In situ tensile tests of Cu single crystalline nanowires in a high-resolution transmission electron microscope reveal a novel effect of sample dimensions on plasticity mechanisms. When the single crystalline nanowire size was reduced to <∼150 nm, the normal full dislocation slip was taken over by partial dislocation mediated plasticity (PDMP). For the first time, we demonstrate this transition in a quantitative manner by assessing the relative contributions to plastic strain from PDMP and full dislocations. The crossover sample size is consistent, well within model predictions. This discovery represents yet another "sample size effect", beyond other reported influence of sample dimensions on the mechanical behavior of metals, such as dislocation starvation or source truncation, and the "smaller is stronger" trend.

Lithium metal anodes are deemed as the “Holy Grail” for next generation high energy density batteries, due to the reported highest specific capacity (3860 mAh g−1) and the lowest negative electrochemical potential (−3.04 V vs the standard hydrogen electrode). However, the notorious tip‐induced dendrite growth leads to low Coulombic efficiency, restricted lifespan, and even catastrophic short‐circuits, blocking the roadmap of their commercialization. Here, a magnetic field is introduced into the lithium plating process. The Li+ concentrated around the tips by the uneven electric field distribution can be taken off the hotpots by the Lorentz force and the tip dendrite growth can be eliminated. The relationship between current density and magnetic flux intensity is established by monitoring the deposited lithium morphology as well as the electrochemical performance, which is confirmed by mathematic modeling and COMSOL Multiphysics simulation. It is also demonstrated that the Lorentz force–induced tip dendrite elimination can be utilized practically by assembling permanent magnet‐containing prototype coin cell. It is anticipated that this physical approach can be applied to other high energy density systems as well.

The paper explores how changes in the lattice parameter at an electrode surface by elastic strain affect the catalytic activity. The focus is on the hydrogen evolution reaction on 111-textured, polycrystalline Au and Pt thin film electrodes in H2SO4 as a model process. A lock-in technique allows the modulation of the reaction current to be measured in situ during small cyclic strain imposed on the electrode. While tensile strain enhances the exchange current density and the reactivity at low overpotential, ∆E, the trend is inverted and the reactivity diminished at higher ∆E. Strain is introduced into the kinetic rate equation for Heyrowsky kinetics by allowing for straindependence of the hydrogen adsorption enthalpy as well as the activation enthalpy. The results link the current modulation to electrocapillary coupling coefficients that are open to investigation by experiment or computer simulation. The inversion in sign of the coupling as the function of ∆E emerges in agreement with experiment.

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Nowadays, Li‐ion batteries have achieved great success and are widely used in various fields. However, the scarcity and uneven distribution of lithium resources together with the increasing cost may hamper the sustainable development of Li‐ion batteries in the future. Hence, many researchers have turned to potassium ion batteries due to their abundant raw materials, low price, and high energy density. Although great progress has been made in recent years, there are still existing many challenges, especially the severe side reaction between electrolyte and K metal, which leads to an unstable solid–liquid interface and low coulombic efficiency. Hence, an excellent electrolyte may be the key to development of K‐ion batteries in the future. Unfortunately, no systematic research has been conducted to study the electrolyte and its role on the performance yet. In order to compensate for this limitation, in this paper, the status and progress of electrolytes for K‐ion batteries are reviewed, the issues and challenges existing in the development of electrolyte are clarified, and the future development is prospected.

We report and validate a method for measuring the strain-response, ς, of the electrode potential of electrically conductive solids in a fluid electrolyte. Simultaneously with cyclic voltammetry, the electrode is subjected to cyclic elastic strain at frequencies of up to 100 Hz. We explore three independent strategies for separating the cyclic variation of potential or current from the voltammogram proper, and find that the results of all three are in quantitative agreement. By means of an example we explore dominantly capacitive processes at a gold electrode in H(2)SO(4) and HClO(4). The response parameter ς is not sensitive to the nature of the electrolyte. Yet, its value varies by more than a factor of two in the potential interval investigated. The potential of largest magnitude of ς agrees closely with the potential of zero charge.

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Development of emerging technologies for the harmless treatment and resource utilization of sewage is an urgent demand for both environment and energy concerns. This work presents the enhanced electrochemical hydrogen generation process from urea sewage by coupling the urea oxidation reaction (UOR) and hydrogen evolution reaction (HER) under the catalysis of nanoporous nickel−iron (NP-NiFe)-based catalysts. The porous structure at the nanoscale facilitates electrocatalysis through exposure and access more active sites as well as improving the mass transfer. The optimized NP-NiFe (NP-Ni 0.7 Fe 0.3 ) displays excellent oxygen evolution reaction (OER) activity. The overpotential can be further lowered to ∼60 mV at 10 mA cm −2 in urea sewage (0.33 M urea and 1 M KOH) because of coupling with the UOR, and therefore, the full water splitting potential is much lower in urea sewage (1.55 vs 1.68 V) at 10 mA cm −2 . The relationship between the UOR and OER at different potentials during electrolysis of urea was further investigated by mass spectrometry. The spontaneous desorption of CO 2 (UOR product) from the surface of NP-NiFe indicates that NP-NiFe has more effective UOR activity. In addition, NP-NiFe has also been proven to be used in the full electrolysis of urea-containing wastewater for hydrogen production.