Local Structure and Dynamics of Next Generation Electrolytes - linking microscopic and macroscopic properties

The electrolyte is a crucial part of a battery in terms of performance, longevity and safety. However, the state-of-the-art electrolytes for lithium-ion batteries are based on organic solvents and Li-salts (typically at 1M concentration) which are volatile and degrade at higher temperatures. In addition, these electrolytes are not suitable for next generation battery concepts where the use of metallic lithium at the anode side is a prerequisite. Thus, there is currently a strong effort to find new electrolyte concepts to both improve safety of current battery technology and pave way for next generation batteries. In the search for new electrolytes, highly concentrated electrolytes and ionic liquids have been proposed as alternatives through properties such as high thermal stability, lower reactivity with cell components and increased electrochemical stability window.A common feature for highly concentrated electrolytes and ionic liquids is an ordering on mesoscopic length scales, normally not found in simple liquids, resulting from the correlation between the ions. This nanostructure can be expected to influence the ion transport and a key to developing these new electrolyte concepts is to understand the structure and dynamics on mesoscopic length scales and how this links to macroscopic transport. In this thesis, the microscopic properties of ionic liquids and diluted ionic liquids are investigated together with highly concentrated electrolytes based on an organic solvent. To achieve this goal X-ray and neutron scattering are invaluable tools as they allow for measurements at the time and length scale of typical molecular motions and interactions. Complementary techniques such as conductivity and viscosity measurements, differential scanning calorimetry, and Raman spectroscopy have been used in order to link between the macroscopic and microscopic properties and between local structure and dynamics

Structure and Dynamics in Ionic Liquid and Highly Concentrated Electrolytes

The electrolyte is a crucial part of a battery in terms of longevity and safety.\ua0However, the state-of-the-art electrolytes for lithium-ion batteries are based\ua0on organic solvents and Li-salts (typically 1M concentration) and are known\ua0to be volatile and to degrade at higher temperature. In the search for a safer\ua0electrolyte, highly concentrated electrolytes (HCEs) and ionic liquids (ILs)\ua0have been proposed as alternatives. The high salt concentration in HCEs\ua0(typically >4M) results in an increased electrochemical stability whereas ionic\ua0liquids, consisting only of ions, are known to have a negligible vapour pressure\ua0and high thermal stability. A common feature for HCEs and ILs is an ordering\ua0on mesoscopic length scales, normally not found in simple liquids, resulting\ua0from correlations between the ions. This nanostructure can be expected to\ua0influence the ion transport and a key to develop these new electrolyte concepts\ua0is to understand the structure and dynamics on the molecular level and how\ua0this links to macroscopic transport properties.The thesis focuses on the understanding of mesoscopic structure and dynamics\ua0in ILs and HCEs with the help of neutron and X-ray scattering with the aim\ua0to identify how local dynamical processes are influenced by the nanostrucutre.\ua0I have investigated an archetypal HCE system where the Li-salt LiTFSI is\ua0dissolved in acetonitrile and a model ionic liquid. Varying the Li-salt concentration\ua0in the HCE we can link the local processes to the development of the\ua0structure. The ion transport in the HCE takes place by the means of a jump\ua0diffusion and is highly dependent on the salt concentration and temperature\ua0of the system. For the ionic liquid we investigate the response of structure\ua0and dynamics to changes in both pressure and temperature with a particular\ua0focus on state points (P,T) where the macroscopic dynamics i.e. conductivity\ua0is constant. A conned diusion was found with a diusion coecient in\ua0agreement with macroscopic conductivity, thus providing a link between the\ua0microscopic and macroscopic dynamics

Ion Dynamics and Nanostructures of Diluted Ionic Liquid Electrolytes

Diluted ionic liquid electrolytes are promising candidates in next-generation batteries enabling the implementation of lithium metal anodes. The diluent should fully mix with the ionic liquid while not interacting with the Li ions to preserve the ionic liquid character, which is beneficial for Li-metal electrode stability. We report on the influence of a hydrofluoroether (HFE) diluent on ion dynamics and nanostructure of an ionic liquid electrolyte. We show that the ionic liquid and the diluent are fully miscible and that the solvation structure of the Li ions is not affected by the presence of HFE. The increase in the conductivity by the addition of the diluent is directly related to a decrease in viscosity with faster dynamics of all ionic species. However, the relative increase in mobility is considerably larger for the ionic liquid cation as a result of a preferred interaction with HFE. On the microscopic scale, more complex local non-Gaussian diffusive dynamics are found, faster than what is expected from the self-diffusion coefficient. The relative change of the dynamics with the addition of HFE on macro- and microscopic length scales correlates well, which underlines the connection between the motions probed on different length and time scales

Structure and dynamics of highly concentrated LiTFSI/acetonitrile electrolytes

High salt concentration has been shown to induce increased electrochemical stability in organic solvent-based electrolytes. Accompanying the change in bulk properties is a structural ordering on mesoscopic length scales and changes in the ion transport mechanism have also been suggested. Here we investigate the local structure and dynamics in highly concentrated acetonitrile electrolytes as a function of salt concentration. Already at low concentrations ordering on microscopic length scales in the electrolytes is revealed by small angle X-ray scattering, as a result of correlations of Li+ coordinating clusters. For higher salt concentrations a charge alternation-like ordering is found as anions start to take part in the solvation. Results from quasi-elastic neutron spectroscopy reveal a jump diffusion dynamical process with jump lengths virtually independent of both temperature and Li-salt concentration. The jump can be envisaged as dissociation of a solvent molecule or anion from a particular Li+ solvation structure. The residence time, 50-800 ps, between the jumps is found to be highly temperature and Li-salt concentration dependent, with shorter residence times for higher temperature and lower concentrations. The increased residence time at high Li-salt concentration can be attributed to changes in the interaction of the solvation shell as a larger fraction of TFSI anions take part in the solvation, forming more stable solvation shells

Pressure and temperature dependence of local structure and dynamics in an ionic liquid

A detailed understanding of the local dynamics in ionic liquids remains an important aspect in the design of new ionic liquids as advanced functional fluids. Here, we use small-angle X-ray scattering and quasi-elastic neutron spectroscopy to investigate the local structure and dynamics in a model ionic liquid as a function of temperature and pressure, with a particular focus on state points (P,T) where the macroscopic dynamics, i.e., conductivity, is the same. Our results suggest that the initial step of ion transport is a confined diffusion process, on the nanosecond timescale, where the motion is restricted by a cage of nearest neighbors. This process is invariant considering timescale, geometry, and the participation ratio, at state points of constant conductivity, i.e., state points of isoconductivity. The connection to the nearest-neighbor structure is underlined by the invariance of the peak in the structure factor corresponding to nearest-neighbor correlations. At shorter timescales, picoseconds, two localized relaxation processes of the cation can be observed, which are not directly linked to ion transport. However, these processes also show invariance at isoconductivity. This points to that the overall energy landscape in ionic liquids responds in the same way to density changes and is mainly governed by the nearest-neighbor interactions

Neutron Reflectometry Study of Solid Electrolyte Interphase Formation in Highly Concentrated Electrolytes

Highly concentrated electrolytes have been found to improve the cycle life and Coulombic efficiency of lithium metal anodes, as well as to suppress dendrite growth. However, the mechanism for these improvements is not well understood. Partly, this can be linked to the difficulty of accurately characterizing the solid electrolyte interphase (SEI), known to play an important role for anode stability and stripping/plating efficiency. Herein, in situ neutron reflectometry is used to obtain information about SEI formation in a highly concentrated ether-based electrolyte. With neutron reflectometry, the thickness, scattering length density (SLD), and roughness of the SEI layer formed on a Cu working electrode are nondestructively probed. The reflectivity data point to the formation of a thin (5 nm) SEI in the highly concentrated electrolyte (salt:solvent ratio 1:2.2), while a considerably thicker (13 nm) SEI is formed in an electrolyte at lower salt concentration (salt:solvent ratio 1:13.7). Further, the SEI formed in the electrolyte with high salt concentration has a higher SLD, suggesting that the chemical composition of the SEI changes. The results from neutron reflectometry correlate well with the electrochemical data from SEI formation

En jämförande studie av Tosoh G11 och Bio-Rad D-100 för HbA1c -analys

Diabetes mellitus is one of the most common diseases worldwide. The continued prevalence increase, together with the complexity of the disease with severe long-term complications makes efficient diagnostical and monitorial methods very important. The determination of glycated hemoglobin, HbA1c, plays an important role in both, underlying the importance of high-quality analytical instruments. Whenever a new instrument is introduced into routine clinical use an evaluation is needed. This study evaluated the agreement between the new Tosoh G11 HbA1c high performance liquid chromatography system as a replacement for the Bio-Rad D-100 at the Chromatographic Department of the Institute of Laboratory Medicine, Faculty of Medicine, University of Debrecen. In total, 66 samples were analyzed using both analyzers and a Bland-Altman comparison was performed together with a correlation study. Additionally, a linearity check, optimal error and routine error testing was carried out specifically for the Tosoh G11. The results showed high agreement between measurements, r=0.9975 (p<0.001) for HbA1c mmol/mol and r=0.9971 (p<0.001) for HbA1c %. High repeatability and accuracy were observed of the Tosoh G11 with the highest variation coefficient of 1.50 % and linearity r =0.9999. The conducted study supports the replacement of the Bio-Rad D-100 to the Tosoh G11.  Diabetes mellitus är en av de vanligaste världsomfattande sjukdomarna. Fortsatt prevalensökning, tillsammans med den komplexa sjukdomsbilden innefattande allvarliga långsiktiga komplikationer gör effektiva diagnostiska och övervakande metoder väldigt viktiga. Bestämning av glykerat hemoglobin, HbA1c, spelar en viktig roll i båda, vilket kräver att analysinstrument av hög kvalitet finns. När ett nytt instrument introduceras inom kliniska rutinanalyser krävs utvärdering. Denna studie utvärderade överrensstämmelsen mellan det nya Tosoh G11 HbA1c högupplösande vätskekromatografisystemet som en ersättning för Bio-Rad D-100 på den kromatografiska enheten av laboratoriemedicin på Debrecens universitet. Totalt analyserades 66 prov med respektive instrument och Bland-Altman jämförelse genomfördes tillsammans med en korrelationsstudie. Dessutom utfördes ett linjäritetstest, optimal- och rutinfeltest specifikt för Tosoh G11. Resultaten visade en hög överrensstämmelse mellan mätningarna, r=9975 (p<0.001) för HbA1c mmol/mol och r =9971 (p<0.001) för HbA1c %. Tosoh G11 visade hög repeterbarhet och noggrannhet, med den högsta variationskoefficient på endast 1.50 % och en linjäritet på r=0.9999. Den genomförda studien stödjer Tosoh G11 som ersättning för Bio-Rad D-100.

En jämförande studie av Tosoh G11 och Bio-Rad D-100 för HbA1c -analys

Diabetes mellitus is one of the most common diseases worldwide. The continued prevalence increase, together with the complexity of the disease with severe long-term complications makes efficient diagnostical and monitorial methods very important. The determination of glycated hemoglobin, HbA1c, plays an important role in both, underlying the importance of high-quality analytical instruments. Whenever a new instrument is introduced into routine clinical use an evaluation is needed. This study evaluated the agreement between the new Tosoh G11 HbA1c high performance liquid chromatography system as a replacement for the Bio-Rad D-100 at the Chromatographic Department of the Institute of Laboratory Medicine, Faculty of Medicine, University of Debrecen. In total, 66 samples were analyzed using both analyzers and a Bland-Altman comparison was performed together with a correlation study. Additionally, a linearity check, optimal error and routine error testing was carried out specifically for the Tosoh G11. The results showed high agreement between measurements, r=0.9975 (p<0.001) for HbA1c mmol/mol and r=0.9971 (p<0.001) for HbA1c %. High repeatability and accuracy were observed of the Tosoh G11 with the highest variation coefficient of 1.50 % and linearity r =0.9999. The conducted study supports the replacement of the Bio-Rad D-100 to the Tosoh G11.  Diabetes mellitus är en av de vanligaste världsomfattande sjukdomarna. Fortsatt prevalensökning, tillsammans med den komplexa sjukdomsbilden innefattande allvarliga långsiktiga komplikationer gör effektiva diagnostiska och övervakande metoder väldigt viktiga. Bestämning av glykerat hemoglobin, HbA1c, spelar en viktig roll i båda, vilket kräver att analysinstrument av hög kvalitet finns. När ett nytt instrument introduceras inom kliniska rutinanalyser krävs utvärdering. Denna studie utvärderade överrensstämmelsen mellan det nya Tosoh G11 HbA1c högupplösande vätskekromatografisystemet som en ersättning för Bio-Rad D-100 på den kromatografiska enheten av laboratoriemedicin på Debrecens universitet. Totalt analyserades 66 prov med respektive instrument och Bland-Altman jämförelse genomfördes tillsammans med en korrelationsstudie. Dessutom utfördes ett linjäritetstest, optimal- och rutinfeltest specifikt för Tosoh G11. Resultaten visade en hög överrensstämmelse mellan mätningarna, r=9975 (p<0.001) för HbA1c mmol/mol och r =9971 (p<0.001) för HbA1c %. Tosoh G11 visade hög repeterbarhet och noggrannhet, med den högsta variationskoefficient på endast 1.50 % och en linjäritet på r=0.9999. Den genomförda studien stödjer Tosoh G11 som ersättning för Bio-Rad D-100.

Comorbidity in patients with Lichen sclerosus: a retrospective cohort study

Abstract Lichen sclerosus (LS) is a chronic lymphocyte mediated inflammatory mucocutaneous disease of unknown aetiology with a predilection for the anogenital region, and affecting both sexes. The disease is characterized by pain, intolerable itching and scarring. In late stages of LS, disfiguring scarring can drastically alter the structural anatomical architecture of the genitals. The association between genital LS and different malignant tumours is a concern that needs to be further investigated. An association between LS and several autoimmune diseases has been confirmed in recent studies. All registered citizens of Region Jönköping, Sweden were included in the present study. Patients diagnosed with LS (n = 5680) between 2001 and 2021 were identified using ICD-10 code L90.0 and selected as cases. All other individuals (n = 362 568) served as controls. Odds ratios (ORs) for the selected comorbidity were calculated and adjusted for age and sex. The cumulative incidence of LS for the entire population over a 20-year period was 1.54% (15.4 per 1000 people). The cumulative incidences over a 20-year period for females and males were 2.13% and 0.97%, respectively. This study confirmed the association between LS and vulvar cancer (OR = 17.4; 95% CI 12.1–25.3), penis cancer (OR = 9.1; 95% CI 4.3–18.9), prostate cancer (OR = 2.0; 95% CI 1.6–2.4) and breast cancer (OR = 1.6; 95% CI 1.4–1.8). LS was also associated with Crohn´s disease (OR = 2.0; 95% CI 1.6–2.6) and diabetes mellitus type 1 (OR = 1.9; 95% CI 1.6–2.1). The present study revealed novel important data regarding the association of LS with cancer and autoimmune diseases, emphasising the importance of sufficient treatment and follow-up of patients with LS. However, future studies are needed to confirm these results and the potential role of LS in the development of cancer