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1.
Molecules ; 29(8)2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38675579

RESUMO

High ionic conductivity, outstanding mechanical stability, and a wide electrochemical window are the keys to the application of solid-state lithium metal batteries (LMBs). Due to their regular channels for ion transport and tailored functional groups, covalent organic frameworks (COFs) have been applied to solid electrolytes to improve their performance. Herein, we report a flexible polyethylene oxide-COF-LZU1 (abbreviated as PEO-COF) electrolyte membrane with a high lithium ion transference number and satisfactory mechanical strength, allowing for dendrite-free and long-time cycling for LMBs. Benefiting from the interaction between bis(triflfluoromethanesulonyl)imide anions (TFSI-) and aldehyde groups in COF-LZU1, the Li+ transference number of the PEO-5% COF-LZU1 electrolyte reached up to 0.43, much higher than that of neat PEO electrolyte (0.18). Orderly channels are conducive to the homogenous Li-+ deposition, thereby inhibiting the lithium dendrites. The assembled LiFePO4|PEO-5% COF-LZU1/Li cells delivered a discharge specific capacity of 146 mAh g-1 and displayed a capacity retention of 80% after 200 cycles at 0.1 C (60 °C). The Li/Li symmetrical cells of the PEO-5% COF-LZU1 electrolyte presented a longer working stability at different current densities compared to that of the PEO electrolyte. Therefore, the enhanced comprehensive performance of the solid electrolyte shows potential application prospects for use in LMBs.

2.
Nanomaterials (Basel) ; 14(4)2024 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-38392711

RESUMO

Biodegradable polymers have become a topic of great scientific and industrial interest due to their environmentally friendly nature. For the benefit of the market economy and environment, biodegradable materials should play a more critical role in packaging materials, which currently account for more than 50% of plastic products. However, various challenges remain for biodegradable polymers for practical packaging applications. Particularly pertaining to the poor oxygen/moisture barrier issues, which greatly limit the application of current biodegradable polymers in food packaging. In this review, various strategies for barrier property improvement are summarized, such as chain architecture and crystallinity tailoring, melt blending, multi-layer co-extrusion, surface coating, and nanotechnology. These strategies have also been considered effective ways for overcoming the poor oxygen or water vapor barrier properties of representative biodegradable polymers in mainstream research.

3.
Chemistry ; 30(18): e202303741, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38206884

RESUMO

Compared with Li+, Na+ with a smaller stokes radius has faster de-solvation kinetics. An electrolyte with ultralow sodium salt (0.3 M NaPF6) is used to reduce the cell cost. However, the organic-dominated interface, mainly derived from decomposed solvents (SSIP solvation structure), is defective for the long cycling performance of sodium ion batteries. In this work, the simple application of dual additives, including sodium difluoro(oxalato)borate (NaDFOB) and tris(trimethylsilyl)borate (TMSB), is demonstrated to improve the cycling performance of the hard carbon/NaNi1/3Fe1/3Mn1/3O2 cell by constructing interface films on the anode and cathode. A significant improvement on cycling stability has been achieved by incorporating dual additives of NaDFOB and TMSB. Particularly, the capacity retention increased from 17 % (baseline) to 79 % (w/w, 2.0 wt % NaDFOB) and 83 % (w/w, 2.0 wt % NaDFOB and 1.0 wt % TMSB) after 200 cycles at room temperature. Insight into the mechanism of improved interfacial properties between electrodes and electrolyte in ultralow concentration electrolyte has been investigated through a combination of theoretical computation and experimental techniques.

4.
Adv Mater ; 36(2): e2306601, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37851917

RESUMO

The cycling instability of metallic Zn anodes hinders the practicability of aqueous Zn-ion batteries, though aqueous Zn-ion batteries may be the most credible alternative technology for future electrochemical energy storage applications. Commercially available trivalent chromium conversion films (TCCF) are successfully employed as robust artificial interphases on Zn metal anodes (ZMAs). Fabricated through a simple immersion method, the TCCF-protected Zn (TCCF@Zn) electrode enables a superlow nucleation overpotential for Zn plating of 6.9 mV under 1 mA cm-2 , outstanding Coulombic efficiency of 99.7% at 3 mA cm-2 for 1600 cycles in Zn||Cu asymmetric cells and superior cyclability in symmetric Zn||Zn batteries at 0.2, 2, and 5 mA cm-2 for 2500 h and 10 mA cm-2 for 1200 h. More importantly, the TCCF@Zn||V2 O5 full cell exhibits a specific capacity of 118.5 mAh g-1 with a retention of 53.4% at 3 A g-1 for 3000 cycles, which is considerably larger than that of the pristine Zn||V2 O5 full cell (59.7 mAh g-1 with a retention of 25.7%). This study demonstrates a highly efficient and low-cost surface modification strategy derived from an industrially applicable trivalent chromium passivation technique aimed at obtaining dendrite-free ZMAs with high reversibility for practical Zn batteries in the near future.

5.
ChemSusChem ; 17(3): e202300293, 2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-37771268

RESUMO

Solid-state electrolytes are key to achieving high energy density, safety, and stability for lithium-ion batteries. In this Review, core indicators of solid polymer electrolytes are discussed in detail including ionic conductivity, interface compatibility, mechanical integrity, and cycling stability. Besides, we also summarize how above properties can be improved by design strategies of functional monomers, groups, and assembly of batteries. Structures and properties of polymers are investigated here to provide a basis for all-solid-state electrolyte design strategies of multi-component polymers. In addition, adjustment strategies of quasi-solid-state polymer electrolytes such as adding functional additives and carrying out structural design are also investigated, aiming at solving problems caused by simply adding liquids or small molecular plasticizer. We hope that fresh and established researchers can achieve a general perspective of solid polymer electrolytes via this Review and spur more extensive interests for exploration of high-performance lithium-ion batteries.

6.
ACS Appl Mater Interfaces ; 15(26): 31491-31501, 2023 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-37341213

RESUMO

Non-aqueous redox flow batteries (RFBs) are highly attractive for grid-scale energy storage applications because of their independent design of energy and power, high energy density and efficiency, easy maintenance, and potentially low cost. In order to develop active molecules with large solubility, excellent electrochemical stability, and high redox potential for a non-aqueous RFB catholyte, herein, two flexible methoxymethyl groups had been attached to a famous redox-active tetrathiafulvalene (TTF) core. The strong intermolecular packing of the rigid TTF unit was effectively depressed, leading to a dramatically improved solubility of up to 3.1 M in conventional carbonate solvents. The performance of the obtained dimethoxymethyl TTF (DMM-TTF) was studied in a semi-solid RFB system with Li foil as the counter electrode. When using porous Celgard as the separator, the hybrid RFB with 0.1 M DMM-TTF had two high discharge plateaus at 3.20 and 3.52 V and a low capacity retention of 30.7% after 100 cycles at 5 mA cm-2. Replacing Celgard with a permselective membrane, the capacity retention was increased to 85.4%. Further increasing the concentration of DMM-TTF to 1.0 M and current density to 20 mA cm-2, the hybrid RFB exhibited a high volumetric discharge capacity of 48.5 A h L-1 and an energy density of 154 W h L-1. The capacity was maintained at 72.2% after 100 cycles (10.7 days). The great redox stability of DMM-TTF was revealed by UV-vis and 1H NMR tests and verified by density functional theory calculations. Therefore, the methoxymethyl group is an excellent group to increase the solubility while maintaining the redox capability of TTF for high-performance non-aqueous RFBs.

7.
Nanomaterials (Basel) ; 13(11)2023 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-37299670

RESUMO

The rapid development of electrochemical CO2 reduction offers a promising route to convert intermittent renewable energy into products of high value-added fuels or chemical feedstocks. However, low faradaic efficiency, low current density, and a narrow potential range still limit the large-scale application of CO2RR electrocatalysts. Herein, monolith 3D bi-continuous nanoporous bismuth (np-Bi) electrodes are fabricated via a simple one-step electrochemical dealloying strategy from Pb-Bi binary alloy. The unique bi-continuous porous structure ensures highly effective charge transfer; meanwhile, the controllable millimeter-sized geometric porous structure enables easy catalyst adjustment to expose highly suitable surface curvatures with abundant reactive sites. This results in a high selectivity of 92.6% and superior potential window (400 mV, selectivity > 88%) for the electrochemical reduction of carbon dioxide to formate. Our scalable strategy provides a feasible pathway for mass-producing high-performance and versatile CO2 electrocatalysts.

8.
Nanomaterials (Basel) ; 13(12)2023 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-37368244

RESUMO

Non-isothermal crystallization kinetics of montmorillonite (MMT)/polyamide 610 (PA610) composites were readily prepared by in situ melt polymerization followed by a full investigation in terms of their microstructure, performance, and crystallization kinetics. The kinetic models of Jeziorny, Ozawa, and Mo were used in turn to fit the experimental data, in all of which Mo's analytical method was found to be the best model for the kinetic data. Differential scanning calorimetry (DSC) and transmission electron microscopy (TEM) studies were used to investigate the isothermal crystallization behavior and MMT dispersion levels in the MMT/PA610 composites. The experiment results revealed that low MMT content can promote the PA610 crystallization, whilst high MMT content result in MMT agglomeration, and reduce the PA610 crystallization rate.

9.
Small ; 19(27): e2300519, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36974576

RESUMO

Li-CO2 battery provides a new strategy to simultaneously solve the problems of energy storage and greenhouse effect. However, the severe polarization of CO2 reduction and CO2 evolution reaction impede the practical application. Herein, anodic TiO2 nanotube arrays are first introduced as carbon-free and free-standing cathode for photo-assisted Li-CO2 battery, and the photo-assisted charge and discharge mechanism is first clarified from the perspective of photocatalysis. Mixed-phase TiO2 exhibits a long cycling life of 580 h (52 cycles) at 0.025 mA cm-2 and delivers a high discharge specific capacity of 3001 µAh cm-2 under UV illumination. The charge voltage dramatically reduces from 4.53 to 3.03 V under UV illumination. The improvement of photo-assisted Li-CO2 battery performance relies on the synergistic effect of the hierarchical porous structure, strong UV absorption, efficient separation, and transfer of photo-generated electrons and holes at hetero-phase junction, and the facilitation of photo-generated electrons and holes on CO2 reduction and CO2 evolution reaction. This work can provide useful guidance for designing efficient photocathode for photo-assisted Li-CO2 battery and other metal-air batteries.

10.
Nanomaterials (Basel) ; 13(2)2023 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-36678019

RESUMO

A semi-aromatic polybenzimidazole (DPBI) is synthesized via polycondensation of decanedioic acid (DCDA) and 3,3-diaminobenzidine (DAB) in a mixed phosphorus pentoxide/methanesulfonic acid (PPMA) solvent. Ascribing to in-situ macromolecular crosslinker of ploly((vinylbenzyl chloride) (PVBC), a robust crosslinked DPBI membrane (DPBI-xPVBC, x refers to the weight percentage of PVBC in the membrane) can be obtained. Comprehensive properties of the DPBI and DPBI-xPVBC membranes are investigated, including chemical structure, antioxidant stability, mechanical strength, PA uptake and electrochemical performances. Compared with pristine DPBI membrane, the PA doped DPBI-xPVBC membranes exhibit excellent antioxidative stability, high proton conductivity and enhanced mechanical strength. The PA doped DPBI-10PVBC membrane shows a proton conductivity of 49 mS cm-1 at 160 °C without humidification. Particularly, it reveals an enhanced H2/O2 single cell performance with the maximum peak power density of 405 mW cm-2, which is 29% higher than that of pristine DPBI membrane (314 mW cm-2). In addition, the cell is very stable in 50 h, indicating the in-situ crosslinked DPBI with a macromolecular crosslinker of PVBC is an efficient way to improve the overall performance of HT-PEMs for high performance HT-PEMFCs.

11.
Mater Horiz ; 10(3): 993-1004, 2023 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-36651348

RESUMO

Bioinspired smart hydrogels with additive-switchable mechanical properties have been attracting increasing attention in recent years. However, most existing hydrogel systems suffer from limited stiffening amplitude and dramatic volume change upon response to environmental triggers. Herein, we propose a novel strategy to prepare additive-responsive hydrogels with ultra-highly adjustable toughness under quasi-isochoric conditions. The key point lies in tuning the softening transition temperature of the hydrogels with non-covalent interactions between the polymer networks and additives, shifting the hydrogels from glassy to rubbery states. As a proof of concept, a variety of glassy hydrogels are prepared and exposed to additives to trigger responsive performances. Young's modulus of the same hydrogel demonstrates up to 36 000 times ultra-broad-range tunability, ranging from 0.0042 to 150 MPa in response to different additives. Meanwhile, negligible volume changes occur, keeping the hydrogels in quasi-isochoric conditions. Interestingly, the mechanical behaviors of the hydrogels manifest remarkable dependence on the additive type and concentration since both the Hofmeister effect and hydrophobicity of the additives play pivotal roles according to mechanism investigations. Furthermore, the regulation with additives reveals satisfactory reversibility and universality. Taken together, this simple and effective approach provides a novel strategy to fabricate hydrogels with highly tunable toughness for versatile applications, including spatially patterned conductive gels and anti-icing coatings.

12.
ACS Appl Mater Interfaces ; 14(19): 22197-22205, 2022 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-35522974

RESUMO

The insufficient activation of a S/C cathode makes insufficient utilization of S in Li-S pouch cells, while the deep activation of a S/C cathode in a formation process is time-consuming and produces lithium polysulfides, which corrode a Li anode. Both situations lead to a low actual capacity of the Li-S pouch cells with a high S loading but are ignored for coin cells. In this work, electrochemical oscillation (EOS) formation employing hundreds of shallow discharge/charge cycles with high frequency was used to replace the resting and/or one deep discharge/charge cycle of traditional (TD) formation protocols. By controlling the discharge/charge capacity separately, symmetric oscillation (SOS) and asymmetric oscillation (ASOS) protocols were performed to facilitate the infiltration of electrolyte into the S cathode and restrict the formed lithium polysulfide in the cathode region. For SOS formation, the batteries were discharged/charged above 2.4 V with the same (symmetric) capacity with 2.78 × 10-3 Hz of oscillation frequency (∼1.4 mAh/g for SOS-500), in which the polysulfide dissolution was suppressed effectively. For ASOS formation, 100% discharge capacity (also ∼1.4 mAh/g for ASOS-500) and 92% charge capacity are set in each oscillation period, which leads to better activation effect but more shuttling polysulfides than SOS. Compared with SOS protocol, for ASOS protocol, more oxidative S (instead of polysulfides) inside original nonactivated cathode will be preferentially reduced in the next discharging process, but all the accumulated polysulfides during discharge of activation are oxidized into elemental S in the final charging process. These efficient formation protocols increase the practical capacity by up to 160% after 50 cycles without any change in pouch cell assembly.

13.
Nanomaterials (Basel) ; 12(5)2022 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-35269265

RESUMO

As a traditional high-temperature proton exchange membrane (HT-PEM), phosphoric acid (PA)-doped polybenzimidazole (PBI) is often subject to severe mechanical strength deterioration owing to the "plasticizing effect" of a large amount of PA. In order to address this issue, we fabricated the HT-PEMs with a crosslinked network of poly (arylene ether ketone) to confine polybenzimidazole in semi-interpenetration network using self-synthesized amino-terminated PBI (PBI-4NH2) as a crosslinker. Compared with the pristine linear poly [2,2'-(p-oxdiphenylene)-5,5'-benzimidazole] (OPBI) membrane, the designed HT-PEMs (semi-IPN/xPBI), in the semi-IPN means that the membranes with a semi-interpenetration structure and x represent the combined weight percentage of PBI-4NH2 and OPBI. In addition, they also demonstrate an enhanced anti-oxidative stability and superior mechanical properties without the sacrifice of conductivity. The semi-IPN/70PBI exhibits a higher proton conductivity than OPBI at temperatures ranging from 80 to 180 °C. The HT-PEMFC with semi-IPN/70PBI exhibits excellent H2/O2 single cell performance with a power density of 660 mW cm-2 at 160 °C with flow rates of 250 and 500 mL min-1 for dry H2 and O2 at a backpressure of 0.03 MPa, which is 18% higher than that of OPBI (561 mW cm-2) under the same test conditions. The results indicate that the introduction of PBI containing crosslinked networks is a promising approach to improve the comprehensive performance of HT-PEMs.

14.
Polymers (Basel) ; 13(23)2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34883713

RESUMO

Lithium-sulfur batteries (LSBs) have attracted wide attention, but the shuttle effect of polysulfide hinders their further practical application. Herein, we develop a new strategy to construct a Ketjen black@zeolite imidazole framework-8/polypropylene composite separator. Such a separator consists of Ketjen black (KB), zeolite imidazole framework-8 (ZIF-8) and polypropylene (PP) with a low coating load of 0.06 mg cm-2 and is denoted as KB@ZIF-8/PP. KB@ZIF-8/PP can absorb polysulfides because of the Lewis acid-base interaction between ZIF-8 and polysulfides. This interaction can reduce the dissolution of polysulfides and suppress the shuttle effect, thereby enhancing the electrochemical performance of the battery. When tested at a current density of 0.1 C, an LSB with a KB@ZIF-8/PP separator exhibits low polarization and achieves a high initial capacity of 1235.6 mAh/g and a high capacity retention rate of 59.27% after 100 cycles.

15.
Small ; 17(41): e2102454, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34514698

RESUMO

Lithium (Li) metal has been generally noticed as the most prospective anode for next-generation batteries attributed to its outstanding theoretical capacity and low electrochemical potential. Nevertheless, the unstable solid-electrolyte interphase (SEI) and uncontrollable dendrite growth cause poor reversibility and fetter the practical application of Li metal anodes. Herein, a new organic-inorganic hybrid polymer artificial SEI (POSS-LiBMAB) layer with uniform lithium-ion paths at a molecular level is designed to stabilize Li metal anodes. The SEI layer is constructed by the thiol-ene "click chemistry" reaction between inorganic polyhedral oligomeric silsesquioxane containing eight-mercaptopropyl (POSS-SH) with lithium bis (allylmalonato) borate (LiBMAB) on Li foil. What is more, the POSS-LiBMAB film can be cross-linked and self-reinforced via intermolecular SC bonds. Benefiting from its flexible polymeric covalent structure and noble inorganic Si8 O16 -type cubes, the organic-inorganic hybrid polymer layer is flexible and effectively tolerates the volume change of Li metal anodes during plating/stripping cycles. In addition, this layer shows loose and uniformly distributed electrostatic interaction between Li+ and charge delocalized sp3 boron-oxygen anions, which aids to form a uniform intermolecular Li+ path regulating the homogeneous distribution of Li+ flux on Li anodes. Finally, the designed POSS-LiBMAB layer has high ionic conductivity and lithium-ion transference number, which can effectively promote Li+ diffusion and guide Li deposition beneath the SEI layer. Therefore, with the protection of the POSS-LiBMAB layer, the Li metal anode exhibits stable cycling at 5 mA cm-2 for more than 1000 h, and the LFP//Li full cells also present outstanding cycling stability.

16.
Small ; 17(29): e2101496, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34142443

RESUMO

Uniform deposition and distribution of lithium ion (Li+ ) on the surface of lithium metal anode is crucial for long-life and high-safety lithium metal batteries. However, the preparation of stable solid-electrolyte interphase (SEI) is mostly based on trial and error in the absence of guideline. Herein, covalent organic framework (COF) with high Young's modulus and low surface work function is in situ synthesized on Li anode to stabilize Li|electrolyte interface. Notably, Young's modulus, mechanical index for Li dendrite resistance, and surface work function, electrical index for Li+ distribution, can be regarded as macroscopically detectable indicators to evaluate the artificial SEI before battery assembly. The COFTpPa modified Li metal anodes delivered stable cycling over 1000 (2000) h at high current density of 5 (2) mA cm-2 in the ether-based electrolyte, and the full cells with commercial LiFePO4 electrode (mass loading of 16.5 mg cm-2 ) demonstrate remarkably enhanced cycling performance with a high reversible capacity of 152.3 mAh g-1 (retention of 96.8%) after 300 cycles.

17.
Angew Chem Int Ed Engl ; 60(17): 9590-9597, 2021 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-33554402

RESUMO

Insufficient catalytic activity and stability and high cost are the barriers for Pt-based electrocatalysts in wide practical applications. Herein, a hierarchically porous PtNi nanoframe/N-doped graphene aerogel (PtNiNF-NGA) electrocatalyst with outstanding performance toward methanol oxidation reaction (MOR) in acid electrolyte has been developed via facile tert-butanol-assisted structure reconfiguration. The ensemble of high-alloying-degree-modulated electronic structure and correspondingly the optimum MOR reaction pathway, the structure superiorities of hierarchical porosity, thin edges, Pt-rich corners, and the anchoring effect of the NGA, endow the PtNiNF-NGA with both prominent electrocatalytic activity and stability. The mass and specific activity (1647 mA mgPt -1 , 3.8 mA cm-2 ) of the PtNiNF-NGA are 5.8 and 7.8 times higher than those of commercial Pt/C. It exhibits exceptional stability under a 5-hour chronoamperometry test and 2200-cycle cyclic voltammetry scanning.

18.
Polymers (Basel) ; 13(4)2021 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-33578764

RESUMO

As a key component of direct methanol fuel cells, proton exchange membranes with suitable thickness and robust mechanical properties have attracted increasing attention. On the one hand, a thinner membrane gives a lower internal resistance, which contributes highly to the overall electrochemical performance of the cell, on the other hand, strong mechanical strength is required for the application of proton exchange membranes. In this work, a sulfonated poly (fluorenyl ether ketone) (SPFEK)-impregnated polyimide nanofiber mat composite membrane (PI@SPFEK) was fabricated. The new composite membrane with a thickness of about 55 µm exhibited a tensile strength of 35.1 MPa in a hydrated state, which is about 65.8% higher than that of the pristine SPFEK membrane. The antioxidant stability test in Fenton's reagent shows that the reinforced membrane affords better oxidation stability than does the pristine SPFEK membrane. Furthermore, the morphology, proton conductivity, methanol permeability, and fuel cell performance were carefully evaluated and discussed.

19.
Macromol Rapid Commun ; 42(1): e2000446, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33108036

RESUMO

Hydrogels and polydimethylsiloxane (PDMS) are complementary to each other, since the hydrophobic PDMS provides a more stable and rigid substrate, while the water-rich hydrogel possesses remarkable hydrophilicity, biocompatibility, and similarity to biological tissues. Herein a transparent and stretchable covalently bonded PDMS-hydrogel bilayer (PHB) structure is prepared via in situ free radical copolymerization of acrylamide and allylamine-exfoliated-ZrP (AA-e-ZrP) on a functionalized PDMS surface. The AA-e-ZrP serves as cross-linking nano-patches in the polymer gel network. The covalently bonded structure is constructed through the addition reaction of vinyl groups of PDMS surface and monomers, obtaining a strong interfacial adhesion between the PDMS and the hydrogel. A mechanical-responsive wrinkle surface, which exhibs transparency change mechanochromism, is created via introducing a cross-linked polyvinyl alcohol film atop the PHB structure. A finite element model is implemented to simulate the wrinkle formation process. The implication of the present finding for the interfacial design of the PHB and PDMS-hydrogel-PVA trilayer (PHPT) structures is discussed.


Assuntos
Dimetilpolisiloxanos , Hidrogéis , Interações Hidrofóbicas e Hidrofílicas , Polímeros , Álcool de Polivinil
20.
ACS Appl Mater Interfaces ; 12(32): 36237-36246, 2020 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-32689786

RESUMO

Organic conjugated carbonyl materials have attracted considerable attention in the field of high-capacity and green energy storage technologies. However, the high solubility in organic electrolyte restrains their further application. In this work, an organic terephthalate compound (Li2M) with propargyl groups is synthesized innovatively and then used to prepare a highly cross-linked anode material (X-Li2M) by simple hydrothermal treatment for rechargeable lithium batteries. The electrochemical properties are enhanced significantly by in situ constructing an interpenetrating network of X-Li2M and the conductive carbon nanotubes (CNTs). The as-synthesized X-Li2M@CNTs composite anode delivers a reversible capacity of ∼200 mAh g-1 at 0.1 C after 200 cycles and exhibits excellent cycle stability at a high rate of 1 C with ∼150 mAh g-1 retention capacity after 1000 cycles and nearly 100% average Coulombic efficiency. Additionally, the superior rate capability is obtained at the high rate of 2 and 10 C and with specific discharge capacities of 140 and 100 mAh g-1, respectively. Highly reversible redox reaction of the electrochemical active site carbonyl group (C═O) is ascertained by ex-situ infrared spectroscopy and X-ray photoelectron spectroscopy. The described approach provides a novel direction for the immobilization of organic electrode molecules and is intended to serve as a universal guide for the research and fabrication of high-performance organic batteries.

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