Historically, the properties of cathode materials for rechargeable lithium-ion batteries (LIBs) have been investigated by predicting the properties by starting from atomistics, or by self-consistently averaging the effect of an individual representative material feature and incorporating it into coarse grained porous electrode theory descriptions that capture the time-dependent electronic and ionic transport. Such approaches are based simplified representations of grains, pores, or inclusions, and averaging them into models that aim to understand or engineer the macroscopic properties of the device or component at hand. However, if effects due to phase transformation kinetics, or the impact of defects such as vacancies or interstitials, dislocations, or grain boundaries are to be engineered, currently used averaging approaches will not capture the underlying multiphysical and microstructural richness of behavior of the device. In general, the modern development of advanced technology for LIBs demands: 1) the formulation of a methodology that provides an accurate description of the materials that integrate these devices at each length scale; 2) the systematic and mindful coarse-graining of lower length scale methodologies into higher length scale descriptions, and 3) the establishment of meaningful databases that enable the development of insight to understand and then engineer advanced, reliable, next generation devices. Here, by defining a thermodynamically consistent representation of materials that spatially resolves the multiphysical fields that results from formally considering microstructural features such as grain size, crystallographic texture, grain boundaries, particle size, and porosity, the time-dependent behavior is analyzed in materials for lithium-ion battery applications. Progress towards integrating the physical contributions of each individual phase and its processing-induced spatial distribution into advanced models is presented. The effect on the performance and degradation is analyzed. Reaches and limitations of well-known and emerging theories will be reviewed and compared, and efforts to accelerate to the limit of real time performance and degradation computations will be presented in an effort to explore the space of what is physically possible.

This study investigates how various dispersion techniques influence the morphological and rheological properties of Vulcan XC-72R carbon black and a new nanostructured catalyst used in PEM fuel cells and electrolyzers. Each method was evaluated using rheology, dynamic light scattering (DLS), and scanning electron microscopy (SEM) to examine particle agglomeration, ink viscosity, and morphology. An optimized dispersion protocol was developed based on the Vulcan study and applied to the nanostructured catalyst system, followed by a catalyst loading analysis to explore structure–performance relationships. The optimized ink formulation showed improved dispersion stability, smaller particle sizes, and more uniform catalyst-ionomer distribution. Electrochemical performance was assessed with polarization curves, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The effect of the optimized dispersion techniques on catalyst utilization and mass transport resistance is also evaluated. These results emphasize the critical role of dispersion processing in shaping ink structure and producing high-performance membrane electrode assemblies (MEAs) for PEM applications.

To address the range anxiety associated with electric vehicles, there is an urgent need to develop affordable, sustainable batteries with high energy density and fast charging capabilities. 1,2 Among emerging candidates, lithium-sulfur (Li-S) batteries stand out due to their high theoretical specific energy (~2600 Wh kg -1 ), low cost, and low toxicity. However, the practical application of sulfur cathodes remains hindered by several challenges, including low active material loading, poor electronic conductivity, the polysulfide shuttle effect, and sluggish sulfur conversion kinetics. In this work, we present a material-agnostic strategy that integrates asymmetric cathode structure customization with a controllable vapor-deposited polymer to enable fast-charging Li-S batteries with high sulfur loading. 3 Specifically, 3D printing via stereolithography was used to tailor the distribution of active materials and cathode tortuosity. This inhomogeneous structural design compensates for the intrinsic Li⁺ gradient across the cathode, thereby reducing polarization at the electrode level. The printing resin was based on 1,3,5-triallyl-1,3,5-triazine-2,4,6-trione, which yields a nitrogen-doped defective carbon network upon sintering. Simultaneously, Fe–N catalytic sites were generated through reactions between iron nitrate and the carbonized resin matrix. This dual catalytic architecture, combined with the optimized structure, synergistically promotes efficient sulfur conversion and minimizes polarization in thick electrodes. To further suppress the shuttle effect and extend battery life, a conformal coating was applied using oxidative chemical vapor deposition (oCVD). In situ XRD measurements reveal a clear distinction in sulfur conversion kinetics between the 3D-printed and conventional 2D planar cathodes of comparable mass loading, highlighting the advantages of the customized architecture. Overall, the designed cathode achieved a high specific capacity of 820 mAh g -1 at 4C with a sulfur loading of 8.3 mg cm -2 . Moreover, the oCVD-coated cathode exhibited excellent capacity retention (85% after 300 cycles), demonstrating that this innovative cathode design enables high sulfur utilization, accelerated reaction kinetics, and stable long-term cycling. These findings offer a promising pathway toward achieving higher energy and power densities in Li-S batteries through structural engineering and materials optimization. This work was supported by the US National Science Foundation, Award numbers CBET-2207302. 1 Zhang, Y., Lee, S., Nanoscale 15, 4195-4218 (2023). doi.org/10.1039/D2NR05701H 2 Zhang, Y., Lee, S., Energy Storage Materials 48, 1-11 (2022). doi.org/10.1016/j.ensm.2022.03.001 3 Zhang, Y., Lee, S., Nano Energy 115, 108756 (2023). doi.org/10.1016/j.nanoen.2023.108756

The technology of Redox Flow Batteries is an important option to store energy from the operating irregularly renewable energy sources. The flow-based electrochemical energy storage systems utilize the appropriate electroactive species dissolved in externally flowing electrolytes which are ready to accumulate all (or part) of the charge. Among important issues is the search for highly efficient (i.e., capable of fast electron transfers) electroactive systems that would yield high power and energy densities during the systems’ operation. In the present work, we concentrate on utilization of highly concentrated iodine/iodide redox systems and their possibility to exhibit high rates of charge propagation. In practical terms, it can be combined with ZnI 2 , or other zinc salt, containing electrolyte. Reactions in the zinc/iodine (polyiodide) redox flow battery are as follows: Zn → Zn 2+ + 2e - (E = −0.76 V vs SHE) at the negative electrode (anode), and 3I - → I 3 − + 2e − (E = 0.54 V vs SHE) at the positive electrode (cathode) thus yielding a total theoretical potential output as high as ∼1.3 V. Obviously, the increase of current density can be achieved by reducing viscosity of the electrolyte. Alternatively - by analogy to the performance of iodine/iodide couple as charge relay in dye-sensitized solar cells – through improvement of the dynamics of charge propagation in highly concentrated iodine/iodide solution via the catalyzed enhancement of rates of electron self-exchange (hopping) between iodine/iodide (polyiodide) redox species as well as by accelerating the interfacial kinetics at electrodes. This can be realized by choosing appropriate electrode materials and through their activation or modification. The electrochemical activities of the redox couples are usually significantly increased through application of nanostructured functionalized carbons. While dispersed in solutions they can improve electron transfers to the redox sites. The proposed chemistry has been first tested using the microelectrode methodology to determine mass-transport (effectively diffusional) coefficients for charge propagation, heterogeneous and homogeneous (electron self-exchange) rates of electron transfers. Unless catalyzed, both interfacial and bulk (self-exchange) electron transfers involving the iodine/iodide redox system are somewhat complicated; there is a need to break the I-I bond in the I 3 - or I 2 molecule; it has also been well-established that platinum (e.g. when deposited on the counter electrode) induces electron transfers within the iodine/iodide redox system. In the presentation, we are going to explore the respective interfacial (electrocatalytic) phenomena on nanostructured metal oxides (e.g. zirconia), in addition to traces of expensive platinum or palladium nanoparticles (provided that catalytic centers are three-dimensionally distributed in the electrolyte phase), and we will utilize them to enhance iodine/iodide electron transfers to develop a new generation of redox mediators or ultra-fast components of redox electrolytes. Based on the results, it has been found that modification of the glassy carbon electrode with a layer of Nafion™ eliminates unwanted follow-up reactions (formation of polyiodides) in the iodine/iodide system, as well as the addition of iodine to the solution increases the reduction currents in each of the electrolytes tested. In addition, catalytic activity in the reduction reactions of the iodine/iodide system has also been demonstrated by cobalt(II,III) hexacyanoferrate(II) Finally, our results show that the catalyzed iodine/iodide system can reach extremely high electron self-exchange rates on the level of 10 9 – 10 10 mol -1 dm 3 s -1 .

With the advancement in semiconductor technology, sophisticated multidimensional geometries are being formed resulting in nonconfined spaces. Wet etching these nanoconfined spaces uniformly across different CD sizes is challenging. Typically, etch (ER) decreases with decrease in CD size. One of the reported mechanisms to explain this behavior is the overlapping of electrical double layer (EDL) which prevents the etchants from entering to the nanochannels. In our previous experimental work, we reported a reverse ER trend (ER increase with decrease in CD size) of SiO2 using HF in organic as medium compared to water as medium. These results suggested that EDL model alone cannot explain the full mechanism and other factors need to be considered. Hence, molecular dynamics (MD) simulations are used to explain the mechanism of nanoconfined etching of SiO2 in water and organic solvent. Fig.1 shows the MD simulation result of the number density distribution of diluted HF at the solid-liquid interface in a nanoconfined spaces. When water is the solvent, HF molecules are strongly adsorbed in the solid interface. However, with the organic solvent, the HF molecules are more uniformly distributed in the volume near the surface. As the CD becomes smaller, the HF molecular density in the intermediate region in the space tends to decrease in the aqueous solution and increase in the organic solution. Next, we calculated the diffusion time of HF molecules in the nano-confined trench using the MD simulations, where we found that HF molecules have a faster diffusion time in water than in the organic solvent. This is due to the difference in the interaction between the solid interface, the HF molecules, and the solvent in addition to the viscosity of the solvent. Using EDL model and etching reaction, here we report the wet etching mechanism of nanoconfined spaces from the MD simulation result. Figure 1

We present a novel method for controlling the growth of perovskite crystals in a vacuum thermal evaporation process by utilizing a vacuum-processable additive, propylene urea (PU). Co-evaporating of perovskite precursors and PU retards the direct reaction between the perovskite precursors. This facilitates larger domain size and reduced defect density. In this study, we present a novel method for controlling the growth of perovskite crystals in a vacuum thermal evaporation process by utilizing a vacuum-processable additive, propylene urea (PU). By co-evaporating perovskite precursors with PU to form the perovskite layer (Figure1), PU, acting as a Lewis base additive, retards the direct reaction between the perovskite precursors. This facilitates larger domain size and reduced defect density (Figure 2). Following the removal of the residual additive, the perovskite layer, exhibiting improved crystallinity, demonstrates reduced charge recombination, as confirmed by time-resolved microwave conductivity analysis. Consequently, there is a notable enhancement in open-circuit voltage and power conversion efficiency, increasing from 1.05 V to 1.15 V and from 17.17% to 18.31%, respectively. The incorporation of a vacuum-processable and removable Lewis’s base additive into the fabrication of vacuum-processed perovskite solar cells offers new avenues for optimizing these devices. Figure 1

As high-performance batteries increase in demand, lithium metal batteries (LMBs) have attracted increasing attention in recent years. Nonetheless, LMBs are limited in their performance due to a low cation transport number (tLi+) of non-aqueous liquid electrolytes, which is the ratio of charge transport of Li-ions to its counterion. This study investigated fluorinated ether-based electrolytes (1,2-(1,1,2,2-tetra fluoroethoxy) ethane, TFEE) with 1,2-dioxolane (DOL) as a co-solvent that were found to have tLi+ of 0.70, which was determined through electrochemical impedance spectroscopy, EIS. This electrolyte mixture gives a low electrolyte coulombic efficiency and poor stability tested in both Li-Cu half and Li – Li4Ti5O12 full cells. The same fluorinated electrolyte with dimethoxy ethane (DME) as a co-solvent showed better coulombic efficiency and stability despite its low tLi+ of 0.18. A significant migration resistance through the porous solid electrolyte interface (SEI) in the case of TFEE-DOL electrolytes is suspected to explain the observed discrepancy, as demonstrated by EIS and X-ray photoelectron spectroscopy. We propose that the properties/process of the Li anode are more crucial for LMBs’ performance than the ionic transport through the bulk electrolyte. Furthermore, the transport number should be determined carefully to avoid any spurious effects associated with SEI properties. Acknowledgments This work has received funding from the European Union Horizon 2020 research and innovation DESTINY program under grant agreement No. 945357. Co-financing from Slovenian Research Agency (ARRS) is fully acknowledged.

Solid-state lithium-ion batteries are being considered as a future energy-storage technology, with superior energy/power density and improved safety over conventional lithium-ion batteries. However, their commercial implementation is hampered by side reactions and electro-chemo-mechanical degradation occurring during cycling (mostly at the positive electrode side). Many efforts have been made to reveal the underlying mechanisms in order to alleviate such problems.In the current study, the Thermo Scientific IGST workflow solution was used to enable a DualBeam to TEM workflow by protecting both bulk sample and prepared lamella under argon atmosphere with a CleanConnect transfer module. Because of the beam and temperature sensitivity of the superionic lithium thiophosphate solid electrolyte and the cathode interphases formed during cycling, the lamella preparation process (incl. bulk milling, lift out, attachment to the TEM grid, and final thinning) was carried out at cryogenic temperature (−178 °C). The lamella was then transferred to a Talos F200X CFEG for TEM analysis using an inert gas sample transfer workflow.STEM and EELS investigations revealed Ni, Co, and Mn dissolution from a Ni-rich cathode and subsequent solid electrolyte poisoning. Transition-metal dissolution/migration during cycling operation has previously only been reported for conventional (liquid-electrolyte-based) batteries.

Due to its important role in the production of fertilizers ammonia is one of the most produced chemicals worldwide. In recent years there has been increasing interest in the electrochemical lithium mediated nitrogen reduction reaction (LMNRR), as a possible alternative to the Haber-Bosch process. The LMNRR is advantageous as it can be carried out under ambient temperatures and pressures [1].The LMNRR process involves electrochemical plating of metallic Li from an organic electrolyte. This plated Li reacts with elemental nitrogen forming an intermediate nitride species, which is subsequently protonated to form ammonia. To ensure high selectivity towards ammonia production the competing hydrogen evolution reaction has to be limited [2]. The solid electrolyte interphase (SEI), formed from electrolyte decomposition at the working electrode plays a crucial role in this as it influences mass transport to the electrode [3]. Studies using neutron reflectometry with one-minute time resolution investigated the initial stages of SEI formation in LiClO4 containing electrolytes [4]. Recent investigations show improved performance using LiBF4 containing electrolytes [5].In this study formation and dynamics of the SEI layer derived from LiClO4 and LiBF4 containing electrolytes were examined in operando using grazing incidence wide-angle X-ray scattering (GI WAXS) in a synchrotron setup. The use of GI WAXS provides a time resolution in the seconds range, enabling the identification of transient species and fluctuations of deposits on the electrode surface.Different SEI species and their dynamics have been observed and correlated with electrolyte composition and faradaic efficiency towards ammonia. Figure 1a) shows the dynamic behavior of diffraction features attributed to Li and LiF in an experiment using LiBF4 as electrolyte salt. In Figure 1b) the development of the corresponding peak intensities is shown and correlated with the start and end of chronopotentiometry (CP), used to study the cell. LiF was formed from the decomposition of LiBF4 and accumulated on the working electrode, showing that LiF is a significant component of the SEI in fluoride-containing electrolytes. Furthermore, metallic Li was found to be more stable when LiBF4 was utilized as electrolyte salt, in contrast to LiClO4. This finding suggests that the SEI derived from LiF has different mass transport characteristics and is more robust than that derived from LiClO4. This may explain the previously reported superior performance of electrolytes containing LiBF4 [5].

Hybrid supercapacitors have gained significant attention in recent years due to their potential to combine the advantages of both batteries and capacitors. In this study, we investigate the use of metal oxides materials in a hybrid supercapacitor using a dendritic gold current collector, the device was implanted on a silicon wafer. Metal oxide materials, such as iron Oxide (Fe2O3) and manganese oxide (Mn2O3), are known for their high pseudo-capacitance and excellent electrochemical performance in water based electrolyte.By integrating dendritic gold current collectors with these materials, we aim to enhance its energy storage capacity and cycling stability. The silicon substrate provides mechanical support and pave the way for on-chip application, while the dendritic gold current collector offers a high surface area for efficient ion adsorption and desorption along the electrode-electrolyte interface. The metal oxide is coated onto the porous gold electrode using a simple and low cost-effective method, the electroplating, by mean of a solution based on FeSO4. The performance of the hybrid supercapacitor is evaluated through various electrochemical tests, including cyclic voltammetry, galvanostatic charge-discharge cycling, and electrochemical impedance spectroscopy, adopting neutral water based electrolyte. The results show that the enhanced hybrid supercapacitor with metal oxide materials exhibits significantly improved electrochemical performance compared to the device with a flat metal oxide electrode. The Fe-coated dendritic electrode exhibits a high specific capacitance over 20 mF cm-2, while the MnO2-coated flat electrode demonstrates similar specific capacitance over 25 mF cm-2. Additionally, the hybrid supercapacitor shows excellent cycling stability with negligible capacitance loss after 1000 cycles.In conclusion,the results suggest that mixing micro-structured current collectors with metal oxides can lead to simplified area's balancing technique for planar electrochemical cells, destinated to the development of on-chip devices with large operating voltage window, high energy storage capability and efficiency. Figure 1