yield (PLQY) and to add optical properties. However, the synthetic methods employed to introduce these defects are currently limited to aqueous dispersions of surfactant-coated SWNTs, often with short tube lengths, residual metallic nanotubes, and poor film-formation properties. In contrast to that, dispersions of polymer-wrapped SWNTs in organic solvents feature unrivaled purity, higher PLQY, and are easily processed into thin films for device applications. Here, we introduce a simple and scalable phase-transfer method to solubilize diazonium salts in organic nonhalogenated solvents for the controlled reaction with polymer-wrapped SWNTs to create luminescent aryl defects. Absolute PLQY measurements are applied to reliably quantify the defect-induced brightening. The optimization of defect density and trap depth results in PLQYs of up to 4% with 90% of photons emitted through the defect channel. We further reveal the strong impact of initial SWNT quality and length on the relative brightening by sp 3 defects. The efficient and simple production of large quantities of defect-tailored polymer-sorted SWNTs enables aerosol-jet printing and spin-coating of thin films with bright and nearly reabsorption-free defect emission, which are desired for carbon nanotube-based near-infrared light-emitting devices.

The increasing demand for a high-performance and low-cost battery technology promotes the search for Li+-conducting materials. Recently, phosphidotetrelates and aluminates were introduced as an innovative class of phosphide-based Li+-conducting materials...

A key for the market penetration of large-scale and high energy All-Solid-State Batteries (ASSBs) are sheet-type cell components. Herein, we report a slurry-based process to obtain free-standing solid electrolyte (SE)/binder composite sheets as ASSB separators. We investigate three different sulfidic solid electrolyte systems (Li6PS5Cl, Li7P3S11 and Li10SnP2S12) in combination with a hydrogenated nitrile butadiene rubber (HNBR). By means of electrochemical impedance spectroscopy (EIS), the influence of separator composition and processing on the ionic sheet conductivity is evaluated. Independent of the solid electrolyte material, a reduction by a factor of three compared to the pristine powder conductivity at 70 MPa operation pressure and by a factor of eight compared to the maximum powder conductivity is observed. This can be attributed to the addition of the ionically isolating binder, which however is necessary for the production of freestanding sheets. We show the beneficial effect of pre-compressing the sheets to little porosity values on the apparent sheet conductivity. Lastly, we investigate and decouple the influence of fabrication and operating cell pressure on the produced separator sheets.

Researchers have been working for many years to find new material and cell systems that can be used as potential post-lithium-ion batteries. Among these, the all-solid-state battery is considered a promising candidate, with sulfide-based materials having essential advantages over other solid electrolyte materials, particularly in terms of their high ionic conductivity. A great challenge, however, is their high reactivity in contact with water, where harmful hydrogen sulfide (H 2 S) is formed. Since H 2 S formation has implications for both worker safety and material quality, it is important to quantify its impact. For this reason, this paper examines the relationship between the product properties and the H 2 S formation as well as influences resulting from the production environment. Exemplary material states along the process chain of a wet coating process route are analyzed for the steps of storage, mixing, coating, drying, and densifying with Li 6 PS 5 Cl (LPSCl) as a solid electrolyte material. By determining the H 2 S formation rate for sulfide-based separator sheets, it is shown that the water content in the surrounding atmosphere has the highest impact, while other investigated parameters are negligibly small in comparison. Among the product properties, the geometric surface and pore surface have a great influence. These results demonstrate the need for a controlled atmosphere in the production facilities at dew points of −40 to −50 °C. At those moisture levels, occupational safety and product quality are ensured for the investigated solid electrolyte sheets of LPSCl. This study is the first to provide quantitative data from the point of view of the production environment on the formation of H 2 S gas when using solid sulfide electrolytes and can therefore serve as a guideline for equipment, material, and cell manufacturers.

Phosphide-based compounds are promising materials for solid electrolytes. In recent times, a multiplicity of compounds featuring isolated MP 4 (M = Si,Ge,Sn,Al,Ga) tetrahedra as structural building units in different arrangements with superionic lithium conductivity have been discovered. ω-Li 9 AlP 4 , ω-Li 9 GaP 4 , and ω-Li 9 InP 4 are presented as new high-temperature modifications with superionic lithium conductivity reaching 4.5 mS cm −1 at room temperature. Impedance spectroscopy and static temperature-dependent 7 Li NMR experiments reveal conductivity values in the range of 0.2 to 4.5 mS cm −1 at room temperature and low activation energies for the title compounds. X-ray and neutron diffraction methods disclose that the phosphorus atoms form a cubicclose packing. The triel element and Li atoms are located in tetrahedral voids, further Li atoms partially fill the octahedral voids. Temperature-dependent neutron diffraction shows for Li 9 AlP 4 a phase transition at 573 K that influences the occupation of voids with Li and significantly affects the Li-ion mobility. The evaluation of nuclear scattering densities by the maximum-entropy approach and application of the one-particle-potential formalism reveal 3D lithium diffusion with a low activation energy preferentially on paths of adjacent tetrahedral and octahedral voids. The investigation of different polymorphs suggests that the equilibrated filling of tetrahedral and octahedral voids is a crucial parameter for the enhancement of superionic lithium conductivity.