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2.
BMC Public Health ; 24(1): 2050, 2024 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-39080646

RESUMEN

OBJECTIVES: Poor cardiorespiratory fitness (CRF) and high body mass index (BMI) increased the risk of developing metabolic Syndrome (MetS) mostly in Caucasians. However, the sex-specific combined association of CRF and BMI on MetS considering health-related behaviors has yet to be thoroughly examined in Japanese. This study aims to investigate the sex-specific independent and combined associations of CRF and BMI with MetS in middle-aged Japanese adults. METHODS: 421 participants were included in this cross-sectional study. CRF was estimated using a submaximal cycle ergometer. CRF and BMI were respectively divided into three categories according to tertile distribution. MetS was diagnosed based on five risk factors: waist circumference, triglycerides, high-density lipoprotein cholesterol, blood pressure, and fasting glucose. Multivariable logistic regression models were used to estimate independent and combined association of CRF and BMI with MetS. RESULTS: Results showed that 154 (57.5%) and 70 (45.8%) of men and women had MetS, respectively. Compared to men with lower CRF or higher BMI, men with middle and higher CRF or middle and lower BMI were less likely to have MetS. Compared with 'unfit and higher BMI' group, 'unfit and lower BMI', 'fit and higher BMI', and 'fit and lower BMI' groups in men showed statistically significant decreased prevalences of MetS. However, no significant associations were found in women. CONCLUSIONS: This study found significant independent and combined associations of CRF and BMI with MetS only in men, but not in women. However, prospective studies are warranted to confirm sex-specific associations of CRF and BMI with MetS.


Asunto(s)
Índice de Masa Corporal , Capacidad Cardiovascular , Síndrome Metabólico , Humanos , Masculino , Femenino , Síndrome Metabólico/epidemiología , Estudios Transversales , Capacidad Cardiovascular/fisiología , Persona de Mediana Edad , Japón/epidemiología , Adulto , Factores de Riesgo , Factores Sexuales , Pueblos del Este de Asia
3.
Artículo en Inglés | MEDLINE | ID: mdl-38822922

RESUMEN

Co-occurring mental health concerns are prevalent among substance use recovery housing residents. We sought to explore how residents with co-occurring mental health and substance use needs experience recovery housing. We conducted semi-structured interviews with residents (N = 92) in recovery homes across Texas and developed themes through thematic analysis. Residents note that living in a group home can exacerbate anxiety and paranoia, especially during periods of high turnover. Overwhelmingly, however, residents believe recovery housing improves their mental health. Residents use their shared lived experiences to support one another. Residents also express appreciation for the transition period offered by recovery housing, allowing them to solidify their recoveries before fully re-entering society. Participants describe recovery homes as a critical support for their co-occurring mental health and substance use concerns. These results provide key insights on how to better support mental health in recovery housing.

4.
Dalton Trans ; 53(25): 10666-10674, 2024 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-38860932

RESUMEN

High-temperature sintering is crucial to achieve good crystallinity and fast-ion conduction in oxide-type solid-electrolytes such as lithium garnets, NASICONs and LISICONs, leading to stiff ceramics which are difficult to integrate in all-solid-state batteries. Developing conventional oxide-based solid-electrolytes in deformable forms that maintain good ion transport properties and allow facile formulation of bulk-type solid-state batteries, hence, remains a challenge. Here, a new γ-Li3PO4/GeO2 composite, that adopts a novel nanostructured architecture and retains deformability after calcination at 500 °C, is successfully synthesized and densified by cold-pressing. Cold-pressed pellets of the new composite showed an ion conductivity that is four orders of magnitude higher than that of the parent γ-Li3PO4 and comparable to those of high-temperature stiff Li3+xP1-xGexO4 ceramics. The γ-Li3PO4/GeO2 composite is stable against high voltages (up to 5 V vs Li+/Li), which suggests a safe use in contact with high-voltage cathodes. The new composite can also be modified to serve as an active anode layer in solid-state cells due to the electrochemical activity of GeO2 at low voltages (<1 V vs. Li+/Li). This study emphasizes the potential of using low-temperature synthesis to develop novel oxide-based nanoarchitectures for all-solid-state battery applications.

5.
Clin Exp Dermatol ; 2024 Apr 09.
Artículo en Inglés | MEDLINE | ID: mdl-38589980

RESUMEN

BACKGROUND: Hidradenitis suppurativa (HS) is a chronic inflammatory skin disorder affecting the skinfold regions. There is growing appreciation of the need for socioeconomic factors to be included in multidisciplinary assessments of HS. However, knowledge regarding HS and workplace function is limited. OBJECTIVES: To assess the relationship between HS and workplace function. METHODS: Cinahl, Embase, MedLine, PsycInfo and PubMed were systematically searched to collect data from studies in which validated surveys of workplace function were administered to HS patients. RESULTS: Out of 1,932 publications, twelve studies were included in this review and seven reported sufficient data for meta-analysis. Included studies encompassed 5,187 HS patients and no controls. All studies employed the Work Productivity and Activity Impairment questionnaire, reporting percentage scores for absenteeism, presenteeism, total work productivity impairment (TWPI) and total activity impairment (TAI). Pooled mean scores for HS were calculated as 10.17% (95%CI 8.68-11.66) for absenteeism, 31.13% (95%CI 25.02-37.23) for presenteeism, 34.25% (95%CI 29.37-39.14) for TWPI, and 42.23% (95%CI 38.56-45.89) for TAI. Significant heterogeneity was identified and most studies were of 'poor' to 'fair' quality. CONCLUSIONS: Current evidence suggests considerable impairment of workplace functioning in HS patients. Our findings point to a significant unmet treatment need with respect to improving working capability in HS. The extant literature is inadequate to reliably assess the mechanisms underlying this effect or to comparatively assess the capabilities of HS therapies to improve workplace function.

6.
Am J Health Promot ; : 8901171241237522, 2024 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-38514206

RESUMEN

PURPOSE: The Sustainable Culturally Adapted Nutrition Program (SCAN) is a novel adaptation to the National Diabetes Prevention Program (NDPP) that aims to improve attendance and effectiveness. This paper presents its feasibility and impact through the initial 6-month outcomes. DESIGN: A pragmatic quasi-experimental pilot study with intervention (DPP plus SCAN) and control (DPP only) groups. SAMPLES AND INCLUSION CRITERIA: Sustainable Culturally Adapted Nutrition Program participants were recruited from federally qualified health center (FQHC) clinic patients enrolled in a NDPP in Houston, Texas. Participants needed to be (1) ≥18 years old, (2) body mass index >25, (3) no prior diagnosis of diabetes, and (4) not pregnant. INTERVENTION: Sustainable Culturally Adapted Nutrition Program cooking classes were designed to teach skills to prepare fresh produce, and utilized Motivational Interviewing (MI) techniques to encourage participants to adapt these skills for foods that were culturally important to them. OUTCOME MEASURES: (1) National Diabetes Prevention Program attendance, (2) BMI and (3) percent weight loss. ANALYSIS: We used linear mixed models to test the association between weights and NDPP attendance. RESULTS: 22 intervention and 15 control participants completed the program to the 6-month point. Intervention participants had increased DPP attendance over controls (7.14 vs 6.87 session). Intervention participants also demonstrated on average, 1.5% weight loss for each additional SCAN class attended (P = .144). CONCLUSIONS: The SCAN adaptation shows promising results for effectively increasing both NDPP attendance and weight loss.

7.
RSC Adv ; 14(11): 7557-7563, 2024 Feb 29.
Artículo en Inglés | MEDLINE | ID: mdl-38440277

RESUMEN

All-solid-state batteries present promising high-energy-density alternatives to conventional Li-ion chemistries, and Li-stuffed garnets based on Li7La3Zr2O12 (LLZO) remain a forerunner for candidate solid-electrolytes. One route to access fast-ion conduction in LLZO phases is to stabilize the cubic LLZO phase by doping on the Li sites with aliovalent ions such as Al3+ or Ga3+. Despite prior attempts, the stabilization of the cubic phase of isostructural Li7La3Sn2O12 (LLSO) by doping on the Li sites has up to now not been realised. Here, we report a novel cubic fast-ion conducting Li7La3Sn2O12-type phase stabilized by doping Ga3+ in place of Li. 0.3 mole of gallium per formula unit of LLSO were needed to fully stabilize the cubic garnet, allowing structural and electrochemical characterizations of the new material. A modified sol-gel synthesis approach is introduced in this study to realise Ga-doping in LLSO, which offers a viable route to preparing new Sn-based candidate solid-electrolytes for all-solid-state battery applications.

8.
J Adolesc Health ; 74(5): 892-899, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38323964

RESUMEN

PURPOSE: To explore the impact of COVID-19 pandemic lockdown (CoPL) on body mass index (BMI) and physical fitness among college students. METHODS: Two one-year cohorts, one with no pandemic lockdown (NoPL) exposure and one with CoPL exposure, were included. Baseline measurements were performed in October 2018 (NoPL) and October 2019 (CoPL), and follow-up data were collected one year later. Participants were divided into "deterioration", "no-change", and "improvement" groups based on their quartile distribution of one-year differences (follow-up-baseline) for lower 25%, middle 50%, and upper 25%. Baseline-category logit regression models were used to determine the odds ratios of deterioration and improvement in BMI and physical fitness, with "no-change" used as baseline. RESULTS: A total of 2,594 and 2,525 students were included in NoPL and CoPL cohorts, respectively. CoPL was associated with higher odds for deterioration in BMI (male), explosive strength, upper-limb muscle strength, abdominal muscle strength, and cardiorespiratory fitness, but lower odds for deterioration in BMI (female) and flexibility. CoPL was associated with lower odds for improvement in BMI (male), explosive strength, lower-limb and upper-limb muscle strength, and cardiorespiratory fitness, but higher odds for improvement in BMI (female) and flexibility. DISCUSSION: Not all dimensions of health outcomes were negatively impacted by the lockdown, as deterioration in BMI in males, muscle strength, and cardiorespiratory fitness following the CoPL were more than that in the absence of the lockdown, while deterioration in BMI in females and flexibility were less than that in the absence of the lockdown.


Asunto(s)
COVID-19 , Pandemias , Humanos , Masculino , Femenino , Índice de Masa Corporal , Control de Enfermedades Transmisibles , Aptitud Física/fisiología , Estudiantes
9.
Dalton Trans ; 53(9): 4139-4146, 2024 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-38318761

RESUMEN

Mechanical stiffness of oxide-type solid-electrolytes is a major drawback which has hindered their practical application in all-solid-state Li-ion batteries to date. Despite their enhanced structural and electrochemical stabilities, lack of deformability of fast-ion conducting oxides impedes the integration of these materials in bulk-type solid-state cells. Deformable solid-electrolytes such as sulfides, on the other hand, lack sufficient electrochemical stability in contact with conventional cathodes. This has recently triggered a search for new materials that combine high ion-conductivity, deformability and sufficient electrochemical stability. Here, we report the synthesis of a novel form of Li4P2O7 that can be densified by cold-pressing and possesses an ion conductivity that is two orders of magnitude higher than conventional Li4P2O7 phases. The material is synthesized by a combination of microwave synthesis and chemical lithiation and adopts a nanostructured morphology with a small amorphous component. The material is electrochemically stable at voltages >5 V vs. Li+/Li, which suggests safe use with high-voltage cathodes. The newly-synthesized material is therefore a bulk, deformable analogue of LiPON, with comparable ion conductivity and phase stability. This research highlights the potential of using novel low-temperature synthetic routes to control the morphology and enhance the electrochemical performance of conventional functional materials.

10.
ACS Appl Mater Interfaces ; 16(6): 7171-7181, 2024 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-38306452

RESUMEN

Layered transition metal oxide cathode materials can exhibit high energy densities in Li-ion batteries, in particular, those with high Ni contents such as LiNiO2. However, the stability of these Ni-rich materials often decreases with increased nickel content, leading to capacity fade and a decrease in the resulting electrochemical performance. Thin alumina coatings have the potential to improve the longevity of LiNiO2 cathodes by providing a protective interface to stabilize the cathode surface. The structures of alumina coatings and the chemistry of the coating-cathode interface are not fully understood and remain the subject of investigation. Greater structural understanding could help to minimize excess coating, maximize conductive pathways, and maintain high capacity and rate capability while improving capacity retention. Here, solid-state nuclear magnetic resonance (NMR) spectroscopy, paired with powder X-ray diffraction and electron microscopy, is used to provide insight into the structures of the Al2O3 coatings on LiNiO2. To do this, we performed a systematic study as a function of coating thickness and used LiCoO2, a diamagnetic model, and the material of interest, LiNiO2. 27Al magic-angle spinning (MAS) NMR spectra acquired for thick 10 wt % coatings on LiCoO2 and LiNiO2 suggest that in both cases, the coatings consist of disordered four- and six-coordinate Al-O environments. However, 27Al MAS NMR spectra acquired for thinner 0.2 wt % coatings on LiCoO2 identify additional phases believed to be LiCo1-xAlxO2 and LiAlO2 at the coating-cathode interface. 6,7Li MAS NMR and T1 measurements suggest that similar mixing takes place near the interface for Al2O3 on LiNiO2. Furthermore, reproducibility studies have been undertaken to investigate the effect of the coating method on the local structure, as well as the role of the substrate.

11.
Inorg Chem ; 63(2): 1395-1403, 2024 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-38176021

RESUMEN

Li3Fe3Te2O12 adopts a crystal structure, described in space group Pnnm, related to that of LiSbO3, in which Te6+, Fe3+, and Li+ cations reside in a partially ordered configuration within an hcp array of oxide ions. Chemical or electrochemical insertion of lithium is accompanied by a fully reversible migration of some of the Fe cations with an initial capacity of 120 mA h g-1 (2.85 Li per formula unit). Long-term cycling stability is limited by the facile reduction of Te6+ to elemental Te, which leads to cathode decomposition. Partial substitution of Fe by In suppresses Te6+ reduction, such that Li3Fe2InTe2O12 shows no sign of this cathode decomposition pathway, even after 100 cycles. In contrast, Al-for-Fe substitution is chemically limited to Li3Fe2.6Al0.4Te2O12 and appears to have almost no influence on cathode longevity. These features of the Li3Fe3-xMxTe2O12 system are discussed on the basis of a detailed structural analysis performed using neutron and synchrotron X-ray diffraction.

12.
J Biol Chem ; 300(1): 105483, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37992805

RESUMEN

Oxidative phosphorylation, the combined activities of the electron transport chain (ETC) and ATP synthase, has emerged as a valuable target for antibiotics to treat infection with Mycobacterium tuberculosis and related pathogens. In oxidative phosphorylation, the ETC establishes a transmembrane electrochemical proton gradient that powers ATP synthesis. Monitoring oxidative phosphorylation with luciferase-based detection of ATP synthesis or measurement of oxygen consumption can be technically challenging and expensive. These limitations reduce the utility of these methods for characterization of mycobacterial oxidative phosphorylation inhibitors. Here, we show that fluorescence-based measurement of acidification of inverted membrane vesicles (IMVs) can detect and distinguish between inhibition of the ETC, inhibition of ATP synthase, and nonspecific membrane uncoupling. In this assay, IMVs from Mycobacterium smegmatis are acidified either through the activity of the ETC or ATP synthase, the latter modified genetically to allow it to serve as an ATP-driven proton pump. Acidification is monitored by fluorescence from 9-amino-6-chloro-2-methoxyacridine, which accumulates and quenches in acidified IMVs. Nonspecific membrane uncouplers prevent both succinate- and ATP-driven IMV acidification. In contrast, the ETC Complex III2IV2 inhibitor telacebec (Q203) prevents succinate-driven acidification but not ATP-driven acidification, and the ATP synthase inhibitor bedaquiline prevents ATP-driven acidification but not succinate-driven acidification. We use the assay to show that, as proposed previously, lansoprazole sulfide is an inhibitor of Complex III2IV2, whereas thioridazine uncouples the mycobacterial membrane nonspecifically. Overall, the assay is simple, low cost, and scalable, which will make it useful for identifying and characterizing new mycobacterial oxidative phosphorylation inhibitors.


Asunto(s)
Antibacterianos , Descubrimiento de Drogas , Mycobacterium tuberculosis , Fosforilación Oxidativa , Adenosina Trifosfato/antagonistas & inhibidores , Adenosina Trifosfato/metabolismo , Complejo III de Transporte de Electrones/efectos de los fármacos , Mycobacterium tuberculosis/efectos de los fármacos , Mycobacterium tuberculosis/metabolismo , Fosforilación Oxidativa/efectos de los fármacos , Antibacterianos/aislamiento & purificación , Antibacterianos/farmacología , Descubrimiento de Drogas/métodos
13.
J Child Psychol Psychiatry ; 65(5): 631-643, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-37088737

RESUMEN

BACKGROUND: There is a lack of longitudinal data to examine the impact of COVID-19 on all types of clinical encounters among United States, underrepresented BIPOC (Black, Indigenous, and people of color), children. This study aims to examine the changes in all the outpatient clinical encounters during the pandemic compared to the baseline, with particular attention to psychiatric encounters and diagnoses. METHOD: This study analyzed 3-year (January 2019 to December 2021) longitudinal clinical encounter data from 3,394 children in the Boston Birth Cohort, a US urban, predominantly low-income, Black and Hispanic children. Outcomes of interest were completed outpatient clinical encounters and their modalities (telemedicine vs. in person), including psychiatric care and diagnoses, primary care, emergency department (ED), and developmental and behavioral pediatrics (DBP). RESULTS: The study children's mean (SD) age is 13.9 (4.0) years. Compared to 2019, psychiatric encounters increased by 38% in 2020, most notably for diagnoses of adjustment disorders, depression, and post-traumatic stress disorders (PTSD). In contrast, primary care encounters decreased by 33%, ED encounters decreased by 55%, and DBP care decreased by 16% in 2020. Telemedicine was utilized the most for psychiatric and DBP encounters and the least for primary care encounters in 2020. A remarkable change in 2021 was the return of primary care encounters to the 2019 level, but psychiatric encounters fluctuated with spikes in COVID-19 case numbers. CONCLUSIONS: Among this sample of US BIPOC children, compared to the 2019 baseline, psychiatric encounters increased by 38% during 2020, most notably for the new diagnoses of adjustment disorder, depression, and PTSD. The 2021 data showed a full recovery of primary care encounters to the baseline level but psychiatric encounters remained sensitive to the pandemic spikes. The long-term impact of the pandemic on children's mental health warrants further investigation.


Asunto(s)
COVID-19 , Trastornos por Estrés Postraumático , Telemedicina , Niño , Humanos , Estados Unidos , Adolescente , Servicio de Urgencia en Hospital , Estudios Retrospectivos
14.
Implement Sci ; 18(1): 68, 2023 Dec 04.
Artículo en Inglés | MEDLINE | ID: mdl-38049844

RESUMEN

BACKGROUND: Under- and uninsured cancer survivors have significant medical, social, and economic complexity. For these survivors, effective care coordination between oncology and primary care teams is critical for high-quality, comprehensive care. While evidence-based interventions exist to improve coordination between healthcare teams, testing implementation of these interventions for cancer survivors seen in real-world safety-net settings has been limited. This study aimed to (1) identify factors influencing implementation of a multicomponent care coordination intervention (nurse coordinator plus patient registry) focused on cancer survivors with multiple comorbidities in an integrated safety-net system and (2) identify mechanisms through which the factors impacted implementation outcomes. METHODS: We conducted semi-structured interviews (patients, providers, and system leaders), structured observations of primary care and oncology operations, and document analysis during intervention implementation between 2016 and 2020. The practice change model (PCM) guided data collection to identify barriers and facilitators of implementation; the PCM, Consolidated Framework for Implementation Research, and Implementation Research Logic Model guided four immersion/crystallization data analysis and synthesis cycles to identify mechanisms and assess outcomes. Implementation outcomes included appropriateness, acceptability, adoption, and penetration. RESULTS: The intervention was appropriate and acceptable to primary care and oncology teams based on reported patient needs and resources and the strength of the evidence supporting intervention components. Active and sustained partnership with system leaders facilitated these outcomes. There was limited adoption and penetration early in implementation because the study was narrowly focused on just breast and colorectal cancer patients. This created barriers to real-world practice where patients with all cancer types receive care. Over time, flexibility intentionally designed into intervention implementation facilitated adoption and penetration. Regular feedback from system partners and rapid cycles of implementation and evaluation led to real-time adaptations increasing adoption and penetration. DISCUSSION: Evidence-based interventions to coordinate care for underserved cancer survivors across oncology and primary care teams can be implemented successfully when system leaders are actively engaged and with flexibility in implementation embedded intentionally to continuously facilitate adoption and penetration across the health system.


Asunto(s)
Supervivientes de Cáncer , Neoplasias , Humanos , Oncología Médica , Neoplasias/terapia , Calidad de la Atención de Salud
16.
Phys Chem Chem Phys ; 25(37): 25728-25733, 2023 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-37721723

RESUMEN

Elucidating Li-ion transport properties is essential for designing suitable methodologies to optimise electrochemical performance in Ni-rich cathodes for high energy density Li-ion batteries. Here, we report the local-scale Li-diffusion characteristics of a series of nickel-rich layered oxide cathodes, prepared via microwave methods, using muon spin relaxation methods. Our results detail the effects of cation dopants, selected for structure stability, on transport properties in candidate nickel-rich chemistries. We find that the local diffusion properties improve with increasing nickel content. Our results demonstrate that these observations are dependant on substitutional effects.

17.
ACS Appl Mater Interfaces ; 15(30): 36512-36518, 2023 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-37465864

RESUMEN

Deformable, fast-ion conducting sulfides enable the construction of bulk-type solid-state batteries that can compete with current Li-ion batteries in terms of energy density and scalability. One approach to optimizing the energy density of these cells is to minimize the size of the electrolyte layer by integrating the solid electrolyte in thin membranes. However, additive-free thin membranes, as well as many membranes based on preprepared scaffolds, are difficult to prepare or integrate in solid cells on a large scale. Here, we propose a scalable solution-based approach to produce bulk-type glass-microfiber-reinforced composites that restore the deformability of sulfide electrolytes and can easily be shaped into thin membranes by cold pressing. This approach supports both the ease of preparation and enhancement of the energy density of sulfide-based solid-state batteries.

18.
New Phytol ; 240(1): 68-79, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37452489

RESUMEN

RNA interference (RNAi) is arguably one of the more versatile mechanisms in cell biology, facilitating the fine regulation of gene expression and protection against mobile genomic elements, whilst also constituting a key aspect of induced plant immunity. More recently, the use of this mechanism to regulate gene expression in heterospecific partners - cross-kingdom RNAi (ckRNAi) - has been shown to form a critical part of bidirectional interactions between hosts and endosymbionts, regulating the interplay between microbial infection mechanisms and host immunity. Here, we review the current understanding of ckRNAi as it relates to interactions between plants and their pathogenic and mutualistic endosymbionts, with particular emphasis on evidence in support of ckRNAi in the arbuscular mycorrhizal symbiosis.


Asunto(s)
Micorrizas , Simbiosis , Simbiosis/genética , Micorrizas/fisiología , Interferencia de ARN , Plantas/genética
19.
Chem Mater ; 35(11): 4149-4158, 2023 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-37332678

RESUMEN

Ni-rich layered oxide cathode materials such as LiNi0.8Mn0.1Co0.1O2 (NMC811) are widely tipped as the next-generation cathodes for lithium-ion batteries. The NMC class offers high capacities but suffers an irreversible first cycle capacity loss, a result of slow Li+ diffusion kinetics at a low state of charge. Understanding the origin of these kinetic hindrances to Li+ mobility inside the cathode is vital to negate the first cycle capacity loss in future materials design. Here, we report on the development of operando muon spectroscopy (µSR) to probe the Å-length scale Li+ ion diffusion in NMC811 during its first cycle and how this can be compared to electrochemical impedance spectroscopy (EIS) and the galvanostatic intermittent titration technique (GITT). Volume-averaged muon implantation enables measurements that are largely unaffected by interface/surface effects, thus providing a specific characterization of the fundamental bulk properties to complement surface-dominated electrochemical methods. First cycle measurements show that the bulk Li+ mobility is less affected than the surface Li+ mobility at full depth of discharge, indicating that sluggish surface diffusion is the likely cause of first cycle irreversible capacity loss. Additionally, we demonstrate that trends in the nuclear field distribution width of the implanted muons during cycling correlate with those observed in differential capacity, suggesting the sensitivity of this µSR parameter to structural changes during cycling.

20.
J Mater Chem A Mater ; 11(24): 13016-13026, 2023 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-37346739

RESUMEN

Short-range ordering in cation-disordered cathodes can have a significant effect on their electrochemical properties. Here, we characterise the cation short-range order in the antiperovskite cathode material Li2FeSO, using density functional theory, Monte Carlo simulations, and synchrotron X-ray pair-distribution-function data. We predict partial short-range cation-ordering, characterised by favourable OLi4Fe2 oxygen coordination with a preference for polar cis-OLi4Fe2 over non-polar trans-OLi4Fe2 configurations. This preference for polar cation configurations produces long-range disorder, in agreement with experimental data. The predicted short-range-order preference contrasts with that for a simple point-charge model, which instead predicts preferential trans-OLi4Fe2 oxygen coordination and corresponding long-range crystallographic order. The absence of long-range order in Li2FeSO can therefore be attributed to the relative stability of cis-OLi4Fe2 and other non-OLi4Fe2 oxygen-coordination motifs. We show that this effect is associated with the polarisation of oxide and sulfide anions in polar coordination environments, which stabilises these polar short-range cation orderings. We propose that similar anion-polarisation-directed short-range-ordering may be present in other heterocationic materials that contain cations with different formal charges. Our analysis illustrates the limitations of using simple point-charge models to predict the structure of cation-disordered materials, where other factors, such as anion polarisation, may play a critical role in directing both short- and long-range structural correlations.

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