In the present work, the recovery of phosphorus and fluorine from process water generated in a water based direct physical recycling process of Li-ion batteries has been studied. The recycling process considered in this work produces significant amounts of process water, which is generated during the opening of the batteries by means of electro-hydraulic fragmentation and the subsequent sorting of the components in aqueous solution. This process produces between 21.6 L and 30.3 L of process water per kg of batteries with a total phosphorus and a total fluorine concentration of 60-85 mg/L and 120-470 mg/L, respectively. Currently, the process water has to be disposed of as hazardous waste. The goal is to discharge the wastewater into the sewer system. For this the total phosphorus and total fluorine concentration must be reduced. The process water is mainly contaminated by the released electrolyte consisting of organic carbonates and conducting salts. 31-P and 19-F NMR shows conclusively that no hydrolysis takes place in this process water. The phosphorus is present exclusively in the form of the complex anion PF₆^- and fluorine as F^-, namely as FSI^- from the conducting salt LiFSI and PF₆^- from the conducting salt LiPF₆. In order to meet the regulatory requirements for discharge into the sewage system, 70.4% of the phosphorus and 89.3% of the fluorine must be removed. The conducting salts are hydrolyzed by adding acid and thereby phosphate and fluoride are precipitated. After critical and valuable materials are recovered the process water can be discharged into the sewer system.

Meeting the increasing demand for energy storage based on lithium-ion batteries (LIB) is not only a question of resource availability but also an issue of resource conservation and efficient recycling management. In this respect, sustainable recycling concepts play a central role in mindful interactions with valuable materials. Based on this approach, a process interconnection of hydromechanical preparation, flotation, and pyrometallurgical treatment was investigated. The hydromechanical preparation showed promising results in achieving highly pure mixtures of LIB-active material. It was found that a pre-opening step could achieve an even better separation of impurities for downstream processes such as Cu and Al to avoid excessive particle size reduction. According to an optimized mixing stage during flotation, the C amount was reduced from 33 wt.% to 19.23 wt.%. A Li-free metal alloy was obtained through the subsequent pyrometallurgical treatment, and evidence for Li removal via the gas phase was provided. Furthermore, heating microscope trials confirmed the results of the process interconnection and showed that further optimization steps for the pre-treatment are necessary for favorable product quality. Therefore, a high-stratification plot was created, which allows a quick future statement about the suitability of the input material for use in the process.

The present paper relates to a method for synthesizing the photostimulable storage phosphor $\mathrm{Ba}\mathrm{F}\mathrm{Br}:{\mathrm{Eu}}^{2+}$ that features high stimulation characteristics for use in image plates. All previous synthesis routes consist of a multistep process whereas the presented route is a one-step synthesis. Starting compounds are $\mathrm{Ba}\mathrm{C}{\mathrm{O}}_3$ , $\mathrm{N}{\mathrm{H}}_4\mathrm{F}$ , and $\mathrm{N}{\mathrm{H}}_4\mathrm{Br}$ , as well as $\mathrm{Eu}{\mathrm{F}}_3$ where the ammonium compounds are highly volatile at temperatures below $300°\mathrm{C}$ . Their reaction products initiate the decomposition of $\mathrm{Ba}\mathrm{C}{\mathrm{O}}_3$ and form BaFBr. The incorporation of F-centers and europium ions occurs at temperature exceeding $550°\mathrm{C}$ . The individual reaction steps are monitored by simultaneous thermal analysis (thermogravimetry/differential thermal analysis) and the gaseous reaction products are detected by in situ mass spectroscopy. Intermediate and final products are characterized by x-ray diffraction techniques to determine the involved phases. Photoluminescence spectra reveal the typical emission peak of ${\mathrm{Eu}}^{2+}$ accompanied by a redshifted emission band at $470\mathrm{nm}$ , which was assigned to oxygen incorporated into the BaFBr lattice. The synthesized powders exhibit small grain sizes well suited for the use in image plates.

We report the photoluminescence and x-ray luminescence of lanthanum-stabilized cubic barium chloride with europium $\left({\text{Eu}}^{2+}\right)$ doping, of general composition ${\text{Ba}}_{1-\text{x}-\text{y}}{\text{Eu}}_{\text{y}}{\text{La}}_{\text{x}}{\text{Cl}}_{2+\text{x}}$ . X-ray diffraction patterns confirm that the material adopts a cubic fluorite structure for $\text{x}=0.125$ and $0<\text{y}<0.1$ . The photoluminescence shows an intense band comprising two components with maxima at 420 and 394 nm. The 394 nm band is assigned to ${\text{Eu}}^{2+}$ substituting for ${\text{Ba}}^{2+}$ giving a site of cubic symmetry, based on the excitation spectra which show a ${\text{T}}_{2\text{g}}$ band and ${\text{E}}_{\text{g}}$ band similar to those in cubic ${\text{SrCl}}_2:\text{Eu}$ . The 420 nm band has a very different lifetime and excitation spectrum and is assigned to ${\text{Eu}}^{2+}$ ions which have an associated chlorine interstitial ion. The two bands are also found in the x-ray luminescence spectra. For both bands, and an additional minor emission at 520 nm found only at low temperatures and for high Eu concentrations, there is a common excitation in the UV from 150 to 200 nm which we attribute to excitons associated with the high concentration of chlorine interstitials. ESR measurements support a two-site model for the interpretation of the optical spectra. A measurement of the x-ray luminescence intensity compared to a standard commercial ${\text{Gd}}_2{\text{O}}_2\text{S}:\text{Tb}$ phosphor sheet shows approximately equal brightness.

Powdered samples of CsBr:O²⁻ and CsBr:Eu²⁺,O²⁻ with oxygen concentrations ranging from 0.01 to 5.00 mol% have been synthesized and are shown to have photostimulated luminescence (PSL) properties which are strongly influenced by the oxygen concentration. In europium free CsBr:O²⁻, it was found that weak PSL emission at 460 nm arises from oxygen impurities while with oxygen concentrations higher than 0.05 mol% the emission shifts to the 379 nm emission of the CsBr matrix, which is attributed to the nonexcitability of oxygen agglomerates. The F-center concentration in CsBr:O²⁻ is observed to increase with oxygen concentration, due to an increase in Br-vacancies as charge compensation centers for the O²⁻ ions. In all CsBr:Eu²⁺ samples studied, intense PSL emission arises only following room temperature hydration in an atmosphere of 99% relative humidity, and it is concluded that the presence of water molecules is essential for the PSL in CsBr:Eu²⁺. In CsBr:Eu²⁺,O²⁻ this enhancement effect of PSL intensity is reduced as the oxygen concentration increases above 0.05 mol% due to competition between the Eu²⁺ and O²⁻ luminescence centers. It was found that the effects of hydration can be partially reversed following exposure to a vacuum while the material is rendered completely PSL inactive following thermal annealing up to 600 °C which is caused by agglomeration of the highly mobile Eu²⁺ ions and subsequent loss of Eu²⁺ luminescence.