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1.
Dalton Trans ; 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38666487

RESUMO

Vanadium-based oxides are considered potential cathode materials for aqueous zinc ion batteries (AZIBs) due to their distinctive layered (or tunnel) structure suitable for zinc ion storage. However, the structural instability and sluggish kinetics of vanadium-based oxides have limited their capacity and cycling stability for large-scale applications. To overcome these shortcomings, here a porous vanadium-based oxide doped with zinc ions and carbon with the molecular formula ZnV2O4@C (ZVO@C) as the cathode material is synthesized by the pyrolysis of a bimetallic MOF precursor containing Zn/V. This electrode demonstrates a remarkable specific capacity of 425 mA h g-1 at 0.5 A g-1 and excellent cycling stability with about 97% capacity retention after 1000 cycles at 10 A g-1. The excellent electrochemical performance of ZVO@C can be attributed to more reaction active sites and the faster reaction kinetics for zinc ion diffusion and storage brought about by the porous layered spinel-type tunnel structure with high surface area and massive mesoporosity, as well as the enhanced electron transport efficiency and more stable channel structure achieved from the doped conductive carbon. The reaction mechanism and structural evolution of the ZVO@C electrode are analyzed using X-ray diffraction and X-ray photoelectron spectroscopy, revealing the formation of a new phase of ZnxV2O5·nH2O during the first charge, which participates in reversible cycling together with ZVO@C during the charging and discharging processes. Moreover, the energy storage mechanism is revealed, in which zinc ions and hydrogen ions jointly participate in intercalation and extraction. The present study demonstrates that constructing composite vanadium-based oxides based on bimetallic organic frameworks as precursor templates is an effective strategy for the development of high-performance cathode materials for AZIBs.

2.
Langmuir ; 2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38635954

RESUMO

Aqueous zinc-ion batteries (AZIBs) suffer from sharp cycling deterioration due to serious interfacial side reactions and corrosion problems on the zinc anode. Herein, an efficacious approach to construct hydrophobic ZnMoO4 coatings on Zn (denoted as Zn@ZMO) is proposed to mitigate direct contact between the zinc anode and electrolyte and enhance its cycle life. The hydrophobic ZnMoO4 layer (contact angle = 128°) with a honeycomb-like structure is prepared by an in situ liquid phase deposition method. The as-prepared ZnMoO4 coating exhibits persistent corrosion protection for Zn through 30 days of immersion in a 2 M ZnSO4 electrolyte, indicating excellent stability of the ZnMoO4 layer and ensuring its available application in AZIBs. Unique microchannels in this kind of honeycomb-like structured coating favor Zn2+ ion diffusion and ease of ion transport, especially at high current cycling. Its robust surface exclusion can effectively counter other side reactions induced by water, simultaneously. As a result, the Zn@ZMO symmetrical cell shows a remarkable cycle lifespan exceeding 2700 h at 1 mA cm-2/1 mA h cm-2, surpassing that of the bare zinc cell by more than 100 folds. At a current density of 5 A g-1, the Zn@ZMO//V2O5 cell can still achieve a specific capacity of 167.0 mA h g-1 after 500 cycles with a capacity retention rate of 88%, which demonstrates its long-term cycling stability.

3.
ACS Appl Mater Interfaces ; 16(11): 13795-13805, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38449335

RESUMO

Designing a stable and highly active catalyst for hydrogen evolution and oxygen evolution reactions (HER/OER) is essential for the industrialization of hydrogen energy but remains a major challenge. This work reports a simple approach to fabricating coupled Co2P/Fe2P nanorod array catalyst for overall water decomposition, demonstrating the source of excellent activity in the catalytic process. Under alkaline conditions, Co2P/Fe2P heterostructures exhibit an overpotential of 96 and 220 mV for HER and OER, respectively, at 10 mA cm-2. For total water splitting, a low voltage of 1.56 V is required to provide a current density of 10 mA cm-2. And the catalyst exhibits long-term durability for 30 h at a high current density of 250 mA cm-2. The analysis of the results revealed that the presence of interfacial oxygen vacancies and the strong interaction between Co2P/Fe2P provided the catalyst with more electrochemically active sites and a faster charge transfer capability, which improved the hydrolysis dissociation process. Electrochemically active metal (oxygen) hydroxide phases were produced after OER stability testing. The results of this study prove its great potential in practical industrial electrolysis and provide a reasonable and feasible strategy for the design of nonprecious metal phosphide electrocatalysts.

4.
ChemSusChem ; : e202301262, 2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38415928

RESUMO

In the current challenging energy storage and conversion landscape, solid-state lithium metal batteries with high energy conversion efficiency, high energy density, and high safety stand out. Due to the limitations of material properties, it is difficult to achieve the ideal requirements of solid electrolytes with a single-phase electrolyte. A composite solid electrolyte is composed of two or more different materials. Composite electrolytes can simultaneously offer the advantages of multiple materials. Through different composite methods, the merits of various materials can be incorporated into the most essential part of the battery in a specific form. Currently, more and more researchers are focusing on composite methods for combining components in composite electrolytes. The ion transport capacity, interface stability, machinability, and safety of electrolytes can be significantly improved by selecting appropriate composite methods. This review summarizes the composite methods used for the components of composite electrolytes, such as filler blending, embedded framework, and multilayer bonding. It also discusses the future development trends of all-solid-state lithium batteries (ASSLBs).

5.
Angew Chem Int Ed Engl ; 63(13): e202315122, 2024 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-38311601

RESUMO

Dendrites growth and unstable interfacial Li+ transport hinder the practical application of lithium metal batteries (LMBs). Herein, we report an active layer of 2,4,6-trihydroxy benzene sulfonyl fluorine on copper substrate that induces oriented Li+ deposition and generates highly crystalline solid-electrolyte interphase (SEI) to achieve high-performance LMBs. The lithiophilic -SO2 - groups of highly crystalline SEI accept the rapidly transported Li+ ions and form a dense inner layer of LiF and Li3 N, which regulate Li+ plating morphology along the (110) crystal surface toward dendrite-free Li anode. Thus, Li||Cu cells with lithiophilic SEI achieve an average deposition efficiency of 99.8 % after 700 cycles, and Li||Li cells operate well for 1100 h. Besides, Li||LiNi0.8 Co0.1 Mn0.1 O2 cells with modified SEI exhibit a capacity retention that is 14 times than that of conventional SEI. Even at -60 °C, Li||Cu cells reach stable deposition efficiency of 83.2 % after 100 cycles.

6.
J Colloid Interface Sci ; 659: 676-686, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38211485

RESUMO

In this study, we prepare a highly efficient BiVO4 photoanode co-catalyzed with an ultrathin layer of N, S co-doped FeCo-Metal Organic Frameworks (MOFs) for photoelectrochemical water splitting. The introduction of N and S into FeCo-MOFs enhances electron and mass transfer, exposing more catalytic active sites and significantly improving the catalytic performance of N, S co-doped FeCo-based MOFs in water oxidation. The optimized BiVO4/NS-FeCo-MOFs photoanode exhibits impressive results, with a photocurrent density of 5.23 mA cm-2 at 1.23 V vs. Reversible Hydrogen Electrode (RHE) and an incident photon-to-charge conversion efficiency (IPCE) of 74.4 % at 450 nm in a 0.1 M phosphate buffered solution (pH = 7). These values are 4.84 times and 6.2 times higher than those of the original BiVO4 photoanode, respectively. Furthermore, the optimized BiVO4/NS-FeCo-MOFs photoanode demonstrates exceptional long-term stability, maintaining 96 % of the initial current after five hours.

7.
J Colloid Interface Sci ; 658: 865-878, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38157611

RESUMO

Aluminum alloy (Al alloy) suffers from severe corrosion in acidic solution. Two-dimensional (2D) MXene-based composite coatings show great prospects for corrosion protection on metals used in special conditions. The composite coatings still face challenges in complex functionalization and orientation control. In harsh conditions, the long-term ability and roles of MXene in corrosion protection are still not clear. Here, a bio-inspired myristic-calcium chloride-Ti3C2Tx MXene (MA + CaCl2 + MXene) composite coating is successfully prepared on aluminum alloy (Al alloy) by electrodeposition process. Electrochemical tests, surface morphology, and chemical composition are analyzed to investigate the corrosion resistance and protection mechanism of the MXene coating in acidic solution (0.5 M H2SO4 + 2 ppm HF). As a result, the incorporation of MXene can significantly reduce corrosion current density (7.498 × 10-8 A/cm2) by âˆ¼ 5 orders of magnitude and impedance modulus at 0.01 Hz (|Z|0.01 Hz) value of the composite coating is 196.8 Ω·cm2, which is over 4 times higher than that of bare Al alloy (40.74 Ω·cm2) after immersion test for 72 h. Furthermore, the in-situ corrosion test confirms the enhanced corrosion resistance of the MA + CaCl2 + MXene composite coating. The MXene can increase coating thickness to 23.6 ± 0.4 µm, reduce porosity to (5.845 ± 1) × 10-5, decrease the diffusion coefficients of H+ to (1.587 ± 0.3) × 10-9 cm2/s, and enhance the adhesion of the coating to the substrate (the delamination time exceeds 5 h), thus providing improved anti-corrosion ability. This strategy opens up new prospects for construction of 2D MXene-based anti-corrosion coatings.

8.
Dalton Trans ; 52(38): 13797-13807, 2023 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-37721207

RESUMO

At present, vanadium-based cathodes for aqueous zinc-ion batteries (AZIBs) are limited by their slow reaction kinetics, poor electrical conductivity, and low capacity retention. To overcome these problems, here, we design a layered porous Mn0.18V2O5@C as the cathode material for AZIBs using a manganese-containing metal-organic framework as a template through a simple solvothermal method. Such an electrode delivers an excellent specific capacity (380 mA h g-1 at 0.1 A g-1) accompanied by superior cycling stability (about 85% capacity retention for 2000 cycles at 6 A g-1). The excellent electrochemical performance of Mn0.18V2O5@C is ascribed to the improved interface activity including smooth zinc ion transport, abundant ion reaction active sites and accelerated charge transfer resulting from the coordination of the porous structure, doped conductive carbon, and the stable channel structure derived from the pillar effect of doping manganese ions, preventing a premature collapse of the electrode structure. It is also revealed by structural evolution analysis that the residual zinc ions also combine with the original Mn0.18V2O5 to form a ZnxMnyV2O5 phase, which serves as an additional structural pillar and in the meantime, also participates in the following cycles. These favorable electrochemical results suggest that Mn0.18V2O5@C is a suitable cathode material for AZIBs.

9.
Inorg Chem ; 62(37): 15138-15147, 2023 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-37676812

RESUMO

Carbon-supported Pd-based clusters are one of the most promising anodic catalysts for ethanol oxidation reaction (EOR) due to their encouraging activity and practical applications. However, unclear growth mechanism of Pd-based clusters on the carbon-based materials has hindered their extensive applications. Herein, we first introduce multi-void spherical PdBi cluster/carbon cloth (PdBi/CC) composites by an electrodeposition routine. The growth mechanism of PdBi clusters on the CC supports has been systemically investigated by evaluating the selected samples and tuning their compositions, which involve the big difference in standard redox potential between Pd2+/Pd and Bi3+/Bi and easy adsorption of Bi3+ on the surface of Pd-rich seeds. Benefitting from the ensembles of many nanocrystal subunits, multi-void spherical PdBi clusters can present collective properties and novel functionalities. In addition, the outstanding characteristics of CC supports enable PdBi clusters with stable nanostructures. Thanks to the unique structure, Pd20Bi/CC catalysts manifest higher EOR activity and better stability compared to Pd/CC. Systematic characterizations and a series of CO poisoning tests further confirm that the dramatically enhanced EOR activity and stability can be attributed to the incorporation of Bi species and the strong coupling of the structure between PdBi clusters and CC supports.

10.
J Colloid Interface Sci ; 650(Pt A): 622-635, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37437442

RESUMO

Lithium metal batteries have garnered significant attention as a promising energy storage technology, offering high energy density and potential applications across various industries. However, the formation of lithium dendrites during battery cycling poses a considerable challenge, leading to performance degradation and safety hazards. This study aims to address this issue by investigating the effectiveness of a protective layer on the lithium metal surface in inhibiting dendrite growth. The hypothesis is that continuous lithium consumption during battery cycling is a primary contributor to dendrite formation. To test this hypothesis, a protective layer of Li3Bi/Li2O was applied to the lithium foil through immersion in a BiN3O9 solution. Experimental techniques including kelvin probe force microscopy (KPFM) and density functional theory (DFT) calculations were employed to analyze the structural and electronic properties of the Li3Bi/Li2O layer. The findings demonstrate successful doping of Bi into the Li coating, forming Bi-Bi and Bi-O bonds. KPFM measurements reveal a higher work function of Li3Bi/Li2O, indicating its potential as an effective protective layer. DFT calculations further support this observation by revealing a greater adsorption energy of lithium on the Li3Bi/Li2O layer compared to the bulk material. Charge density analysis suggests that the adsorption of Li atoms onto the Li3Bi/Li2O layer induces a redistribution of charge, resulting in increased electron availability on the surface and preventing electrode-electrolyte contact. This study provides insights into the role of the Li3Bi/Li2O protective layer in inhibiting dendrite growth in lithium metal batteries. By mitigating dendrite formation, the protective layer holds promise for enhancing battery performance and longevity. These findings contribute to the development of strategies for improving the stability and reliability of lithium metal batteries, facilitating their wider adoption in energy storage applications.

11.
RSC Adv ; 13(23): 15640-15650, 2023 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-37228684

RESUMO

Herein, an efficient CuO QDs/TiO2/WO3 photoanode and a Cu doped Co3S4/Ni3S2 cathode were successfully synthesized. The optimized CuO QDs/TiO2/WO3 photoanode achieved a photocurrent density of 1.93 mA cm-2 at 1.23 vs. RHE, which was 2.27 times that of a WO3 photoanode. The CuO QDs/TiO2/WO3-buried junction silicon (BJS) photoanode was coupled with the Cu doped Co3S4/Ni3S2 cathode to construct a novel photocatalytic fuel cell (PFC) system. The as-established PFC system showed a high rifampicin (RFP) removal ratio of 93.4% after 90 min and maximum power output of 0.50 mW cm-2. Quenching tests and EPR spectra demonstrated that ˙OH, ˙O2- and 1O2 were the main reactive oxygen species in the system. This work provides a possibility to construct a more efficient PFC system for environmental protection and energy recovery in the future.

12.
ACS Appl Mater Interfaces ; 15(4): 5198-5208, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36691303

RESUMO

Designing high-efficiency and newly developed Pd-based bifunctional catalytic materials still faces tremendous challenges for oxygen reduction reaction (ORR) and formic acid oxidation reaction (FAO). Metallene materials with unique structural features are considered strong candidates for enhancing the catalytic performance. In this work, we synthesized copper-doped two-dimensional curved porous Pd metallene nanomaterials via a simplistic one-pot solvothermal method. The updated catalysts served as sturdy bifunctional electrocatalysts for cathodal ORR and anodic FAO. In particular, the developed PdCu metallene exhibits excellent half-wave potential (0.943 V vs RHE) and mass activity (MA) (1.227 A mgPt-1) in alkaline solutions, which are 1.09 and 6.26 times higher than those of commercial Pt/C, respectively, indicating that the nanomaterials have abundant active sites, displaying surpassing catalytic performance for oxygen reduction. Furthermore, in an acidic formic acid electrolyte, PdCu metallene exhibits prominent MA with a value of 0.905 A mgPd-1, which is 2.76 times that of commercial Pd/C. The remarkable bifunctional catalytic performance of metallene materials can be attributed to the special structure and electronic effects. This work shows that metallene materials with curved and porous properties provide a scientific idea for the development and design of efficient and steady electrocatalysts.

13.
Waste Manag ; 155: 129-136, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36370622

RESUMO

Developing green and high-efficient pyrometallurgy processes to recycle precious metals from spent lithium-ion batteries (LIBs) is of great importance for resource sustainability and environmental protection. Herein, a novel reduction roasting approach relying on spent LIB separator to refine the spent cathode is proposed. The efficiency of repurposing separator as a reductant for roasting the spent LiCoO2 cathode and the underlying mechanisms were investigated. After the separator-mediated roasting at 500 °C for 2 h, Li+ leaching efficiency of the cathode reached 93.2 %, >2.6 times higher than those after roasting without reductant (25.2 %) or with benchmark reductant graphite (26.1 %). Under the separator-added roasting condition, the cathode was converted to the desired products, CoO and Li2CO3. Based on the analysis of in-situ reaction using thermogravimetric/differential scanning calorimetry and pyrolysis gas species identification, the separator-mediated reduction roasting of cathode was composed of two stages, i.e., reducing gas generation due to separator pyrolysis, followed by the reducing gas mediated LiCoO2 reduction. During the process, the generated C2H4 and CO dominated the reduction. The use of co-existing separator to recover precious metals from spent LIBs is an effective and sustainable strategy to maximize the utilization of spent LIBs.

14.
J Hazard Mater ; 440: 129784, 2022 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-36029735

RESUMO

Microplastic-derived dissolved organic matter (MP-DOM) is ubiquitous in water environment and exhibits photosensitivity. However, little is known about the effects of MP-DOM on the photodegradation of organic micropollutants in natural water. In this study, we investigated the effect of MP-DOM derived from two typical plastics, i.e., polystyrene (PS), and polyethylene (PE), on the photodegradation of a typical organic micropollutants sulfamethoxazole (SMX) in a simulative natural water system. MP-DOM exerted a significant inhibition on the SMX photodegradation, mainly attributed to the direct photolysis inhibition of SMX caused by the inner filter effect and the complexation effect. Despite the enhanced reactive oxygen species (ROS) generation with the increase of their steady-state concentration by 41.1 - 160.7 %, PS-DOM exhibited high oxidation resistance, causing an inhibition on the photodegradation of SMX probably through transferring electrons to the SMX intermediates. This study helps to deepen the understanding of microplastic photochemical behavior in natural water.


Assuntos
Microplásticos , Poluentes Químicos da Água , Matéria Orgânica Dissolvida , Fotólise , Plásticos , Polietilenos , Poliestirenos , Espécies Reativas de Oxigênio , Sulfametoxazol , Água
15.
J Colloid Interface Sci ; 619: 257-266, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35397459

RESUMO

In this work, we modified a BiVO4 photoanode with bilayer Fe-MOF and Ni-MOF as cocatalysts for the first time and obtained a highly efficient BiVO4 composite photoanode whose photocurrent density was increased by 2.7 times. The optimized BiVO4/Fe-MOF/Ni-MOF photoanode demonstrated a photocurrent density of 1.80 mA/cm2 at 1.23 V vs. a reversible hydrogen electrode (RHE). The onset potential of the BiVO4/Fe-MOF/Ni-MOF photoanode markedly decreased from 0.9 V to 0.69 V in comparison with the pure BiVO4 photoanode. It is speculated that Fe-MOF and Ni-MOF led to more reactive oxygen evolution sites and that the bilayer cocatalysts synergistically promoted the separation of photogenerated electron-hole pairs, which may be the influencing factor for the photoelectrochemical performance of the BiVO4/Fe-MOF/Ni-MOF photoanode being distinctively enhanced. Thus, this work sheds some interesting new light on the construction of a high-efficiency photoanode for photoelectrochemical applications.

16.
J Colloid Interface Sci ; 613: 652-660, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35065439

RESUMO

Based on the strategy that electrocatalysts can be used as additives to improve the performance of photocatalysts, and the unique metalloid properties of tungsten nitride (WN), it can form a Schottky junction with the semiconductor at the heterogeneous interface to improve the photocatalytic performance of semiconductor catalysts. In this paper, WN with excellent electrical conductivity was selected as a new noble-metal-free co-catalyst to improve the photoreduction hydrogen (H2) evolution performance of CdS nanoparticles (NPs). Firstly, WN nanosheets were prepared by sol-gel method; then, a novel and noble-metal-free heterojunction photocatalyst, which is CdS NPs deposited on the surface of WN, was successfully fabricated via one-pot solvothermal method. Under visible light irradiation, the H2 production rate of the WN/CdS composite catalyst is 24.13 mmol/g/h, which is 9.28 times that of pure CdS NPs. The observably boosted H2 generation activity could be ascribed to the broadened visible-light absorption and intimate interfacial contact between CdS NPs and WN engenders Schottky junction. This study provides a novel and cost-effective approach for designing efficient noble-metal-free photocatalysts and improving H2 evolution activity of CdS under visible-light-driven photocatalytic water splitting.

17.
ACS Appl Mater Interfaces ; 14(1): 1092-1101, 2022 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-34968036

RESUMO

Prussian blue analogues (PBAs) have been considered as promising cathodes for aqueous zinc-ion batteries because of their open framework for accommodating large ions, tunable valence state, and facile synthesis. Among PBAs, potassium manganese hexacyanoferrate (KMHCF) is favored due to its high working voltage, high specific capacity, and low cost. However, it suffers from severe capacity decay and poor rate capability, which are mainly a result of poor intrinsic conductivity, irreversible phase transition, transition metal dissolution, and structural collapse during charge/discharge cycling. These issues extremely limit its practical application. In order to solve these problems, conductive polypyrrole (PPy) was used to coat KMHCF microcubes to form KMHCF@PPy composites to achieve superior rate capability and prolonged cycle life. With the PPy coating, the KMHCF@PPy composite delivers a discharge capacity of 107.6 mA h g-1 after 100 cycles at 100 mA g-1, and even at 500 mA g-1 after 500 cycles, 64.2 mA h g-1 still remained. The excellent electrochemical performance can be attributed to the effects from PPy. On the one hand, PPy supplies an effective electronic transmission network for KMHCF to enhance the electronic conductivity. On the other hand, it plays the role of a protective layer to effectively inhibit the dissolution of Mn and the phase transition during the cycling.

18.
Chemosphere ; 291(Pt 3): 132911, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34798112

RESUMO

Efficient high-concentration organics degradation (including 2-CP, phenol, and tetracycline) and simultaneous electricity generation were achieved via in situ producing H2O2 and synchronous catalytic conversion to more reactive oxygen species at stable modified copper foam cathode. The cathode was synthesized using the one-pot electrodeposition method and was used to in-situ generate H2O2 through the two-electron reduction of oxygen. The produced H2O2 was then catalytically converted into ·OH and ·O2- simultaneously. The results showed that the system using the Au-Fe co-modified cathode achieved an optimal rhodamine b (50 mg L-1) removal ratio and the removal ratios of 2-CP, phenol and tetracycline were all higher than 90% in 120 min. Meanwhile, it exhibited a high conversion performance of organics into electricity, which is superior to most of the reported PFC (Photocatalytic Fuel Cell) systems. Electron spin resonance test was conducted to ascertain the role of ·O2- and ·OH in the organics degradation. Furthermore, the Au-Fe-modified cathode exhibited superior stability for long-term application in the pH range of 3-7, which can be attributed to the protection of photocurrent and the interaction between Cu and Fe.


Assuntos
Cobre , Purificação da Água , Eletricidade , Eletrodos , Peróxido de Hidrogênio , Espécies Reativas de Oxigênio , Águas Residuárias
19.
ACS Appl Mater Interfaces ; 13(51): 60907-60920, 2021 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-34927413

RESUMO

The performance of lithium batteries is largely dependent on the ionic conductivity within robust solid electrolytes. Poly(ethylene oxide) (PEO)-based electrolytes, however, have a low lithium ionic conductivity, which limits the hop of Li+. Herein, a novel PEO-based composite electrolyte is prepared that contains nonstoichiometric transition molybdenum trioxide (MoO3-x) nanosheets as fillers to improve the ionic conductivity. The MoO3-x nanosheets containing many oxygen vacancies can cross-link with PEO chains to reduce the energy barrier of Li+ migration and the matrix crystallinity, leading to an increase in the lithium-ion transference number (up to 0.56) and a high ionic conductivity (up to 6 × 10-4 S cm-1) at 60 °C. Meanwhile, the incorporation of MoO3-x nanosheets alleviates the decomposition of the electrolyte, enhancing the tensile strength by ∼4 times compared to PEO. As a result, a LiFePO4/Li cell with PEO/LiTFSI/MoO3-x (PLM3-x) delivers an excellent rate capability, high capacity, and lifespan during high rates (2 C, ≥10 000 cycles), which demonstrates a facile yet effective strategy toward high-performance lithium batteries.

20.
ACS Appl Mater Interfaces ; 13(50): 60678-60688, 2021 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-34878253

RESUMO

Commercially, lithium metal batteries are still limited by the growth of lithium dendrites and excessive consumption of the electrolyte. A stable multifunctional solid electrolyte interface is the development strategy of lithium metal batteries in the future. However, most of the artificial solid electrolyte interphases (SEIs) cannot meet the original intention of multifunctional design and cannot form an SEI film with a high conductivity and low nucleation potential. In this work, we report a universal and simple method of adding multifunctional fluorosulfonate to a commercial electrolyte, so increasing the inorganic LiF in the SEI. In addition, the imidazole ring in the fluorosulfonate combines with the alkyl group in the electrolyte to form a flexible interface layer, which inhibits the growth of lithium dendrites and makes lithium deposition more uniform, thereby realizing a stable fast charge cycle. With an ultralow capacity of 2 mAh/cm2 deposited, the symmetrical battery can be deposited stably for nearly 300 h at a high current density of 20 mA/cm2. The capacity retention rate of the Li-LiFePO4 (LFP) full cell was still at 90.6% after 1000 cycles at 5 C. Even with 5 C high-rate fast charging, the capacity was maintained at 76.56% after 200 cycles, which is four times that of commercial electrolytes. This simple addition strategy gives insights into the practical application of the new electrolyte and provides a new idea for the construction of a stable SEI for commercial lithium metal batteries.

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