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1.
Angew Chem Int Ed Engl ; 63(17): e202400619, 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38403860

RESUMO

The unstable interface between Li metal and ethylene carbonate (EC)-based electrolytes triggers continuous side reactions and uncontrolled dendrite growth, significantly impacting the lifespan of Li metal batteries (LMBs). Herein, a bipolar polymeric protective layer (BPPL) is developed using cyanoethyl (-CH2CH2C≡N) and hydroxyl (-OH) polar groups, aiming to prevent EC-induced corrosion and facilitating rapid, uniform Li+ ion transport. Hydrogen-bonding interactions between -OH and EC facilitates the Li+ desolvation process and effectively traps free EC molecules, thereby eliminating parasitic reactions. Meanwhile, the -CH2CH2C≡N group anchors TFSI- anions through ion-dipole interactions, enhancing Li+ transport and eliminating concentration polarization, ultimately suppressing the growth of Li dendrite. This BPPL enabling Li|Li cell stable cycling over 750 cycles at 10 mA cm-2 for 2 mAh cm-2. The Li|LiNi0.8Mn0.1Co0.1O2 and Li|LiFePO4 full cells display superior electrochemical performance. The BPPL provides a practical strategy to enhanced stability and performance in LMBs application.

2.
Angew Chem Int Ed Engl ; 63(10): e202318516, 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38241198

RESUMO

In this work, full-color and stable white organic afterglow materials with outstanding water, organic solvents, and temperature resistances have been developed for the first time by embedding the selected polycyclic aromatic hydrocarbons into melamine-formaldehyde polymer via solution polymerization. The afterglow quantum yields and lifetimes of the resulting polymer films were up to 22.7 % and 4.83 s, respectively, under ambient conditions. For the coronene-doped sample, its afterglow color could be linearly tuned between yellow and blue by adjusting the temperature, and it could still emit an intense blue afterglow with a lifetime of 0.68 s at 440 K. Moreover, the films showed a bright and stable white afterglow at 370 K with a lifetime of 2.80 s and maintained an excellent afterglow performance after soaking in water and organic solvents for more than 150 days. In addition, the application potential of the polymer films in information encryption and anti-counterfeiting was also demonstrated.

3.
Small ; 20(8): e2305576, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37821400

RESUMO

Garnet solid electrolyte Li6.4 La3 Zr1.4 Ta0.6 O12 (LLZTO) is an excellent inorganic ceramic-type solid electrolyte; however, the presence of Li2 CO3 impurities on its surface hinders Li-ion transport and increases the interface impedance. In contrast to traditional methods of mechanical polishing, acid corrosion, and high-temperature reduction for removing Li2 CO3 , herein, a straightforward "waste-to-treasure" strategy is proposed to transform Li2 CO3 into Li3 PO4 and LiF in LiPF6 solution under 60 °C. It is found that the formation of Li3 PO4 during LLZTO pretreatment facilitates rapid Li-ion transport and enhances ionic conductivity, and the LLZTO/PAN composite polymer electrolyte shows the highest Li-ion transference number of 0.63. Additionally, the dense LiF layer serves to safeguard the internal garnet solid electrolyte against solvent decomposition-induced chemical adsorption. Symmetric Li/Li cells assembled with treated LLZTO/PAN composite electrolyte exhibit a critical current density of 1.1 mA cm-2 and a long lifespan of up to 700 h at a current density of 0.2 mA cm-2 . The Li/LiFePO4 solid-state cells demonstrate stable cycling performances for 141 mAh g-1 at 0.5 C, with capacity retention of 93.6% after 190 cycles. This work presents a novel approach to converting waste into valuable resources, offering the advantages of simple processes, and minimal side reactions.

4.
ACS Appl Mater Interfaces ; 15(33): 39896-39904, 2023 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-37555378

RESUMO

Developing polymer-based organic afterglow materials with switchable ultralong organic phosphorescence (UOP) that are insensitive to moisture remains challenging. Herein, two organic luminogens, BBCC and BBCS, were synthesized by attaching 7H-benzo[c]carbazole (BBC) to benzophenone and diphenyl sulfone. These two emitters were employed as guest molecules and doped into epoxy polymers (EPs), which were constructed by in situ polymerization to achieve polymer materials BBCC-EP and BBCS-EP. It was found that BBCC-EP and BBCS-EP films exhibited significant photoactivated UOP properties. After light irradiation, they could produce a conspicuous organic afterglow with phosphorescence quantum yields and lifetimes up to 5.35% and 1.91 s, respectively. Meanwhile, BBCS-EP also presented photochromic characteristics. Upon thermal annealing, the UOP could be turned off, and the polymer films recovered to their pristine state, showing switchable organic afterglow. In addition, BBCC-EP and BBCS-EP displayed excellent water resistance and still produced obvious UOP after soaking in water for 4 weeks. Inspired by the unique photoactivated UOP and photochromic properties, BBCC and BBCS in the mixtures of diglycidyl ether of bisphenol A (DGEBA) and 1,3-propanediamine were employed as security inks for light-controlled multilevel anticounterfeiting. This work may provide helpful guidance for developing photostimuli-responsive polymer-based organic afterglow materials, especially those with stable UOP under ambient conditions.

5.
Food Chem ; 428: 136800, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37433252

RESUMO

Developing potentially toxic metal ion probes is significant for environment and food safety. Although Hg2+ probes have been extensively studied, small molecule fluorophores that can integrate two applications of visual detection and separation into one unit remain challenging to access. Herein, by incorporating triphenylamine (TPA) into tridentate skeleton with an acetylene bridge, 2,6-bisbenzimidazolpyridine-TPA (4a), 2,6-bisbenzothiazolylpyridine-TPA (4b) and 2,6-bisbenzothiazolylpyridine-TPA (4c) were first constructed, expectably showing distinct solvatochromism and dual-state emission properties. Since the diverse emission properties, the fluorescence detection of 4a-4b can be achieved with an ultrasensitive response (LOD = 10-11 M) and efficient removal of Hg2+. More interestingly, 4a-4b can not only be developed into paper/film sensing platform, but also reliably detect Hg2+ in real water and seaweed samples, with recoveries ranging from 97.3% to 107.8% and a relative standard deviation of less than 5%, indicating that they have excellent application potential in the field of environmental and food chemistry.


Assuntos
Mercúrio , Mercúrio/química , Corantes Fluorescentes/química , Água , Espectrometria de Fluorescência
6.
BMC Genomics ; 24(1): 68, 2023 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-36759768

RESUMO

BACKGROUND: The early craniofacial development is a highly coordinated process involving neural crest cell migration, proliferation, epithelial apoptosis, and epithelial-mesenchymal transition (EMT). Both genetic defects and environmental factors can affect these processes and result in orofacial clefts. Mutations in MID1 gene cause X-linked Opitz Syndrome (OS), which is a congenital malformation characterized by craniofacial defects including cleft lip/palate (CLP). Previous studies demonstrated impaired neurological structure and function in Mid1 knockout mice, while no CLP was observed. However, given the highly variable severities of the facial manifestations observed in OS patients within the same family carrying identical genetic defects, subtle craniofacial malformations in Mid1 knockout mice could be overlooked in these studies. Therefore, we propose that a detailed morphometric analysis should be necessary to reveal mild craniofacial dysmorphologies that reflect the similar developmental defects seen in OS patients. RESULTS: In this research, morphometric study of the P0 male Mid1-cKO mice were performed using Procrustes superimposition as well as EMDA analysis of the size-adjusted three-dimensional coordinates of 105 skull landmarks, which were collected on the bone surface reconstructed using microcomputed tomographic images. Our results revealed the craniofacial deformation such as the increased dimension of the frontal and nasal bone in Mid1-cKO mice, in line with the most prominent facial features such as hypertelorism, prominent forehead, broad and/or high nasal bridge seen in OS patients. CONCLUSION:  While been extensively used in evolutionary biology and anthropology in the last decades, geometric morphometric analysis was much less used in developmental biology. Given the high interspecies variances in facial anatomy, the work presented in this research suggested the advantages of morphometric analysis in characterizing animal models of craniofacial developmental defects to reveal phenotypic variations and the underlining pathogenesis.


Assuntos
Fenda Labial , Fissura Palatina , Masculino , Camundongos , Animais , Fissura Palatina/genética , Fenda Labial/genética , Crânio/diagnóstico por imagem , Ubiquitina-Proteína Ligases , Camundongos Knockout
7.
Angew Chem Int Ed Engl ; 62(7): e202217616, 2023 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-36537720

RESUMO

Color-tunable dual-mode organic afterglow excited by ultraviolet (UV) and white light was achieved from classical aggregation-caused quenching compounds for the first time. Specifically, two luminescent systems, which could produce significant organic afterglow composed of persistent thermally activated delayed fluorescence and ultralong organic phosphorescence under ambient conditions, were constructed by doping fluorescein sodium and calcein sodium into aluminum sulfate. Their lifetimes surpassed 600 ms, and the dopant concentrations were as low as 5×10-6  wt %. Moreover, the persistent luminescence colors of the materials could be tuned from blue to green and then to yellow by simply varying the concentrations of guest compounds or the temperature in the range of 260-340 K. Inspired by these exciting results, the afterglow materials were used for UV- and white-light-manipulated anti-counterfeiting and preparation of elastomers with different colors of persistent luminescence.

8.
Chemistry ; 29(5): e202202594, 2023 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-36318097

RESUMO

The development of circularly polarized thermally activated delayed fluorescence (CP-TADF) luminogens with stimuli-response characteristics remains challenging. Herein, a pair of organic enantiomers, S-CzTA and R-CzTA, with aggregation-induced emission properties, have been successfully developed by introducing chiral 1,2,3,4-tetrahydronaphthalene and carbazole to phthalimide. They present CP-TADF properties in toluene solutions, giving dissymmetric factors of 0.84×10-3 and -1.03×10-3 , respectively. In the crystalline state, both S-CzTA and R-CzTA can emit intense blue TADF and produce very bright sky-blue mechanoluminescence (ML) and remarkable mechanofluorochromism (MFC) under the stimuli of mechanical force. Single-crystal analysis and theoretical calculation results suggest that their ML activities are probably associated with their chiral and polar molecular structures and unique non-centrosymmetric molecular packing modes. Furthermore, the MFC properties of the enantiomers likely originate from the destruction of crystal structure, leading to the planarization of molecular conformation. This work may provide helpful guidance for developing new CP-TADF materials with force-stimuli-responsive properties.


Assuntos
Tetra-Hidronaftalenos , Fluorescência
9.
ACS Appl Mater Interfaces ; 14(42): 47822-47830, 2022 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-36227175

RESUMO

With the advantages of organic and inorganic solid electrolytes, composite electrolytes are a promising option for use in all-solid-state Li-metal batteries. However, the considerable disparity in interfacial energy between ceramic and polymer electrolytes results in poor solid-solid contacts and the internal creation of a space charge layer in the composite electrolyte. Here, we report a melamine (MA) transition layer for the sake of strengthening the bond between Li1.5Al0.5Ge1.5(PO4)3 (LAGP) and poly(ethylene oxide) (PEO) to enhance physical and electrochemical properties. The MA is absorbed on LAGP by electron transfer from LAGP to MA's triazine ring, resulting in intimate contact and good mechanical stability. Simultaneously, the MA stabilizes the Li-salt anion, reduces its decomposition reactions at the interface between PEO and LAGP in the electrolyte, and promotes free Li+ dissociation, resulting in superior ionic conductivity and interfacial stability. Thus, the solid electrolyte film enables symmetric Li/Li batteries to achieve steady Li plating/stripping for more than 1300 h at a current density of 0.25 mA cm-2. The all-solid-state Li|PEO-MA@LAGP|LFP cell exhibits improved cycling stability. The Li/PEO-MA@LAGP/NCM523 cell shows a cycling life that is a factor of 5 times greater than that of a cell based on PEO-LAGP.

10.
Molecules ; 27(16)2022 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-36014438

RESUMO

Solid electrolyte interphase (SEI) on a Li anode is critical to the interface stability and cycle life of Li metal batteries. On the one hand, components of SEI with the passivation effect can effectively hinder the interfacial side reactions to promote long-term cycling stability. On the other hand, SEI species that exhibit the active site effect can reduce the Li nucleation barrier and guide Li deposition homogeneously. However, strategies that only focus on a separated effect make it difficult to realize an ideal overall performance of a Li anode. Herein, a dual functional artificial SEI layer simultaneously combining the passivation effect and the active site effect is proposed and constructed via a facial surface chemistry method. Simultaneously, the formed LiF component effectively passivates the anode/electrolyte interface and contributes to the long-term stable cycling performance, while the Li-Mg solid solution alloy with the active site effect promotes the transmission of Li+ and guides homogeneous Li deposition with a low energy barrier. Benefiting from these advantages, the Li||Li cell with the modified anode performs with a lower nucleation overpotential of 2.3 mV, and an ultralong cycling lifetime of over 2000 h at the current density of 1 mA cm-2, while the Li||LiFePO4 full battery maintains a capacity retention of 84.6% at rate of 1 C after 300 cycles.

11.
Angew Chem Int Ed Engl ; 61(23): e202201820, 2022 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-35315193

RESUMO

It remains a great challenge to develop polymer-based materials with efficient and color-tunable organic afterglow. Two indolocarbazole derivatives IaCzA and IbCzA have been synthesized and doped into poly(vinyl alcohol) (PVA) matrices. It is found that the resulting films can produce unique dual-mode afterglow, which is composed of persistent thermally activated delayed fluorescence and ultralong organic phosphorescence. Besides, the IbCzA-doped PVA film exhibits intense blue afterglow with Φafterglow and τafterglow up to 19.8 % and 1.81 s, respectively, representing state-of-the-art dual-mode organic afterglow performance. Moreover, our reported film has high flexibility, excellent transparency, and large-area producibility; and the afterglow color of the film can be linearly tuned by temperature. Inspired by these distinctive properties, the PVA doped with IbCzA was employed as temperature-sensitive security ink for anti-counterfeiting and information encryption.

12.
ACS Appl Mater Interfaces ; 13(36): 42957-42965, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34476943

RESUMO

Polymer electrolytes are the key candidates for solid-state batteries benefiting from their intrinsic advantages over inorganic electrolytes in terms of flexibility and easy processability. However, they suffer from low ionic conductivity and poor mechanical strength, which restrict their wide utilization. Conventional ceramic fillers are used to improve the mechanical properties of polymer electrolytes but lack sufficient Li+ conductivity. In this work, a framework with vertical channels that possess fast Li+ movement is designed. It is found that the poly(ethylene oxide) (PEO) compound in the vertical channel framework benefits to improve the ionic conductivity and mechanical strength synchronously. The framework in which ionic liquids are loaded on a zirconium dioxide surface (ZrO2@ILs) helps to improve ionic conductivity by 2 orders of magnitude compared with PEO, which is due to the enhanced orientation of ion transport. By optimizing the content of ZrO2@ILs, the elastic modulus is also tripled. Therefore, the symmetric lithium battery can cycle stably for more than 800 h at a current density of 0.25 mA cm-1, whereas the lithium metal battery has a specific capacity of 135 mAh g-1 at a current density of 2C and can cycle stably for more than 200 cycles at 60 °C.

13.
Environ Pollut ; 284: 117208, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-33930779

RESUMO

Organophosphate esters (OPEs) are ubiquitous contaminants in the environment, whereas their atmospheric processes and fate are poorly understood. The present study revealed the spatial heterogeneity and seasonal variations of traditional and novel OPEs in PM2.5 (particulate matter with diameters < 2.5 µm) across a megacity (including residential areas and potential source sites) in South China. Potential influencing factors on the contamination levels of OPEs were addressed. The total concentrations of 11 traditional OPEs ranging from 262 to 42,194 pg/m3 (median = 1872 pg/m3) were substantially higher than those of 10 novel OPEs (33.5-3835 pg/m3, median = 318 pg/m3). Significant spatial and temporal variations in the concentrations of most OPEs were observed. The overall district-specific contamination levels in this city showed dependence on the secondary industry sector for non-predominant OPEs and on the tertiary industry for predominant OPEs. The seasonal variations of the OPE concentrations suggest difference in their sources or influence of meteorological conditions. The correlations between the individual OPEs in PM2.5 are determined largely by either their applications or physicochemical properties (in particular vapor pressure). The correlations between OPE concentrations and each meteorological factor (temperature, relative humidity, wind speed, and surface solar radiation) were inconsistent (positive and negative). Wind speed had the greatest effect on the OPE levels; While most OPEs bound to PM2.5 were not efficiently scavenged by below-cloud rainfall. The results suggest that atmospheric half-life and Henry's Law Constant of OPEs are also determining factors for the wind speed and rainfall influence, respectively. However, mechanisms underlying the influence of meteorological conditions on atmospheric OPEs still need further research.


Assuntos
Retardadores de Chama , China , Cidades , Monitoramento Ambiental , Ésteres/análise , Retardadores de Chama/análise , Organofosfatos/análise , Material Particulado/análise
14.
Int J Biol Macromol ; 181: 919-927, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-33878354

RESUMO

MiR-203 was identified as a hub of a potential regulatory miRNA network in central nervous system. Overexpressing of miR-203 in the frontal cortex of C57BL/6J wild type mouse induced neurodegeneration by increasing the apoptotic pathway and neuron death. AFF4, a transcription factor, was identified as a new bona fida protein target of miR-203 in CNS. The miRNA:mRNA interaction of miR-203 and AFF4 was verified using Dural-luciferase assay. Down-regulated expression of AFF4 was induced by overexpressing miR-203 both in vitro and in vivo. Open field test, Y maze and Morris water maze test were conducted for the behavioral assessment of the mice with stereotactic injection of lentiviral vector overexpressing miR-203 in the hippocampus. No anxiety-like behavior or impaired cognition was noticed in these mice. Consistent with the results of the behavioral assessment, the electron micrograph and Nissl staining revealed no significant change in the synaptic density and no neuron injuries in the hippocampus of mice overexpressing miR-203, respectively. Our results indicated that instead of promoting neurodegenerative phenotype, a more profound function should be ascribed to miR-203 in regulating neuron behavioral activities and cognition. Neuron-type specific functions of miR-203 are likely to be executed via its various downstream protein interactors.


Assuntos
MicroRNAs/genética , Neurônios/metabolismo , Fatores de Elongação da Transcrição/genética , Animais , Apoptose/genética , Sistema Nervoso Central/metabolismo , Sistema Nervoso Central/patologia , Modelos Animais de Doenças , Regulação da Expressão Gênica/genética , Hipocampo/metabolismo , Hipocampo/patologia , Humanos , Aprendizagem em Labirinto/efeitos dos fármacos , Camundongos , Neurônios/patologia , Transdução de Sinais/genética
15.
Environ Pollut ; 275: 116601, 2021 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33549891

RESUMO

DNA methylation (DNAm) plays a significant role in deleterious health effects inflicted by fine particulate matter (PM2.5) on the human body. Recent studies have reported that DNAm of imprinted control regions (ICRs) in imprinted genes may be a sensitive biomarker of environmental exposure. Less is known about specific biomarkers of imprinted genes after PM2.5 exposure. The relationship between PM2.5 and its chemical constituents and DNAm of ICRs in imprinted genes after short-term exposure was investigated to determine specific human biomarkers of its adverse health effects. A panel study was carried out in healthy young people in Guangzhou, China. Mixed-effects models were used to evaluate the influence of PM2.5 and its constituent exposure on DNAm while controlling for potential confounders. There was no significant correlation between DNAm and personal PM2.5 exposure mass. DNAm changes in eight ICRs (L3MBTL1, NNAT, PEG10, GNAS Ex1A, MCTS2, SNURF/SNRPN, IGF2R, and RB1) and a non-imprinted gene (CYP1B1) were significantly associated with PM2.5 constituents. Compared to non-imprinted genes, imprinted gene methylation was more susceptible to interference with PM2.5 constituent exposure. Among those genes, L3MBTL1 was the most sensitive to personal PM2.5 constituent exposure. Moreover, transition metals derived from traffic sources (Cd, Fe, Mn, and Ni) significantly influenced DNAm of the imprinted genes, suggesting the importance of more targeted measures to reduce toxic constituents. Bioinformatics analysis indicated that imprinted genes (RB1) may be correlated with pathways and diseases (non-small cell lung cancer, glioma, and bladder cancer). The present study suggests that screening the imprinted gene for DNAm can be used as a sensitive biomarker of PM2.5 exposure. The results will provide data for prevention of PM2.5 exposure and a novel perspective on potential mechanisms on an epigenetic level.


Assuntos
Poluentes Atmosféricos , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Adolescente , Poluentes Atmosféricos/análise , China , Metilação de DNA , Exposição Ambiental/análise , Humanos , Material Particulado/análise , Adulto Jovem
16.
Sensors (Basel) ; 22(1)2021 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-35009852

RESUMO

The presence of fake pictures affects the reliability of visible face images under specific circumstances. This paper presents a novel adversarial neural network designed named as the FTSGAN for infrared and visible image fusion and we utilize FTSGAN model to fuse the face image features of infrared and visible image to improve the effect of face recognition. In FTSGAN model design, the Frobenius norm (F), total variation norm (TV), and structural similarity index measure (SSIM) are employed. The F and TV are used to limit the gray level and the gradient of the image, while the SSIM is used to limit the image structure. The FTSGAN fuses infrared and visible face images that contains bio-information for heterogeneous face recognition tasks. Experiments based on the FTSGAN using hundreds of face images demonstrate its excellent performance. The principal component analysis (PCA) and linear discrimination analysis (LDA) are involved in face recognition. The face recognition performance after fusion improved by 1.9% compared to that before fusion, and the final face recognition rate was 94.4%. This proposed method has better quality, faster rate, and is more robust than the methods that only use visible images for face recognition.


Assuntos
Algoritmos , Processamento de Imagem Assistida por Computador , Face , Redes Neurais de Computação , Reprodutibilidade dos Testes
17.
Environ Sci Technol ; 53(7): 3782-3790, 2019 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-30831022

RESUMO

Spatiotemporal trends in pro-inflammatory (interleukin (IL)-6 and IL-8) release after exposure to the water-soluble fractions of PM2.5 sampled in 10 large Chinese cities over 1 year were investigated. Chemical components (water-soluble ions, metal(loid) elements, water-soluble organic carbon (WSOC), humic-like substances (HULIS), and endotoxins) in PM2.5 samples were measured, and the molecular structure of WSOC was also analyzed by nuclear magnetic resonance. Changes in DNA methylation and gene expression of candidate genes were also evaluated to explore the potential mechanisms. PM2.5 from southern cities induced lower pro-inflammatory responses compared to those from northern cities. Seasonal differences in toxicity were noted among the cities. IL-6 was significantly correlated with HULIS (as the main fraction of WSOC with oxygenated carbohydrate structures characteristic), Pb, and endotoxin. Furthermore, DNA methylation and gene expression changes in RASSF2 and CYP1B1 were related to pro-inflammatory secretion. Certain components of PM2.5, rather than PM2.5 mass itself, determine the pro-inflammatory release. In particular, HULIS, which originated from primary biomass burning and residual coal combustion, and secondary organic aerosols, appear to be the key component in PM2.5 to induce human health risk.


Assuntos
Poluentes Atmosféricos , Material Particulado , Cidades , Carvão Mineral , Monitoramento Ambiental , Humanos , Inflamação , Estações do Ano , Água
18.
Nanotechnology ; 29(49): 495601, 2018 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-30211699

RESUMO

Fibrous mats piled by nitrogen-doped porous carbon nanofibers with seeded TiO2 are fabricated and punched directly into circles as lithium-ion battery anodes. The seeding structure is composed of semi-wrapped TiO2 nanoparticles on carbon nanofibers (CNFs) coated with a thin layer of carbon. Synchronously, pores with various widths are formed on CNFs. As a freestanding anode, an initial discharge capacity of 615 mAh g-1 with a coulombic efficiency of 56% is reached, and 322 mAh g-1 is obtained after 100 cycles at a current density of 100 mA g-1. This is assigned to the increasing number of active sites for the lithium ion from pores with various widths and improved conductivity originating from nitrogen doping. Superior rate performance (179 mAh g-1 at the current density of 2000 mA g-1) under various current densities compared with that of other counterparts is attributed to the structural stability originating from the seeding structure with the help of the C-O-Ti bond. An additional 800 cycles are displayed at the current density of 2000 mA g-1, and superior stability is also exhibited.

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