Electrolyte Transport Research Articles

Constructing superhydrophilic CoRu-LDH/PANI nanowires with optimized electronic structure for hydrogen evolution reaction

Promoting the dissociation of water and desorption of hydrogen are both crucial challenges for improving the hydrogen evolution reaction (HER) activity and stability in alkaline media, especially at large current densities. Herein, we demonstrate a polyaniline-coated CoRu-LDH (CoRu-LDH/PANI) nanowire array electrocatalyst for efficient and stable alkaline HER. Benefiting from the optimized electronic structure and surface properties, the as-prepared CoRu-LDH/PANI shows an excellent HER activity with low overpotentials of 250, and 275 mV, respectively, at large current densities of 500 and 1000 mA cm−2 in 1.0 M KOH, superior to the benchmark 20% Pt/C and the pristine CoRu-LDH. Furthermore, CoRu-LDH/PANI exhibits an unprecedented stability at a large current density of 500 mA cm−2 even after 50 h. The combined experimental and density functional theory (DFT) investigations reveal that PANI coating not only performs as an electronic regulator to lift the valence states and reduces the binding strength to hydrogen intermediates, leading to the superior HER performance, but also affords a superhydrophilic surface to promote the rapid transport of electrolytes and bubbles, which is crucial for the long-term stability at large current density. This work provides an effective guidance for engineering efficient alkaline HER eletrocatalysts towards practical water electrolysis.

Circadian Regulation of Electrolyte and Water Transport in the Rat Kidney

Circadian Regulation of Electrolyte and Water Transport in the Rat Kidney

Relationship between Ion Transport and Phase Behavior in Acetal-Based Polymer Blend Electrolytes Studied by Electrochemical Characterization and Neutron Scattering

We have studied ion transport in electrolytes created by blending two different polymers and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI). The polymers covered in this study are poly(ethylene oxide) (PEO), poly(1,3,6-trioxocane) (P(2EO-MO)), and poly(1,3-dioxolane) (P(EO-MO)). Ion transport is quantified by the product κρ+ which is defined as the efficacy of the electrolytes, where κ is conductivity and ρ+ is the current fraction determined by the Bruce–Vincent method. Polymer blends can be either one-phase or macrophase-separated. We used small-angle neutron scattering (SANS) to distinguish between these two possibilities. The random phase approximation (RPA) was used to interpret SANS data from one-phase blends. The effect of added salt on polymer blend thermodynamics is quantified by an effective Flory–Huggins interaction parameter. All polymer blends were one-phase in the absence of salt. Adding salt in small concentrations results in macrophase separation in all cases. One-phase systems were observed in the PEO/P(EO-MO)/LiTFSI blends at high salt concentrations. In most of the polymer blend electrolytes, the measured κρ+ was either lower than or comparable to that of the homopolymer electrolytes. An exception to this was one-phase PEO/P(EO-MO)/LiTFSI blends electrolytes at high salt concentrations.

End-capping of hydrogen bonds: A strategy for blocking the proton conduction pathway in aqueous electrolytes

Sustainable battery development is becoming a key goal for storing renewable energy on a large scale. Toward this goal, great hopes are placed on the use of aqueous electrolytes. However, with high expectations, come increasing challenges, represented by the parasitic hydrogen evolution reaction (HER) on the anode of aqueous batteries. Here, we propose a new strategy to mitigate HER in aqueous batteries by the regulation of mass transfer kinetics, namely blocking the pathway of proton conduction by the end-capping of H-bond using N-methyl-2-pyrrolidone (NMP). The NMP structure possesses the H-bond acceptor but no H-bond donor sites, a feature that can effectively cut off H-bond propagation, and further block the pathway of proton transport in aqueous electrolytes. Hence, the modulated electrolyte confers a combination of enhanced cathodic and anodic stability, dendrite-free metal plating/stripping, and a high average Coulombic efficiency (CE) of 99.2%. Further, the end-capping of the H-bond network in electrolytes results in substantially more stable full-cell batteries that pair the metal anode with Prussian blue analogue (PBA) and polyaniline (PANI) cathodes at both room and low temperature. The “end-capping” concept in polymers is broadened to aqueous solutions for the first time here, providing a potential direction to revolutionize aqueous batteries for efficient energy storage.

Unlocking Charge Transfer Limitations for Extreme Fast Charging of Li‐Ion Batteries

AbstractExtreme fast charging (XFC) of high‐energy Li‐ion batteries is a key enabler of electrified transportation. While previous studies mainly focused on improving Li ion mass transport in electrodes and electrolytes, the limitations of charge transfer across electrode–electrolyte interfaces remain underexplored. Herein we unravel how charge transfer kinetics dictates the fast rechargeability of Li‐ion cells. Li ion transfer across the cathode–electrolyte interface is found to be rate‐limiting during XFC, but the charge transfer energy barrier at both the cathode and anode have to be reduced simultaneously to prevent Li plating, which is achieved through electrolyte engineering. By unlocking charge transfer limitations, 184 Wh kg−1 pouch cells demonstrate stable XFC (10‐min charge to 80 %) which is otherwise unachievable, and the lifetime of 245 Wh kg−1 21700 cells is quintupled during fast charging (25‐min charge to 80 %).

Unlocking Charge Transfer Limitations for Extreme Fast Charging of Li-Ion Batteries.

Extreme fast charging (XFC) of high-energy Li-ion batteries is a key enabler of electrified transportation. While previous studies mainly focused on improving Li ion mass transport in electrodes and electrolytes, the limitations of charge transfer across electrode-electrolyte interfaces remain underexplored. Herein we unravel how charge transfer kinetics dictates the fast rechargeability of Li-ion cells. Li ion transfer across the cathode-electrolyte interface is found to be rate-limiting during XFC, but the charge transfer energy barrier at both the cathode and anode have to be reduced simultaneously to prevent Li plating, which is achieved through electrolyte engineering. By unlocking charge transfer limitations, 184 Wh kg-1 pouch cells demonstrate stable XFC (10-min charge to 80 %) which is otherwise unachievable, and the lifetime of 245 Wh kg-1 21700 cells is quintupled during fast charging (25-min charge to 80 %).

Effect of polymerizing on lithium-ion transport in electrolyte

Effect of polymerizing on lithium-ion transport in electrolyte

Effect of the mechanical strength on the ion transport in a transition metal lithium halide electrolyte: first-principle calculations

The transition metal lithium halides (such as Li 3 InCl 6 , Li 3 ScCl 6 and Li 3 ErBr 6 ) have high ionic conductivity and good stability with air that can be used as solid electrolyte. However, the effect of mechanical strength on ion transport cannot be ignored in transition metal lithium halides. The relationship between the ion transport and mechanical strength of the transition metal lithium halide solid electrolyte were investigated by the first-principle based density functional theory. The bulk structure was optimized, the mechanical properties and ion transport of the solid electrolyte were analyzed, and the mechanical constants and ideal strength were calculated. The elastic energy band (NEB) method was used to simulate the diffusion of lithium ions in the bulk phase. The results show that Li 3 InCl 6 , Li 3 ScCl 6 and Li 3 ErBr 6 have better ductility, as their bulk shear modulus ratios are all greater than 1.75. The Li 3 ScCl 6 inorganic solid electrolyte with higher shear modulus (7.568 GPa) and tensile stress (3.0885 GPa) is more favorable for inhibiting the growth of lithium dendrites. The Li 3 ScCl 6 has a lower migration energy barrier along the O-T-O channel than that of Li 3 ScCl 6 and Li 3 ErBr 6 in the bulk structure. The energy barrier for lithium ion migration has changed in the channel of the solid electrolyte due to the effect of mechanical strength. The lattice distortion will affect the transport of lithium ions. These results provide comprehensive insights into the practical application of these halides as solid electrolytes. • The mechanics and transport of solid electrolyte are coupled to calculate. • The channel bottleneck of lattice distortion affects transport energy barrier. • The mechanical strength of SSEs inhibits the longitudinal growth of dendrites.

Investigation of MnO2/CuO/rGO ternary nanocomposite as electrode material for high-performance supercapacitor

• Various morphologies are interlaced in the development of MnO 2 /CuO/rGO nanomaterials for supercapacitors application. • Significant enhancement of capacitive active sites and encourage electrolyte transport during the electrochemical process. • Showed excellent cycling stability with capacitance retention of 83.74% after 5000 cycles at 10 A/g and high specific capacitance of 658.97 F/g at a current density of 1 A/g. Here, utilising easily available precursor, we technologically advanced a modest and affordable way to form carbon-grounded material interlaced with metal oxides to form a controlled structure. As a hard substrate, interconnect microstructures were built via the in-situ creation of rGO/MnO 2 -rod/CuO-sphere (MCR) nanoparticles, which could significantly enhance capacitive active sites and encourage electrolyte transport during the electrochemical process. The modified sample showed excellent cycling stability with capacitance retention of 83.74% after 5000 cycles at 10 A/g and high specific capacitance of 658.97 F/g at a current density of 1 A/g. Additionally, at an energy density of 118.61 Wh/kg, the supercapacitor made of MCR electrodes demonstrated a power density of 1.5 kW/kg. This research presents a viable method for creating supercapacitor electrodes with great performance.

Mechano-electrochemical coupling in flexible all-solid-state lithium metal batteries

Bending and stretching are critical mechanical behaviors affecting the electrochemical performance of flexible batteries in wearable electronic devices. Herein, a mechano-electrochemical model is developed for solid-state Li metal batteries under bending deformation. It is found that bending alters ion transport and electric potential in solid polymer electrolytes, and its influence relies on the bending direction. By means of the curvature and coupling coefficient, a phase map is constructed for the critical current density that leads to ion depletion at the Li metal-electrolyte interface. In addition, a positive curvature helps to decrease the overpotential for electrochemical reactions on the Li metal electrode. Though the direct influence of bending on electrochemical kinetics is limited, the bending deformation could substantially increase the stress and cause potential mechanical failure of electrodes and electrode-electrolyte interfaces, thereby degrading electrochemical performance.

Nutrient-sensing mTORC1 and AMPK pathways in chronic kidney diseases.

Nutrients such as glucose, amino acids and lipids are fundamental sources for the maintenance of essential cellular processes and homeostasis in all organisms. The nutrient-sensing kinases mechanistic target of rapamycin (mTOR) and AMP-activated protein kinase (AMPK) are expressed in many cell types and have key roles in the control of cell growth, proliferation, differentiation, metabolism and survival, ultimately contributing to the physiological development and functions of various organs, including the kidney. Dysregulation of these kinases leads to many human health problems, including cancer, neurodegenerative diseases, metabolic disorders and kidney diseases. In the kidney, physiological levels of mTOR and AMPK activity are required to support kidney cell growth and differentiation and to maintain kidney cell integrity and normal nephron function, including transport of electrolytes, water and glucose. mTOR forms two functional multi-protein kinase complexes, mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2). Hyperactivation of mTORC1 leads to podocyte and tubular cell dysfunction and vulnerability to injury, thereby contributing to the development of chronic kidney diseases, including diabetic kidney disease, obesity-related kidney disease and polycystic kidney disease. Emerging evidence suggests that targeting mTOR and/or AMPK could be an effective therapeutic approach to controlling or preventing these diseases.

Highly dispersed iron/nickel dual-sites in hierarchical porous carbon materials as high-performance bifunctional oxygen electrocatalysts for Zn-air batteries

Designing non-precious metal electrocatalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) not only should improve the activity of the catalytic reaction sites, but also need to consider the transport channels of the reactants and electrolyte inside the catalysts to enhance the utilization of active sites. Here, Fe/Ni dual-active sites anchored on the unique honeycomb hierarchical porous carbon materials are successfully prepared by pyrolysis of Fe and Ni bimetal co-doped covalent organic polymer with the assistance of pore-forming agents. The unique honeycomb hierarchical porous structures are favorable for transport and diffusion of oxygen and electrolyte during the electrochemical reaction process, so that the internal active sites can be fully utilized to improve the catalytic activity. The as-synthesized catalyst exhibits excellent ORR (E1/2 = 874 mV) and OER (overpotential = 352 mV at 10 mA cm−2) performance. More importantly, the rechargeable liquid Zn-air battery assembled with the catalyst exhibits a large specific capacity of 781.7 mA h g−1 and a long-term cycle stability with repeatedly charging and discharging for 450 h at 20 mA cm−2. Additionally, an all-solid-state flexible Zn-air battery based on this catalyst as cathode shows a maximum power density of 83.5 mW cm−2.

Inhibition of Transforming Growth Factor-β Improves Primary Renal Tubule Cell Differentiation in Long-Term Culture.

Patient-oriented applications of cell culture include cell therapy of organ failure like chronic renal failure. Clinical deployment of a cell-based device for artificial renal replacement requires qualitative and quantitative fidelity of a cultured cell to its in vivo counterpart. Active specific apicobasal ion transport reabsorbs 90-99% of the filtered load of salt and water in the kidney. In a bioengineered kidney, tubular transport concentrates wastes and eliminates the need for hemodialysis, but renal tubule cells in culture transport little or no salt and water due to dedifferentiation that mammalian cells undergo in vitro thereby losing important cell-type specific functions. We previously identified transforming growth factor-β (TGF-β) as a signaling pathway necessary for in vitro differentiation of renal tubule cells. Inhibition of TGF-β receptor-1 led to active and inhibitable electrolyte and water transport by primary human renal tubule epithelial cells in vitro. Addition of metformin increased transport, in the context of a transient effect on 5'-AMP-activated kinase phosphorylation. These data motivated us to examine whether increased transport was an idiosyncratic effect of SB431542, probe pathways downstream of TGF-β receptors possibly responsible for the improved differentiation, evaluate whether TGF-β inhibition induced a range of differentiated tubule functions, and to explore crosstalk between the effects of SB431542 and metformin. In this study, we use multiple small-molecule inhibitors of canonical and noncanonical pathways to confirm that inhibition of canonical TGF-β signaling caused the increased apicobasal transport. Hallmarks of proximal tubule cell function, including sodium reabsorption, para-amino hippurate excretion, and glucose uptake increased with TGF-β inhibition, and the specificity of the response was shown using inhibitors of each transport protein. We did not find any evidence of crosstalk between metformin and SB431542. These data suggest that the TGF-β signaling pathway governs multiple features of differentiation in renal proximal tubule cells in vitro. Inhibition of TGF-β by pharmacologic or genome engineering approaches may be a viable approach to enhancing differentiated function of tubule cells in vitro. Impact statement Cell therapy of renal failure requires qualitative and quantitative fidelity between in vitro and in vivo phenotypes, which has been elusive. We show that control of transforming growth factor-β signaling can promote differentiation of renal tubule cells grown in artificial environments. This is a key enabling step for cell therapy of renal failure.

Using Numerical Models to Accelerate Electrolyte Transport Parameter Identification

A new electrolyte transport parameter identification methodology, based on the numerical solution of a symmetric Li–Li cell model, is presented. In contrast to available techniques in the literature, where small concentration perturbations are generated in testing setups and linearization is assumed to identify transport properties for the initial salt concentration, large currents are used here to excite nonlinear dynamics able to reveal concentration dependent transport properties. This approach allows a significant reduction in the experimental effort. The proposed methodology is applied to two synthetic experiments. Firstly, an ideal case (where all difficulties associated to stripping and plating dynamics on Li metal surface are neglected) is considered in order to show both the details of the proposed methodology and its performance (specially its robustness, including the effect of the noise level in the voltage measurements in the experiment). A second case considers the effect of complex stripping and plating dynamics to show that, provided (macroscopic) modelling/identification of this dynamics is carried out, the proposed methodology is still able to accurately identify electrolyte transport properties using a simple experimental test setup.

Influence of the Polymer Structure and its Crystallization on the Interface Resistance in Polymer-LATP and Polymer-LLZO Hybrid Electrolytes

For many years, composite electrolytes (CEs) consisting of a mixture of inorganic solid electrolytes (ISEs) and polymer electrolytes (PEs) have been investigated as promising materials for the scalable production of solid-state batteries (SSBs). It is believed that CEs can overcome limitations of the single components, namely the low room-temperature conductivity and lithium ion transference number of PEs and the poor mechanical properties and high temperature processing necessary for ISE ceramics. To facilitate ion transport in the CE between the electrodes a low and stable charge transfer resistance between PEs and ISEs is required. In this study, we investigate by means of electrochemical impedance spectroscopy (EIS) how polymer crystallinity influences the charge-transfer resistance of hetero-ionic interfaces between polyethylene oxide (PEO)-based electrolytes and Li1.5Al0.5Ti1.5(PO4)3 (LATP) as well as Li6.25Al0.25La3Zr2O12 (LLZO) as ISEs. Crystallization of PEO based electrolytes below their melting temperature leads to an increased charge-transfer resistance. On the other hand, electrolytes based on the amorphous poly[2-(2-(2-methoxyethoxy)ethoxy)ethyl glycidyl ether (PTG) do not show an increased charge transfer resistance. Finally, the conductivity of ISE-rich CEs is measured as a function of their temperature and composition for elucidating how the interface resistance influences charge transport in ISE-rich composite electrolytes.

Intestinal secretory mechanisms in Okadaic acid induced diarrhoea.

Okadaic acid (OA) is an important marine lipophilic phycotoxin responsible for diarrhetic shellfish poisoning (DSP). This toxin inhibits protein phosphatases (PPs) like PP2A and PP1, though, this action does not explain OA-induced toxicity and symptoms. Intestinal epithelia comprise the defence barrier against external agents where transport of fluid and electrolytes from and to the lumen is a tightly regulated process. In some intoxications this balance becomes dysregulated appearing diarrhoea. Therefore, we evaluated diarrhoea in orally OA-treated mice as well as in mice pre-treated with several doses of cyproheptadine (CPH) and then treated with OA at different times. We assessed stools electrolytes and ultrastructural alteration of the intestine, particularly evaluating tight and adherens junctions. We detected increased chloride and sodium faecal concentrations in the OA-exposed group, suggesting a secretory diarrhoea. Pre-treatment with CPH maintains chloride concentration in values similar to control mice. Intestinal cytomorphological alterations were observed for OA mice, whereas CPH pre-treatment attenuated OA-induced damage in proximal colon and jejunum at 2h. Conversely, tight junctions' distance was only affected by OA in jejunum at the moment diarrhoea occurred. In this study we found cellular mechanisms by which OA induced diarrhoea revealing the complex toxicity of this compound.

Osmotic concentration of urine in the dynamics of the development of alloxan-induced experimental diabetes

In order to clarify the peculiarities of the osmotic concentration of urine in the dynamics of the development of alloxan-induced experimental diabetes mellitus (DDM), studies were conducted on 54 sexually mature non-linear male white rats, in which DDM was simulated by a single intraperitoneal injection of alloxan solution (Alloxan monohydrate, "Acros Organics", Belgium) at a dose of 160 mg/kg of body weight after a previous 12-hour food deprivation with preserved access to water. 10, 25, and 45 days after the introduction of the diabetogenic substance, 24 alloxan-diabetic rats, as well as 30 control (intact) animals, were loading with tap water in a volume of 5% of body weight, urine was collected for 2 hours, euthanasia was performed by decapitation under light ether anesthesia. In blood samples, the level of glucose and creatinine was determined, in urine samples, after evaluating the water-induced 2-hour diuresis (in ml/100 g of body weight in 2 hours), the concentration of creatinine was determined, the clearance of endogenous creatinine, the clearance of osmotically free water, as well as relative (tubular) reabsorption of water, determined the content of glucose, urea, its excretion, including per 100 μl of glomerular filtrate, as well as urine osmolarity. The results of the study allow us to state that as the duration of experimental diabetes is prolonged, the pathogenetic significance of hyperfiltration, which determines the speed of fluid movement along the tubule and the intensity of its absorption, weakens in relation to the processes of osmotic concentration of urine, yielding to other factors, such as the osmolarity of the medulla of the kidneys, as well as the presence of substances in the liquid of the distal segment and collecting tubes, the reabsorption of which can change their concentration in the collecting tubes as the urine progresses. In diabetes, in addition to glucose, such substances include urea. Attempts to analyze the renal excretion of urea revealed that changes in its urinary concentration are definitely correlated with the dynamics of changes in urine osmolality. Moreover, it can be assumed that urea transport disorders in the diabetic kidney occur earlier than the ability to excrete osmotically active substances in general. A joint study of the processes of renal transport of urea and urine osmolarity can serve as an early verifier of tubulointerstitial damage. Nevertheless, to increase the reliability of the interpretation of the features of the osmotic concentration of urine in diabetes, we consider it necessary to study the nature of the renal transport of electrolytes (sodium, potassium, calcium, and ammonium).

Simulation of potential and species distribution in a Li[formula omitted]Bi liquid metal battery using coupled meshes

In this work a 1D finite volume based model using coupled meshes is introduced to capture potential and species distribution throughout the discharge process in a lithium–bismuth liquid metal battery while neglecting hydrodynamic effects, focusing on the electrochemical properties of the cell and the mass transport in electrolyte and cathode. Interface reactions in the electrical double layer are considered through the introduction of a discrete jump of the potential modelled as periodic boundary condition to resolve interfacial discontinuities in the cell potential. A balanced-force like approach is implemented to ensure consistent calculation at the interface level. It is found that mass transport and concentration gradients have a significant effect on the cell overpotentials and thus on cell performance and cell voltage. By quantifying overvoltages in the Li||Bi cell with a mixed cation electrolyte, it is possible to show that diffusion and migration current density could have counteractive effects on the cell voltage. Furthermore, the simulated limiting current density is observed to be much lower than experimentally measured, which can be attributed to convective effects in the electrolyte that need to be addressed in future simulations. The solver is based on the open source library OpenFOAM and thoroughly verified against the equivalent system COMSOL multiphysics and further validated with experimental results.

Portraying the ionic transport and stability window of solid electrolytes by incorporating bond valence-Ewald with dynamically determined decomposition methods

Designing inorganic solid electrolytes (ISEs) with both excellent electrochemical stability and high ionic conductivity is an important research direction for all-solid-state batteries. However, due to the electronic conduction of hierarchical decomposition products, there is an imbalance between the ionic transport and electrochemical stability window of the ISEs. Here, we propose a computational approach that incorporates bond valence-Ewald energy analysis and dynamically determined decomposition pathway to portray the competing relationship between ionic transport and stable electrochemical window in solid electrolytes. Following this, we explain the high ionic conductivity and wide electrochemical stability window of Li–Si–B–S solid electrolytes, which features shared corner and edge from tetrahedral SiS4/BS4. Our approach is not only applicable to efficiently characterize the previously reported inorganic solid electrolytes but also expected to accelerate the discovery of more systems.

Spider chrysanthemum-like Co flowers on a Ni foam for highly efficient H2O2 electroreduction in alkaline media

Transition metal oxides have shown potential as hydrogen peroxide (H2O2) reduction catalysts because of their low cost, good catalytic properties, and excellent stability in alkaline solutions. In this study, a CNF-0.25 composite electrode comprising spider chrysanthemum-like Co flowers on a Ni foam is synthesized as an efficient cathode for H2O2 electroreduction in alkaline media. CNF-0.25 exhibited superior stability and highly desirable electrocatalytic properties for H2O2 reduction with a high current density of 0.42 A cm−2 at − 0.5 V. The voltage of an Al-H2O2 semi-fuel cell prepared using CNF-0.25 as the cathode remains stable during a 50 h discharge test. The specific mechanism for the promotion of H2O2 electroreduction using CNF-0.25 is investigated according to the mechanism of H2O2 reduction over a cobalt-based catalyst. The spider chrysanthemum-like Co flowers are mainly composed of metallic Co, which improves the conductivity of the electrode. On the surface of the metallic Co, the presence of a layer of cobalt oxides or hydroxides provides sufficient catalytic active sites (Co2+/Co3+) and prevents further oxidation of internal Co. In addition, the unique spider chrysanthemum-like structure of CNF-0.25 increases the specific surface area of the electrode and facilitates electrolyte transport. This work offers another approach for designing highly efficient transition metal oxide electrodes in alkaline media.