Electrode-electrolyte Interface Research Articles

Enhancing the performance of LiNi0.8Mn0.1Co0.1O2-based pouch cells through advanced electrolyte additive systems for high-temperature lithium-ion batteries

Next-generation lithium-ion batteries, which achieve high energy densities and prolonged cycle performance, require cathode materials with high operating voltages and specific capacities. Because of their high capacity and operating voltage, nickel-rich layered oxides like LiNi0.8Mn0.1Co0.1O2 (NMC811) are attractive cathodes; nevertheless, they have drawbacks such capacity loss, poor cycle performance, structural instability, and thermal instability. Enhancing the stability of the NMC811 cathode-electrolyte interphase demands improvements in both cathode materials and electrolytes. This study explores the enhancement of NMC811-based battery systems through electrolyte modification, focusing on mixed additive combinations to evaluate their synergistic effects at elevated temperatures, relevant for tropical climates. A ternary additive system comprising vinylene carbonate (VC), lithium difluorophosphate (LiPO2F2), and p-toluenesulfonyl isocyanate (PTSI) in a LiPF6-based electrolyte showed significant improvements. This system mitigated capacity fading for cells cycled over 3 V–4.2 V at both 25 °C and 45 °C, outperforming the baseline electrolyte. The designed electrolyte stabilized the electrode-electrolyte interface, enhancing cell performance and the cathode's structural integrity. Notably, the graphite/NMC811 pouch cell's cycling performance showed an increase in capacity retention from 82.4% to 90.2% after 150 cycles at C/2 at 45 °C. Moreover, the deactivation of PF5 by PTSI can help to suppress the side reaction from the instability of LiPF6-based electrolytes, especially at elevated temperatures. These findings carried out from this strategic electrolyte additive system can substantially improve nickel-rich LIBs, especially in challenging thermal environments.

Unraveling the Dynamic Properties of New-Age Energy Materials Chemistry Using Advanced In Situ Transmission Electron Microscopy.

The field of energy storage and conversion materials has witnessed transformative advancements owing to the integration of advanced in situ characterization techniques. Among them, numerous real-time characterization techniques, especially in situ transmission electron microscopy (TEM)/scanning TEM (STEM) have tremendously increased the atomic-level understanding of the minute transition states in energy materials during electrochemical processes. Advanced forms of in situ/operando TEM and STEM microscopic techniques also provide incredible insights into material phenomena at the finest scale and aid to monitor phase transformations and degradation mechanisms in lithium-ion batteries. Notably, the solid-electrolyte interface (SEI) is one the most significant factors that associated with the performance of rechargeable batteries. The SEI critically controls the electrochemical reactions occur at the electrode-electrolyte interface. Intricate chemical reactions in energy materials interfaces can be effectively monitored using temperature-sensitive in situ STEM techniques, deciphering the reaction mechanisms prevailing in the degradation pathways of energy materials with nano- to micrometer-scale spatial resolution. Further, the advent of cryogenic (Cryo)-TEM has enhanced these studies by preserving the native state of sensitive materials. Cryo-TEM also allows the observation of metastable phases and reaction intermediates that are otherwise challenging to capture. Along with these sophisticated techniques, Focused ion beam (FIB) induction has also been instrumental in preparing site-specific cross-sectional samples, facilitating the high-resolution analysis of interfaces and layers within energy devices. The holistic integration of these advanced characterization techniques provides a comprehensive understanding of the dynamic changes in energy materials. This review highlights the recent progress in employing state-of-the-art characterization techniques such as in situ TEM, STEM, Cryo-TEM, and FIB for detailed investigation into the structural and chemical dynamics of energy storage and conversion materials.

An ultrafast, stable and highly reversible nickel magnesium vanadate cathode for magnesium ion batteries

Rechargeable magnesium batteries are one among the strongest candidates over lithium ion batteries with abundance, cost effective and less environmental hazard. However, limitations including slow Mg2+ ion kinetics in the electrode-electrolyte interface and formation of passivating layers on the surface of magnesium metal anode affecting the rechargeable behavior of a cathode. Herein, hydrothermally synthesized NiMg2(VO4)2 nanomaterial used as cathode. The oxidation and reduction properties of Mg and V facilitates the diffusion pathway for Mg2+ and Li+ ions. Additionally, the employment of activated carbon cloth as anode diminishes the strong ionic interactions between Mg2+ ions and crystal lattice, enabling the faster diffusion of Mg2+ ions. All the electrochemical investigations are carried out at room temperature in the potential window of 1.23 V to 3.83 V against Mg/Mg2+. At a lower current density of 100 mA g−1, the specific discharge capacity have been 220 mAh g−1 for the 2nd cycle and retention of 97.1 % over 25 cycles. The specific capacity increases with more Mg2+ involvement in the reaction. At the highest current rate of 5000 mA g−1 the capacity retention is 96.8 % after 1000 cycles. Calculated energy density for a low current density is 556 Wh kg−1. The presence of multivalent V ions in the cathode reduces volume expansion, assisting charge redistribution to maintain electroneutrality. The dynamic valence property of. Vanadium ions (V2+/V5+) assist the intercalation of Mg2+ ions into the crystal lattice of cathode and possibly contribute to the highly stable and reversible discharge capacity over cycles. These findings provide a new perspective on NiMg2(VO4)2 as cathode material for magnesium ion batteries.

Ostwald‐Ripening Induced Interfacial Protection Layer Boosts 1,000,000‐Cycled Hydronium‐Ion Battery

Collapsing and degradation of active materials caused by the electrode/electrolyte interface instability in aqueous batteries are one of the main obstacles that mitigate the capacity. Herein by reversing the notorious side reactions include the loss and dissolution of electrode materials: as we applied Ostwald ripening (OR) in the electrochemical cycling of a copper hexacyanoferrate electrode in a hydronium‐ion batteries, the dissolved Cu and Fe ions undergo a crystallization process that creates a stable interface layer of cross‐linked cubes on the electrode surface. The layer exposed the low‐index crystal planes (100) and (110) through OR‐induced electrode particle growth, supplemented by vacancy‐ordered (100) superlattices that facilitated ion migration. Our design stabilized the electrode–electrolyte interface considerably, achieving a cycle life of one million cycles with capacity retention of 91.6%, and a capacity retention of 91.7% after 3000 cycles for a full battery.

Ostwald-Ripening Induced Interfacial Protection Layer Boosts 1,000,000-Cycled Hydronium-Ion Battery.

Collapsing and degradation of active materials caused by the electrode/electrolyte interface instability in aqueous batteries are one of the main obstacles that mitigate the capacity. Herein by reversing the notorious side reactions include the loss and dissolution of electrode materials: as we applied Ostwald ripening (OR) in the electrochemical cycling of a copper hexacyanoferrate electrode in a hydronium-ion batteries, the dissolved Cu and Fe ions undergo a crystallization process that creates a stable interface layer of cross-linked cubes on the electrode surface. The layer exposed the low-index crystal planes (100) and (110) through OR-induced electrode particle growth, supplemented by vacancy-ordered (100) superlattices that facilitated ion migration. Our design stabilized the electrode-electrolyte interface considerably, achieving a cycle life of one million cycles with capacity retention of 91.6%, and a capacity retention of 91.7% after 3000 cycles for a full battery.

Entropy-Assisted Anion-Reinforced Solvation Structure for Fast-Charging Sodium-Ion Full Batteries.

Anion-reinforced solvation structure favors the formation of inorganic-rich robust electrode-electrolyte interface, which endows fast ion transport and high strength modulus to enable improved electrochemical performance. However, such a unique solvation structure inevitably injures the ionic conductivity of electrolytes and limits the fast-charging performance. Herein, a trade-off in tuning anion-reinforced solvation structure and high ionic conductivity is realized by the entropy-assisted hybrid ester-ether electrolyte. Anion-reinforced solvation sheath with more anions occupying the inner Na+ shell is constructed by introducing the weakly coordinated ether tetrahydrofuran into the commonly used ester-based electrolyte, which merits the accelerated desolvation energy and gradient inorganic-rich electrode-electrolyte interface. The improved ionic conductivity is attributed to the weakly diverse solvation structures induced by entropy effect. These enable the enhanced rate performance and cycling stability of Prussian blue||hard carbon full cells with high electrode mass loading. More importantly, the practical application of the designed electrolyte was further demonstrated by industry-level 18650 cylindrical cells.

LaMnO3-Mn3O4 nanocomposite: Synergetic effect towards high electrochemical performance

Metal oxides have been a focus of research for energy storage devices. Herein, xLaMnO3 – (100-x) Mn3O4 (LMO-MO) composites (xwt%: 100, 90, 70, and 50) were prepared via one-pot synthesis to elucidate the synergistic effect of the composite constituents on composite’s electrochemical performance. The X-ray diffraction analysis confirmed the presence of individual compounds in the desired ratio and phase. The X-ray photoelectron spectroscopy confirmed the presence of Mn2+ and Mn3+ oxidation states, indicating the presence of both LaMnO3 (LMO) and Mn3O4 (MO) in the composite. The electrochemical performance of composite electrodes prepared using nickel foam was assessed in 1 and 6 M KOH solutions. High specific capacitance measured via cyclic voltammetry of ∼ 770 Fg−1 at a scan rate of 1 mVs−1 was recorded for the composite of LMO-MO (70 %: 30 %) in 6 M KOH. At the same time, charge-discharge curves revealed a maximum specific capacitance of around 405 Fg−1 for an x =70 % sample at a current density of 0.5 Ag−1. The EIS studies show a reduction in the internal resistance of the composite due to the interconnected structure and reversible faradic process at the interface with a high degree of Coulombic efficiency. A higher overall electrochemical performance of the electrode was recorded in a 6 M KOH electrolyte. The enhanced electrochemical performance of the composite is attributed to efficient charge transfer kinetics through the electrode-electrolyte interface via easy electron hopping pathways between LMO and MO in the composite. These findings suggest that the studied LMO-MO composites could be a potential material for pseudocapacitor energy devices.

Heterogeneity in Point Defect Distribution and Mobility in Solid Ion Conductors.

Alkali metal anodes paired with solid ion conductors offer promising avenues for enhancing battery energy density and safety. To facilitate rapid ion transport crucial for fast charging and discharging of batteries, it is essential to understand the behavior of point defects in these conductors. In this study, we investigate the heterogeneity of defect distribution in two prototypical solid ion conductors, Li3OCl and Li2PO2N (LiPON), by quantifying the defect formation energy (DFE) as a function of distance from the surface and interface through first-principles simulations. To simulate defects at the electrode-electrolyte interface, we perform calculations of Li+ vacancy in Li3OCl near its interface with lithium metal. Our results reveal a significant difference between the bulk and surface/interface DFE which could lead to defect aggregation/depletion near the surface/interface. Interestingly, while Li3OCl has a lower surface DFE than the bulk in most cases, LiPON follows the opposite trend with a higher surface DFE compared to the bulk. Due to this difference between bulk and surface DFE, the defect density can be up to 14 orders of magnitude higher at surfaces compared to the bulk. Further, we reveal that the DFE transition from surface/interface to bulk is precisely characterized by an exponentially decaying function. By incorporating this exponential trend, we develop a revised model for the average behavior of defects in solid ion conductors that offers a more accurate description of the influence of grain sizes. Surface effects dominate for grain sizes ≲1 μm, highlighting the importance of surface defect engineering and the DFE function for accurately capturing ion transport in devices. We further explore the kinetics of defect redistribution by calculating the migration barriers for defect movement between bulk and surfaces. We find a highly asymmetric energy landscape for the lithium vacancies, exhibiting lower migration barriers for movement toward the surface compared to the bulk, while interstitial defects exhibit comparable kinetics between surface and bulk regions. These insights highlight the importance of considering both thermodynamic and kinetic factors in designing solid ion conductors for improved ion transport at surfaces and interfaces.

Electrospun Quasi‐Composite Polymer Electrolyte with Hydoxyl‐Anchored Aluminosilicate Zeolitic Network for Dendrite Free Lithium Metal Batteries

AbstractAll‐solid‐state lithium metal batteries have reshaped emerging safe battery technologies. However, their low metal ion transport and unstable electrode electrolyte interface make their mass production a huge question. To bridge the emerging solid state and traditional liquid electrolytes, we focus on Quasi‐Composite Polymer electrolytes (QCPE). Herein, we develop QCPE with active 3D alumino‐silicate zeolitic ion conduction pathways embedded in a polymer matrix using two techniques‐ solution casting and electrospinning. Electrospun QCPE outperforms Solution cast QCPE by achieving high amorphous behavior. Prompt elimination of solvent during electrospinning decreases bulk resistance and increases its ionic conductivity. The Zeolitic pathway anchored by hydroxyl groups of PVA polymer acts as a highway for Li+ ions. It exhibits highly stable platting stripping vs Li+/Li for 450 hours with low overpotential, confirming the interfacial compatibility and dendrite‐free cycling at lithium metal anode. Controlled lithium‐ion nucleation regulated by evenly distributed zeolitic pathway is an interesting front of this work. To test QCPE's performance in Lithium metal battery (LMB), the electrospun QCPE is used to fabricate LMB with LiFePO4 cathode. This battery system delivered a high capacity of 155 mAh g−1 at 0.1 C. In addition to the high performance, electrospun QCPE production is scalable at an industrial scale.

A nonlinear phase-field model of corrosion with charging kinetics of electric double layer

Abstract A nonlinear phase-field model is developed to simulate corrosion damage. The motion of the electrode-electrolyte interface follows the usual kinetic rate theory for chemical reactions based on the Butler-Volmer equation. The model links the surface polarization variation associated with the charging kinetics of an electric double layer (EDL) to the mesoscale transport. The effects of the EDL are integrated as a boundary condition on the solution potential equation. The boundary condition controls the magnitude of the solution potential at the electrode$-$electrolyte interface. The ion concentration field outside the EDL is obtained by solving the electro$-$diffusion equation and Ohm's law for the solution potential. The model is validated against the classic benchmark pencil electrode test. The framework developed reproduces experimental measurements of both pit kinetics and transient current density response. The model enables more accurate information on corrosion damage, current density, and environmental response in terms of the distribution of electric potential and charged species. The sensitivity analysis for different properties of the EDL is performed to investigate their role in the electrochemical response of the system. Simulation results show that the properties of the EDL significantly influence the transport of ionic species in the electrolyte.

Promoting Preferential Zn (002) Deposition with a Low-Concentration Electrolyte Additive for Highly Reversible Zn-Ion Batteries.

Aqueous zinc-ion batteries have promising potential as energy storage devices due to their low cost and environmental friendliness. However, their development has been hindered by zinc dendrite formation and parasitic side reactions. Herein, we introduce a low-concentration sodium benzoate (NaBZ) electrolyte additive to stabilize the electrode-electrolyte interface and promote deposition on the Zn (002) crystal plane. From experimental characterization and computational analyses, NaBZ was found to adsorb on the Zn surface and inhibit side reactions while guiding homogeneous Zn deposition on the (002) plane. Consequently, Zn|Zn symmetric cells with the NaBZ additive cycled stably for over 1000 h at a current density of 0.5 mA cm-2 and an areal capacity of 0.5 mAh cm-2, while Zn|Cu cells showed excellent reversibility with a Coulombic efficiency of 99.05%. Moreover, Zn|Na0.33V2O5 full cells achieve a high specific capacity of 124 mAh g-1 while cycling for 600 h at 2 A g-1. These findings present a low-cost electrolyte modification strategy for reversible zinc-ion batteries.

Development of Solid-State Lithium-Ion Batteries (LIBs) to Increase Ionic Conductivity through Interactions between Solid Electrolytes and Anode and Cathode Electrodes

Although in general ions are not able to migrate in the solid-state position due to rigid skeletal structure, in some solid electrolytes with a low energy barrier and high ionic conductivities, these ion transition can occur. In this work, we considered several solid electrolytes including lithium phosphorus oxy-nitride (LIPON), a lithium super-ionic conductor (SILICON), and thio-LISICON. For the fabrication and characterization of the solid electrolyte’s fabrication, we used a single-step ball milling (SSBM) procedure. Through this research on all-solid-state rechargeable lithium-ion batteries, our target is to discuss solving several problems in solid LIBs that have recently escalated due to raised concerns relating to safety hazards such as solvent leakage and the flammability of the liquid electrolytes used for commercial LIBs. Through this research, we tested the conductivity amounts of various substrates containing amorphous glass, SSBM, and glass-ceramic samples. Obviously, the SSBM glass-ceramics increased the conductivity, and we also found that the values for conductivity attained by SSBM were higher than those values for glass-ceramics. Using an SSBM technique, silicon nanoparticles were used as an anode material and it was found that the charge and discharge curves in the battery cell cycled between 0.009 and 1.45 V versus Li+/Li at a current density of 210 mA g−1 at room temperature. Since high resistance causes degradation between the cathode material (LiCoO2) and the solid electrolyte, we added GeS2 and SiS2 to the Li2S-P2S5 system to obtain higher conductivities and better stability of the electrode–electrolyte interface.

Composition and Structure of the solid electrolyte interphase on Na-Ion Anodes Revealed by Exo- and Endogenous Dynamic Nuclear Polarization─NMR Spectroscopy.

Sodium ion batteries (SIB) are among the most promising devices for large scale energy storage. Their stable and long-term performance depends on the formation of the solid electrolyte interphase (SEI), a nanosized, heterogeneous and disordered layer, formed due to degradation of the electrolyte at the anode surface. The chemical and structural properties of the SEI control the charge transfer process at the electrode-electrolyte interface, thus, there is great interest in determining these properties for understanding, and ultimately controlling, SEI functionality. However, the study of the SEI is notoriously challenging due to its heterogeneous nature and minute quantity. In this work, we present a powerful approach for probing the SEI based on solid state NMR spectroscopy with increased sensitivity from dynamic nuclear polarization (DNP). Utilizing exogenous (organic radicals) and endogenous (paramagnetic metal ion dopants) DNP sources, we obtain not only a detailed compositional map of the SEI but also, for the first time for the native SEI, determine the spatial distribution of its constituent phases. Using this approach, we perform a thorough investigation of the SEI formed on Li4Ti5O12 used as a SIB anode. We identify a compositional gradient, from organic phases at the electrolyte interface to inorganic phases toward the anode surface. We find that the use of fluoroethylene carbonate as an electrolyte additive leads to performance degradation which can be attributed to formation of a thicker SEI, rich in NaF and carbonates. We expect that this methodology can be extended to examine other titanate anodes and new electrolyte compositions, offering a unique tool for SEI investigations to enable the development of effective and long-lasting SIBs.

Suppressing hydrogen evolution reaction by constructing interfacial proton blocking layer for highly reversible zinc anode

Zinc (Zn) anodes are severely threatened by the hydrogen evolution reaction (HER) triggered by highly active water molecules. Motivated by the process of the HER in weakly acidic aqueous, we propose a strategy to construct a proton-blocking layer at the electrode-electrolyte interface by introducing robust hydrogen bonding, aiming to significantly suppress the HER. Isonicotinic acid (INA) possesses N and carboxyl sites that can form strong interactions with protons and can adsorb onto the surface of Zn. Thus, by introducing trace amounts (10 mM) of INA into the electrolyte, proton transfer at the interface can be effectively impeded. In addition, INA can also facilitate Zn uniform growth and inhibit dendrite formation. Consequently, the Zn//Zn symmetrical battery can perform for 3400 h at 1 mA/cm2@1 mAh/cm2, and the coulombic efficiency of the Zn//Cu battery can reach 99.74 % after 1800 cycles. Furthermore, due to the suppression of HER, the Zn//MnO2 batteries achieved high performance of 79.3 mAh/g after 2000 cycles at the current density of 2 A/g. This study provides a new approach to suppress HER and improve the stability of Zn anode.

Polyelectrolyte Additive-Modulated Interfacial Microenvironment Boosting CO2 Electrolysis in Acid.

Acidic CO2 electrolysis offers a promising strategy to achieve high carbon utilization and high energy efficiency. However, challenges remain in suppressing the competitive hydrogen evolution reaction (HER) and improving product selectivity. High concentrations of potassium ions (K+) can suppress HER and accelerate CO2 reduction, but they still inevitably suffer from salt precipitation problems. In this study, we demonstrate that the sulfonate-based polyelectrolyte, polystyrene sulfonate (PSS), enables to reconstruct the electrode-electrolyte interface to significantly enhance the acidic CO2 electrolysis. Mechanistic studies reveal that PSS induces high local K+ concentrations through electrostatic interaction between PSS anions and K+. In situ spectroscopy reveals that PSS reshapes the interfacial hydrogen-bond (H-bond) network, which is attributed to the H-bonds between PSS anions and hydrated proton as well as the steric hindrance of the additive molecules. This greatly weakens proton transfer kinetics and leads to the suppression of undesirable HER. As a result, a Faradaic efficiency of 93.9% for CO can be achieved at 250 mA cm-2, simultaneous with a high single-pass carbon efficiency of 72.2% on commercial Ag catalysts in acid. This study highlights the important role of the electrode-electrolyte interface induced by polyelectrolyte additives in promoting electrocatalytic reactions.

Improved electrochemical performance of Fe3O4/TiO2 composite thin film electrode for energy storage applications

This study is the first attempt to examine the electrochemical properties of TiO2 composite with Fe3O4 thin film. In our analysis, X-Ray diffraction (XRD) confirms the formation of Fe3O4 on TiO2. Fourier Transform Infrared Spectroscopy (FT-IR) and Raman spectroscopy confirmed the functional groups. The UV–Vis spectroscopy analysis shows that the addition of Fe3O4 results in decrease in optical band gap. Our Cyclic Voltammetry (CV) results demonstrate that, under steady state conditions, the behaviors of TiO2 and Fe3O4/TiO2 electrodes regarding ion adsorption and charge transmission vary. Pseudocapacitive effects and charge transfer affects the functionality of the TiO2 electrode, whereas two-layer capacitance effects primarily control the response of the Fe3O4/TiO2 electrode. Numerous factors, including ion diffusion, rate capability, charge transfer, and series resistance, can be directly determined using electrochemical impedance spectroscopy (EIS). The experimental results and analysis presented in this work brings to light the significance of Fe3O4 in the electrochemical response of an electrode-electrolyte interface.

Achieving High-Capacity Cathode Presodiation Agent Via Triggering Anionic Oxidation Activity in Sodium Oxide.

Compensating for the irreversible loss of limited active sodium (Na) is crucial for enhancing the energy density of practical sodium-ion batteries (SIBs) full-cell, especially when employing hard carbon anode with initially lower coulombic efficiency. Introducing sacrificial cathode presodiation agents, particularly those that own potential anionic oxidation activity with a high theoretical capacity, can provide additional sodium sources for compensating Na loss. Herein, Ni atoms are precisely implanted at the Na sites within Na2O framework, obtaining a (Na0.89Ni0.05□0.06)2O (Ni-Na2O) presodiation agent. The synergistic interaction between Na vacancies and Ni catalyst effectively tunes the band structure, forming moderate Ni-O covalent bonds, activating the oxidation activity of oxygen anion, reducing the decomposition overpotential to 2.8V (vs Na/Na+), and achieving a high presodiation capacity of 710 mAh/g≈Na2O (Na2O decomposition rate >80%). Incorporating currently-modified presodiation agent with Na3V2(PO4)3 and Na2/3Ni2/3Mn1/3O2 cathodes, the energy density of corresponding Na-ion full-cells presents an essential improvement of 23.9% and 19.3%, respectively. Further, not limited to Ni-Na2O, the structure-function relationship between the anionic oxidation mechanism and electrode-electrolyte interface fabrication is revealed as a paradigm for the development of sacrificial cathode presodiation agent.

Surface engineering of TiSiO4 nano-coating for high-voltage nickel-rich ternary cathodes: An approach to improve cyclic performance

In recent years, layered ternary transition metal oxides with a high nickel content have gained substantial attention as a potential positive electrode material for lithium-ion batteries. However, its poor rate capability, cyclability, and capacity retention at high working voltages limit its use in commercial lithium-ion batteries. To overcome these challenges, we synthesize a cost-effective wet-chemical deposition of novel TiSiO4 nano-coatings over the surface of LiNi0.83Mn0.06Co0.11O2 (NMC-83). X-ray diffraction and electron microscopy confirm the presence of a coating and verify that the deposition process did not alter the crystallinity and morphology of the NMC-83 particles. In addition, during cycling, it completely protects NMC-83 with enhancements in hexagonal phase transitions between H2 and H3, resulting in excellent cycling stability at upper cut-off voltages. Likewise, when the amount of coated material is equal to 1 wt%, it provides faster ion kinetics and a stable electrode-electrolyte interface. The 1 wt% TiSiO4 coating provides 35 % retention after 250 cycles at a 0.5C rate, while the pristine NMC-83 shows only 13.7 %. From postmortem analysis, the 1 wt% TiSiO4-coated NMC-83 cathode maintains its stable polycrystalline nature compared with pristine NMC-83. Thus, this novel TiSiO4 nanocoating has significant implications for developing high-performance rechargeable batteries for energy applications.

Selective detection of alpha synuclein amyloid fibrils by faradaic and non-faradaic electrochemical impedance spectroscopic approaches

This study utilized faradaic and non-faradaic electrochemical impedance spectroscopy to detect alpha synuclein amyloid fibrils on gold interdigitated tetraelectrodes (AuIDTE), providing valuable insights into electrochemical reactions for clinical use. AuIDE was purchased, modified with zinc oxide for increased hydrophobicity. Functionalization was conducted with hexacyanidoferrate and carbonyldiimidazole. Faradaic electrochemical impedance spectroscopy has been extensively explored in clinical diagnostics and biomedical research, providing information on the performance and stability of electrochemical biosensors. This understanding can help develop more sensitive, selective, and reliable biosensing platforms for the detection of clinically relevant analytes like biomarkers, proteins, and nucleic acids. Non-faradaic electrochemical impedance spectroscopy measures the interfacial capacitance at the electrode–electrolyte interface, eliminating the need for redox-active species and simplifying experimental setups. It has practical implications in clinical settings, like real-time detection and monitoring of biomolecules and biomarkers by tracking changes in interfacial capacitance. The limit of detection (LOD) for normal alpha synuclein in faradaic mode is 2.39-fM, The LOD for aggregated alpha synuclein detection is 1.82-fM. The LOD for non-faradaic detection of normal alpha synuclein is 2.22-fM, and the LOD for nonfaradaic detection of aggregated alpha synuclein is 2.40-fM. The proposed EIS-based AuIDTEs sensor detects alpha synuclein amyloid fibrils and it is highly sensitive.

Improving high-voltage cycling and stabilizing the electrode-electrolyte interface of nickel-rich layered cathodes by magnesium doping

Next-generation lithium-ion batteries will rely on nickel-rich layered oxides as cathode materials, but these materials are associated with structural and voltage losses. Magnesium (Mg) doping helps improve the performance of the nickel-rich layered cathode material. The Mg-modified LiNi0·90Mn0·05Co0·05O2 (NMC-90) has been successfully synthesized through a co-precipitation technique followed by calcination at 850 °C. Modified NMC-90 exhibits better-organized layers and improved interfacial properties than pristine ones based on structural, chemical, and morphological studies. In a voltage range of 2.8–4.5 V, Mg (0.01 mol%)-doped NMC-90 (NMC-M1) composite cathode shows an excellent discharge capacity of 211.11 mAh/g, whereas pristine NMC-90 (NMC-M0) attains only 210.59 mAh/g at 0.1C with an initial coulombic efficiency of 89.5 % for NMC-M1 and 87.5 % for NMC-M0 cathode. The NMC-M1 cathode demonstrated an impressive enhancement in cyclability after 60 cycles compared to the NMC-M0 at 1C rate, in which the NMC-M1 cathode attains a high capacity retention of 80 % while the NMC-M0 cathode shows only 37 %. This study illustrates the importance of studying the effects of elemental doping on cell performance. It will drive the future development of cathode materials with high Ni and low Co content.