Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 150
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Nature ; 614(7949): 694-700, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36755091

RESUMO

The ideal electrolyte for the widely used LiNi0.8Mn0.1Co0.1O2 (NMC811)||graphite lithium-ion batteries is expected to have the capability of supporting higher voltages (≥4.5 volts), fast charging (≤15 minutes), charging/discharging over a wide temperature range (±60 degrees Celsius) without lithium plating, and non-flammability1-4. No existing electrolyte simultaneously meets all these requirements and electrolyte design is hindered by the absence of an effective guiding principle that addresses the relationships between battery performance, solvation structure and solid-electrolyte-interphase chemistry5. Here we report and validate an electrolyte design strategy based on a group of soft solvents that strikes a balance between weak Li+-solvent interactions, sufficient salt dissociation and desired electrochemistry to fulfil all the aforementioned requirements. Remarkably, the 4.5-volt NMC811||graphite coin cells with areal capacities of more than 2.5 milliampere hours per square centimetre retain 75 per cent (54 per cent) of their room-temperature capacity when these cells are charged and discharged at -50 degrees Celsius (-60 degrees Celsius) at a C rate of 0.1C, and the NMC811||graphite pouch cells with lean electrolyte (2.5 grams per ampere hour) achieve stable cycling with an average Coulombic efficiency of more than 99.9 per cent at -30 degrees Celsius. The comprehensive analysis further reveals an impedance matching between the NMC811 cathode and the graphite anode owing to the formation of similar lithium-fluoride-rich interphases, thus effectively avoiding lithium plating at low temperatures. This electrolyte design principle can be extended to other alkali-metal-ion batteries operating under extreme conditions.

2.
J Am Chem Soc ; 146(17): 11711-11718, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38632847

RESUMO

Lithium metal batteries (LMB) have high energy densities and are crucial for clean energy solutions. The characterization of the lithium metal interphase is fundamentally and practically important but technically challenging. Taking advantage of synchrotron X-ray, which has the unique capability of analyzing crystalline/amorphous phases quantitatively with statistical significance, we study the composition and dynamics of the LMB interphase for a newly developed important LMB electrolyte that is based on fluorinated ether. Pair distribution function analysis revealed the sequential roles of the anion and solvent in interphase formation during cycling. The relative ratio between Li2O and LiF first increases and then decreases during cycling, suggesting suppressed Li2O formation in both initial and long extended cycles. Theoretical studies revealed that in initial cycles, this is due to the energy barriers in many-electron transfer. In long extended cycles, the anion decomposition product Li2O encourages solvent decomposition by facilitating solvent adsorption on Li2O which is followed by concurrent depletion of both. This work highlights the important role of Li2O in transitioning from an anion-derived interphase to a solvent-derived one.

3.
Nat Mater ; 22(12): 1531-1539, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37932334

RESUMO

Liquid electrolytes in batteries are typically treated as macroscopically homogeneous ionic transport media despite having a complex chemical composition and atomistic solvation structures, leaving a knowledge gap of the microstructural characteristics. Here, we reveal a unique micelle-like structure in a localized high-concentration electrolyte, in which the solvent acts as a surfactant between an insoluble salt in a diluent. The miscibility of the solvent with the diluent and simultaneous solubility of the salt results in a micelle-like structure with a smeared interface and an increased salt concentration at the centre of the salt-solvent clusters that extends the salt solubility. These intermingling miscibility effects have temperature dependencies, wherein a typical localized high-concentration electrolyte peaks in localized cluster salt concentration near room temperature and is used to form a stable solid-electrolyte interphase on a Li metal anode. These findings serve as a guide to predicting a stable ternary phase diagram and connecting the electrolyte microstructure with electrolyte formulation and formation protocols of solid-electrolyte interphases for enhanced battery cyclability.

4.
Nano Lett ; 23(15): 7135-7142, 2023 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-37462326

RESUMO

Spinel-structured ordered-LiNi0.5Mn1.5O4 (o-LNMO) has experienced a resurgence of interest in the context of reducing scarce elements such as cobalt from the lithium-ion batteries. O-LNMO undergoes two two-phase reactions at slow rates. However, it is not known if such phenomenon also applies at fast rates. Herein, we investigate the rate-dependent phase transition behavior of o-LNMO through in operando time-resolved X-ray diffraction. The results indicate that a narrow region of the solid solution reaction exists for charge and discharge at both slow and fast rates. The overall phase transition is highly asymmetric at fast rates. During fast charge, it is a particle-by-particle mechanism resulting from an asynchronized reaction among the particles. During fast discharge, it is likely a core-shell mechanism involving transition from Li0+xNi0.5Mn1.5O4 to Li1+xNi0.5Mn1.5O4 in the outer layer of particles. The Li0.5Ni0.5Mn1.5O4 phase is suppressed during fast discharge and appears only through Li redistribution upon relaxation.

5.
Zhongguo Dang Dai Er Ke Za Zhi ; 26(2): 164-168, 2024 Feb 15.
Artigo em Zh | MEDLINE | ID: mdl-38436314

RESUMO

OBJECTIVES: To study the association of hypercoagulability with urinary protein and renal pathological damage in children with immunoglobulin A vasculitis with nephritis (IgAVN). METHODS: Based on the results of coagulation function, 349 children with IgAVN were divided into a hypercoagulability group consisting of 52 children and a non-hypercoagulability group consisting of 297 children. Urinary protein and renal pathological features were compared between the two groups, and the factors influencing the formation of hypercoagulability in children with IgAVN were analyzed. RESULTS: Compared with the non-hypercoagulability group, the hypercoagulability group had significantly higher levels of urinary erythrocyte count, 24-hour urinary protein, urinary protein/creatinine, urinary immunoglobulin G/creatinine, and urinary N-acetyl-ß-D-glucosaminidase (P<0.05). The hypercoagulability group also had a significantly higher proportion of children with a renal pathological grade of III-IV, diffuse mesangial proliferation, capillary endothelial cell proliferation, or >25% crescent formation (P<0.05). The multivariate logistic regression analysis showed that capillary endothelial cell proliferation and glomerular crescent formation >25% were associated with the formation of hypercoagulability in children with IgAVN (P<0.05). CONCLUSIONS: The renal injury in IgAVN children with hypercoagulability is more severe, with greater than 25% crescent formation and increased proliferation of glomerular endothelial cells being important contributing factors that exacerbate the hypercoagulable state in IgAVN.


Assuntos
Vasculite por IgA , Nefrite , Trombofilia , Criança , Humanos , Creatinina , Células Endoteliais , Rim , Vasculite por IgA/complicações , Trombofilia/etiologia , Imunoglobulina A
6.
Zhongguo Dang Dai Er Ke Za Zhi ; 26(7): 683-689, 2024 Jul 15.
Artigo em Zh | MEDLINE | ID: mdl-39014943

RESUMO

OBJECTIVES: To explore the evidence, urinary biomarkers, and partial mechanisms of hypercoagulability in the pathogenesis of IgA vasculitis (IgAV). METHODS: Differential expression of proteins in the urine of 10 healthy children and 10 children with IgAV was screened using high-performance liquid chromatography-tandem mass spectrometry, followed by Reactome pathway analysis. Protein-protein interaction (PPI) network analysis was conducted using STRING and Cytoscape software. In the validation cohort, 15 healthy children and 25 children with IgAV were included, and the expression levels of differential urinary proteins were verified using enzyme-linked immunosorbent assay. RESULTS: A total of 772 differential proteins were identified between the IgAV group and the control group, with 768 upregulated and 4 downregulated. Reactome pathway enrichment results showed that neutrophil degranulation, platelet activation, and hemostasis pathways were involved in the pathogenesis of IgAV. Among the differential proteins, macrophage migration inhibitory factor (MIF) played a significant role in neutrophil degranulation and hemostasis, while thrombin was a key protein in platelet activation and hemostasis pathways. PPI analysis indicated that thrombin directly interacted with several proteins involved in inflammatory responses, and these interactions involved MIF. Validation results showed that compared to healthy children, children with IgAV had significantly higher urine thrombin/creatinine and urine MIF/creatinine levels (P<0.05). CONCLUSIONS: Thrombin contributes to the pathogenesis of IgAV through interactions with inflammatory factors. Urinary thrombin and MIF can serve as biomarkers reflecting the hypercoagulable and inflammatory states in children with IgAV.


Assuntos
Vasculite por IgA , Proteômica , Trombina , Humanos , Criança , Masculino , Proteômica/métodos , Feminino , Vasculite por IgA/urina , Trombina/metabolismo , Fatores Inibidores da Migração de Macrófagos/urina , Mapas de Interação de Proteínas , Pré-Escolar , Oxirredutases Intramoleculares
7.
BMC Pediatr ; 23(1): 235, 2023 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-37173710

RESUMO

BACKGROUND: The study aims to investigate the clinical characteristics of early postnatal period in children with prenatal hydronephrosis (HN) in our single center for 8 years. STUDY DESIGN: The clinical data of 1137 children with prenatal HN from 2012 to 2020 were retrospectively analyzed in our center. Variables of our study mainly included different malformations and urinary tract dilation (UTD) classification, and main outcomes were recurrent hospitalization, urinary tract infection (UTI), jaundice, and surgery. RESULTS: Among the 1137 children with prenatal HN in our center, 188 cases (16.5%) were followed-up in early postnatal period, and 110 cases (58.5%) were found malformations. The incidence of recurrent hospitalization (29.8%) and UTI (72.5%) were higher in malformation, but the incidence of jaundice (46.2%) was higher in non-malformation(P < 0.001). Furthermore, UTI and jaundice were higher in vesicoureteral reflux (VUR) than those in uretero-pelvic junction obstruction (UPJO) (P < 0.05). Meanwhile, Children with UTD P2 and UTD P3 were prone to recurrent UTI, but UTD P0 was prone to jaundice (P < 0.001). In addition, 30 cases (16.0%) of surgery were all with malformations, and the surgical rates of UTD P2 and UTD P3 were higher than those of UTD P0 and UTD P1 (P < 0.001). Lastly, we concluded that the first follow-up should be less than 7 days, the first assessment should be 2 months, and the follow up should be at least once every 3 months. CONCLUSION: Children with prenatal HN have been found many malformations in early postnatal period, and with high-grade UTD were more prone to recurrent UTI, even to surgery. So, prenatal HN with malformations and high-grade UTD should be followed up in early postnatal period regularly.


Assuntos
Hidronefrose , Infecções Urinárias , Sistema Urinário , Criança , Gravidez , Feminino , Humanos , Lactente , Estudos Retrospectivos , Hidronefrose/complicações , Hidronefrose/diagnóstico por imagem , Infecções Urinárias/complicações , Infecções Urinárias/epidemiologia , Dilatação Patológica
8.
Proc Natl Acad Sci U S A ; 117(26): 14712-14720, 2020 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-32554498

RESUMO

Lithium sulfur batteries (LSBs) are promising next-generation rechargeable batteries due to the high gravimetric energy, low cost, abundance, nontoxicity, and high sustainability of sulfur. However, the dissolution of high-order polysulfide in electrolytes and low Coulombic efficiency of Li anode require excess electrolytes and Li metal, which significantly reduce the energy density of LSBs. Quasi-solid-state LSBs, where sulfur is encapsulated in the micropores of carbon matrix and sealed by solid electrolyte interphase, can operate under lean electrolyte conditions, but a low sulfur loading in carbon matrix (<40 wt %) and low sulfur unitization (<70%) still limit the energy density in a cell level. Here, we significantly increase the sulfur loading in carbon to 60 wt % and sulfur utilization to ∼87% by dispersing sulfur in an oxygen-rich dense carbon host at a molecular level through strong chemical interactions of C-S and O-S. In an all-fluorinated organic lean electrolyte, the C/S cathode experiences a solid-state lithiation/delithiation reaction after the formation of solid electrolyte interphase in the first deep lithiation, completely avoiding the shuttle reaction. The chemically stabilized C/S composite retains a high reversible capacity of 541 mAh⋅g-1 (based on the total weight of the C/S composite) for 200 cycles under lean electrolyte conditions, corresponding to a high energy density of 974 Wh⋅kg-1 The superior electrochemical performance of the chemical bonding-stabilized C/S composite renders it a promising cathode material for high-energy and long-cycle-life LSBs.

9.
Nano Lett ; 22(18): 7535-7544, 2022 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-36070490

RESUMO

The rechargeability of aqueous zinc metal batteries is plagued by parasitic reactions of the zinc metal anode and detrimental morphologies such as dendritic or dead zinc. To improve the zinc metal reversibility, hereby we report a new solution structure of aqueous electrolyte with hydroxyl-ion scavengers and hydrophobicity localized in solvent clusters. We show that although hydrophobicity sounds counterintuitive for an aqueous system, hydrophilic pockets may be encapsulated inside a hydrophobic outer layer, and a hydrophobic anode-electrolyte interface can be generated through the addition of a cation-philic, strongly anion-phobic, and OH--reactive diluent. The localized hydrophobicity enables less active water and less absorbed water on the Zn anode surface, which suppresses the parasitic water reduction; while the hydroxyl-ion-scavenging functionality further minimizes undesired passivation layer formation, thus leading to superior reversibility (an average Zn plating/stripping efficiency of 99.72% for 1000 cycles) and lifetime (80.6% capacity retention after 5000 cycles) of zinc batteries.


Assuntos
Eletrólitos , Zinco , Ânions , Cátions , Interações Hidrofóbicas e Hidrofílicas , Solventes , Água
10.
Bull Environ Contam Toxicol ; 111(5): 66, 2023 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-37904018

RESUMO

As one of the most widely used herbicides in agricultural industry, the residues of glyphosate (GLY) are frequent environmental pollutants. Freshwater planarian Dugesia japonica has been developed as a model for neurotoxicology. In this study, the effects of GLY on locomotion and feeding behavior, as well as neuroenzyme activities and mRNA expressions of D. japonica were determined. Additionally, histochemical localization was executed to explore the damage to the central nervous system (CNS) of planarians stressed by GLY. The results showed that the locomotor velocity, ingestion rate and the neuroenzyme activity were inhibited and the gene expressions were altered. Also, histo-architecture injury to CNS of planarians upon GLY exposure in a time-dependent manner was observed. Collectively, our results indicate that GLY can cause neurotoxicity to freshwater planarians representing as reduction in locomotor velocity and feeding rate by disturbing the neurotransmission systems and damaging the structure of CNS.


Assuntos
Planárias , Animais , Planárias/genética , Glicina/toxicidade , Glicina/metabolismo , Glifosato
11.
Respir Res ; 23(1): 51, 2022 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-35248022

RESUMO

BACKGROUND: With an increase in the diagnosis of plastic bronchitis (PB) cases, to enhance paediatricians' knowledge and add to the few existing studies, we explored the clinical characteristics, diagnosis, and treatment of PB in children. METHODS: The clinicopathological data of 43 children admitted to the Xiamen Children's Hospital and the Women and Children's Hospital, affiliated to the Xiamen University from December 2016 to December 2019, were retrospectively analysed. RESULTS: All the children had cough, with 41 of them having associated fever. A peak temperature > 40 â„ƒ was observed in 25 children. Twenty-six children had shortness of breath, 27 had reduced respiratory sounds on the affected side, and 35 had audible moist rales on the affected side. Lactate dehydrogenase in all children increased to different degrees, and 29 had elevated D-dimer and fibrinogen degradation products. Lung imaging showed pulmonary consolidation and atelectasis, mainly in the bilateral lower lung lobes, in all the children. However, 31 had pleural effusion, mainly a small parapneumonic effusion. The infections were mainly caused by adenovirus and Mycoplasma pneumoniae. The casts in all 43 children were sucked or clamped out under bronchoscopy, and 10 were found to have type I PB on pathological examination. All children were treated with anti-infective therapy in addition to bronchoscopic cast removal. Thirty-one children were treated with methylprednisolone, and 16 with gamma globulin. Except for one child who was non-adherent to treatment, all other children showed improvement, or were cured and discharged from the hospital. Follow-up lung imaging at 3 months revealed that the lungs were fully re-expanded in 40 children. At the 6-month follow-up, six children had small airway lesions, four had obliterative bronchiolitis, and one had bronchiectasis. CONCLUSIONS: Paediatric PB often occurs secondary to respiratory tract infections and progresses rapidly, with hyperpyrexia, cough, and shortness of breath as the main clinical manifestations. Pulmonary consolidation, atelectasis, and pleural effusion are seen on lung imaging, and early bronchoscopy and removal of casts in the trachea and bronchi are effective treatment options.


Assuntos
Brônquios/diagnóstico por imagem , Bronquite/diagnóstico , Broncoscopia/métodos , Radiografia Torácica/métodos , Tomografia Computadorizada por Raios X/métodos , Biópsia/métodos , Bronquite/epidemiologia , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Masculino , Estudos Retrospectivos
12.
BMC Nephrol ; 23(1): 250, 2022 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-35836154

RESUMO

BACKGROUND: Glomerulopathy with fibronectin deposits (GFND) is a rare autosomal dominant genetic disorder, and proteinuria and hematuria are the most common clinical manifestations. The pathogenesis of this disease is primarily related to mutation of the fibronectin 1 gene. Unfortunately, without specific treatment, the prognosis remains poor. Here we present a case report that investigates the clinical characteristics, renal pathology, and gene testing of childhood GFND. CASE PRESENTATION: A two-year-old child was brought to our hospital for "persistent hematuria for 1 year and 10 months." The disease onset was at the age of 4 months, with persistent microscopic hematuria accompanied by intermittent gross hematuria, occasionally with proteinuria, and without hypertension or renal failure. The chief complaint was intermittent gross hematuria, without massive proteinuria, hypertension, or renal failure. Family history: The child's mother had microscopic hematuria, his maternal aunt had nephrotic syndrome due to focal segmental glomerulosclerosis, and his maternal grandmother had end-stage renal disease. No significant pathological changes were found in the renal pathological biopsy of the child under a light microscope. Under the electron microscope, the basement membrane was found to be of uneven thickness, ranging from 150 to 400 nm. The stratum compactum of the basement membrane was thickened, with a small part showing tear-like and cobweb-like morphology. No electron-dense deposits were found. The renal tubular epithelial cells were vacuolated, and there were no unique pathological changes in the renal interstitium. Immunofluorescence showed that IgG, IgM, IgA, C3, and C1q were all negative. Alport syndrome was preliminarily considered. However, exome sequencing revealed a mutated site in the fibronectin 1 gene. The child's mother was the carrier of the pathogenic gene and the final diagnosis was GFND. CONCLUSIONS: Fibronectin deposition is a typical pathological change in GFND, and the disease progresses slowly to end-stage renal disease. There is no specific treatment so far, and the prognosis is poor. The early onset of childhood patients may not show typical renal pathological changes, but only changes in the thickness of basement membrane, etc. Genome sequencing technology may helpful for the early diagnosis of GFND.


Assuntos
Hipertensão , Falência Renal Crônica , Nefrite Hereditária , Insuficiência Renal , Biópsia/efeitos adversos , Criança , Pré-Escolar , Fibronectinas/genética , Glomerulonefrite Membranoproliferativa , Hematúria/complicações , Hematúria/genética , Humanos , Hipertensão/complicações , Lactente , Falência Renal Crônica/complicações , Mutação/genética , Nefrite Hereditária/complicações , Proteinúria/complicações , Insuficiência Renal/complicações
13.
Angew Chem Int Ed Engl ; 61(35): e202205967, 2022 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-35789166

RESUMO

LiNix Coy Mnz O2 (x+y+z=1)||graphite lithium-ion battery (LIB) chemistry promises practical applications. However, its low-temperature (≤ -20 °C) performance is poor because the increased resistance encountered by Li+ transport in and across the bulk electrolytes and the electrolyte/electrode interphases induces capacity loss and battery failures. Though tremendous efforts have been made, there is still no effective way to reduce the charge transfer resistance (Rct ) which dominates low-temperature LIBs performance. Herein, we propose a strategy of using low-polarity-solvent electrolytes which have weak interactions between the solvents and the Li+ to reduce Rct , achieving facile Li+ transport at sub-zero temperatures. The exemplary electrolyte enables LiNi0.8 Mn0.1 Co0.1 O2 ||graphite cells to deliver a capacity of ≈113 mAh g-1 (98 % full-cell capacity) at 25 °C and to remain 82 % of their room-temperature capacity at -20 °C without lithium plating at 1/3C. They also retain 84 % of their capacity at -30 °C and 78 % of their capacity at -40 °C and show stable cycling at 50 °C.

14.
J Am Chem Soc ; 143(8): 3143-3152, 2021 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-33595314

RESUMO

Metal anodes represent as a prime choice for the coming generation rechargeable batteries with high energy density. However, daunting challenges including electrode volume variation and inevitable side reactions preclude them from becoming a viable technology. Here, a facile replacement reaction was employed to fabricate a three-dimensional (3D) interdigitated metal/solid electrolyte composite electrode, which not only provides a stable host structure for buffering the volume change within the composite but also prevents side reactions by avoiding the direct contact between active metal and liquid electrolyte. As a proof-of-concept demonstration, a 3D interdigitated zinc (Zn) metal/solid electrolyte architecture was fabricated via a galvanic replacement reaction between Zn metal foil and indium (In) chloride solution followed by electrochemical activation, featuring the interdigitation between metallic Zn and amorphous indium hydroxide sulfate (IHS) with high Zn2+ conductivity (56.9 ± 1.8 mS cm-1), large Zn2+ transference number (0.55), and high electronic resistivity [(2.08 ± 0.01) × 103 Ω cm]. The as-designed Zn/IHS electrode sustained stable electrochemical Zn plating/stripping over 700 cycles with a record-low overpotential of 8 mV at 1 mA cm-2 and 0.5 mAh cm-2. More impressively, it displayed cycle-stable performance with low overpotential of 10 mV under ultrahigh current density and areal capacity (20 mA cm-2, 20 mAh cm-2), which outperformed all the reported Zn metal electrodes in mild aqueous electrolyte. The fabrication of interdigitated metal/solid electrolyte was generalized to other metal pairs, including Zn/Sn and Zn/Co, which provide inspiration for next-generation Zn metal batteries with high energy density and reversibility.

15.
Angew Chem Int Ed Engl ; 60(40): 22026-22034, 2021 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-34378281

RESUMO

Anionic redox is an effective way to boost the energy density of layer-structured metal-oxide cathodes for rechargeable batteries. However, inherent rigid nature of the TMO6 (TM: transition metals) subunits in the layered materials makes it hardly tolerate the inner strains induced by lattice glide, especially at high voltage. Herein, P2-Na0.8 Mg0.13 [Mn0.6 Co0.2 Mg0.07 □0.13 ]O2 (□: TM vacancy) is designed that contains vacancies in TM sites, and Mg ions in both TM and sodium sites. Vacancies make the rigid TMO6 octahedron become more asymmetric and flexible. Low valence Co2+ /Co3+ redox couple stabilizes the electronic structure, especially at the charged state. Mg2+ in sodium sites can tune the interlayer spacing against O-O electrostatic repulsion. Time-resolved in situ X-ray diffraction confirms that irreversible structure evolution is effectively suppressed during deep desodiation benefiting from the specific configuration. X-ray absorption spectroscopy (XAS) and density functional theory (DFT) calculations demonstrate that, deriving from the intrinsic vacancies, multiple local configurations of "□-O-□", "Na-O-□", "Mg-O-□" are superior in facilitating the oxygen redox for charge compensation than previously reported "Na-O-Mg". The resulted material delivers promising cycle stability and rate capability, with a long voltage plateau at 4.2 V contributed by oxygen, and can be well maintained even at high rates. The strategy will inspire new ideas in designing highly stable cathode materials with reversible anionic redox for sodium-ion batteries.

16.
Angew Chem Int Ed Engl ; 60(34): 18845-18851, 2021 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-34196094

RESUMO

Aqueous Zn batteries promise high energy density but suffer from Zn dendritic growth and poor low-temperature performance. Here, we overcome both challenges by using an eutectic 7.6 m ZnCl2 aqueous electrolyte with 0.05 m SnCl2 additive, which in situ forms a zincophilic/zincophobic Sn/Zn5 (OH)8 Cl2 ⋅H2 O bilayer interphase and enables low temperature operation. Zincophilic Sn decreases Zn plating/stripping overpotential and promotes uniform Zn plating, while zincophobic Zn5 (OH)8 Cl2 ⋅H2 O top-layer suppresses Zn dendrite growth. The eutectic electrolyte has a high ionic conductivity of ≈0.8 mS cm-1 even at -70 °C due to the distortion of hydrogen bond network by solvated Zn2+ and Cl- . The eutectic electrolyte enables Zn∥Ti half-cell a high Coulombic efficiency (CE) of >99.7 % for 200 cycles and Zn∥Zn cell steady charge/discharge for 500 h with a low overpotential of 8 mV at 3 mA cm-2 . Practically, Zn∥VOPO4 batteries maintain >95 % capacity with a CE of >99.9 % for 200 cycles at -50 °C, and retain ≈30 % capacity at -70 °C of that at 20 °C.

17.
Angew Chem Int Ed Engl ; 60(15): 8258-8267, 2021 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-33480154

RESUMO

Manganese-rich layered oxide materials hold great potential as low-cost and high-capacity cathodes for Na-ion batteries. However, they usually form a P2 phase and suffer from fast capacity fade. In this work, an O3 phase sodium cathode has been developed out of a Li and Mn-rich layered material by leveraging the creation of transition metal (TM) and oxygen vacancies and the electrochemical exchange of Na and Li. The Mn-rich layered cathode material remains primarily O3 phase during sodiation/desodiation and can have a full sodiation capacity of ca. 220 mAh g-1 . It delivers ca. 160 mAh g-1 specific capacity between 2-3.8 V with >86 % retention over 250 cycles. The TM and oxygen vacancies pre-formed in the sodiated material enables a reversible migration of TMs from the TM layer to the tetrahedral sites in the Na layer upon de-sodiation and sodiation. The migration creates metastable states, leading to increased kinetic barrier that prohibits a complete O3-P3 phase transition.

18.
J Am Chem Soc ; 142(51): 21404-21409, 2020 12 23.
Artigo em Inglês | MEDLINE | ID: mdl-33290658

RESUMO

Aqueous Zn batteries are promising energy storage devices for large-scale energy-storage due to low cost and high energy density. However, their lifespan is limited by the water decomposition and Zn dendrite growth. Here, we suppress water reduction and Zn dendrite growth in dilute aqueous electrolyte by adding dimethyl sulfoxide (DMSO) into ZnCl2-H2O, in which DMSO replaces the H2O in Zn2+ solvation sheath due to a higher Gutmann donor number (29.8) of DMSO than that (18) of H2O. The preferential solvation of DMSO with Zn2+ and strong H2O-DMSO interaction inhibit the decomposition of solvated H2O. In addition, the decomposition of solvated DMSO forms Zn12(SO4)3Cl3(OH)15·5H2O, ZnSO3, and ZnS enriched-solid electrolyte interphase (SEI) preventing Zn dendrite and further suppressing water decomposition. The ZnCl2-H2O-DMSO electrolyte enables Zn anodes in Zn||Ti half-cell to achieve a high average Coulombic efficiency of 99.5% for 400 cycles (400 h), and the Zn||MnO2 full cell with a low capacity ratio of Zn:MnO2 at 2:1 to deliver a high energy density of 212 Wh/kg (based on both cathode and anode) and maitain 95.3% of the capacity over 500 cycles at 8 C.

19.
J Am Chem Soc ; 142(19): 8918-8927, 2020 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-32319764

RESUMO

Li-rich layered-oxide cathodes have the highest theoretical energy density among all the intercalated cathodes, which have attracted intense interests for high-energy Li-ion batteries. However, O3-structured layered-oxide cathodes suffer from a low initial Coulombic efficiency (CE), severe voltage fade, and poor cycling stability because of the continuous oxygen release, structural rearrangements due to irreversible transition-metal migration, and serious side reactions between the delithiated cathode and electrolyte. Herein, we report that these challenges are migrated by using a stable O2-structured Li1.2Ni0.13Co0.13Mn0.54O2 (O2-LR-NCM) and all-fluorinated electrolyte. The O2-LR-NCM can restrict the transition metals migrating into the Li layer, and the in situ formed fluorinated cathode-electrolyte interphase (CEI) on the surface of the O2-LR-NCM from the decomposition of all-fluorinated electrolyte during initial cycles effectively restrains the structure transition, suppresses the O2 release, and thereby safeguards the transition metal redox couples, enabling a highly reversible and stable oxygen redox reaction. O2-LR-NCM in all fluorinated electrolytes achieves a high initial CE of 99.82%, a cycling CE of >99.9%, a high reversible capacity of 278 mAh/g, and high capacity retention of 83.3% after 100 cycles. The synergic design of electrolyte and cathode structure represents a promising direction to stabilize high-energy cathodes.

20.
Med Sci Monit ; 26: e921510, 2020 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-32238796

RESUMO

BACKGROUND SOX7 exerts a repressing effect against tumors and imposes vital influences on malignancies. Our research discussed the importance of SOX7 in breast cancer prognoses. MATERIAL AND METHODS SOX7 mRNA expression in breast cancer tissues samples and matched adjacent normal controls of breast cancer patients was measured by quantitative real-time-polymerase chain reaction (qRT-PCR). The relationship of SOX7 with clinicopathological characteristics were analyzed via chi-square test. The association of SOX7 levels with clinical outcomes was evaluated adopting the Kaplan-Meier method and multivariate Cox proportional hazards regression model. RESULTS SOX7 mRNA degree of expression exhibited a declining tendency in breast cancer tissue compared to paired bordering normal tissue specimens (P<0.001). In addition, the reduced SOX7 degree of expression had a strong correlation to larger cancer mass dimension (P=0.006) and lymph node metastasis (P=0.001). Survival analysis revealed that the overall survival (OS) time was much shorter among cases harboring low SOX7 degree of expression compared to high degree of expression (P=0.005). Moreover, SOX7 expression alone could predict OS among breast cancer patients (hazard ratio=3.956, 95% confidence interval=1.330-11.772, P=0.013). CONCLUSIONS SOX7 expression was downregulated in breast cancer tissues, and it could function as a useful prognostic marker in breast cancer.


Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Reação em Cadeia da Polimerase em Tempo Real/métodos , Fatores de Transcrição SOXF/metabolismo , Biomarcadores Tumorais/genética , Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , Regulação para Baixo , Feminino , Perfilação da Expressão Gênica , Humanos , Metástase Linfática , Prognóstico , Modelos de Riscos Proporcionais , Fatores de Transcrição SOXF/genética , Análise de Sobrevida
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA