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1.
Cryobiology ; 114: 104846, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38295926

RESUMO

Petunia × Calibrachoa 'Light Yellow' (× Petchoa 'Light Yellow') is a kind of perennial herbaceous flower obtained through intergeneric hybridization of Petunia and Calibrachoa with high ornamental value and wide application, facing challenges in seed acquisition. Expanding propagation through tissue culture is an economically efficient means. Hence, establishing an effective procedure for the storage of callus is essential for × Petchoa 'Light Yellow'. Cryopreservation is an effective method for the in vitro propagation and long-term preservation of × Petchoa 'Light Yellow' germplasms. For formulating the optimization of the vitrification procedure, first, an orthogonal experimental design was employed to pinpoint critical steps in the vitrification protocol (pre-culture, osmoprotection, dehydration, and dilution) for Petunia × Calibrachoa callus tissues and then five additional factors (pre-culture, osmoprotection I and II, dehydration, and dilution) were optimized to further reduce the sample water content and enhance cell viability levels. The vitrification procedure was described as follows: callus tissues were precultured in MS solid medium with 0.3 M sucrose for 5 d, incubated with osmoprotection solution I and II for 15 min at 25 °C, respectively, cryoprotected with PVS2 for 30 min at 0 °C, and rapidly immersed in liquid nitrogen. Cryopreserved callus tissues were then diluted in MS liquid medium with 1.2 M sucrose for 20 min at 25 °C and recovered on MS solid medium with 0.5 mg/L 6-BA and 0.1 mg/L NAA, and sucrose. The cell viability measured by TTC staining was approximately 16 %-18 % after 72 h-recovery. Following 45 days, the relative survival of callus reached up to 49.48 %. Furthermore, EST-SSR analysis showed no significant difference in the genetic stability of cryopreserved callus compared to the control. Based on the cryopreservation of × Petchoa 'Light Yellow' callus, we further evaluated the response of callus water contents to the osmotic stress in the optimized and original protocols (CK) for a higher cryopreservation survival. A comparative analysis of water content demonstrated that the procedure of gradual and gentle dehydration significantly improved water content and cell survival. Ultrastructural changes between cryopreserved and non-cryopreserved callus were examined and high vacuolation emerged as a key determinant, indicating its substantial impact on the low survival of cryopreserved cells, which should help us to understand the effectiveness of osmotic protectants in dehydration.


Assuntos
Criopreservação , Petunia , Criopreservação/métodos , Crioprotetores/farmacologia , Desidratação , Vitrificação , Sacarose , Água , Brotos de Planta/fisiologia
2.
Ecotoxicol Environ Saf ; 279: 116470, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38772147

RESUMO

Several studies have suggested an association between exposure to various metals and the onset of type 2 diabetes (T2D). However, the results vary across different studies. We aimed to investigate the associations between serum metal concentrations and the risk of developing T2D among 8734 participants using a prospective cohort study design. We utilized inductively coupled plasmamass spectrometry (ICP-MS) to assess the serum concentrations of 27 metals. Cox regression was applied to calculate the hazard ratios (HRs) for the associations between serum metal concentrations on the risk of developing T2D. Additionally, 196 incident T2D cases and 208 healthy control participants were randomly selected for serum metabolite measurement using an untargeted metabolomics approach to evaluate the mediating role of serum metabolite in the relationship between serum metal concentrations and the risk of developing T2D with a nested casecontrol study design. In the cohort study, after Bonferroni correction, the serum concentrations of zinc (Zn), mercury (Hg), and thallium (Tl) were positively associated with the risk of developing T2D, whereas the serum concentrations of manganese (Mn), molybdenum (Mo), barium (Ba), lutetium (Lu), and lead (Pb) were negatively associated with the risk of developing T2D. After adding these eight metals, the predictive ability increased significantly compared with that of the traditional clinical model (AUC: 0.791 vs. 0.772, P=8.85×10-5). In the nested casecontrol study, a machine learning analysis revealed that the serum concentrations of 14 out of 1579 detected metabolites were associated with the risk of developing T2D. According to generalized linear regression models, 7 of these metabolites were significantly associated with the serum concentrations of the identified metals. The mediation analysis showed that two metabolites (2-methyl-1,2-dihydrophthalazin-1-one and mestranol) mediated 46.81% and 58.70%, respectively, of the association between the serum Pb concentration and the risk of developing T2D. Our study suggested that serum Mn, Zn, Mo, Ba, Lu, Hg, Tl, and Pb were associated with T2D risk. Two metabolites mediated the associations between the serum Pb concentration and the risk of developing T2D.


Assuntos
Diabetes Mellitus Tipo 2 , Metais , Humanos , Diabetes Mellitus Tipo 2/sangue , Estudos Prospectivos , Masculino , Feminino , Pessoa de Meia-Idade , China , Metais/sangue , Adulto , Idoso , Poluentes Ambientais/sangue , Estudos de Coortes , Metabolômica , Estudos de Casos e Controles , Tálio/sangue , Exposição Ambiental/estatística & dados numéricos , População do Leste Asiático
3.
Zhongguo Zhong Yao Za Zhi ; 48(9): 2512-2521, 2023 May.
Artigo em Chinês | MEDLINE | ID: mdl-37282880

RESUMO

This study aimed to demonstrate the effect of Banxia Baizhu Tianma Decoction(BBTD) on realizing withdrawal of anti-epileptic drugs and explore the relationship between BBTD and the amino acid metabolism by transcriptomic analysis in the rat model of epilepsy induced by lithium chloride-pilocarpine. The rats with epilepsy were divided into a control group(Ctrl), an epilepsy group(Ep), a BBTD & antiepileptic drug integrative group(BADIG), and an antiepileptic drug withdrawal group(ADWG). The Ctrl and Ep were given ultrapure water by gavage for 12 weeks. The BADIG was given BBTD extract and carbamazepine solution by gavage for 12 weeks. The ADWG was given carbamazepine solution and BBTD extract by gavage for the former 6 weeks, and then only given BBTD extract for the latter 6 weeks. The therapeutic effect was evaluated by behavioral observation, electroencephalogram(EEG), and hippocampal neuronal morphological changes. High-throughput sequencing was used to obtain amino acid metabolism-related differen-tial genes in the hippocampus, and the mRNA expression in the hippocampus of each group was verified by real-time quantitative polymerase chain reaction(RT-qPCR). The hub genes were screened out through protein-protein interaction(PPI) network, and Gene Ontology(GO) functional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment analysis were performed. Two ceRNA networks, namely circRNA-miRNA-mRNA and lncRNA-miRNA-mRNA, were constructed for ADWG vs BADIG. The experimental results showed that compared with those in Ep, rats in ADWG were significantly improved in the behavioral observation, EEG, and hippocampal neuronal impairment. Thirty-four amino acid metabolism-related differential genes were obtained by transcriptomic analysis, and the sequencing results were confirmed by RT-qPCR. Eight hub genes were obtained through PPI network, involving several biological processes, molecular functions, and signal pathways related to amino acid metabolism. Finally, the circRNA-miRNA-mRNA ternary transcription network of 17 circRNA, 5 miRNA, and 2 mRNA, and a lncRNA-miRNA-mRNA ternary network of 10 lncRNA, 5 miRNA, and 2 mRNA were constructed in ADWG vs BADIG. In conclusion, BBTD can effectively achieve the withdrawal of antiepileptic drugs, which may be related to the transcriptomic regulation of amino acid metabolism.


Assuntos
MicroRNAs , RNA Longo não Codificante , Ratos , Animais , RNA Circular/genética , Transcriptoma , RNA Longo não Codificante/genética , Anticonvulsivantes , MicroRNAs/genética , RNA Mensageiro , Carbamazepina , Aminoácidos , Redes Reguladoras de Genes
4.
Int J Mol Sci ; 22(9)2021 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-34063617

RESUMO

A lot of researches have been focused on the evolution and function of MYB transcription factors (TFs). For revealing the formation of petunia flower color diversity, MYB gene family in petunia was identified and analyzed. In this study, a total of 155 MYB genes, including 40 1R-MYBs, 106 R2R3-MYBs, 7 R1R2R3-MYBs and 2 4R-MYBs, have been identified in the Petunia axillaris genome. Most R2R3 genes contain three exons and two introns, whereas the number of PaMYB introns varies from 0 to 12. The R2R3-MYB members could be divided into 28 subgroups. Analysis of gene structure and protein motifs revealed that members within the same subgroup presented similar exon/intron and motif organization, further supporting the results of phylogenetic analysis. Genes in subgroup 10, 11 and 21 were mainly expressed in petal, not in vegetative tissues. Genes in subgroup 9, 19, 25 and 27 expressed in all tissues, but the expression patterns of each gene were different. According to the promoter analysis, five R2R3-MYB and two MYB-related genes contained MBSI cis-element, which was involved in flavonoid biosynthetic regulation. PaMYB100/DPL has been reported to positively regulate to pigmentation. However, although PaMYB82, PaMYB68 and Pa1RMYB36 contained MBSI cis-element, their function in flavonoid biosynthesis has not been revealed. Consistent with existing knowledge, PaMYBs in subgroup 11 had similar function to AtMYBs in subgroup 6, genes in which played an important role in anthocyanin biosynthesis. In addition, PaMYB1 and PaMYB40 belonged to P9 (S7) and were potentially involved in regulation of flavonoid synthesis in petunia vegetative organs. This work provides a comprehensive understanding of the MYB gene family in petunia and lays a significant foundation for future studies on the function and evolution of MYB genes in petunia.


Assuntos
Antocianinas/biossíntese , Genes myb/genética , Petunia/genética , Fatores de Transcrição/genética , Antocianinas/genética , Proteínas de Arabidopsis/genética , Flores/genética , Regulação da Expressão Gênica de Plantas , Genoma de Planta/genética , Família Multigênica/genética , Filogenia , Pigmentação/genética , Plantas Geneticamente Modificadas/genética , Regiões Promotoras Genéticas , Fatores de Transcrição/classificação , Fatores de Transcrição/isolamento & purificação
5.
Angew Chem Int Ed Engl ; 60(7): 3781-3790, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33176045

RESUMO

Despite of the good stability with Li-metal, Li6.75 La3 Zr1.75 Ta0.25 O12 (LLZTO) suffers from large interfacial resistance and severe Li-metal penetration. Herein, a dual layer ceramic electrolyte of Ti-doped LLZTO(Ti-LLZTO)/LLZTO was developed, with the reducible Ti-LLZTO layer contacting Li-metal and the LLZTO layer contacting cathode. The identical crystal structures of Ti-LLZTO and LLZTO enables a seamless contact and a barrierless Li+ transport between them. The densities of Ti-LLZTO pellets are higher than that of LLZTO. With an in situ reduction of Ti-LLZTO by Li-metal, the interfacial wettability was improved and a mixed ion-electron conducting layer was created. Both features help to reduce defects/pores on interface and homogenize the interfacial ionic/electronic flux, facilitating the reduction of interfacial resistance and suppression of dendrites. With the help of Ti-LLZTO layer, long-term stable lithium plating/stripping was reached in an areal capacity of 3.0 mAh cm-2 .

6.
J Am Chem Soc ; 142(42): 18035-18041, 2020 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-32986953

RESUMO

Superionic conductors with ionic conductivity on the order of mS cm-1 are expected to revolutionize the development of solid-state batteries (SSBs). However, currently available superionic conductors are limited to only a few structural families such as garnet oxides and sulfide-based glass/ceramic. Interfaces in composite systems such as alumina in lithium iodide have long been identified as a viable ionic conduction channel, but practical superionic conductors employing the interfacial conduction mechanism are yet to be realized. Here we report a novel method that creates continuous interfaces in the bulk of composite thin films. Ions can conduct through the interface, and consequently, the inorganic phase can be ionically insulating in this type of bulk interface superionic conductors (BISCs). Ionic conductivities of lithium, sodium, and magnesium ion BISCs have reached 1.16 mS cm-1, 0.40 mS cm-1, and 0.23 mS cm-1 at 25 °C in 25 µm thick films, corresponding to areal conductance as high as 464 mS cm-2, 160 mS cm-2, and 92 mS cm-2, respectively. Ultralow overpotential and stable long-term cycling for up to 5000 h were obtained for solid-state Li metal symmetric batteries employing Li ion BISCs. This work opens new structural space for superionic conductors and urges for future investigations on detailed conduction mechanisms and material design principles.

7.
Phys Chem Chem Phys ; 19(4): 2940-2949, 2017 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-28079211

RESUMO

Tuning the composition of discharge products is an important strategy to reduce charge potential, suppress side reactions, and improve the reversibility of metal-oxygen batteries. In the present study, first-principles calculations and experimental confirmation were performed to unravel the influence of O2 pressure, particle size, and electrolyte on the composition of charge products in Na-O2 batteries. The electrolytes with medium and high donor numbers (>12.5) are favorable for the formation of sole NaO2, while those with low donor numbers (<12.5) may permit the formation of Na2O2 by disproportionation reactions. Our comparative experiments under different electrolytes confirmed the calculation prediction. Our calculations indicated that O2 pressure and particle size hardly affect discharge products. On the electrode, only one-electron-transfer electrochemical reaction to form NaO2 takes place, whereas two-electron-transfer electrochemical and chemical reactions to form Na2O2 and Na3O4 are prevented in thermodynamics. The present study explains why metastable NaO2 was identified as a sole discharge product in many experiments, while thermodynamically more stable Na2O2 was not observed. Therefore, to achieve low overpotential, a high-donor-number electrolyte should be applied in the discharge processes of Na-O2 batteries.

8.
Acta Chim Slov ; 63(3): 489-95, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27640376

RESUMO

The space charge layer (SCL) effects were initially developed to explain the anomalous conductivity enhancement in composite ionic conductors. They were further extended to qualitatively as well as quantitatively understand the interfacial phenomena in many other ionic-conducting systems. Especially in nanometre-scale systems, the SCL effects could be used to manipulate the conductivity and construct artificial conductors. Recently, existence of such effects either at the electrolyte/cathode interface or at the interfaces inside the composite electrode in all solid state lithium batteries (ASSLB) has attracted attention. Therefore, in this article, the principle of SCL on basis of defect chemistry is first presented. The SCL effects on the carrier transport and storage in typical conducting systems are reviewed. For ASSLB, the relevant effects reported so far are also reviewed. Finally, the perspective of interface engineer related to SCL in ASSLB is addressed.

9.
Phys Chem Chem Phys ; 16(29): 15646-52, 2014 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-24958445

RESUMO

Metal-air batteries are thought to be the ultimate solution for energy storage systems owing to their high energy density. Here we report a long-life Na-O2 battery with a high capacity of 750 mA h g(carbon)(-1) by manipulating the nucleation and growth of nano-sized NaO2 particles in a vertically aligned carbon nanotubes (VACNTs) network with a large surface area. Benefiting from the kinetically favorable formation of NaO2 reaction with a low overpotential of ~0.2 V, the electrical energy efficiency is as high as 90% for up to 100 cycles. A good rate performance (~1500 mA h g(carbon)(-1) at 667 mA g(carbon)(-1)) can be achieved through pre-deposition of a thin NaO2 layer. This study encourages the exploration of the key factors influencing the performance of metal-air batteries, as well as Na-based batteries characterized by phase transformation or conversion reactions.

10.
J Colloid Interface Sci ; 665: 582-591, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38552575

RESUMO

The polyacrylonitrile (PAN) is an attractive matrix of polymer electrolytes owing to its wide electrochemical window and strong coordination with Li salts. However, the PAN-based electrolytes undergo severe interfacial problems from both cathode and anode sides, including uneven ionic transfer induced by high rigidity of dry PAN-based polymer, as well as inferior stability against Li-metal anode. Herein, the composition regulation of PAN-based electrolytes is proposed by introducing succinonitrile (SN) plastic crystal and LiNO3 salt for the construction of interfacially stable solid-state lithium batteries. The plastic nature of SN enables the rapid ionic transfer in electrolytes, along with the establishment of conformally interfacial contacts. Meanwhile, a stable solid-electrolyte-interface (SEI) layer consisting of Li3N and LiNO2 is in-situ formed at Li/electrolyte interface, contributing to the inhibition of uncontrol reactions between PAN and Li-metal. Consequently, the resultant Li symmetric cell delivers an extended critical current density of 1.7 mA cm-2 and an outstanding cycling lifespan of 700 h at 0.1 mA cm-2. Moreover, the corresponding solid-state LiNi0.6Co0.2Mn0.2O2/Li full cell shows an initial discharge capacity of 161 mAh/g followed by an outstanding capacity retention of 88.7 % after 100 cycles at 0.1C. This work paves the way for application of PAN-based electrolytes in the field of solid-state batteries by facile composition regulation.

11.
ACS Appl Mater Interfaces ; 16(32): 42995-43005, 2024 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-39092637

RESUMO

The use of solid electrolytes (SE) in solid-state batteries holds the promise of achieving higher energy densities and enhancing safety. However, current solid-state batteries face significant interface impedance issues, mainly dealing with the effect of the evolution of the solid-solid interface on ion transport. Semi-solid-state batteries (SSB), containing a small amount of liquid electrolyte, serve as appropriate transitional products in the development process of solid-state batteries. More importantly, the clarity of the relevant interface dynamics can provide theoretical guidance for the subsequent all-solid-state batteries. Therefore, this paper investigates SSB through Electrochemical Impedance Spectroscopy (EIS), primarily employing a combination of theoretical modeling, simulation predictions, and experimental analyses to elucidate the complex electrochemical processes within these batteries. Based on detailed exploration of the complex electrochemical processes within SSB, we have discovered additional electrochemical processes beyond Li+ penetration through the solid-electrolyte interphase (SEI) film and charge transfer. We attribute the additional electrochemical reaction processes to the resistance present at the SE/SEI interface of SSB on account of numerical analysis and interface characterization. Furthermore, this interface resistance exhibits a trend of initial decrease followed by continuous increase, elucidating the attribution and numerical variations of various impedance components within the EIS. The application of EIS techniques to analyze ion transport processes in SSB serves as a suitable transition toward achieving all-solid-state batteries as well as provides guidance for subsequent interface optimization of solid-state batteries and propels their transition from laboratory experimentation to commercialization.

12.
ACS Appl Mater Interfaces ; 16(26): 33388-33395, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38912593

RESUMO

All-solid-state lithium (Li) batteries have attracted considerable interest due to their potential in high energy density as well as safety. However, the realization of a stable Li/solid-state electrolyte (SSE) interface remains challenging. Herein, two-dimensional graphene-like C3N4 (g-C3N4) as a coating layer on Li1.3Al0.3Ti1.7(PO4)3 (LATP) electrolyte (LATP@CN) has been applied to construct the stable Li/SSE interface. The g-C3N4 layer is uniformly coated on the LATP surface using the in situ calcination method, which not only enhances the dispersibility of LATP particles in poly(ethylene oxide) (PEO) through the interaction between surface functional groups but also suppresses the side reactions between Li and LATP. The coating layer can effectively improve the interfacial stability. As a result, the conductivity and stability of the obtained composite solid-state electrolytes (CSEs) against Li are enhanced. The Li∥CSEs∥Li symmetric cells stably cycle for 670 and 600 h at 0.1 and 0.2 mA cm-2, respectively. The Li∥CSEs∥LiFePO4 cells stably cycle more than 100 times at 0.1 and 0.2 C with a capacity retention rate of about 86% and 88%, respectively. This work inspires a new strategy to avoid the reactions between LATP and Li.

13.
Nano Lett ; 12(3): 1241-6, 2012 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-22304487

RESUMO

The thermodynamically required redistribution of ions at given interfaces is being paid increased attention. The present investigation of the contact LiF/TiO(2) offers a highly worthwhile example, as the redistribution processes can be predicted and verified. It consists in Li ion transfer from LiF into the space charge zones of TiO(2). We not only can measure the resulting increase of lithium vacancy conductivity in LiF, we also observe a transition from n- to p-type conductivity in TiO(2) in consistency with the generalized space charge model.


Assuntos
Fluoretos/química , Compostos de Lítio/química , Lítio/química , Membranas Artificiais , Modelos Químicos , Nanoestruturas/química , Semicondutores , Titânio/química , Absorção , Simulação por Computador , Íons , Modelos Moleculares , Nanoestruturas/ultraestrutura , Tamanho da Partícula , Eletricidade Estática
14.
ChemSusChem ; 16(2): e202201801, 2023 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-36401564

RESUMO

Solid lithium batteries (SLBs) have received much attention due to their potential to achieve secondary batteries with high energy density and high safety. The solid electrolyte (SE) is believed to be the essential material for SLBs. Among the recent SEs, composite electrolytes have good interfacial compatibility and customizability, which have been broadly investigated as promising contenders for commercial SLBs. The high Li+ transference number (t Li + ${{_{{\rm Li}{^{+}}}}}$ ) of composite electrolytes is critically important concerning the power/energy density and cycling life of SLBs, however, which is often overlooked. This Review presents a current opinion on the key factors in high t Li + ${{_{{\rm Li}{^{+}}}}}$ composite electrolytes, including polymers, Li-salts, inorganic fillers, and additives. Various strategies concerning providing a continuous pathway for Li-ions and immobilizing anions via component interaction are discussed. This Review highlights the major obstacles hindering the development of high t Li + ${{_{{\rm Li}{^{+}}}}}$ composite electrolytes and proposes future research directions for developing composite electrolytes with high t Li + ${{_{{\rm Li}{^{+}}}}}$ .

15.
J Nanosci Nanotechnol ; 12(1): 213-7, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22523968

RESUMO

Amorphous Ge nanotubes, featured of a top-closed tubular structure, were synthesized directly on metallic current collector substrates via a template technique. Measurement of electrochemical cycling reveals that these nanotubes can deliver reversible capacities of -1300 mAh/g (81% of the theoretical capacity) at the current density of C/20 (1C = 1600 mAh/g) and retain -700 mAh/g at 2C with columbic efficiencies over 99%. Such performance is comparable to that of the recently reported Ge nanowire anodes grown directly on the metallic substrates by the chemical vapor deposition, indicating that the present Ge nanotubes are a type of anode materials with high capacity and good rate performance for lithium storage.


Assuntos
Germânio/química , Lítio/química , Lítio/isolamento & purificação , Nanotubos/química , Nanotubos/ultraestrutura , Absorção , Cristalização/métodos , Substâncias Macromoleculares/química , Teste de Materiais , Conformação Molecular , Tamanho da Partícula , Propriedades de Superfície
16.
ACS Appl Mater Interfaces ; 14(21): 24929-24937, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35594362

RESUMO

High-energy density and safe solid lithium batteries call for cathodes with high capacity and good kinetic properties. In this work, LiNi0.6Co0.2Mn0.2O2 (NCM622) cathodes are coated with the ionic-electronic dual-conductive polymers composed of poly(ethylene glycol) (PEG)-doped polyaniline (PANI). Scanning electron microscopy, transmission electron microscopy, Fourier transform infrared, and thermogravimetric analysis reveal that the dual-conductive polymers are homogeneously coated on the surfaces of NCM622 cathodes with a thickness of approximately 10 nm. The solid-state lithium batteries consisting of the NCM622 cathodes coated with PANI-PEG show a specific capacity of 158 mA h g-1 and a retention rate of 88% after 100 cycles at the rate of 0.1 C and room temperature, which are superior to the discharge capacity of 153 mA h g-1 and capacity retention of 59% after 100 cycles for the batteries with the pristine NCM622 cathodes. Moreover, the cells with the coated cathodes display a better rate performance of 84 mA h g-1 at 1 C than those with the uncoated ones which show a rate performance of 11 mA h g-1 at 1 C.

17.
Chem Commun (Camb) ; 58(62): 8638-8641, 2022 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-35820145

RESUMO

An ionic-electronic dual-conductive polymer, fabricated by doping polyethylene glycol into polyaniline, is used to modify LiCoO2 cathodes for solid lithium batteries. The polymer enables uniform and fast conductive networks in cathodes and stabilizes the generation of cathode interface layers. The cell maintains high cycle stability of 91.8% capacity retention after 200 cycles.

18.
ACS Appl Mater Interfaces ; 13(8): 9856-9864, 2021 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-33595270

RESUMO

The gel polymer electrolyte (GPE) is the key to assembling high-performance solid-state supercapacitors (SSCs). The commercial poly(vinyl alcohol) (PVA) GPE has developed a reputation due to low ionic conductivity endowed by its high crystallinity and poor water retention capacity. In this work, density functional theory (DFT) calculations first revealed that the high crystallinity of PVA can be greatly disrupted by forming hydrogen bonds with natural agarose macromolecules. The hydrogen bond interpenetrated three-dimensional agarose/PVA network offers high water retention and large amounts of channels for movement of Li+ on hydroxyl oxygen atoms. So, an optimized formation of the Li-O coordinate bond (gLi-O(r) = 8.78) and improved diffusion coefficient of Li+ (DLi+) (71 × 10-6 cm2 s-1) were obtained in the agarose/PVA model. When assembled into SSCs, agarose/PVA-GPE with 2 M LiOAc (AP-GPE) exhibits an outstanding specific capacitance (697.22 mF cm-2 at 5 mA cm-2). The high water retention of agarose and large amounts of -OH groups in the agarose macromolecular can generate H2O by dehydration reaction, reducing the flammability of PVA and greatly enhancing the safety of SSCs.

19.
ACS Appl Mater Interfaces ; 13(12): 14321-14326, 2021 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-33749227

RESUMO

Li2CO3 is a ubiquitous byproduct in Li-air (O2) batteries, and its accumulation on the cathode could be detrimental to the devices. As a result, much efforts have been devoted to investigating its formation and decomposition, in particular, upon cycling of Li-O2 batteries. At high voltages, Li2CO3 is expected to decompose into CO2 and O2. However, as recognized from the work of many authors, only CO2, and no O2, has been identified, and the underlying mechanism remains uncertain so far. Herein, a solid-state Li-O2 battery (Li|Li6.4La3Zr1.4Ta0.6O12|Au) has been designed to interrogate the Li2CO3 oxidation without interferences from the decomposition of other battery components (organic electrolyte, binder, and carbon cathode) widely applied in conventional Li-O2 batteries. It is revealed that Li2CO3 can indeed be oxidized to CO2 and O2 in a more stable solid-state Li-O2 battery configuration, highlighting the feasibility of reversible operation of Li-O2 batteries with ambient air as the feeding gas.

20.
ACS Appl Mater Interfaces ; 13(33): 39157-39164, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34378380

RESUMO

All-solid Li-O2 batteries have been constructed with Ag nanowire (AgNW) cathodes coated on Au-buffered garnet ceramic electrolytes and Li anodes on the other sides. Benefiting from the clean contacts of Li+, e-, and O2 on the AgNWs, the surface pathway reactions are demonstrated. Upon discharge, two types of Li2O2 morphologies appear. The film-like Li2O2 forms around the smooth surfaces of AgNWs, and hollow disk-like Li2O2 forms at the joints in between the AgNWs as well as at the garnet/AgNW interfaces. The formation of films and hollow disks is in accordance with the process of O2 + Li+ + e- → LiO2 and 2LiO2 → Li2O2 + O2, indicating that the disproportionation of LiO2 occurs at the solid interfaces. During the initial charge, decomposition occurs below the potential of 3.5 V, indicating the process of Li2O2 → LiO2 + Li+ + e- and LiO2 → Li+ + e- + O2 rather than Li2O2 → 2Li+ + 2e- + O2. The Li2O2 decomposition starts at the AgNWs/Li2O2 interfaces, causing the film-like Li2O2 to shrink and the gas to release, followed by the collapse of hollow disk-like Li2O2. The results here clearly disclose the Li-O2 reaction mechanism at the all-solid interfaces, facilitating a deep understanding of key factors influencing the electrochemical performance of the solid-state Li-O2 batteries.

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