bluuebunny/crossref_metadata_2025 huggingface dataset:
(Invited) Integrated Electrochemical Devices for Microphysiological Systems
Authors: Ino Kosuke
Published: December 2024

Animal testing has been used for drug screening applications. However, the accuracy of this testing is low due to the difference in metabolization activities between animals and humans. To challenge this issue, there is a growing interest in employing in-vitro assays using human culture cells. These assays involve three-dimensional cell cultures or stimulation within microfluidic devices to replicate in-vivo functions, known as microphysiological systems (MPSs). Also, porous membranes are used to prepare biological interfaces for MPSs, such as gut, lungs, skin, and vasculature, by culturing cells on these membranes.

MPSs have been widely evaluated using qPCR and immunostaining methods. However, these methods damage cells, making them unsuitable for real-time or time-course analysis. To challenge this issue, electrochemical (bio)sensors are being explored, as they enable real-time and time-course evaluations of metabolization without cell damage [1].

In this study, integrated electrochemical devices have been developed for MPSs. As one example, porous membrane electrodes were fabricated to cultivate cell monolayers and measure cellular activities in situ for MPS applications. Human umbilical vein endothelial cells (HUVECs) were cultured on the membrane as a vascular model and measured the release of nitric oxide (NO) from HUVECs (Fig.: Reprinted with permission from Ref. 2. Copyright 2023 American Chemical Society) [2]. This method allows for the monitoring of short-lifetime molecules like NO because the cells are attached to the electrode.

As another example, electrochemiluminescence (ECL) devices were developed for cell analysis [3]. In ECL measurements, electrochemical reactions are converted to optical signals, resulting in successful electrochemical imaging for cell analysis using only a single working electrode. In this study, the ECL devices were applied to visualize cellular respiration activity and cell adhesion.

Moving forward, these electrochemical MPS devices hold promise for drug screening and biomedical research, serving as an alternative to animal testing.

References

[1] Curr. Opin. Electrochem., 39, 101270, 2023; Electrochem. Sci. Adv., e2300026, 2024

[2] Anal Chem., 95, 49, 18158, 2023

[3] Biosens. Bioelectron., 181, 113123, 2021; Electrochim. Acta, 415, 140240, 2022; Electrochim. Acta, 458, 142507, 2023; Electrochemistry, 92, 022009, 2024

Figure 1
(Invited) Using Molecular Dynamics Simulations to Design Mediated Bioelectrochemical Interfaces
Authors: Mtemeri Lincoln , Calabrese Barton Scott , Hickey David P.
Published: December 2024

Cell-free bioelectrocatalysis has drawn significant research attention as a Green approach for producing commodity and fine chemicals. Enzymatic bioelectrocatalysis utilizes electrodes to drive challenging enzymatic redox reactions, such as CO2 reduction and selective oxidation of lignocellulosic biomass to generate value-added products. For many oxidoreductases, the redox cofactor is buried within the insulating protein matrix and, thus, inaccessible to the heterogeneous electrode surface. In such cases, electrochemically active small molecules, called redox mediators, have been proven effective in enabling efficient electron transfer by acting as electron shuttles between the electrode and enzyme cofactor. To this end, redox-active hydrogels have become a critical component of many bioelectrocatalysis applications as a way to create an efficient enzyme/electrode interface. Polymers containing covalently attached redox mediators are cross-linked in the presence of a desired oxidoreductase onto the surface of an electrode to form a bioelectrocatalytic hydrogel. This strategy simultaneously immobilizes enzymes at the electrode interface – thereby simplifying product purification and mitigating mass transfer limitations – and improving electron transfer kinetics necessary for electrochemically regenerating the redox cofactor. Despite the success and broad application of redox polymers in enzymatic bioelectrocatalysis, critical interactions between polymer-bound mediators and redox enzymes remain poorly understood, thereby adding significant complications to the design of novel redox polymers. Moreover, there are notable (and seemingly contradictory) discrepancies between the activity of commonly used enzymes, such as glucose oxidase, with freely solvated mediators compared to their polymer-bound counterparts. We have employed a combination of electroanalytical techniques with an array of computational tools (including density function theory (DFT), static docking simulations, and molecular dynamics simulations) to provide new insights into the role that both protein structure and redox polymer composition play in designing efficient bioelectrochemical interfaces. Specifically, we compare the interactions of a commonly used naphthoquinone-modified linear poly(ethylenimine) hydrogel with two structurally analogous enzymes, GOx and FAD-dependent glucose dehydrogenase, that lead to divergent electrocatalytic activity despite both being equally active towards a comparable freely diffusing mediator.
Characterization of Extracellular Vesicles Via Simultaneous Resistive-Pulse Sensing and Fluorescence Imaging
Authors: Schmeltzer Alexandra J. , German Sean R. , Peterson Eric M. , White Henry S.
Published: December 2024

Recent studies suggest extracellular vesicles (EVs) of cancerous origin contribute to cancer metastasis, immune suppression, and the emergence of therapy-resistant cancer cells. Distinguishing oncogenic EVs from ‘healthy’ EVs poses a challenge for current technologies, where a range of various analytical techniques is required to assess EVs characteristics (e.g., size, contents). Traditional methods such as Cryogenic TEM are low-throughput, while others such as flow cytometry and nanoparticle tracking lack the size precision to quantify small, <50 nm, EVs. Herein, we introduce simultaneous resistive-pulse sensing and fluorescence imaging on an EV-by-EV basis to comprehensively characterize EV size, surface charge, surface biomarkers, cargo, and concentration. Individual EVs are multipassed through the orifice of a laser-pulled glass nanopipette approximately 100-200 nm in radius, enabling sub-nanometer sizing precision while simultaneously quantifying the fluorescence emission of labeled EV surface markers and internal contents. A fiber optic cable is placed within the interior of the nanopipette, which serves as a waveguide to direct the excitation light to the resistive-pulse sensing zone at the pipette orifice. By characterizing EVs one-at-a-time, accurate statistics of unique EV subpopulations within the population ensemble are obtained. This multipass resistive-pulse sensing approach offers a high-throughput solution for rapidly characterizing heterogeneous EV populations, promising advancements in our understanding of EV-mediated processes in cancer progression and therapy resistance.

Figure 1
(Invited) Electrochemical Biosensor Using Direct Electron Transfer and an Antibody–Aptamer Hybrid Sandwich
Authors: Kim Gyeongho , Yang Haesik
Published: December 2024

Direct electron transfer (DET) between an electrode and redox labels is feasible in electrochemical biosensors using small aptamer–aptamer sandwiches; however, its application is limited in biosensors that rely on larger antibody–antibody sandwiches. The development of sandwich-type biosensors utilizing DET is challenged by the scarcity of aptamer–aptamer sandwich pairs with high affinity in complex biological samples. In this presentation, we introduce an electrochemical biosensor using an antibody–aptamer hybrid sandwich for detecting thrombin in human serum. The biosensor enables rapid DET through an antibody–aptamer hybrid configuration comprising (i) an antibody capture probe that provides high and specific affinity to the target in human serum, (ii) the target thrombin, and (iii) an aptamer detection probe that facilitates convenient terminal conjugation with long flexible spacer DNA and polylinker peptide containing multiple amine-reactive phenazine ethosulfate (arPES) redox labels, allowing the conjugated labels to easily approach the electrode. Rapid repeated DET using arPES-catalyzed NADH oxidation strongly enhanced the electrochemical signals. Properly sized spacer and polylinker provided low nonspecific adsorption of the aptamer probe conjugated with multiple arPESs and low interference with the binding of the aptamer probe. Methods for immobilizing thiol-terminated antibodies on Au electrodes were compared and optimized. The developed biosensor using the antibody–aptamer hybrid sandwich exhibited high sensitivity and selectivity in detecting thrombin, surpassing the limitations of an aptamer–aptamer sandwich owing to the low affinity of thrombin aptamers in human serum. The calculated detection limit of the biosensor was ∼1.5 pM in buffer and ∼2.7 nM in human serum.

References

1. G. Kim, H. Yang, Biosens. Bioelectron. 253, 116184 (2024)

2. G. Kim, H. Cho, P. Nandhakumar, J. K. Park, K. Kim, H. Yang, Anal. Chem. 94, 2163 (2022)

3. S. Park, J.-E. Jeong, V. S. Le, J. Seo, B. Yu, D.-Y. Kim, S.-H. Kwon, S. Jon, H. Y. Woo, H. Yang, J. Am. Chem. Soc. 140, 2409 (2018)
Direct Contact Prelithiation of Silicon-Dominant Anodes Using Ultra-Thin Lithium Foils
Authors: Diller Felix , Wittmann Oskar , Daub Rüdiger
Published: December 2024

With the steady growth of the electric vehicle market, the development of high-energy-density lithium-ion batteries is increasingly coming into focus. Silicon has a nearly ten times higher specific capacity for lithium storage than conventionally used graphite, making silicon a promising anode material for high-performance lithium-ion battery applications[1]. However, silicon shows a high volume expansion upon lithiation, leading to a rapid capacity fade due to the loss of active lithium associated with continuous solid electrolyte interphase formation[2]. Direct contact prelithiation is a method to compensate for the loss of active lithium by incorporating additional lithium metal during battery cell production. The use of lithium foil is a facile approach but depends on the availability of ultra-thin lithium foils[3].

In this study, silicon-dominant anodes with a silicon content of ca. 70 % were prelithiated by lithium foils with a thickness of 5 and 10 µm using a calendering process. A glove box integrated calender under an argon atmosphere was used to transfer the ultra-thin lithium foils from a carrier foil on the entire anode surface. This facilitates a homogenous prelithiation of the anode and equal compression force over the entire anode surface. A process study was conducted to find suitable process parameters for the full-surface lithium foil application on the anodes. The formed anode-lithium-composite was investigated with and without the presence of an electrolyte. Pouch cells with nickel-rich cathodes were built to show the performance improvement through the presented prelithiation technique in the full cell setup.

An increase of 16 % in full cell capacity shows the potential of direct contact prelithiation to boost the energy density of already high-energy lithium-ion battery material systems. The incorporated lithium metal compensates for the loss of active lithium and thereby enhances the cycle life of the battery cells, making the proposed prelithiation method an enabler for the use of silicon-dominant anodes for high-performance applications.

References

[1] M. N. Obrovac and L. Christensen, Electrochem. Solid-State Lett., 7, A93–A96 (2004).

[2] A. J. Louli, L. D. Ellis and J. R. Dahn, Joule, 3(3), 745-761 (2019).

[3] B. Stumper, A. Mayr and G. Reinhart, Procedia CIRP, 93, 156-161 (2020).

Acknowledgements

The authors gratefully acknowledge funding from the German Federal Ministry of Economic Affairs and Climate Action through the project CAESAR (grant number 03EI3046F). We thank the project partners from Wacker Chemie AG, BASF SE, and E-Lyte Innovations GmbH for the collaboration within the CAESAR project and for providing us with the used silicon, the cathode active material, and the electrolyte.
Enhancing Anode-Free Lithium Battery Stability By One-Step Thermal Treatment of Porous Carbon Fibers for Controlled SEI Formation and Surface Activation
Authors: Kim Woosung , Lu Wei
Published: December 2024

Anode-free lithium batteries (AFLBs) hold great promise for high energy density, yet challenges such as low coulombic efficiency and dendrite formation impede their practical use. Herein, we present an optimal defect design of a carbon current collector that markedly enhances stable cycling reactions in AFLBs. A one-step thermal treatment is introduced to create defective surfaces with nano-sized pores on carbon fibers, guided by a comparative analysis of defect evolution under varying thermal energy and oxidation conditions. The thermally derived atomic vacancies and functional groups on the graphitized surface create uniform edge planes on the basal background of graphite, thereby facilitating lithium-ion diffusion and electrolyte reduction. Additionally, molecular dynamics simulations are employed to model the lithiated nano-defects and calculate lithium adsorption energy according to the lithiation and defect configurations. The experimental/computational analyses demonstrate the beneficial role of carbon defects in inducing uniform lithium deposition and controlling the properties of a robust solid electrolyte interphase (SEI), which is crucial for suppressing lithium dendrite. Consequently, the highly defective carbon current collector exhibits much longer cycling stability and higher coulombic efficiency compared to pristine carbon current collector and copper foil in half-cell tests. Furthermore, it shows a stable high-rate capacity at the high cut-off voltage (4.5 V) in full cell with NMC cathode. The results suggest innovative design strategies for carbon-based electrodes, focusing on the correlations between intercalation and plating mechanisms. Moreover, the rapid yet systematic thermal process demonstrates significant utility in carbon treatment, indicating its promising potential for making next-generation lithium batteries.
Understanding Solid-State Direct Recycling of Ni-rich Layered Positive Electrodes
Authors: Gnutzmann Maike Michelle , Makvandi Ardavan , Buchmann Julius , Winter Martin , Kasnatscheew Johannes
Published: December 2024

With ever-increasing production volumes of lithium ion batteries (LIBs), the worldwide quantity of end-of-life (EoL) electric vehicle (EV) LIBs is expected to be 3.6 to 5.3 million metric tons until 2030. In order to meet legislative regulations, and reduce environmental and health risks, effective recycling strategies are crucial. Direct recycling, i.e. the direct reuse of battery components without breaking down the chemical structure, is a closed-loop approach allowing the reduction of costs, energy consumption and greenhouse gas emissions during recycling. Compared to well-known low- to mid-Ni layered oxides, LiFePO3 (LFP) and LiCoO2 (LCO), the promising Ni-rich layered oxides are supposed to be even more prone to severe morphological and structural degradation during charge/discharge cycling, making direct recycling particularly challenging. Here, spent cathode active material, i.e. LiNi0.83Co0.12Mn0.05O2 (NCM-831205), is directly recycled via re-lithiation and reconstruction. Re-lithiation is performed via a solid-state reaction with lithium hydroxide monohydrate under oxygen atmosphere at 800 °C, i.e. mimicking original synthesis procedures of pristine Ni-rich NCM. In the directly recycled powders, polycrystallinity and high tap density are maintained, and the evolution of particle size and shape, specific surface area, crystal structure at the surface and in the bulk, and lithium content, are explored. Pristine-original performance is reached for 100 cycles in graphite-based full-cells and remaining issues including possible strategies are highlighted. In summary, the current status of direct recycling is reviewed, presented experimental results are contextualized and economic feasibility is discussed.

Figure 1
Effect of Electrode Curvature on Cell Behavior in Cylindrical Lithium-Ion Batteries
Authors: Jeon Byeong-jin , Lee Yeong-Hyeon , Jeong Kyeong-Min
Published: December 2024

Lithium-ion batteries come in various form factors, with cylindrical lithium-ion batteries featuring electrodes wound in a jellyroll shape. This winding process introduces curvature to the electrodes, resulting in varying curvatures depending on the radius of the jellyroll.

In this study, we investigated the influence of electrode curvature within cylindrical lithium-ion batteries on battery performance. We fabricated single-coated electrode pouch cells using an NCM622 cathode and graphite-silicon composite anode. We developed devices to simulate various curvatures based on the radius of the jellyroll and applied these devices to the pouch cells to analyze the effect of curvature on the cell’s charging and discharging behavior.

The results revealed that changes in electrode curvature, depending on the radius of the jellyroll, alter the area available for reaction at the anode. As a result, the potential of the anode changed, leading to a corresponding change in the potential of the cathode at the same full cell's cut-off charging voltage. Additionally, we observed differences in cathode/anode utilization depending on whether they were on the inner or outer coated surface, even with the same curvature. Particularly, we found an increased risk of lithium deposition when the curvature is large with the anode on the outer coated surface. Furthermore, these effects influence changes in silicon utilization in the anode, affecting the thickness expansion and degradation differences in the anode. Consequently, the non-uniformity of cell reactions due to electrode curvature increases. Therefore, we propose methods for designing cylindrical lithium-ion batteries to minimize such non-uniformity in reactions.

Our research emphasizes the importance of curvature within cylindrical lithium-ion batteries and its impact on battery performance by elucidating the mechanism of battery performance changes due to electrode curvature. These findings are expected to contribute to the design and development of cylindrical lithium-ion batteries.

Figure 1
Thermal Runaway Suppression of High-Energy Lithium-Ion Batteries with Nonflammable Liquid Electrolyte
Authors: Song Seung-Wan , Tran Yen Hai Thi , An Kihun , Seo Yuri
Published: December 2024

Lithium-ion batteries (LIBs) are the essential power sources of portable energy devices, electric vehicles, e-mobilities, and large-scale energy storage systems. However, commercial LIBs consist of highly flammable liquid electrolyte that possesses the risk of thermal runaway and fire hazards when the battery’s malfunction or any abuse event. Advancement of liquid electrolyte is urgently needed, aiming to attain battery safety without losing energy density and performance. Herein, we report the design and application of a new class of nonflammable liquid electrolyte, which is readily replaceable for flammable commercial liquid electrolyte and is designed for industrial 800 mAh graphite//NCM811 Li-ion pouch cells. Cell test results highlight the benefits of nonflammable liquid electrolyte-driven well-working advanced LIB and suppressing thermal runaway. A fundamental understanding of well-working mechanism and thermal runaway suppression mechanism regarding the solid electrolyte interphase (SEI) stabilization of anode and cathode will be discussed in the meeting.
Impact of Mixed Salt Electrolytes for LiMnxFe1-XPO4/Graphite Li-Ion Cells
Authors: James Abraham Jeffin , Leslie Kate , Yang Chongyin , Metzger Michael , Dahn Jeff R.
Published: December 2024

Lithium Manganese Iron Phosphate, LiMnxFe1-xPO4, (LMFP), is a promising positive electrode material for Lithium-ion batteries. Introduced by Pahdi et al. in 1997 [1], it is an alternative to the high-cost Nickel Manganese Cobalt (NMC) layered oxides and the low energy density Lithium Iron Phosphate (LFP) positive electrode materials. The LMFP material has a higher operating voltage than LFP, shows good cyclability, is low cost, and has a stable structure. However, the LMFP material suffers from poor rate capability due to its poor electronic conductivity and poor ionic diffusion. This hampers its use for high C-rate applications. Tailoring electrolytes to ensure better ionic diffusion at the solid/electrolyte interface is one solution to improve rate capability of these LMFP cells. Herein, we study the effect of different salts and mixed salts on LMFP/graphite Li-ion pouch cells and come up with a suitable electrolyte combination for LMFP cells. The salts used in this study are readily available salts and the mixed salts were made with a combination of these readily available salts at different ratios. The tests were conducted in a 70 °C temperature box to accelerate failure in these cells, as a method to screen these salts/mixed salts. Our observations show that mixed salts play a significant role in improving the lifetime of these cells, with the best cell reaching the end of life (EOL) after ~280 cycles at 70 °C. As LMFP is prone to manganese dissolution, the amount of manganese deposited on the negative electrode was quantified using X-ray Fluorescence spectroscopy (XRF). The cells using mixed salts display a lower amount of manganese deposited on the graphite compared to the individual salts. The use of readily available mixed salt electrolytes seems to improve cycle life, which is promising for the future commercialization of the LMFP positive electrode Li-ion cells.

References:

K. Padhi et al. 1997 J. Electrochem.
Soc.
144 1188

Figure 1. a) Discharge capacity, b) normalized discharge capacity, and c) normalized voltage hysteresis of LMFP cells containing different salts/mixed salts, cycled at 70 °C.

Figure 1
Nonflammable Organic Liquid Electrolyte for Improved Performance of SiOx-Graphite//NCM811 Lithium-Ion Battery
Authors: Lee Jiin , An Kihun , Tran Yen Hai Thi , Oh Taekeon , Song Seung-Wan
Published: December 2024

Lithium-ion batteries (LIBs) are the power sources of portable electronics, e-mobilities, and energy storage systems. To advance the LIBs toward a better working and safer one, challenges of enhancing simultaneously energy density, cycle life, and safety remain. To achieve a high energy density LIB, various silicon based anode materials have been studied worldwide for decades. However, their performance is often limited due to, a large volume change of SiOx and interfacial instability with traditional electrolyte. In this presentation, we will report the strategies of advanced electrolyte and interfacial stability control for performance improvement of SiOx-based lithium-ion full-cell. Mechanistic studies of electrolyte-derived formation of stable solid electrolyte interphase (SEI) layer at SiOx-based anode as well as high nickel cathode in the full-cell will be discussed in this meeting.
Enhancing Lithium-Ion Battery Performance of Silicon Microparticle-Embedded Wrinkled Multilayered Graphene Structures for High Areal Capacity
Authors: Lee Seongchan , Heo Incheol , Kang Min seok , Yoo Won Cheol , Kim Jaeseong
Published: December 2024

Even nanostructured Si electrodes have demonstrated stable electrochemical performances in lithium-ion batteries (LIBs), complex process and high-cost of nanostructured Si electrodes are far from industry standards. Thus, utilization of commercially available low-cost Si microparticles with high-performance is highly necessary for high-energy-density LIBs. In this presentation, we demonstrate a simple and scalable method to utilize commercially available Si microparticles (ca. 7 μm) with wrinkled-multilayered-graphenes (Si-WMGs) for high-areal-capacity LIBs. The WMGs provide not only mechanical flexibility for mitigating large volume change of Si microparticles during deep charge/discharge processes, but also good adhesion property to effectively coalesce Si microparticles, and high electrical conductivity, resulting in binder- and conductor-free thick electrodes. The Si-WMG electrodes showed high initial areal capacities of 12.5 mAh cm-2 at 0.1 C and 7.1 mAh cm-2 even at a very high rate of 2 C, with outstanding long-term stability with 5.3 mAh cm-2 at 2 C for over 240 cycles. Furthermore, a full cell composed of Si-WMG and lithium cobalt oxide presented 3.13 mAh cm-2 and a stable cycling performance (90.3% retention after 100 cycles) in a practical cell setting, clearly demonstrating the practical applicability of Si-WMG electrodes. Therefore, the WMG as a binder and conductor could be applicable to other electrodes with a large volume change and high mass-loading for high-areal-capacity LIBs.
Hydrodynamic Voltammetry of Fe2+/3+ Redox Couple in Eutectic Electrolytes for Flow Batteries
Authors: Prado Desiree Mae , Shen Xiaochen , Savinell Robert F. , Burda Clemens
Published: December 2024

Deep eutectic solvents (DESs) demonstrate potential as non-aqueous electrolytes for next-generation redox flow batteries (RFBs). DESs are considered not only as environmentally sustainable but also economically attractive electrolytes because they can be resourced from biological feedstock (alcohols, urea, choline) and are earth-abundant and of low toxicity. However, their inherent hydrogen bonding leads to high viscosity, hindering ion and reactant transport, thereby limiting power density. This study investigates the influence of controlled water addition on the Fe²⁺/Fe³⁺ redox couple in DES ethaline (a mixture of choline chloride and ethylene glycol in 1:2 molar ratio) to gradually disrupt the hydrogen bond network between its components. Our results show that the stoichiometric introduction of water effectively reduces viscosity and increases ionic conductivity within the DES electrolyte. The reduced viscosity and three-fold improvement in conductivity enhances mass transport and kinetics of Fe²⁺/Fe³⁺ redox couple in DES ethaline, potentially leading to higher power density RFBs. Also, iron chloride salts exhibit increasing solubility (>2 M) in DES electrolyte with the addition of increasing quantities of water. Notably, the electrochemical stability window remains around 1.90 V, mitigating concerns about water-induced instabilities. These findings suggest that strategically incorporating water into DES electrolytes can overcome mass transport limitations, paving the way for high-performance, environmentally friendly RFBs. This approach eliminates the need for harmful solvents and fossil fuel-based processes.
Electrochemical Biomass Upgrading of 5-Hydroxymethylfurfural to 2,5-Furandicarboxylic Acid Under Mild Alkaline Media
Authors: Lee Eunchong , Hwang Yun Jeong
Published: December 2024

Biomass holds promise as a substitute for carbon sources derived from fossil fuels, which are known for their production of CO2 emissions and contribution to microplastic pollution. 2,5-Furandicarboxylic acid (FDCA) from biomass-derived 5-hydroxymethylfurfural (HMF) has emerged as a green plastic because it is a monomer of poly(ethylene furoate), poised as a viable alternative to poly(ethylene terephthalate) due to its robust mechanical properties and environmentally sustainable production. An electrochemical oxidation reaction of HMF to FDCA (HMFOR) has been studied actively due to the high performance and cost-effectiveness of transition metal catalysts. Furthermore, it demonstrates a lower overpotential for water splitting by substituting the anodic reaction from oxygen evolution reaction (OER) to HMFOR with value-added FDCA production than oxygen. The majority of HMFOR research has been carried out in highly alkaline media (1 M KOH) because the OH- serves as a reactant and accelerates the HMFOR. Nevertheless, this approach is not conducive to scaling up concentrated HMFOR processes due to the risk of high OH- concentrations, which leads to the instability of HMF through polymerization into humin. Herein, we investigate the HMFOR under mild alkaline media, ensuring the preservation of HMF, facilitated by a Cu-Ni based catalyst. In contrast to the conditions at high pH, the oxidation of aldehyde groups was inhibited due to the lack of sufficient OH-, which hindered the OH- mediated formation of germinal diols. Through several in situ studies, we proposed that Cu induces the adsorption of OH- and HMF, promoting the geminal diol formation, and Ni acts as the most active site of HMFOR. This research would be expected to provide strategies for achieving highly efficient HMFOR while maintaining the stability of HMF via suppression of the OH- mediated humin polymerization.
Catalyst Deactivation on Transition Metal Oxides during Ammonia Electrooxidation
Authors: Chen Sijie , Zheng Weiran
Published: December 2024

Electrochemical ammonia oxidation reaction (AOR) offers a sustainable approach for waste ammonia remediation, energy conversion, and valuable product production.[1] Despite the promise of transition metal oxides as effective catalysts, the AOR mechanism on their surface remains elusive, along with factors leading to deactivation, which often involve surface poisoning species formation and site corrosion. Moreover, the AOR potential overlaps with the oxygen evolution reaction (OER), leading to the formation of O2 as a byproduct and an overall decline in energy efficiency. Therefore, it is critical to understand the molecular behavior of ammonia and other species on the oxide surface under reaction conditions.

In this work, we systematically investigate the AOR mechanism on NiOOH and CuOOH, emphasizing the influence of OER and dissolved O2, which has been previously largely overlooked. Utilizing three in situ techniques: differential electrochemical mass spectrometry (DEMS) for detecting gaseous intermediates and products, Raman spectroelectrochemistry for monitoring surface transformations, and UV-vis spectroelectrochemistry for observing species within the electrical double layer, we reveal that the formation of NiOOH/CuOOH, the AOR catalytic activity and selectivity, and the deactivation pathway are all significantly modulated by OER and the presence of O2.

It is established that AOR on NiOOH is potential-dependent, with N2 production being initiated at potentials coinciding with OER commencement and the generation of NOx species being favored at elevated potentials (Figure 1 left). Moreover, OER competes with the AOR to N2 pathway but promotes the AOR to NOx (N2O, NO, and NO2), which is further elucidated through the protective role of O2 to remove *N poisoning species, mitigating surface deactivation and decreasing charge transfer resistance (Figure 1 right). On CuOOH, however, the O2 can promote NO formation and Cu dissolution from the CuOOH layer, leading to complete deactivation at high potential. Our findings offer an in situ insight into the AOR mechanisms on metal oxides with co-existing OER and provide a critical direction for designing electrocatalysts for environmental applications, particularly for systems where long-term electrolysis is desired.

Figure 1. Left: DEMS results during linear sweep voltammetry of NiOOH electrode in Ar/O2-saturated electrolytes (1.0 M KOH + 100 mM NH3).
Right: Electrolysis results of NiOOH electrode in Ar/O2 saturated electrolytes (1.0 M KOH + 100 mM NH3) at various potentials.

References

MacFarlane, D. R.; Cherepanov, P. V.; Choi, J.; Suryanto, B. H. R.; Hodgetts, R. Y.; Bakker, J. M.; Ferrero Vallana, F. M.; Simonov, A. N. Joule, 4 (6), 1186-1205 (2020).

Figure 1
Unraveling the Importance of Electrochemical Activation in Nickel Iron Selenides for Improving Alkaline Oxygen Evolution Activity
Authors: Jang Yeongeun , Lee Seunghwa
Published: December 2024

Water electrolysis emerges as a pivotal technology for hydrogen production in the quest for sustainable energy solutions, distinguished by its lack of carbon dioxide emissions. This study zeroes in on the oxygen evolution reaction (OER), a critical yet energy-intensive component of the electrolysis process. We study the effects of modulating the nickel-iron (NiFe) ratio in NiFe selenides, a leading non-precious metal catalyst for OER, on the reaction's efficiency. Our findings elucidate how variations in the NiFe ratio and electrochemical activation methods on nickel selenium (NiSe) significantly influence catalytic performance. We elucidate the performance variations in catalysts using in situ Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). These advanced analytical techniques have allowed us to uncover the pivotal role of selenium not only in increasing active surface area via its dissolution but also in enhancing the activity of catalysts for the OER.
Utilizing Cladding Processes to Enhance Structural Stability of Aluminum-Foil Anodes for Rechargeable Lithium Batteries
Authors: LIU Weiqi , Li Hongyi , Nakata Yuki , Matsumoto Shingo , Yamaguchi Takitaro , Hoshikawa Hiroaki , Kumagai Toshiaki , Ichitsubo Tetsu
Published: December 2024

Al-foil anodes are attractive candidate materials for rechargeable lithium batteries owing to their high theoretical capacities (993 mAh g-1, Al+Li++e
-=LiAl) and low production costs. Within appropriate hardness and composition, the Al foils can work as self-standing anodes, where the surface layer reacts with Li as the active material, and the base layer remain unreacted to hold the structural stability as the current collector. However, during battery cycling, the base layer of Al foils is prone to be consumed due to surface passivation by cathodic decomposition products of electrolyte species. Eventually, the Al-foil anodes are totally pulverized, and the reversible capacity is completely diminished.

To limit the reaction depth and protect the base layer, we combine Al foils with various alloy additions (such as Si, Mn, and Mg) by roll-bonding processes to prepare clad foils. [2] The alloy additions change the mechanical properties of Al matrix and affect the lithiation potentials.[3] Thus, the clad Al foils with different alloy additions can create lithiation potential gaps to prevent the Li penetration into the base layer. In particular, the lithiation potentials of 99.99%Al, Al-1%Si, Mn-based A3003 and Mg-based A5052 foils are compared using galvanostatic intermittent titration technique (GITT) measurements. Among the various Al foils, A5052 shows lowest lithiation potential close to 0 V vs Li, where the hard matrix significantly retards the lithiation reaction. The clad foils of Al / A5052 and Al-1%Si / A5052 exhibit a lithiation potential gap up to 0.15 V. By setting the appropriate cutoff potential to utilize the lithiation potential gap, the Li penetration to the base layer is successfully blocked and the structural stability is enhanced.

[1] H. Li, T. Ichitsubo et al, Nat. Commun.
11, 1584 (2020).

[2] H. Li, T. Ichitsubo et al, J. Mater. Chem. A
11, 23311 (2023).

[3] T. Ichitsubo et al, J. Electrochem. Soc. 159, A14 (2011).
Enhancing the Lifetime of Co-Free SC640/Graphite Pouch Cells Operated at 4.4 V
Authors: Azam Saad , Aiken Connor P , Meisner Quinton , Song Wentao , MacLennan Holden , Zhang Zhengcheng , Dahn Jeff R.
Published: December 2024

Abstract: Medium-Ni, Co-free NMC640/graphite cells have the potential to compete in volumetric energy density with high-Ni materials like NMC811/graphite cells when charged to high voltages like 4.4 V. Employing NMC640 can significantly reduce cost and alleviate the demand for precious transition metals such as Ni and Co. This study focuses on assessing the impact of electrolyte additives on the operation of high voltage NMC640/graphite pouch cells. Initially, various generations of electrolyte additives were screened in NMC442/graphite pouch cells using a rigorous 24-hour voltage-hold protocol at 40°C, targeting an upper cutoff voltage (UCV) of 4.4 V. This approach accelerates the screening process, allowing for quicker identification of promising additives, as cell failures primarily stem from impedance growth and transition metal loss. Subsequently, promising candidates of electrolyte additives were evaluated in NMC640/graphite cells through long-term cycling (CCCV) to UCVs of 4.3 V, 4.4 V, and 4.5 V at temperatures ranging from 20°C to 55°C, employing a conventional CCCV protocol.

Figure 1
Bayesian Deep Operator Network-Based Optimization for Battery Thermal Management System
Authors: Kim KyungHyun , Choi Jung-Il
Published: December 2024

This study tackles the critical need for efficient thermal management in battery systems, a key factor in improving the lifespan and performance of electric vehicles and energy storage applications. A groundbreaking method is introduced by utilizing the Bayesian Deep Operator Network (B-DeepONet) framework to develop a surrogate model capable of predicting and optimizing thermal behavior in battery systems across various operating conditions.

We first identify key variables that significantly influence the thermal management of battery packs. These variables lay the groundwork for generating simulation data through Finite Element Method (FEM)-based models. This data, spanning a broad range of battery configurations and thermal load scenarios, is crucial for training the surrogate model.

The model, constructed within the B-DeepONet framework, efficiently maps diverse battery configurations and operating conditions to their corresponding temperature distributions, effectively capturing the complex thermal dynamics. Incorporating uncertainty quantification capabilities enhances the model’s predictive accuracy and reliability, enabling significant advancements in system design even when data availability is limited. This proves particularly advantageous when obtaining high-quality training data is difficult or economically unfeasible.

Finally, the B-DeepONet-based surrogate model is employed to optimize the performance of battery thermal management systems, contributing to more efficient and sustainable energy solutions. This study not only advances predictive modeling in thermal regulation but also improves the ability to effectively manage thermal behaviors in complex battery systems.

Figure 1
Influence of Vinylene Carbonate on Fe-Dissolution in Lfp/Graphite Pouch Cells Cycled at High Temperatures of 70 °C
Authors: Black William , Azam Saad , MacLennan Holden , Adamson Anu , Dahn Jeff R.
Published: December 2024

Olivine LiFePO4 (LFP) has emerged as a compelling alternative to its counterpart, layered Li[NixMnyCoz]O2 (NMC), in commercial lithium-ion cells due to its cost-effectiveness, utilization of abundantly available Fe, and superior safety characteristics. However, LFP/graphite cells exhibit notable degradation in lifetime when subjected to high temperatures compared to NMC. To address this issue, we explore the efficacy of incorporating the electrolyte additive Vinylene Carbonate (VC) to improve the lifetime of LFP/graphite cells at 70 °C. Through μXRF and GCMS analyses conducted at end-of-life (EOL), we observe significant capacity loss in part to Fe-dissolution on the graphite surface at elevated temperatures. This phenomenon triggers SEI rejuvenation and solvent decomposition, resulting in the depletion of lithium inventory. Additionally, we propose a refined SEI-growth model that accounts for the influence of transition metal (Fe) on SEI development of the graphite electrode.

Figure 1
Testing and Characterization of Tubular Na-ZnCl2 Battery Cells for Stationary Energy Storage
Authors: Solem Cathrine Kyung Won , Simonsen Thomas Park , Rørvik Stein , Wang Zhaohui , Sommerseth Camilla , Kjos Ole Sigmund
Published: December 2024

The SALT battery (ZEBRA® battery) was first patented in 1978, and its technology is based on a liquid sodium (Na) anode in charged state, and a solid nickel (Ni) cathode in discharged state, having an electrolyte consisting of a molten nickel chloride/sodium chloride with sodium tetrachloroaluminate (NiCl2/NaCl-NaAlCl4) salt and a solid beta alumina (β''-Al2O3) electrolyte. The Na-NiCl2 cell operates at ~300°C to ensure a molten electrolyte and good Na+ conductivity, as the β''-Al2O3 also operates as a membrane allowing the Na+ ions to pass, but not the e-.

Today, the technology is commercialized, and industrial production sites exist in Switzerland and China. The SALT batteries are used for railways as a back-up energy supply, and in electric vehicles for the mining and construction market. The Na current collector is also the cell housing, making sure that the SALT battery cell is completely hermitized to avoid any contact with air and humidity, as the electrolyte is hygroscopic salts. It is, however, important to reduce the amount of Critical Raw Materials (CRMs) utilizing more abundant materials to make it more competitive for future markets.

In the SOLSTICE project, it has been investigated how the SALT battery can reduce and/or substitute Ni/NiCl2 with Zn/ZnCl2. The present work has covered characterization of a tubular Na-ZnCl2 battery cell, and measured the cell resistance by Electrochemical Impedance Spectroscopy (EIS), cell resistance when fully charged and discharged, as well as the post-mortem analyses, such as SEM and XRD. The study proved that Ni can be replaced by Zn in the full-size SALT battery cell, but the morphology still needs to be studied to optimize the chemistry.

Acknowledgments: This work has been funded by the European Union’s Horizon 2020 research and innovation programme under Grant Agreement No. 963599.
Ether-Functionalized Phosphonium Ionic Liquids: Molecular Dynamics, Ion Conformation, and Intermolecular Interaction
Authors: Matsumoto Mitsuhiro , Nawate Shoki , Inoue Yohtaro , Tsunashima Katsuhiko , Yamada Hirohisa
Published: December 2024

Ionic liquids have many potential applications because they have non-flammability, high thermal stability, high ionic conductivity, and so on. Among various types of ionic liquids, quaternary-phosphonium-cation-based ionic liquids (P-ILs) have better physicochemical properties such as ionic conductivity, potential window compared with corresponding quaternary-ammonium-cation-based ionic liquids (N-ILs). Therefore, we have considered that P-ILs are better suitable for applications in electrochemical devices such as electrolytes for lithium-ion batteries than N-ILs [1].

Recently, we spectroscopically demonstrated that such higher ionic conductivity for P-ILs can be explained by weaker intermolecular interaction between anion and cation [2]. This provided us a consideration that molecular interactions are controlling factors in translational motion of ions. For deeper discussion, we focused on the ether-functionalized P-ILs displayed in the Figure 1 because ether structure in phosphonium cations enhanced ionic conductivity and investigated by pulsed field gradient NMR (PFG-NMR), Raman, and terahertz spectroscopies.

Based on the PFG-NMR, we calculated transport number of each ion specie and found that transport number of P111(1O1) cation was slightly higher than that for P1113 cation. In Raman spectroscopy, we obtained enthalpy change in conformational change of anion (ΔH) and demonstrated that ΔH for P111(1O1)cation was somewhat lower than that for P1113 cation. Terahertz spectroscopy indicated the weaker intermolecular interaction of P111(1O1) cation with anion than that of P1113 cation. Despite these differences in P111X cations, such ether group effects were hardly observed in P222X cations, which would be due to the different symmetry of cation and steric hindrance.

References

[1] M. Matsumoto et al., (2023). Available at SSRN: http://dx.doi.org/10.2139/ssrn.4690007

[2] M. Matsumoto et al., J. Phys. Chem. B, 126, 10490 (2022).

Figure 1
Insight into Modulation of Ionic Liquids for Na-Ion Batteries: Cation Modification
Authors: Zhang Shaoning , Wada Hiroki , Wu Shengan , Hwang Jinkwang , Yoshii Kazuki , Matsumoto Kazuhiko
Published: December 2024

Sodium-ion batteries (SIBs) have gained global attention as cost-effective energy storage solutions, thanks to the abundance of sodium resources. Ionic liquid electrolytes (ILs) are increasingly recognized as promising candidates for SIBs due to their advantageous properties, including low volatility, reduced flammability, and high electrochemical stability.[1-3] However, their application in SIBs is hindered by irreversible decomposition during the initial charging of negative electrodes, resulting in low initial Coulombic efficiency. Our recent research suggested that the addition of lithium with high Lewis acidity into ILs weakens the interaction between organic cations and anions, leading to the formation of unprotected cations.[4]

In this study, we investigate the interaction properties of ILs based on [C3C1pyrr][FSA]-based ILs ([C3C1pyrr]+= N-methyl-N-propylpyrrolidinium and [FSA]− = bis(fluorosulfonyl)amide) and their effects on the Coulombic efficiency at hard carbon negative electrodes for sodium-ion batteries. Furthermore, we explore the impact of pyrrolidinium cations with ether functional group ([Pyr1,2O1]+; N-methoxyethyl-N-methylpyrrolidinium) on the coordination environment of ions and the interfacial properties with negative electrodes through computational analysis.

Our series presentation, titled "Insight into Modulation of Ionic Liquids for Li-ion Batteries: Unprotected Cation", explains the effects of Li concentration on the coordination environment of ionic liquid in lithium systems.

Reference

[1] K. Matsumoto, J. Hwang, S. Kaushik, C.-Y. Chen, R. Hagiwara, Energy Environ. Sci. 12 (2019) 3247.

[2] K. Yoshii, T. Masese, M. Kato, K. Kubota, H. Senoh, M. Shikano, ChemElectroChem 6(2019)3901.

[3] M. Watanabe, M. L. Thomas, S. Zhang, K. Ueno, T. Yasuda, K. Dokko, Chem. Rev. 117, (2017), 7190.

[4] S. Zhang, S. Wu, J. Hwang, K. Matsumoto, R. Hagiwara, J. Am. Chem. Soc. 146 (2024) 8352-8361.
Creating Neoteric Inorganic-Organic Hybrid Functional Biocomposites By Fiber Welding
Authors: Larm Nathaniel E. , Cho Whirang , Stachurski Christopher D. , Ishtaweera Piyuni , Baker Gary , Durkin David P. , Trulove Paul C.
Published: December 2024

Natural fiber welding (NFW) is a process by which ionic liquids (ILs) are used to partially solvate and restructure biopolymer fibers. During NFW, the biopolymer fibers of adjacent cloth threads are intermingled, resulting in a highly nanoporous matrix surrounding a non-welded and structurally robust native thread core. Recent developments in this technique have led to the creation of all-biopolymer xerogel composites with pores of an ideal size regime (<20 nm) for growing and entrapping nanoscale materials, such as metal and semiconductor nanoparticles. However, larger nanoscale materials, such as traditional clay minerals, are too large (>100 nm in length and width) to include within the formed nanoporous matrix. These minerals are often used as fillers to enhance the properties of other polymeric materials, and their exclusion from NFW products is a significant limitation. Recent developments have shown that similar large additives can be entrapped in the welded matrix by first dispersing them in the welding solvent, though traditional clays (e.g., montmorillonite) are minimally soluble in typical welding IL. Fortunately, polyionic nanoclays (PINCs), an emergent class of synthetic and highly tailorable cationic clay minerals, are uniquely soluble in common NFW ILs. The present work aims to unite these two IL-based technologies by combining them into a suite of novel inorganic-organic hybrid functional composites. We will discuss the process for pre-treating NFW IL with PINCs to best aid their entrapment, then provide adequate characterization using microscopy, gas physisorption, and spectroscopic techniques to prove their inclusion within the NFW matrix. We will also demonstrate several basic applications of the hybrid cloth based on recent advances of PINC minerals, with a focus on selective dye sorption, fluorescence sensing, and catalysis.