Topical Collection "State of the Art in Analysis of Energies"

A topical collection in Separations (ISSN 2297-8739). This collection belongs to the section "Analysis of Energies".

Editor

Dr. Sascha Nowak
E-Mail Website
Collection Editor
MEET Battery Research Center, University of Münster, Corrensstrasse 46, 48149 Münster, Germany
Interests: gas chromatography; high-performance liquid chromatography; ion chromatography; capillary electrophoresis; mass spectrometry; sample preparation; solid-phase extraction and microextraction; ionic liquids; battery electrolytes; lithium ion batteries
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Topical Collection Information

Dear Colleagues,

In general terms, “energies” can be defined as developments and applications with regard to energy supply, conversion, application, and storage.

In this Topical Collection on “State of the Art in Analysis of Energies”, we welcome original research and review articles on the development and application of analytical methods in this field.

Analysis of energies is a broad field and can range over all separation techniques and detection methods. However, theory and methodology aspects should focus on instrumentation and not on modeling or theories with regard to energy application. Impurity analysis and especially identification/quantification of compounds are of particular interest. Reports on quality control and standardization of energy products or materials will also be considered on the basis of their significance in the field.

In all cases, novelty will be the major suitability criterion of submitted articles. Authors should always address the novelty of their proposed methodology and comparison with previously reported methods.

Dr. Sascha Nowak
Collection Editor

Manuscript Submission Information

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Keywords

  • Analysis of energies
  • Gas chromatography
  • High-performance liquid chromatography
  • Ion chromatography
  • Capillary electrophoresis
  • Mass spectrometry
  • Sample preparation
  • Solid-phase extraction and microextraction
  • Ionic liquids
  • Battery electrolytes
  • Lithium-ion batteries

Published Papers (4 papers)

2022

Article
New Approach for Trace Thallium Removal in High Purity Ammonium Rhenate Solution by P204 Extraction
Separations 2022, 9(8), 221; https://doi.org/10.3390/separations9080221 - 17 Aug 2022
Viewed by 521
Abstract
Thallium (Tl) is an extremely toxic rare metal to the eco-environment. Trace thallium impurity in ammonium perrhenate is harmful to the high-temperature mechanical properties of rhenium metal used for aeroengine single crystal blade. The di(2-ethylhexyl) phosphoric acid (P204) extraction to remove thallium in [...] Read more.
Thallium (Tl) is an extremely toxic rare metal to the eco-environment. Trace thallium impurity in ammonium perrhenate is harmful to the high-temperature mechanical properties of rhenium metal used for aeroengine single crystal blade. The di(2-ethylhexyl) phosphoric acid (P204) extraction to remove thallium in ammonium perrhenate solution without additive was innovatively proposed. The migration behavior of trace thallium with the concentration of P204, saponification degree and organic/aqueous phase (O/A) ratio, distribution law of thallium in the extraction system of P204, and mechanism of thallium removal were revealed. It was found Tl removal was rapidly increased to 98.5%, at conditions of P204 0.75 mol/L saponified 70% by ammonia, Tl 3.27 mg/L, O/A 1:1, T 298.15 ± 2 K, 250 rpm, and 3 min. McCabe-Thiele Tl extraction equilibrium isotherms indicates Tl concentration of raffinate less than 18.7 μg/L, a theoretical extraction of two stages and a theoretical stripping of two stages are required when both O/A work lines were at 1.0. Therefore, the method of the P204 solvent extraction system can effectively extract Tl in the forms of TlA(org), TlA3(org), TlOHA2(org), and Tl(OH)2A(org). Meanwhile, the new approach can be a promising process for ammonium rhenate refining. Full article
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Article
Effects and Mechanism of Fe3+ on Flotation Separation of Feldspar and Epidote with Sodium Oleate at Natural pH
Separations 2022, 9(5), 110; https://doi.org/10.3390/separations9050110 - 28 Apr 2022
Viewed by 1095
Abstract
The most common beneficiation method for feldspar is flotation with a cationic (amine) collector under acidic conditions. However, there are several disadvantages to this, such as environmental pollution and equipment corrosion. In order to resolve such problems, it is important to study the [...] Read more.
The most common beneficiation method for feldspar is flotation with a cationic (amine) collector under acidic conditions. However, there are several disadvantages to this, such as environmental pollution and equipment corrosion. In order to resolve such problems, it is important to study the flotation of feldspar using anionic collectors under natural pH conditions. The purpose of this paper is to study the effects and mechanism of Fe3+ on flotation separation of feldspar and epidote using sodium oleate (NaOL) at a natural pH. Through flotation experiments, adsorption measurements, zeta potential testing, FTIR analysis and X-ray photoelectron spectroscopy (XPS), the mechanism of Fe3+ on the surface of feldspar and epidote is revealed, and the reason behind the difference in flotation of the two minerals is discussed. The flotation test results show that Fe3+ can significantly improve the flotation behavior of minerals when NaOL is used as a collector under natural pH, and the highest recovery rates of feldspar and epidote are 90% and 43%, respectively. Analysis of the solution and adsorption measurement results show that Fe3+ is adsorbed on the minerals′ surface in the form of Fe(OH)3, which promotes the adsorption of NaOL on the minerals’ surface through Fe(OH)3, activating the flotation of feldspar and epidote. The difference in adsorption of Fe3+ between feldspar and epidote is the reason for this difference in flotation behavior. The results of the zeta potentials show that after being treated with Fe3+, the electrostatic adsorption of NaOL displays a significant negative shift on the surface of feldspar, while there is almost no electrostatic adsorption of NaOL on the surface of Fe3+-treated epidote. FTIR analysis confirmed that the difference in the adsorption of Fe3+ and NaOL on the surface of feldspar and epidote is due to the fact that there are more active particles (metal bonds) on the surface of feldspar than on the surface of epidote, and the properties of these metal bonds can be changed by Fe3+, which allows NaOL to be more easily adsorbed on the mineral surface through –COO. The possible adsorption form is “mineral-Fe3+–COO“. Compared with the infrared spectrum of epidote, there is a new absorption peak at 1713.68 cm−1, which can be attributed to the C=O characteristic peak of NaOL in the infrared spectrum of Fe3+–NaOL-treated feldspar, which is why the floatability of feldspar is better than epidote. XPS confirmed that the Fe on the surface of feldspar is Fe3+ in the form of Fe(OH)3, while Fe on the surface of epidote is mainly Fe2O3 (Fe–O) contained in mineral crystals. Furthermore, there is less adsorption of Fe3+ on the surface of epidote, and this discrepancy leads to the difference in the adsorption of NaOL on the minerals’ surface, which itself leads to the difference in flotation behavior between feldspar and epidote. These findings indicate that the flotation separation of feldspar and epidote can be achieved using Fe3+ and NaOL under natural pH. This study may provide a reference for the flotation mechanism of feldspar and epidote under natural pH. Full article
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Article
Identification of Soluble Degradation Products in Lithium–Sulfur and Lithium-Metal Sulfide Batteries
Separations 2022, 9(3), 57; https://doi.org/10.3390/separations9030057 - 24 Feb 2022
Viewed by 2049
Abstract
Most commercially available lithium ion battery systems and some of their possible successors, such as lithium (metal)-sulfur batteries, rely on liquid organic electrolytes. Since the electrolyte is in contact with both the negative and the positive electrode, its electrochemical stability window is of [...] Read more.
Most commercially available lithium ion battery systems and some of their possible successors, such as lithium (metal)-sulfur batteries, rely on liquid organic electrolytes. Since the electrolyte is in contact with both the negative and the positive electrode, its electrochemical stability window is of high interest. Monitoring the electrolyte decomposition occurring at these electrodes is key to understand the influence of chemical and electrochemical reactions on cell performance and to evaluate aging mechanisms. In the context of lithium-sulfur batteries, information about the analysis of soluble species in the electrolytes—besides the well-known lithium polysulfides—is scarcely available. Here, the irreversible decomposition reactions of typically ether-based electrolytes will be addressed. Gas chromatography in combination with mass spectrometric detection is able to deliver information about volatile organic compounds. Furthermore, it is already used to investigate similar samples, such as electrolytes from other battery types, including lithium ion batteries. The method transfer from these reports and from model experiments with non-target analyses are promising tools to generate knowledge about the system and to build up suitable strategies for lithium-sulfur cell analyses. In the presented work, the aim is to identify aging products emerging in electrolytes regained from cells with sulfur-based cathodes. Higher-molecular polymerization products of ether-based electrolytes used in lithium-sulfur batteries are identified. Furthermore, the reactivity of the lithium polysulfides with carbonate-based solvents is investigated in a worst-case scenario and carbonate sulfur cross-compounds identified for target analyses. None of the target molecules are found in carbonate-based electrolytes regained from operative lithium-titanium sulfide cells, thus hinting at a new aging mechanism in these systems. Full article
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Review
Separation and Recycling Potential of Rare Earth Elements from Energy Systems: Feed and Economic Viability Review
Separations 2022, 9(3), 56; https://doi.org/10.3390/separations9030056 - 24 Feb 2022
Cited by 8 | Viewed by 2131
Abstract
This review explores the potential of separating and recycling rare earth elements (REEs) from different energy conversion systems, such as wind turbines, electric vehicles batteries, or lighting devices. The REEs include 17 elements (with global production of 242 kilometric tons in 2020) that [...] Read more.
This review explores the potential of separating and recycling rare earth elements (REEs) from different energy conversion systems, such as wind turbines, electric vehicles batteries, or lighting devices. The REEs include 17 elements (with global production of 242 kilometric tons in 2020) that can be found abundantly in nature. However, they are expensive and complicated to extract and separate with many environmental challenges. The overall demand for REEs is continuously growing (with a 10% yearly increase) and it is quite clear that recycling has to be developed as a supply strategy in addition to conventional mining. However, the success of both mining and recycling depends on appropriate separation and processing technologies. The overall REE recycling situation today is very weak (only 2% of REEs are recovered by recycling processes compared with 90% for iron and steel). The biggest recycling potentials rely on the sectors of lamp phosphors (17%), permanent magnets (7%), and NiMH batteries (10%) mainly at the end-of-life stage of the products. The profitability of rare earth recycling mostly depends on the prices of the elements to accommodate the processing costs. Therefore, end-of-life REE recycling should focus on the most valuable and critical REEs. Thus, the relevant processes, feed, and economic viability warrant the detailed review as reported here. Full article
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