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This work proposes a theoretical description of ion exchange in glass involving mechano–electrochemical coupling, distinct from the previous models. The generalized Maxwell viscoelastic constitutive relation and large‐deformation formulae are employed, which is indispensable for thin glass panels widely used in consumer electronics. With the theory, two‐dimensional numerical simulations based on axisymmetric and plan‐strain models are conducted. The numerical results signify lateral deformation in a double‐side ion‐exchanged glass and bending caused by single‐side or electric‐field‐assisted ion exchange. With the decrease in glass thickness, the increase in time, or applied electric potential, these deformations become more significant, leading to the relief of in‐plane stresses in the ion‐exchanged layer and the increase in stresses in other parts. This could lead to a remarkable decrease in fracture strength or cracking of an ultrathin glass panel. As the stress and diffusion are coupled, the decrease in stress in the ion‐exchanged layer leads to the increase in the depth of layer of invading ions. These numerical results clearly show the necessity to incorporate the mechano–electrochemical coupling and large deformation in modeling ion exchange, which is uninvolved in previous theoretical models. Moreover, the proposed theoretical model is directly extendable to three‐dimensional scenarios, such as curved or foldable ultrathin glass panels. [ABSTRACT FROM AUTHOR]

Dendrite formation is a critical issue in uranium recovery from spent nuclear fuel (SNF) through a molten-salt electrorefining process. To understand and modulate uranium dendritic formation, we developed a computation model that involves all the complexities in the mechano-electrochemical process, such as diffusion–reaction kinetics, interfacial anisotropy and the variations of electric and stress fields. In particular, the lattice mismatch between deposit and substrate is considered which addressed the importance of cathode material. The model explains various morphologies of dendrites, which in a two-dimensional scenario can be demarcated based on the perimeter-to-area ratio, χ/S. Dendrites can be needle-like, tooth-like, or tree-like when χ/S

Mechanotransduction is the initiation of an electrochemical signal as a result of mechanical stimuli. It is found predominately in biological tissue and its mechanisms are well documented. In the gel like tissues of the body, such as articular cartilage and intervertebral discs, mechanotransduction regulates matrix building and degrading processes as well as keeping the tissues adequately hydrated, both with the aim of minimizing degradation. The electrochemical responses to mechanical loading at constant volume of an inanimate hydrogel could assist in the understanding of these processes.There is considerable evidence that the modulus of hydrated tissues and hydrogels depend explicitly on ionic concentration. By modeling the mechano-electrochemical relationship of a hydrogel, the coupling of the elastic and electrochemical energies can be quantified. In turn, the mechanisms that govern this phenomenon can be better understood. This study modifies the Flory-Rehner theory of gels, using material-specific experimental data as input. The results show up to a 11% difference in equilibrium swelling magnitude compared to the Flory-Rehner model. Furthermore, under isochoric deformation, an increase in electrical potential is shown with increasing shear strain, something which is not possible with conventional Flory-Rehner and Donnan theory. This aligns the continuum model presented here more closely with both experiment and microscopic theories. The mechanosensing capabilities as well as varying swelling responses in different solution concentrations highlight the models potential applications in both biological and technological settings.

Batteries can be activated by external mechanical force and generate current, enabling a smart class of electrochemical-mechanical strain energy harvesters therefrom. Here, we have developed a Na x Sb alloy-based harvester that is able to electrochemically convert low-frequency bending or pressing mechanical energy into electrical energy. The device is designed as a flexible symmetric cell incorporating two sodiated antimony nanoflake electrodes, whose peak power and energy output are more than twice those of other sodium-alloyed electrochemical-mechanical strain energy harvesters reported. We demonstrate that the open-circuit voltage of the device is an asymptotic function of the curvature radius in the bending mode and a linear function of pressure in the pressing mode. Taking advantage of the tunability of voltage, we present a new technology that simulates various tastes by releasing low-voltage electrical signals from the harvester. This technology can not only help people with impaired taste but also be integrated into a virtual reality system to create immersive taste experiences.

Unclear reaction mechanisms and unsatisfactory power performance hinder the further development of advanced lithium/fluorinated carbon (Li/CF x ) batteries. Herein, the mechano-electrochemical coupling behavior of a CF x cathode is investigated by in situ monitoring strain/stress using digital image correlation (DIC) techniques, electrochemical methods, and theoretical equations. The DIC monitoring results present the distribution and dynamic evolution of the plane strain and indicate strong dependence toward the material structure and discharge rate. The average plane principal strain of fully discharged 2D fluorinated graphene nanosheets (FGNSs) at 0.5 C is 0.50%, which is only 38.5% that of conventional bulk-structure CF x . Furthermore, the superior structural stability of the FGNSs is demonstrated by the microstructure and component characterization before and after discharge. The plane stress evolution is calculated based on theoretical equations, and the contributions of electrochemical and mechanical factors are examined and discussed. Subsequently, a structure-dependent three-region discharge mechanism for CF x electrodes is proposed from a mechanical perspective. Additionally, the surface deformation of Li/FGNSs pouch cells formed during the discharge process is monitored using in situ DIC. This study reveals the discharge mechanism of Li/CF x batteries and facilitates the design of advanced CF x materials., (© 2023 Wiley-VCH GmbH.)

Abstract Free-standing MWCNTs/V 2 O 5 nanobelts composite architecture electrodes for lithium ion batteries (LIBs) are prepared based on hydrothermal method, electrostatic self-assembly approach and vacuum filtration deposition technique. Such kind of nanoarchitecture enhances the electrochemical kinetics and structural stability of V 2 O 5 cathodes. The distribution and evolution features of plane strains in free-standing MWCNTs/V 2 O 5 cathodes surface are in-operando monitored by using digital image correlation method and systematically discussed. The strain results show that the evolution of strain against potential obeys general Arrhenius relation under galvanostatic charge-discharge cycling. Considering the effect of lithium ion concentration, the elastic modulus of 20 wt% MWCNTs/V 2 O 5 electrode is confirmed via nanoindentation. The evolutions of average plane stresses in the free-standing MWCNTs/V 2 O 5 electrodes, as well as the contributions of mechanical and electrochemical components, are evaluated and discussed by mechano-electrochemical constitutive equation during electrochemical process. The analytical methods used in this article are universal for revealing the electrode mechano-electrochemical failure mechanism in LIBs. Highlights • MWCNTs/V 2 O 5 nanobelt nanocomposites were prepared by electrostatic self-assembly. • The evolution of plane strain in MWCNTs/V 2 O 5 cathodes is in-operando monitored. • The relationship of voltage and strain was established by general Arrhenius formula. • The stresses in MWCNTs/V 2 O 5 cathode varied with charging-discharging cycles. • The results are useful for revealing mechano-electrochemical mechanisms of LIBs. [ABSTRACT FROM AUTHOR]

A fully coupled electrochemical-mechanical model of all-solid-state Li-ion batteries (ASSLBs) considering the interfacial contact loss is established. The influences of current and partial molar volume of cathode/anode on the interfacial contact and performance of the ASSLB are numerically studied. The results show that the range of stress changes within the ASSLB are dependent on the current applied. Lithium (Li) partially inserted into anode cannot return to cathode during discharging, which causes a "residual stress" and then can improves the interface contact. The interfacial contact loss gives rise to an increase in local current density. Cycling with a current density of 0.2 mA cm−2, the local current density across the electrode/electrolyte interface is as high as 0.66 mA cm−2, which increases risks such as dendrite formation. We further show that a large partial molar volume of cathode/anode may directly reduce the capacity retention. Moreover, higher partial molar volume of cathode or lower that of anode reduces the (stack) stress, which can deteriorate the interface contact area. Finally, the cathode materials with lower partial molar volume are recommend to balance capacity and interfacial contact. As for anodes, the moderate partial molar volumes are required for robust ASSLBs with improved performance characteristics. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mechano-electrochemical phase-field model is developed to tackle effects concentration, electric and stress fields and interfacial anisotropy in molten-salt electrorefining. • The role of plating stress on the dendric growth is firstly considered. • Dendrite patterns can be needle-like, tooth-like, or tree-like, which are consistent with experimental observations and quantitively demarcated based on the perimeter-to-area ratio. • The coupling effects of applied voltage, molten-salt diffusivity and plating stress on dendritic growth are investigated and quantified in parametric diagrams. Dendrite formation is a critical issue in uranium recovery from spent nuclear fuel (SNF) through a molten-salt electrorefining process. To understand and modulate uranium dendritic formation, we developed a computation model that involves all the complexities in the mechano-electrochemical process, such as diffusion–reaction kinetics, interfacial anisotropy and the variations of electric and stress fields. In particular, the lattice mismatch between deposit and substrate is considered which addressed the importance of cathode material. The model explains various morphologies of dendrites, which in a two-dimensional scenario can be demarcated based on the perimeter-to-area ratio, χ / S. Dendrites can be needle-like, tooth-like, or tree-like when χ / S < 2 mm−1, 2 mm−1 ≤ χ / S < 6 mm−1, and χ / S ≥ 6 mm−1, respectively. With these conditions, the parameter maps for modulating dendritic patterns are drawn to elucidate the effects of interfacial anisotropy, nuclei site geometry, diffusivity, electric and stress fields, which can be employed to design a molten-salt electroplating process to minimize failures caused by dendrite formation. [ABSTRACT FROM AUTHOR]

Mechanotransduction is the initiation of an electrochemical signal as a result of mechanical stimuli. It is found predominately in biological tissue and its mechanisms are well documented. In the gel like tissues of the body, such as articular cartilage and intervertebral discs, mechanotransduction regulates matrix building and degrading processes as well as keeping the tissues adequately hydrated, both with the aim of minimizing degradation. The electrochemical responses to mechanical loading at constant volume of an inanimate hydrogel could assist in the understanding of these processes. There is considerable evidence that the modulus of hydrated tissues and hydrogels depend explicitly on ionic concentration. By modeling the mechano-electrochemical relationship of a hydrogel, the coupling of the elastic and electrochemical energies can be quantified. In turn, the mechanisms that govern this phenomenon can be better understood. This study modifies the Flory-Rehner theory of gels, using material-specific experimental data as input. The results show up to a 11% difference in equilibrium swelling magnitude compared to the Flory-Rehner model. Furthermore, under isochoric deformation, an increase in electrical potential is shown with increasing shear strain, something which is not possible with conventional Flory-Rehner and Donnan theory. This aligns the continuum model presented here more closely with both experiment and microscopic theories. The mechanosensing capabilities as well as varying swelling responses in different solution concentrations highlight the models potential applications in both biological and technological settings. Unlabelled Image • A mechano-electrochemical material model for hydrogels was derived. • Mechanical loading changes the electrical potential at constant volume. • The modulus changes effect hydrogel swelling magnitude at different concentrations. • The results indicate potential applications in biology and technology. [ABSTRACT FROM AUTHOR]

• A galvanic pitting and mechano-electrochemical multi-phase-field model is proposed. • Occluded cell corrosion process is numerically studied. • Pitting corrosion is assisted by aggressive chemical environment and concentrated stress. • External electric field can arrest assisted corrosion and prolong service lifetime. A new multi-phase-field (multi-PF) model is proposed to study a complex localized corrosion process that involves mechano-electrochemical coupling, anodic dissolution, insoluble depositions (IDs) formation, and resulted Galvanic-pitting corrosion. Based on a quantitative investigation into the effects of Cl − concentration, pH value, mechanical loading, and electric field, we reveal the autocatalytic process of pitting assisted by increasingly aggressive chemical environment and concentrated stress and study how the external electric field can arrest assisted corrosion and prolong service lifetime. The proposed model can be a useful tool for the lifetime management of metallic components serving in ocean or other more aggressive environments. [ABSTRACT FROM AUTHOR]