Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Adv Mater ; 36(26): e2403803, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38598181

RESUMO

Aqueous zinc-ion batteries are attractive post-lithium battery technologies for grid-scale energy storage because of their inherent safety, low cost and high theoretical capacity. However, their practical implementation in wide-temperature surroundings persistently confronts irregular zinc electrodeposits and parasitic side reactions on metal anode, which leads to poor rechargeability, low Coulombic efficiency and short lifespan. Here, this work reports lamellar nanoporous Cu/Al2Cu heterostructure electrode as a promising anode host material to regulate high-efficiency and dendrite-free zinc electrodeposition and stripping for wide-temperatures aqueous zinc-ion batteries. In this unique electrode, the interconnective Cu/Al2Cu heterostructure ligaments not only facilitate fast electron transfer but work as highly zincophilic sites for zinc nucleation and deposition by virtue of local galvanic couples while the interpenetrative lamellar channels serving as mass transport pathways. As a result, it exhibits exceptional zinc plating/stripping behaviors in aqueous hybrid electrolyte of diethylene glycol dimethyl ether and zinc trifluoromethanesulfonate at wide temperatures ranging from 25 to -30 °C, with ultralow voltage polarizations at various current densities and ultralong lifespan of >4000 h. The outstanding electrochemical properties enlist full cell of zinc-ion batteries constructed with nanoporous Cu/Al2Cu and ZnxV2O5/C to maintain high capacity and excellent stability for >5000 cycles at 25 and -30 °C.

2.
Small ; : e2311509, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38587968

RESUMO

Developing robust non-platinum electrocatalysts with multifunctional active sites for pH-universal hydrogen evolution reaction (HER) is crucial for scalable hydrogen production through electrochemical water splitting. Here ultra-small ruthenium-nickel alloy nanoparticles steadily anchored on reduced graphene oxide papers (Ru-Ni/rGOPs) as versatile electrocatalytic materials for acidic and alkaline HER are reported. These Ru-Ni alloy nanoparticles serve as pH self-adaptive electroactive species by making use of in situ surface reconstruction, where surface Ni atoms are hydroxylated to produce bifunctional active sites of Ru-Ni(OH)2 for alkaline HER, and selectively etched to form monometallic Ru active sites for acidic HER, respectively. Owing to the presence of Ru-Ni(OH)2 multi-site surface, which not only accelerates water dissociation to generate reactive hydrogen intermediates but also facilitates their recombination into hydrogen molecules, the self-supported Ru90Ni10/rGOP hybrid electrode only takes overpotential of as low as ≈106 mV to deliver current density of 1000 mA cm-2, and maintains exceptional stability for over 1000 h in 1 m KOH. While in 0.5 m H2SO4, the Ru90Ni10/rGOP hybrid electrode exhibits acidic HER catalytic behavior comparable to commercially available Pt/C catalyst due to the formation of monometallic Ru shell. These electrochemical behaviors outperform some of the best Ru-based catalysts and make it attractive alternative to Pt-based catalysts toward highly efficient HER.

3.
Angew Chem Int Ed Engl ; 63(18): e202402327, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38467561

RESUMO

Metallic zinc is a promising anode material for rechargeable aqueous multivalent metal-ion batteries due to its high capacity and low cost. However, the practical use is always beset by severe dendrite growth and parasitic side reactions occurring at anode/electrolyte interface. Here we demonstrate dynamic molecular interphases caused by trace dual electrolyte additives of D-mannose and sodium lignosulfonate for ultralong-lifespan and dendrite-free zinc anode. Triggered by plating and stripping electric fields, the D-mannose and lignosulfonate species are alternately and reversibly (de-)adsorbed on Zn metal, respectively, to accelerate Zn2+ transportation for uniform Zn nucleation and deposition and inhibit side reactions for high Coulombic efficiency. As a result, Zn anode in such dual-additive electrolyte exhibits highly reversible and dendrite-free Zn stripping/plating behaviors for >6400 hours at 1 mA cm-2, which enables long-term cycling stability of Zn||ZnxMnO2 full cell for more than 2000 cycles.

4.
Small ; 20(26): e2310722, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38229525

RESUMO

Aqueous aluminum-ion batteries are attractive post-lithium battery technologies for large-scale energy storage in virtue of abundant and low-cost Al metal anode offering ultrahigh capacity via a three-electron redox reaction. However, state-of-the-art cathode materials are of low practical capacity, poor rate capability, and inadequate cycle life, substantially impeding their practical use. Here layered manganese oxide that is pre-intercalated with benzoquinone-coordinated aluminum ions (BQ-AlxMnO2) as a high-performance cathode material of rechargeable aqueous aluminum-ion batteries is reported. The coordination of benzoquinone with aluminum ions not only extends interlayer spacing of layered MnO2 framework but reduces the effective charge of trivalent aluminum ions to diminish their electrostatic interactions, substantially boosting intercalation/deintercalation kinetics of guest aluminum ions and improving structural reversibility and stability. When coupled with Zn50Al50 alloy anode in 2 m Al(OTf)3 aqueous electrolyte, the BQ-AlxMnO2 exhibits superior rate capability and cycling stability. At 1 A g-1, the specific capacity of BQ-AlxMnO2 reaches ≈300 mAh g-1 and retains ≈90% of the initial value for more than 800 cycles, along with the Coulombic efficiency of as high as ≈99%, outperforming the AlxMnO2 without BQ co-incorporation.

5.
Nat Commun ; 14(1): 1811, 2023 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-37002220

RESUMO

Developing robust nonprecious-metal electrocatalysts with high activity towards sluggish oxygen-evolution reaction is paramount for large-scale hydrogen production via electrochemical water splitting. Here we report that self-supported laminate composite electrodes composed of alternating nanoporous bimetallic iron-cobalt alloy/oxyhydroxide and cerium oxynitride (FeCo/CeO2-xNx) heterolamellas hold great promise as highly efficient electrocatalysts for alkaline oxygen-evolution reaction. By virtue of three-dimensional nanoporous architecture to offer abundant and accessible electroactive CoFeOOH/CeO2-xNx heterostructure interfaces through facilitating electron transfer and mass transport, nanoporous FeCo/CeO2-xNx composite electrodes exhibit superior oxygen-evolution electrocatalysis in 1 M KOH, with ultralow Tafel slope of ~33 mV dec-1. At overpotential of as low as 360 mV, they reach >3900 mA cm-2 and retain exceptional stability at ~1900 mA cm-2 for >1000 h, outperforming commercial RuO2 and some representative oxygen-evolution-reaction catalysts recently reported. These electrochemical properties make them attractive candidates as oxygen-evolution-reaction electrocatalysts in electrolysis of water for large-scale hydrogen generation.

6.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 48(10): 610-4, 2013 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-24438569

RESUMO

OBJECTIVE: To compare curative effect between complete denture with lingualized occlusion and anatomic occlusion on temporomandibular joint disorders (TMD) of aged edentulous patients with severe residual alveolar ridge resorption. METHODS: Seventy aged edentulous patients with severe residual alveolar ridge resorption were recruited in this study and randomly assigned into two groups, thirty-five each. In Group A, patients received complete denture with lingualized occlusion, and in Group B, patients received complete denture with anatomic occlusion. The condition of TMD was examined and recorded by the same TMD specialist at baseline, 3 months and 6 months following denture delivery. The recovery effect of TMD was evaluated according to Fricton Index. Related data were analyzed statistically with t-test and rank sum test. RESULTS: Three months following denture delivery, the craniomandibular index (CMI) decrease value was (0.064 ± 0.022) in group A, and was significantly higher than that in group B (0.043 ± 0.018) (P < 0.01). Six months following denture delivery, the CMI decrease value was (0.084 ± 0.020) in group A, and was significantly higher than that in group B (0.070 ± 0.021) (P = 0.011<0.05). CONCLUSIONS: Complete denture with lingualized occlusion may be more conducive to the remission of TMD for aged edentulous patients with severe residual alveolar ridge resorption.


Assuntos
Oclusão Dentária , Prótese Total , Arcada Edêntula/complicações , Transtornos da Articulação Temporomandibular , Idoso , Idoso de 80 Anos ou mais , Oclusão Dentária Central , Feminino , Humanos , Masculino , Transtornos da Articulação Temporomandibular/etiologia , Transtornos da Articulação Temporomandibular/terapia
7.
J Mol Model ; 18(12): 5035-40, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22752546

RESUMO

In this contribution, the size dependent band gap variation of (Zn(4/6)Cu(2/6)O)(L)/(Zn(5/6)Cu(1/6)O)(L) (L is the periodic size) superlattices are investigated with the change of L. The results show that the variation tendency of band gap appears a minimum in S(4) (L = 4) which is nearly a conductor. The band gap of S(3) (L = 3) and S(5) (L = 5) also decrease obviously compared to the other three configurations. Especially, the band gap of S(3) has decreased to 2.16 eV which is in the region of narrow bandgap semiconductor. Thus, the band gap can be modulated by alloying through constructing an appropriate variation period. Our ZnCuO superlattices can absorb light in both visible and UV region. These properties make the superlattices a potential application in photocatalysis and the visible light emitter.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...