Printable magnesium ion quasi-solid-state asymmetric supercapacitors for flexible solar-charging integrated units.

Wearable and portable self-powered units have stimulated considerable attention in both the scientific and technological realms. However, their innovative development is still limited by inefficient bulky connections between functional modules, incompatible energy storage systems with poor cycling stability, and real safety concerns. Herein, we demonstrate a flexible solar-charging integrated unit based on the design of printed magnesium ion aqueous asymmetric supercapacitors. This power unit exhibits excellent mechanical robustness, high photo-charging cycling stability (98.7% capacitance retention after 100 cycles), excellent overall energy conversion and storage efficiency (ηoverall = 17.57%), and outstanding input current tolerance. In addition, the Mg ion quasi-solid-state asymmetric supercapacitors show high energy density up to 13.1 mWh cm-3 via pseudocapacitive ion storage as investigated by an operando X-ray diffraction technique. The findings pave a practical route toward the design of future self-powered systems affording favorable safety, long life, and high energy

Electrochemical interfacial influences on deoxygenation and hydrogenation reactions in CO reduction on a Cu(100) surface.

Electroreduction of CO2 to hydrocarbons on a copper surface has attracted much attention in the last few decades for providing a sustainable way for energy storage. During the CO2 and further CO electroreduction processes, deoxygenation that is C-O bond dissociation, and hydrogenation that is C-H bond formation, are two main types of surface reactions catalyzed by the copper electrode. In this work, by performing the state-of-the-art constrained ab initio molecular dynamics simulations, we have systematically investigated deoxygenation and hydrogenation reactions involving two important intermediates, COHads and CHOads, under various conditions of (i) on a Cu(100) surface without water molecules, (ii) at the water/Cu(100) interface and (iii) at the charged water/Cu(100) interface, in order to elucidate the electrochemical interfacial influences. It has been found that the electrochemical interface can facilitate considerably the C-O bond dissociation via changing the reaction mechanisms. However, C-H bond formation has not been affected by the presence of water or electrical charge. Furthermore, the promotional roles of an aqueous environment and negative electrode potential in deoxygenation have been clarified, respectively. This fundamental study provides an atomic level insight into the significance of the electrochemical interface towards electrocatalysis, which is of general importance for understanding electrochemistry

Elucidation of the surface structure-selectivity relationship in ethanol electro-oxidation over platinum by density functional theory

We have successfully built a general framework to comprehend the structure-selectivity relationship in ethanol electrooxidation on platinum by density functional theory calculations. Based on the reaction mechanisms on three basal planes and five stepped surfaces, it was found that only (110) and n(111) × (110) sites can enhance CO2 selectivity but other non-selective step sites are more beneficial to activity

Improving Communication Efficiency of Federated Distillation via Accumulating Local Updates

As an emerging federated learning paradigm, federated distillation enables communication-efficient model training by transmitting only small-scale knowledge during the learning process. To further improve the communication efficiency of federated distillation, we propose a novel technique, ALU, which accumulates multiple rounds of local updates before transferring the knowledge to the central server. ALU drastically decreases the frequency of communication in federated distillation, thereby significantly reducing the communication overhead during the training process. Empirical experiments demonstrate the substantial effect of ALU in improving the communication efficiency of federated distillation.Comment: 2 pages, 3 figure

[N,N-Bis(diphenyl­phosphan­yl)propanamine-κ2 P,P′]dichloridonickel(II)

In the title complex, [NiCl2(C27H27NP2)], the Ni2+ ion is coordinated by two chloride ions and two P atoms of the bidentate N,N-bis­(diphenyl­phosphan­yl)propyl ligand to generate a strongly distorted cis-NiCl2P2 square-planar geometry for the metal ion. A NiP2N rhombus occurs within the chelating ligand

[N,N-Bis(diphenyl­phosphan­yl)benzyl­amine-κ2 P,P′]dichloridonickel(II) dichloro­methane monosolvate

In the title solvated complex, [NiCl2(C31H27NP2)]·CH2Cl2, the Ni2+ ion is coordinated by two chloride ions and two P atoms of the chelating N,N-bis­(diphenyl­phosphan­yl)benzyl ligand to generate a strongly distorted cis-NiCl2P2 square-planar geometry for the metal ion. In the crystal, the components are linked by C—H⋯Cl inter­actions