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PURPOSE: To investigate the efficacy and safety of repeated low-level red-light (RLRL) therapy combined with orthokeratology among children who, despite undergoing orthokeratology, exhibited an axial elongation of at least 0.50 mm over 1 year. DESIGN: Multicenter, randomized, parallel-group, single-blind clinical trial (ClinicaTrials.gov identifier, NCT04722874). PARTICIPANTS: Eligible children were 8-13 years of age with a cycloplegic spherical equivalent refraction of -1.00 to -5.00 diopters at the initial orthokeratology fitting examination and had annual axial length (AL) elongation of ≥0.50 mm despite undergoing orthokeratology. Forty-eight children were enrolled from March 2021 through January 2022, and the final follow-up was completed in March 2023. METHODS: Children were assigned randomly to the RLRL therapy combined with orthokeratology (RCO) group or to the orthokeratology group in a 2:1 ratio. The orthokeratology group wore orthokeratology lenses for at least 8 hours per night, whereas the RCO group received daily RLRL therapy twice daily for 3 minutes in addition to orthokeratology. MAIN OUTCOME MEASURES: The primary outcome was AL change measured at 12 months relative to baseline. The primary analysis was conducted in children who received the assigned intervention and completed at least 1 follow-up after randomization using the modified intention-to-treat principle. RESULTS: Forty-seven children (97.9%) were included in the analysis (30 in the RCO group and 17 in the orthokeratology group). The mean axial elongation rate before the trial was 0.60 mm/year and 0.61 mm/year in the RCO and orthokeratology groups, respectively. After 12 months, the adjusted mean AL changes were -0.02 mm (95% confidence interval [CI], -0.08 to +0.03 mm) in the RCO group and 0.27 mm (95% CI, 0.19-0.34 mm) in the orthokeratology group. The adjusted mean difference in AL change was -0.29 mm (95% CI, -0.44 to -0.14 mm) between the groups. The percentage of children achieving an uncorrected visual acuity of more than 20/25 was similar in the RCO (64.3%) and orthokeratology (65.5%) groups (P = 0.937). CONCLUSIONS: Combining RLRL therapy with orthokeratology may offer a promising approach to optimize axial elongation control among children with myopia. This approach also potentially allows children to achieve satisfactory visual acuity, reducing daytime dependence on corrective eyewear. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.
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PURPOSE: This study evaluated the structural features of the retinal and choroidal regions and their correlations with ocular biometric and vascular parameters in Chinese children using optical coherence tomography angiography (OCTA). METHODS: A total of 159 children, 6-13 years of age, were included in this prospective study. The sample consisted of 55 emmetropes (spherical equivalent ≤ +0.75 and > -0.50 D), 53 low-moderate myopes (≤ -0.50 to > -6.00 D) and 51 high myopes without pathological changes (≤ -6.00 D). Optical coherence biometry was used to measure axial length (AL) and anterior segment parameters. Swept-source optical coherence tomography/OCTA was used to assess the macular structures and vascular characteristics in a 6 × 6 mm region centred on the macula. RESULTS: In a comprehensive analysis adjusting for age, sex, AL, macular blood perfusion, intraocular pressure and anterior segment parameters, retinal thickness (RT) showed a significant positive association with deep retinal vascular density and superficial retinal vascular density in the foveal area, but not with AL. Moreover, RT exhibited a significant negative association with AL in the parafoveal and perifoveal regions. Further, a significant positive correlation was observed between choroidal thickness and both choroidal vascular volume and choriocapillaris perfusion area, along with a negative correlation with AL across the entire macular region. CONCLUSIONS: This study showed that the thickness of retina and choroid in Chinese children was not only associated with AL but also showed dynamic properties such as the blood perfusion of the retina and choroid, particularly in the foveal area.
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Miopia , Retina , Criança , Humanos , Estudos Prospectivos , Retina/diagnóstico por imagem , Retina/patologia , Miopia/diagnóstico , Miopia/patologia , Corioide/patologia , China , Tomografia de Coerência Óptica/métodos , Vasos Retinianos/diagnóstico por imagem , Vasos Retinianos/patologiaRESUMO
Despite the exceptionally high energy density of lithium metal anodes, the practical application of lithium-metal batteries (LMBs) is still impeded by the instability of the interphase between the lithium metal and the electrolyte. To formulate a functional electrolyte system that can stabilize the lithium-metal anode, the solvation behavior of the solvent molecules must be understood because the electrochemical properties of a solvent can be heavily influenced by its solvation status. We unambiguously demonstrated the solvation rule for the solid-electrolyte interphase (SEI) enabler in an electrolyte system. In this study, fluoroethylene carbonate was used as the SEI enabler due to its ability to form a robust SEI on the lithium metal surface, allowing relatively stable LMB cycling. The results revealed that the solvation number of fluoroethylene carbonate must be ≥1 to ensure the formation of a stable SEI in which the sacrificial reduction of the SEI enabler subsequently leads to the stable cycling of LMBs.
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Hydrofluoroethers (HFEs) have been adopted widely as electrolyte cosolvents for battery systems because of their unique low solvating behavior. The electrolyte is currently utilized in lithium-ion, lithium-sulfur, lithium-air, and sodium-ion batteries. By evaluating the relative solvating power of different HFEs with distinct structural features, and considering the shuttle factor displayed by electrolytes that employ HFE cosolvents, we have established the quantitative structure-activity relationship between the organic structure and the electrochemical performance of the HFEs. Moreover, we have established the linear free-energy relationship between the structural properties of the electrolyte cosolvents and the polysulfide shuttle effect in lithium-sulfur batteries. These findings provide valuable mechanistic insight into the polysulfide shuttle effect in lithium-sulfur batteries, and are instructive when it comes to selecting the most suitable HFE electrolyte cosolvent for different battery systems.
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Relative solvating power, that is, the ratio of the coordination ratios between a solvent and the reference solvent, was used to probe the quantitative structure-activity relationship of electrolyte solvents and the lithium polysulfide (LiPS) dissolution in lithium-sulfur batteries. Internally referenced diffusion-ordered nuclear magnetic resonance spectroscopy (IR-DOSY) was used to determine the diffusion coefficient and coordination ratio, from which the relative solvating power can be easily measured. The higher the relative solvating power of an ethereal solvent, the more severe will be the LiPS dissolution and the lower the coulombic efficiency of the lithium-sulfur battery. A linear relationship was established between the logarithm of relative solvating power of a solvent and the degree of LiPS dissolution, rendering relative solvating power an important parameter in choosing the electrolyte solvent for lithium-sulfur batteries.
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Aim: The aim of this study is to explore the association between red blood cell distribution width-to-albumin ratio (RAR) and the risk of peripheral artery disease (PAD) in patients with diabetes. Methods: This cross-sectional study extracted the data of 1,125 participants with diabetes from the National Health and Nutrition Examination Survey database. A weighted univariable logistic regression model was used to explore variables associated with PAD. With PAD as the outcome variable, a weighted logistic regression model was established. The odds ratio (OR) and 95% confidence interval (CI) were effect size. Results: After adjusting for covariates, the risk of PAD in patients with diabetes was observed in those with higher RAR (OR = 1.83; 95% CI: 1.06-3.15). In addition, RAR ≥3.25 was related to increased risk of PAD in patients with diabetes (OR = 2.04; 95% CI: 1.05-3.95). In people with diabetes aged ≥65, RAR was a risk factor for PAD with an OR value of 2.67 (95% CI: 1.30-5.46). RAR ≥3.25 was associated with increased risk of PAD (OR = 3.06; 95% CI: 1.15-8.11) relative to RAR <2.80. In people with diabetes who smoked, the risk of PAD was elevated in those with RAR ≥3.25 (OR = 2.85; 95% CI: 1.28-6.32). As for patients with cardiovascular disease, the risk of PAD was elevated as the increase of RAR (OR = 2.31; 95% CI: 1.05-5.10). RAR ≥3.25 was correlated with increased risk of PAD (OR = 3.75; 95% CI: 1.42-9.87). The area under the curve of RAR for the risk of PAD in patients with diabetes was 0.631 (95% CI: 0.588-0.675). Conclusion: A higher RAR was related to increased risk of PAD in patients with diabetes. The findings might offer a reference for the management of PAD in patients with diabetes.
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Diabetes Mellitus , Doença Arterial Periférica , Humanos , Índices de Eritrócitos , Inquéritos Nutricionais , Estudos Transversais , Diabetes Mellitus/epidemiologia , Doença Arterial Periférica/complicações , Doença Arterial Periférica/epidemiologia , AlbuminasRESUMO
The structure-activity relationships of nonsolvating cosolvents for organosulfur-based electrolyte systems were revealed. The performance of nonsolvating dilutant fluorobenzene (FB) was compared to various fluorinated ether dilutants in high-voltage electrolytes containing a concentration of 1.2 M LiPF6 dissolved in fluoroethylene carbonate (FEC), ethyl methyl sulfone (EMS), and the dilutant. In a high-voltage and high-loading LiNi0.8Mn0.1Co0.1O2 (NMC811) full cell configuration, the organosulfur-based electrolyte containing FB dilutant enabled superior electrochemical performance compared to the electrolytes using other nonsolvating fluorinated ether formulations. Moreover, the FB-containing electrolyte exhibited the highest ionic conductivity and lowest viscosity among all organosulfur-based electrolytes containing nonsolvating dilutant. These improvements are attributed to the enhanced physical properties of electrolyte and lithium-ion mobility. Furthermore, by employing first-principles simulations, the observed suppression of side reactions at high voltage is linked to FB's lower reactivity toward singlet dioxygen, which is likely produced at the NMC interface. Overall, FB is considered an excellent diluent that does not impede cell operation by mass decomposition at the cathode.
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To guide the selection of a suitable fluorinated ether (FE) co-solvent for lithium metal batteries, it is crucial to understand the relationship between the organic structures of the FEs and the electrochemical performance of an FE-containing electrolyte. In this work, 1,1,2,2-tetrafluoro-1-(2,2,2-trifluoroethoxy)ethane (FEE), 1,1,2,2-tetrafluoro-3-(1,1,2,2-tetrafluoroethoxy)propane (TTE), and 1,2-bis(1,1,2,2-tetrafluoroethoxy)ethane (OFDEE) were chosen as representative FE co-solvents because of their distinct structural properties. The structure-activity relationship between the FEs and the electrochemical performance of Li||LiNi0.6Mn0.2Co0.2O2 (Li||NMC622) cells was correlated and quantified by Fourier-transform infrared and multi-dimensional nuclear magnetic resonance techniques. Sand's model was also employed to assess the extent of lithium dendrite formation in the cells using various FE electrolytes. The cycling performance of Li||NMC622 cells using different FE co-solvents follows the order FEE > TTE > OFDEE. Since the direct measurement of Sand's time is difficult, we introduced relative Sand's time to probe the diffusion behavior of each electrolyte, and the results showed that the best performance was obtained in the electrolyte with the longest relative Sand's time. Moreover, the lithium metal cell using the electrolyte with FEE co-solvent showed similar capacity retention compared with the baseline electrolyte at room temperature, but it demonstrated significantly improved low-temperature performance. The results indicate that FEE is a promising co-solvent candidate for improving the low-temperature performance of lithium metal batteries because it possesses not only non-solvating behavior but also very low viscosity and non-flammability. The advanced electrolyte LiPF6-FEC-DMC-FEE enables very stable cycling of lithium metal batteries at various temperatures.
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OBJECTIVE: This study aimed to compare the vision-related quality of life (VRQoL) between Defocus Incorporated Soft Contact (DISC) lenses and single-vision spectacles in Chinese children, in order to evaluate their visual performance and subjective acceptance of this bifocal designed contact lenses treatment. METHODS: Chinese participants aged 7 to 12 years, with myopia of -4.00 to -0.75 D, astigmatism < 1.50 D, and monocular best-corrected visual acuity 0.0 or better, were recruited in the study. All participants had been wearing DISC lenses, or single-vision spectacles, for the last 6 to 18 months and were requested to complete the routine ocular examination and Chinese version of the Pediatric Refractive Error Profile (PREP 2) questionnaire. The questionnaire consisted of 7 scales: vision, symptoms, appearance, activities, handling, peer perception, and overall score. According to their habitual correction modalities, fifty-four children were allocated to the DISC group and 56 to the single-vision spectacles group. A generalized linear model was fitted to assess variables associated with the PREP 2 score. RESULTS: Participants wearing DISC lenses scored significantly higher than those wearing single-vision spectacles for vision, appearance, activities, peer perception, and overall (all P < 0.05). The improvement of VRQoL in the DISC group was mainly represented in appearance, peer perception, and activities. The quality of life improved more for older participants on scales of vision, symptoms, handling, appearance, and overall score (all P < 0.05). The interaction between treatment and age was statistically significant for the activities scale (P < 0.05). CONCLUSION: DISC lens wear significantly improves VRQoL in Chinese children compared with single-vision spectacles for most of the survey scales, especially in the areas of appearance, peer perception, and activities. The benefits provided by DISC lenses contribute to greater satisfaction than single-vision spectacles for myopic children.
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Lentes de Contato Hidrofílicas , Miopia , Humanos , Criança , Qualidade de Vida , Óculos , Visão Ocular , Miopia/terapiaRESUMO
OBJECTIVE: This study aimed to develop and evaluate an adapted Chinese version of the Pediatric Refractive Error Profile2 (PREP2) and to evaluate its acceptability, reliability, and validity in a population of Chinese children with refractive error. METHODS: The Chinese version of the PREP2 was translated using a standardized procedure and then administered to consecutive outpatients with refractive error. Reliability was assessed by the Cronbach's alpha coefficient for internal consistency and test-retest reliability. Validity of the questionnaire was assessed by item discriminant validity, construct validity, known-groups validity, and concurrent validity. RESULTS: A total of 104 subjects were recruited for the study and all completed the Chinese version of the PREP2 questionnaire with no problems. A random sample of 50 patients completed the questionnaire twice within one week. The Cronbach's alpha coefficients ranged from 0.71 to 0.89 across scales, and the intraclass correlation coefficient ranged from 0.86 to 0.92, indicating excellent internal consistency and test-retest reliability. The item-scale correlation coefficients between the items and the corresponding scales ranged from 0.39 to 0.88. The translated questionnaire had good discriminatory power between contact lens wearers and spectacle wearers. Significant correlations were found between the scales and traditional clinical parameters, such as spherical equivalent and uncorrected visual acuity, showing good construct and concurrent validity. CONCLUSION: The Chinese version of the PREP2 exhibited good internal consistency, test-retest reliability, item-scale correlation, discriminatory power, construct validity, and concurrent validity. Therefore, it may be adopted as an acceptable, reliable, and valid instrument for the measurement of vision-related quality of life in Chinese children with refractive error.
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Qualidade de Vida , Erros de Refração , Criança , China , Humanos , Psicometria , Erros de Refração/diagnóstico , Erros de Refração/terapia , Reprodutibilidade dos Testes , Inquéritos e Questionários , TraduçõesRESUMO
A complementary electrolyte system with 0.8 M lithium bis(fluorosulfonylimide) (LiFSI) salt and 2 wt % lithium perchlorate (LiClO4) additive in fluoroethylene carbonate (FEC)/ethyl methyl carbonate (EMC) solution enables not only stable cycling of lithium metal batteries (LMBs) with practical loading (<30 µm lithium anode, cathode loading > 4 mAh/cm2) but also outstanding degradation stability toward the end of cycle life when compared to the conventional electrolyte. Although the use of LiFSI salt can increase the electrolyte conductivity and lengthen the cycle life of LMBs, the aged lithium anode morphology formed by the sacrificial decomposition of LiFSI is highly porous, leading to an abrupt cell capacity drop toward the end of cycling. Moreover, the inability to stop aluminum corrosion by the LiFSI-based electrolyte also causes cracking of the cathode tab during prolonged cycling. It is observed that a highly porous aged lithium consumed electrolyte at a higher rate, leading to the dry-out of electrolyte solvents. On the contrary, dense aged lithium anode morphology increased the localized current applied on the lithium, causing the formation of lithium dendrite. Thus, porosity control is the key to enhance battery performance. In this complementary system, LiClO4 was introduced as an advanced additive to not only improve the capacity retention rate but also mitigate the abrupt capacity drop toward the end of cycle life because LiClO4 acted as a pore astringent reducing the porosity of the aged lithium metal anode to the desired level. Moreover, the addition of LiClO4 can also suppress the Al corrosion, allowing stable high-voltage cycling of LMBs. The synergistic effect of combining LiFSI salt and a LiClO4 additive leads to an electrolyte system that can facilitate the application of high-energy LMBs with practical electrode loading.
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AIM: To evaluate the effect of posterior sclera collagen cross-linking induced by riboflavin-ultraviolet A (UVA) on form-deprived myopia in guinea pigs. METHODES: Twenty-five pigmented guinea pigs of 3-week-old were randomly assigned into 4 groups that included normal control (NOR, n=7), form-deprived (FDM, n=7), normal with riboflavin-UVA cross-linking (NOR+CL, n=5) and form-deprived with cross-linking (FDM+CL, n=6). The NOR+CL group and the FDM+CL group received the riboflavin-UVA induced cross-linking at day 0. FDM was induced by monocularly deprived with facemask in the right eyes. The refraction, axial length and corneal curvature were measured by retinoscopy, A-scan and keratometer respectively in scheduled time points (day 0 and 1, 2, 3, 4wk after form-deprivation). At the end of 4 weeks' experiment, stress-strain tests of sclera were measured and morphological changes of sclera and retina were examined. RESULTS: After 4wk, the interocular difference of refractive error were -0.11±0.67, -2.93±0.56, 1.10±0.58, and -1.63±0.41 D in the NOR, FDM, NOR+CL, and FDM+CL groups respectively. Mixed-effect linear model revealed significant effect of FDM (P<0.01) and CL (P<0.001). Also, after 4wk, the interocular difference of axial length were 0.01±0.04, 0.29±0.07, -0.13±0.06, and 0.11±0.05 mm in the NOR, FDM, NOR+CL, and FDM+CL group. Mixed-effect linear model revealed significant effect of FDM (P<0.001) and CL (P<0.01). As for corneal curvature, significant interocular difference have not found between any of the two groups. At the end of this experiment, the ultimate stress and elastic modulus were found significantly increased in both CL groups. But no difference was found in the groups without cross-linked. There was no abnormality observed in the retina and RPE cells of the treated eyes. CONCLUSION: The posterior sclera collagen cross-linking induced by riboflavin-UVA can slow down the progress of myopia and increase the sclera biomechanical strength in the guinea pig model of form-deprived myopia.
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BACKGROUND: Co-morbidity of SRY gene turner syndrome (TS) with positive SRY gene and non-classical congenital adrenal hyperplasia (NCAH) is extremely rare and has never been reported to date. CASE SUMMARY: In this article, we present a 14-year-old girl who was referred to our hospital with short stature (weight of 43 kg and height of 143 cm, < -2 SD) with no secondary sexual characteristics (labia minora dysplasia). Laboratory tests indicated hypergonadotropic hypogonadism with significantly increased androstenedione and 17-hydroxyprogesterone (17-OHP) levels. This was accompanied by the thickening of the extremity of the left adrenal medial limb. The patient's karyotype was 45,X/46,X, +mar, and cytogenetic analysis using multiplex ligation-dependent probe amplification and high-throughput sequencing indicated that the SRY gene was positive with compound heterozygous mutations in CYP21A2 as the causative gene for congenital adrenal hyperplasia. The sites of the suspected candidate mutations were amplified and verified using Sanger sequencing. The patient was finally diagnosed as having SRY positive TS with NCAH. The patient and her family initially refused medical treatment. At her most recent follow-up visit (age = 15 years old), the patient presented facial hair, height increase to 148 cm, and weight of 52 kg, while androstenedione and 17-OHP levels remained high. The patient was finally willing to take small doses of hydrocortisone (10 mg/d). CONCLUSION: In conclusion, upon evaluation of the patient mentioned in the report, we feel that 17-OHP measurement and cytogenetic analysis are necessary for TS patients even in the absence of significant virilization signs. This will play a significant role in guiding diagnosis and treatment.
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A novel methodology is reported on the use of internally referenced diffusion-ordered spectroscopy (IR-DOSY) in divulging the solution structure of lithium-ion battery electrolytes. Toluene was utilized as the internal reference for 1H-DOSY analysis due to its exceptionally low donor number and reasonable solubility in various electrolytes. With the introduction of the internal reference, the solvent coordination ratio of different species in the electrolytes can be easily determined by 1H-DOSY or 7Li-DOSY. This new technique was applied to different carbonate electrolytes, and the results were consistent with a Fourier transform infrared (FTIR) analysis. Compared to conventional vibrational spectroscopy, this IR-DOSY technique avoids the complicated deconvolution of the spectrum and allows determination of the solvent coordination ratio of different species in electrolyte systems with two or more organic solvents.
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A new class of electrolyte additives based on cyclic fluorinated phosphate esters was rationally designed and identified as being able to stabilize the surface of a LiNi0.5Mn0.3Co0.2O2 (NMC532) cathode when cycled at potentials higher than 4.6 V vs Li+/Li. Cyclic fluorinated phosphates were designed to incorporate functionalities of various existing additives to maximize their utilization. The synthesis and characterization of these new additives are described and their electrochemical performance in a NMC532/graphite cell cycled between 4.6 and 3.0 V are investigated. With 1.0 wt % 2-(2,2,2-trifluoroethoxy)-1,3,2-dioxaphospholane 2-oxide (TFEOP) in the conventional electrolyte the NMC532/graphite cell exhibited much improved capacity retention compared to that without any additive. The additive is believed to form a passivation layer on the surface of the cathode via a sacrificial polymerization reaction as evidenced by X-ray photoelectron spectroscopy (XPS) and nuclear magnetic resonsance (NMR) analysis results. The rational pathway of a cathode-electrolyte-interface formation was proposed for this type of additive. Both experimental results and the mechanism hypothesis suggest the effectiveness of the additive stems from both the polymerizable cyclic ring and the electron-withdrawing fluorinated alkyl group in the phosphate molecular structure. The successful development of cyclic fluorinated phosphate additives demonstrated that this new functionality selection principle, by incorporating useful functionalities of various additives into one molecule, is an effective approach for the development of new additives.
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Through coupled experimental analysis and computational techniques, we uncover the origin of anodic stability for a range of nonaqueous zinc electrolytes. By examination of electrochemical, structural, and transport properties of nonaqueous zinc electrolytes with varying concentrations, it is demonstrated that the acetonitrile-Zn(TFSI)2, acetonitrile-Zn(CF3SO3)2, and propylene carbonate-Zn(TFSI)2 electrolytes can not only support highly reversible Zn deposition behavior on a Zn metal anode (≥99% of Coulombic efficiency) but also provide high anodic stability (up to â¼3.8 V vs Zn/Zn(2+)). The predicted anodic stability from DFT calculations is well in accordance with experimental results, and elucidates that the solvents play an important role in anodic stability of most electrolytes. Molecular dynamics (MD) simulations were used to understand the solvation structure (e.g., ion solvation and ionic association) and its effect on dynamics and transport properties (e.g., diffusion coefficient and ionic conductivity) of the electrolytes. The combination of these techniques provides unprecedented insight into the origin of the electrochemical, structural, and transport properties in nonaqueous zinc electrolytes.
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Triethlylphosphite (TEP) and tris(2,2,2-trifluoroethyl) phosphite (TTFP) have been evaluated as electrolyte additives for high-voltage Li-ion battery cells using a Ni-rich layered cathode material LiNi0.5Co0.2Mn0.3O2 (NCM523) and the conventional carbonate electrolyte. The repeated charge/discharge cycling for cells containing 1 wt % of these additives was performed using an NCM523/graphite full cell operated at the voltage window from 3.0-4.6 V. During the initial charge process, these additives decompose on the cathode surface at a lower oxidation potential than the baseline electrolyte. Impedance spectroscopy and post-test analyses indicate the formation of protective coatings by both additives on the cathode surface that prevent oxidative breakdown of the electrolyte. However, only TTFP containing cells demonstrate the improved capacity retention and Coulombic efficiency. For TEP, the protective coating is also formed, but low Li(+) ion mobility through the interphase layer results in inferior performance. These observations are rationalized through the inhibition of electrocatalytic centers present on the cathode surface and the formation of organophosphate deposits isolating the cathode surface from the electrolyte. The difference between the two phosphites clearly originates in the different properties of the resulting phosphate coatings, which may be in Li(+) ion conductivity through such materials.
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A series of strong Lewis acid-free alkoxide/siloxide-based Mg electrolytes were deliberately developed with remarkable oxidative stability up to 3.5 V (vs. Mg/Mg(2+)). Despite the perception of ROMgCl (R=alkyl, silyl) as a strong base, ROMgCl acts like Lewis acid, whereas the role of MgCl2 in was unambiguously demonstrated as a Lewis base through the identification of the key intermediate using single crystal X-ray crystallography. This Lewis-acid-free strategy should provide a prototype system for further investigation of Mg-ion batteries.
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Fontes de Energia Elétrica , Eletrólitos/química , Bases de Lewis/química , Cloreto de Magnésio/química , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Microscopia Eletrônica de VarreduraRESUMO
Battery safety is critical for many applications including portable electronics, hybrid and electric vehicles, and grid storage. For lithium ion batteries, the conventional polymer based separator is unstable at 120 °C and above. In this research, we have developed a pure aluminum oxide nanowire based separator; this separator does not contain any polymer additives or binders; additionally, it is a bendable ceramic. The physical and electrochemical properties of the separator are investigated. The separator has a pore size of about 100 nm, and it shows excellent electrochemical properties under both room and high temperatures. At room temperature, the ceramic separator shows a higher rate capability compared to the conventional Celgard 2500 separator and life cycle performance does not show any degradation. At 120 °C, the cell with the ceramic separator showed a much better cycle performance than the conventional Celgard 2500 separator. Therefore, we believe that this research is really an exciting scientific breakthrough for ceramic separators and lithium ion batteries and could be potentially used in the next generation lithium ion batteries requiring high safety and reliability.