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1.
J Environ Sci (China) ; 138: 671-683, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38135430

RESUMO

Developing high-efficiency photothermal seawater desalination devices is of significant importance in addressing the shortage of freshwater. Despite much effort made into photothermal materials, there is an urgent need to design a rapidly synthesized photothermal evaporator for the comprehensive purification of complex seawater. Therefore, we report on all-in-one FeOx-rGO photothermal sponges synthesized via solid-phase microwave thermal shock. The narrow band gap of the semiconductor material Fe3O4 greatly reduces the recombination of electron-hole pairs, enhancing non-radiative relaxation light absorption. The abundant π orbitals in rGO promote electron excitation and thermal vibration between the lattices. Control of the surface hydrophilicity and hydrophobicity promotes salt resistance while simultaneously achieving the purification of various complex polluted waters. The optimized GFM-3 sponge exhibitedan enhanced photothermal conversion rate of 97.3% and a water evaporation rate of 2.04 kg/(m2·hr), showing promising synergistic water purification properties. These findings provide a highly efficient photothermal sponge for practical applicationsof seawater desalination and purification,as well as develop a super-rapid processing methodology for evaporation devices.


Assuntos
Purificação da Água , Água , Micro-Ondas , Água do Mar , Água Doce , Elétrons
2.
ACS Nano ; 17(20): 20689-20698, 2023 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-37796083

RESUMO

The successful substitution of Li metal for the conventional intercalation anode can promote a significant increase in the cell energy density. However, the practical application of the Li metal anode has long been fettered by the unstable solid electrolyte interface (SEI) layer on the Li metal surface and notorious dendritic Li growth. Herein, a stabilized SEI layer with in situ constructed fast ion transport channels has successfully been achieved by a robust In2S3-cemented poly(vinyl alcohol) coating. The modified Li metal demonstrates significantly enhanced Coulombic efficiency, high rate performance (10 mA cm-2), and ultralong life cycling stability (∼4900 cycles). The Li|LiCoO2 (LCO) cell presents an ultralong-term stable operation over 500 cycles at 1 C with an extremely low capacity decay rate (∼0.018% per cycle). And the Li|LCO full cell with the ultrahigh loading cathode (∼25 mg cm-2) and ultrathin Li foil (∼40 µm) also reveals a prolonged cycling performance under the low negative-to-positive capacity ratio of 2.2. Furthermore, the Li|LCO pouch cell with a commercial cathode and ultrathin Li foil still manifests excellent cycling performance even under the harsh conditions of limited Li metal and lean electrolyte. This work provides a cost-effective and scalable strategy toward high performance practical Li metal batteries.

3.
Polymers (Basel) ; 15(9)2023 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-37177373

RESUMO

In this study, three-dimensional (3D) bioactive glass/lignocellulose (BG/cellulose) composite scaffolds were successfully fabricated by the 3D-bioprinting technique with N-methylmorpholine-N-oxide (NMMO) as the ink solvent. The physical structure, morphology, mechanical properties, hydroxyapatite growth and cell response to the prepared BG/cellulose scaffolds were investigated. Scanning electron microscopy (SEM) images showed that the BG/cellulose scaffolds had uniform macropores of less than 400 µm with very rough surfaces. Such BG/cellulose scaffolds have excellent mechanical performance to resist compressive force in comparison with pure cellulose scaffolds and satisfy the strength requirement of human trabecular bone (2-12 MPa). Furthermore, BG significantly increased the excellent hydroxyapatite-forming capability of the cellulose scaffolds as indicated by the mineralization of the scaffolds in simulated body fluid (SBF). The BG/cellulose scaffolds showed low cytotoxicity to human bone marrow mesenchymal stem cells (hBMSCs) in the CCK8 assay. The cell viability reached maximum (percent of the control group) when the weight ratio of cellulose to BG was 2 in the scaffold. Therefore, the 3D-printed BG/cellulose scaffolds show a potential application in the field of bone tissue engineering.

4.
ACS Appl Mater Interfaces ; 15(15): 19043-19054, 2023 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-37027815

RESUMO

The poor electrochemical reaction kinetics of Li polysulfides is a key barrier that prevents the Li-S batteries from widespread applications. Ni single atoms dispersed on carbon matrixes derived from ZIF-8 are a promising type of catalyst for accelerating the conversion of active sulfur species. However, Ni favors a square-planar coordination that can only be doped on the external surface of ZIF-8, leading to a low loading amount of Ni single atoms after pyrolysis. Herein, we demonstrate an in situ trapping strategy to synthesize Ni and melamine-codoped ZIF-8 precursor (Ni-ZIF-8-MA) by simultaneously introducing melamine and Ni during the synthesis of ZIF-8, which can remarkably decrease the particle size of ZIF-8 and further anchor Ni via Ni-N6 coordination. Consequently, a novel high-loading Ni single-atom (3.3 wt %) catalyst implanted in an N-doped nanocarbon matrix (Ni@NNC) is obtained after high-temperature pyrolysis. This catalyst as a separator modifier shows a superior catalytic effect on the electrochemical transitions of Li polysulfides, which endows the corresponding Li-S batteries with a high specific capacity of 1232.4 mA h g-1 at 0.3 C and an excellent rate capability of 814.9 mA h g-1 at 3 C. Furthermore, a superior areal capacity of 4.6 mA h cm-2 with stable cycling over 160 cycles can be achieved under a critical condition with a low electrolyte/sulfur ratio (8.4 µL mg-1) and high sulfur loading (4.85 mg cm-2). The outstanding electrochemical performances can be attributed to the strong adsorption and fast conversion of Li polysulfides on the highly dense active sites of Ni@NNC. This intriguing work provides new inspirations for designing high-loading single-atom catalysts applied in Li-S batteries.

5.
Chem Rec ; 23(6): e202200211, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36193960

RESUMO

Industrial waste gas emissions from fossil fuel over-exploitation have aroused great attention in modern society. Recently, metal-organic frameworks (MOFs) have been developed in the capture and catalytic conversion of industrial exhaust gases such as SO2 , H2 S, NOx , CO2 , CO, etc. Based on these resourceful conversion applications, in this review, we summarize the crucial role of the surface, interface, and structure optimization of MOFs for performance enhancement. The main points include (1) adsorption enhancement of target molecules by surface functional modification, (2) promotion of catalytic reaction kinetics through enhanced coupling in interfaces, and (3) adaptive matching of guest molecules by structural and pore size modulation. We expect that this review will provide valuable references and illumination for the design and development of MOF and related materials with excellent exhaust gas treatment performance.


Assuntos
Estruturas Metalorgânicas , Resíduos Industriais , Adsorção , Catálise , Gases
6.
Polymers (Basel) ; 14(24)2022 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-36559801

RESUMO

In this study, we printed three-dimensional (3D) titanium dioxide (TiO2)/chitin/cellulose composite photocatalysts with ordered interconnected porous structures. Chitin microparticles were mixed with cellulose in the N-methylmorpholine-N-oxide (NMMO) solution to prepare the printing "ink". TiO2 nanoparticles were embedded on the chitin/cellulose composite in the NMMO removal process by water before the freeze-drying process to build the 3D cellulosic photocatalysts with well-defined porous structures. The 3D-printed TiO2/chitin/cellulose composites were characterized by X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and Energy Disperse Spectroscopy (EDS). The XRD and FTIR analyses showed that chitin had an interference effect on the crystal regeneration of cellulose and resulted in a large amount of amorphous phase. The SEM images show that the printed cellulosic strands had a hollow structure, and the EDS analysis showed that TiO2 nanoparticles were embedded on the chitin/cellulose composite surfaces. In the photocatalytic degradation process of methylene blue (MB) dye in an aqueous solution, the TiO2/chitin/cellulose 3D composite photocatalysts demonstrated efficient MB degradation activities with excellent reusability and stability, in which the chitin content performed the function of adjusting the MB degradation efficiency.

7.
ACS Nano ; 16(11): 18058-18070, 2022 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-36259968

RESUMO

O3-Type layered oxides are widely studied as cathodes for sodium-ion batteries (SIBs) due to their high theoretical capacities. However, their rate capability and durability are limited by tortuous Na+ diffusion channels and complicated phase evolution during Na+ extraction/insertion. Here we report our findings in unravelling the mechanism for dramatically enhancing the stability and rate capability of O3-NaNi0.5Mn0.5-xSbxO2 (NaNMS) by substitutional Sb doping, which can alter the coordination environment and chemical bonds of the transition metal (TM) ions in the structure, resulting in a more stable structure with wider Na+ transport channels. Furthermore, NaNMS nanoparticles are obtained by surface energy regulation during grain growth. The synergistic effect of Sb doping and nanostructuring greatly reduces the ionic migration energy barrier while increasing the reversibility of the structural evolution during repeated Na+ extraction/insertion. An optimized NaNMS-1 electrode delivers a reversible capacity of 212.3 mAh g-1 at 0.2 C and 74.5 mAh g-1 at 50 C with minimal capacity loss after 100 cycles at a low temperature of -20 °C. Such electrochemical performance is superior to most of the reported layered oxide cathodes used in rechargeable SIBs.

8.
ACS Appl Mater Interfaces ; 14(32): 37059-37067, 2022 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-35938577

RESUMO

Highly conductive corrosion protection coatings are necessary for metallic bipolar plates (BPs) of the proton-exchange membrane fuel cell. Graphene coatings have the potential of protecting metal substrates from corrosion without obscuring their excellent electrical conductivity. The electron transfer in the coatings facilitates the formation of galvanic cells, so the challenge is to block the mass transfer of the corrosion process. Here, we constructed highly compacted hybrid coatings with aligned water-dispersible graphene layers. The water-dispersible graphene (SG) held an electrical conductivity of >270 S cm-1 while providing an unprecedented dispersibility, which can be redispersed from filter cake with a concentration of 120 mg mL-1 or even dry state. The cohesion of the hybrid coatings was attributed to the interaction between highly aligned SG layers and the heterointerface between SG and polydopamine (PDA), as proven by the molecular dynamics simulations. The hybrid coatings presented a corrosion current density of 0.023 µA cm-2 and an interfacial contact resistance of 9.94 mΩ cm2, which meets the requirements of corrosion protection and electron transfer for the coatings on metallic BPs. The water-based fabrication method of the graphene-dominated hybrid coatings was a promising alternative of the vacuum-based deposition method for industrial production.

9.
PLoS One ; 17(8): e0272956, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35994471

RESUMO

Road accidents are one of the primary causes of death worldwide; hence, they constitute an important research field. Taiwan is a small country with a high-density population. It particularly has a considerable number of locomotives. Furthermore, Taiwan's traffic accident fatality rate increased by 23.84% in 2019 compared with 2018, primarily because of human factors. Road safety has long been a challenging problem in Taiwanese cities. This study collected public data pertaining to traffic accidents from the Taoyuan city government in Taiwan and generated six datasets based on the various accident frequencies at the same location. To find key attributes, this study proposes a three-stage dimension reduction to filter attributes, which includes removing multicollinear attributes, the integrated attribute selection method, and statistical factor analysis. We applied five rule-based classifiers to classify six different frequency datasets and generate the rules of accident severity. The order of top ten key attributes was hit vehicle > certificate type > vehicle > action type > drive quality > escape > accident type > gender > job > trip purposes in the maximum accident frequency CF ≥ 10 dataset. When locomotives, bicycles, and people collide with other locomotives or trucks, injury or death can easily occur, and the motorcycle riders are at the highest risk. The findings of this study provide a reference for governments and stakeholders to reduce the road accident risk factors.


Assuntos
Lesões Acidentais , Acidentes de Trânsito/prevenção & controle , Humanos , Veículos Automotores , Fatores de Risco , Taiwan/epidemiologia
10.
J Colloid Interface Sci ; 626: 59-67, 2022 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-35780552

RESUMO

Despite of great interests in aqueous asymmetric supercapacitors (ASC), their performance is often restricted by unsatisfactory specific capacitance of anode materials. Herein, accordion-like V2CTx MXene has been prepared and exploited as novel anode material for aqueous ASC in neutral ZnSO4 electrolyte. Profitting from the layered structure with expanded interlayer distance, the V2CTx electrode exhibits a high specific capacitance of 481F g-1 at 1 A g-1, a reasonable rate performance and intriguing cycling stability with capacitance retention of 84.3% after 60,000 cycles at 10 A g-1 in 2 M ZnSO4 electrolyte. Furthermore, an ASC device based on the V2CTx as anode and activated carbon (AC) as cathode was successfully assembled in the ZnSO4 electrolyte, which achieves a wide potential window up to 1.8 V. Remarkably, the V2CTx//AC ASC delivers a high energy density of 34 W h kg-1 at a power density of 954 W kg-1, as well as superb cycling stability with capacitance retention of 79% even after 100,000 charge/discharge cycles at 10 A g-1. The intriguing electrochemical performance, especially the ultralong cycling life, make the V2CTx MXene electrode promising in aqueous energy storage devices.

11.
Plant Sci ; 323: 111383, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35850285

RESUMO

It is well documented that the CO/NF-YB/NF-YC trimer (NF-Y-CO) binds and regulates the FT promoter. However, the FT/TFL1-like (FLOWERING LOCUS T/TERMINALFLOWER1-like) genes in gymnosperms are all flowering suppressors, and the regulation model of NF-Y in gymnosperms is different from that in angiosperms. Here, using Chinese pine (Pinus tabuliformis), we identified a CONSTANS-LIKE gene, PtCOL5, the expression of which was strongly induced during cones development and it functioned as a repressor of flowering. PtNF-YC4, which interacted with PtCOL5, was highly correlated with PtCOL5 during growth and development, has been demonstrated. Moreover, PtNF-YC4 and PtCOL5 can bind to PtTFL2 promoter, and their interaction can enhance PtTFL2 expression. Interestingly, we found PtNF-YC4 and PtCOL5 were involved in gibberellin signaling and their interaction was inhibited by PtDELLA protein, thus affecting PtTFL2 expression. Collectively, PtCOL5-PtNF-YC4 was involved in reproductive cone development and gibberellin signaling in Chinese pine. Our findings uncovered reproductive cone development and signal transduction mechanism of COL-NF-Y in gymnosperms.


Assuntos
Regulação da Expressão Gênica de Plantas , Pinus , China , Flores/genética , Giberelinas , Pinus/genética , Pinus/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Transdução de Sinais
12.
Adv Sci (Weinh) ; 9(8): e2104391, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35289134

RESUMO

Li metal is considered as one of the most promising candidates for constructing advanced high-energy energy storage due to its ultrahigh theoretical capacity and lowest electrochemical potential. However, its practical commercialization is seriously hindered by the challenges of Li dendrite growth, low Coulombic efficiency, and huge volumetric variation. Herein, an efficient in situ generated Li2 S-rich interface layer joint with preplanted Sb nano active sites in hosted Li metal anode is easily achieved with the nanosized Sb2 S3 decorated carbonaceous network. The yielded CC@Sb2 S3 @Li anode demonstrates uniform Li deposition, high Coulombic efficiency, and alleviated volumetric variation. Therefore, the Li symmetric cells show ultralong lifespan stable cycling over 3200 cycles with a very low voltage hysteresis (≈18 mV) at 5 mA cm-2 . Impressively, the Li|LiFePO4 full cell delivers an exceptionally prolonged cycling over 180 cycles with a superior capacity retention as high as ≈90% even under the harsh condition of an extremely low negative to positive capacity ratio of ≈0.44 with lean electrolyte (4.4 µL mAh-1 ). Moreover, the Li|LiNi0.5 Co0.2 Mn0.3 O2 full cell also maintains an excellent cycling performance under the more realistic harsh conditions. This work provides a new avenue and significant step paving the Li metal toward the practical application.

13.
Cell ; 185(1): 204-217.e14, 2022 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-34965378

RESUMO

Conifers dominate the world's forest ecosystems and are the most widely planted tree species. Their giant and complex genomes present great challenges for assembling a complete reference genome for evolutionary and genomic studies. We present a 25.4-Gb chromosome-level assembly of Chinese pine (Pinus tabuliformis) and revealed that its genome size is mostly attributable to huge intergenic regions and long introns with high transposable element (TE) content. Large genes with long introns exhibited higher expressions levels. Despite a lack of recent whole-genome duplication, 91.2% of genes were duplicated through dispersed duplication, and expanded gene families are mainly related to stress responses, which may underpin conifers' adaptation, particularly in cold and/or arid conditions. The reproductive regulation network is distinct compared with angiosperms. Slow removal of TEs with high-level methylation may have contributed to genomic expansion. This study provides insights into conifer evolution and resources for advancing research on conifer adaptation and development.


Assuntos
Epigenoma , Evolução Molecular , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Pinus/genética , Aclimatação/genética , Cromossomos de Plantas/genética , Cycadopsida/genética , Elementos de DNA Transponíveis/genética , Florestas , Redes Reguladoras de Genes , Tamanho do Genoma , Genômica/métodos , Íntrons , Magnoliopsida/genética
14.
ACS Nano ; 15(12): 20287-20299, 2021 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-34817165

RESUMO

Even though lithium-sulfur (Li-S) batteries have made much progress in terms of the delivered specific capacity and cycling stability by the encapsulation of sulfur within conductive carbon matrixes or polar materials, challenges such as low active sulfur utilization and unacceptable Coulombic efficiency are still hindering their commercial use. Herein, a lithium-rich conjugated sulfur-incorporated, polymeric material based on poly(Li2S6-r-1,3-diisopropenylbenzene) (DIB) is developed as a cathode material for high rate and stable Li-S batteries. Motivated by extra Li+ ions affording fast Li+ redox kinetics across the conjugated aromatic backbones, the Li-rich sulfur-based copolymer exhibits high delivery capacities (934 mAh g-1 at 120 cycles), impressive rate capabilities (727 mAh g-1 even under a current of 2 A g-1), and long electrochemical cycling performance over 500 cycles. Moreover, by use of the elastic nature and thermoplastic properties of the sulfur-incorporated, polymeric material, a prototype of a flexible Li-S pouch cell is constructed by using a poly(Li2S6-r-DIB) copolymer cathode and paired with the flexible carbon cloth/Si/Li anode, which exhibits stable electrochemical performance (658 mAh g-1 after 100 cycles) and operational capability even under folding at various angle (30°, 60°, 90°, 120°, 150°, 180°). This work extends the molecular-design approach to obtaining a high-performance organosulfur cathode material by introducing extra Li+ ions to promote redox kinetics, which provides valuable guidance for the development of high-performance Li-S batteries for practical applications.

15.
Nanoscale ; 13(36): 15343-15351, 2021 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-34494627

RESUMO

Ti3C2Tx, as novel members of the two-dimensional material family, hold great promise for electrochemical energy storage and catalysis, however, the electrochemical performance of Ti3C2Tx is largely limited by the self-restacking of their layers due to van der Waals forces. In this study, we report a high-performance electrode material, Ti3C2Tx supported Fe3O4 nanoplates (denoted as MXene-Fe), synthesized by a simple in situ wet chemistry method in a solvothermal system. The mesoporous MXene-Fe material as a supercapacitor electrode exhibits a high specific capacitance of 368.0 F g-1 at 1.0 A g-1 and long cycling stability with about 81% capacitance retention after 10 000 cycles at 10.0 A g-1. Moreover, the optimized MXene-Fe also displays high electrocatalytic activity and stability toward the oxygen evolution reaction in alkaline solution (1.0 M KOH) with a low overpotential of 290 mV at 10 mA cm-2 and a small Tafel slope of 65.1 mV dec-1. This work provides an effective strategy for developing novel Ti3C2Tx-based functional materials with outstanding electrochemical performance for supercapacitors and electrocatalysis.

16.
Molecules ; 26(12)2021 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-34201358

RESUMO

Polyacrylonitrile (PAN)-based porous carbon was prepared by different methods of activation with PAN polymer microsphere as precursor. The morphology, structure and electrical properties for supercapacitor of the porous carbon were investigated. It was found that the morphology of PAN nanospheres tended to be destroyed in the process of one-step activation (activation and carbonization were carried out simultaneously, and could only be retained when the amount of activating agent KOH was small). While the spherical morphology could be well reserved during the two-step activation method (carbonization and activation sequentially). The specific surface area and pore volume increased first and then decreased, with the increase in activation holding time for both one-step and two-step activation methods. The specific surface area reached the maximum value with 2430 m2 g-1 for the one-step activation method and 2830 m2 g-1 for the two-step activation method. Additionally, their mass-specific capacitances were 178.8 F g-1 and 160.2 F g-1, respectively, under the current density of 1 A g-1. After 2000 cycles, the specific capacitance retentions were 92.9% and 91.3%.

17.
Educ Technol Res Dev ; 69(5): 2589-2613, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34220171

RESUMO

This mixed-methods study explored K-12 teachers' feelings, experiences, and perspectives regarding online teaching during the COVID-19 pandemic. The study also examined teachers' perspectives of the "new normal" after COVID-19 and of what should be done to better prepare teachers for future emergencies. Both quantitative and qualitative data were collected from an online survey and follow-up interviews. A total of 107 teachers from 25 different states in the United States completed the online survey, and 13 teachers from 10 different states participated in the follow-up interviews. The results revealed teachers' feelings about online teaching and various strategies and tools they used during the early stage of the COVID-19 pandemic. The major challenges faced by teachers during the pandemic included lack of student participation and engagement (or lack of parental support), students without access to technology, concerns about students' well-being, no face-to-face interactions with students, no work-life balance, and learning new technology. Four major themes emerged regarding how to better prepare teachers for future emergencies: (1) professional development for online learning, (2) technology access, (3) technology training for both teachers and students, and (4) action plans and communication. Regarding teachers' perspectives of the "new normal," five major themes emerged: (1) more online or blended learning, (2) rethinking normal, (3) hygiene and social distancing, (4) smaller classes and different school schedules, and (5) uncertainty and concerns about the "new normal."

18.
Polymers (Basel) ; 13(14)2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-34301081

RESUMO

With the development of integrated devices, the local hot spot has become a critical problem to guarantee the working efficiency and the stability. In this work, we proposed an innovative approach to deliver graphene foam/polyaniline@epoxy composites (GF/PANI@EP) with improvement in the thermal and mechanical property performance. The graphene foam was firstly modified by the grafting strategy of p-phenylenediamine to anchor reactive sites for further in-situ polymerization of PANI resulting in a conductive network. The thermal conductivity (κ) and electromagnetic interference shielding (EMI) performance of the optimized GF/PANI4:1@EP is significantly enhanced by 238% and 1184%, respectively, compared to that of pristine EP with superior reduced modulus and hardness. Such a method to deliver GF composites can not only solve the agglomeration problem in traditional high content filler casting process, but also provides an effective way to build up conductive network with low density for thermal management of electronic devices.

19.
Adv Sci (Weinh) ; 8(16): e2100899, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34075725

RESUMO

Rational structure design is a successful approach to develop high-performance composite solid electrolytes (CSEs) for solid-state Li metal batteries. Herein, a novel CSE membrane is proposed, that consists of interwoven garnet/polyethylene oxide-Li bis(trifluoromethylsulphonyl)imide (LLZO/PEO-LiTFSI) microfibers. This CSE exhibits high Li-ion conductivity and exceptional Li dendrite suppression capability, which can be attributed to the uniform LLZO dispersion in PEO-LiTFSI and the vertical/horizontal anisotropic Li-ion conduction in the CSE. The uniform LLZO particles can generate large interaction regions between LLZO and PEO-LiTFSI, which thus form continuous Li-ion transfer pathways, retard the interfacial side reactions and strengthen the deformation resistance. More importantly, the anisotropic Li-ion conduction, that is, Li-ion transfers much faster along the microfibers than across the microfibers, can effectively homogenize the electric field distribution in the CSE during cycling, which thus prevents the excessive concentration of Li-ion flux. Finally, solid-state Li||LiFePO4 cells based on this CSE show excellent electrochemical performances. This work enriches the structure design strategy of high-performance CSEs and may be helpful for further pushing the solid-state Li metal batteries towards practical applications.

20.
Nanoscale ; 13(18): 8658-8664, 2021 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-33949558

RESUMO

Fiber-shaped supercapacitors (FSCs) are promising power sources for wearable electronic devices due to their small size, excellent flexibility and deformability. The performance of FSCs has been severely affected by the framework of the fibrous electrodes and the interface between the electrode materials and current collector. Herein, we propose an ingenious strategy that combines anodizing etching and CVD methods to transform the less-active titanium wires into unique hierarchical carbon/TiO2 nanotube/Ti (CTNT) core-sheath wires, which have high conductivity, good mechanical strength and porous structure on the surface. CTNT wires can be used not only as a high-performance electrode, but also as an ideal substrate for depositing active materials. We have demonstrated the deposition of MnO2 and MoS2 on the surface of CTNT to prepare MnO2@CTNT and MoS2@CTNT core-sheath composite wires through electrochemical deposition and hydrothermal reaction, respectively. The specific areal capacitance of a single wire (MoS2@CTNT) can reach up to 557.83 mF cm-2 in a three-electrode system. Two such wires were further used as electrodes for making an all-solid-state asymmetric fiber-shaped supercapacitor (AFSC). The prepared AFSC has a wide voltage window of 2.7 V, a large areal capacitance of 121.42 mF cm-2 and an excellent energy density of 74.37 µW h cm-2. It also shows good rate performance and stability, and even after 10 000 cycles of charging and discharging, a capacitance retention rate of 76.5% can be achieved.

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