bluuebunny/crossref_metadata_2025 huggingface dataset:
Using Reference Electrodes to Validate Parameterization of Individual Electrode Soh in the Single Particle Model with Electrolyte
Authors: Pannala Sravan , Olide Everardo , Siegel Jason
Published: September 2023

Most model parametrization techniques for reduced order physics-based Lithium-ion battery models like the single particle model rely on minimizing the error in the measured and predicted cell terminal voltage. The battery terminal voltage is the difference between the voltages of the positive and negative electrode solid phase potentials. If the individual contribution of each electrode overpotential to the terminal voltage, is not measured, there could be multiple combinations of parameters that provide similar RMSE for voltage prediction, yielding non-unique solutions and local minima. Misattributing the parameters for kinetics and diffusion in each electrode could result in increased plating or over-conservative designs at higher operating currents.

Adding a reference electrode to the battery allows us to measure the individual electrode potentials experimentally. Using this extra measurement, we can parametrize the kinetic and diffusion reactions in positive and negative electrodes with better confidence [1], and validate the electrode-specific state of health parameterization, specifically the increased resistances due to SEI growth and shift in the stoichiometric window as the cell ages [2,3]. In our experiments, we used a pouch cell manufactured in the U of M Battery Lab with Targray NMC 622 Single Crystal cathode powder, Superior SLC 1520-T anode powder, and a custom fabricated Lithium Iron Phosphate (LFP) reference electrode deposited on a porous electrode layer. Further details of the reference electrode are given in [4]. The model was parametrized using discharge data at different C-rates and a modified Hybrid Pulse Power Characterization test. Finally, the RMSE for both the modeled negative and positive electrode potentials are calculated for the validation data set which uses the US06 Drive cycle.

References:

[1] Zhengyu Chu et al., Journal of Energy Storage, Volume 27 (2020).

[2] Suhak Lee et al 2020., J. Electrochem. Soc., 167, 090531 (2020).

[3] Hannah M. Dahn et al., 2012 J. Electrochem. Soc. 159, A1405 (2012).

[4] Taylor R. Garrick et al., J. Electrochem. Soc. 168, 010530 (2021).
(Invited) An Industrial Perspective on Electrochemistry and the Energy Transition
Authors: Endler Elizabeth , Stephens Ryan
Published: September 2023

As wind and solar become an increasingly larger share of primary energy, the use of electrochemical storage and conversions is growing. Traditionally, carbon-based fuels such as oil, coal and natural gas have been globally traded and served as energy storage media for the power and transportation sectors. With the growth of lower-carbon energy technologies, particularly wind and solar power, effective use of renewable electrons requires high-performing, cost-effective solutions for storage and distribution services that are analogous to traditional fuels. Electrochemical energy storage technologies are increasingly used for a range of applications from kW to GW scales, with this deployment momentum built from improved performance and declining costs.

This talk will address where multiple types of storage exist in the historical & current energy system, their scales, and the roles of storage in the emerging energy transition from the perspective of an international energy company. Our energy storage and conversion research & development over the past decade will also be discussed, with a focus on current and emerging electrochemical systems designed for use in mobility, the power sector, and industry. Systems of active research include metal anodes used with high voltage cathodes and high energy density stationary batteries. This work has been driven by business challenges, with a range of modeling approaches used to generate insights that complement theory & experiment. Techniques include large-scale energy system modeling, modeling of power market operations, technoeconomic analyses to guide cost & performance targets of new technologies, and new ways to capture and predict physical phenomena that underpin device life and performance. Finally, commercial operation examples of energy storage operation will be provided, along with challenges still to be resolved through improved system understanding across scales.
(Invited) Selected Legacy of Dr. Ralph White’s Contributions – Relevance for Current and Next-Generation Batteries/Electrochemical Systems/Students/Researchers
Authors: Subramanian Venkat R.
Published: September 2023

In this talk, a few selected contributions of Professor White will be briefly summarized. His contributions towards modeling and numerical simulation of batteries, and electrochemical systems will be reviewed. In addition, my personal perspective on the relevance of his contributions to the current and next-generation batteries/electrochemical-systems/students/researchers will be presented.

Selected examples of model-based BMS, mechano-electrochemical models, phase-field models, dendrite growth in 2D, and precise and efficient simulation of the same will be presented.
(Invited) Electrochemical Route for Cement Production
Authors: Viswanathan Venkatasubramanian , Houchins Gregory
Published: September 2023

Sustainable route to cement production is critical for achieving net-zero goals. In this talk, we will discuss a novel scheme for direct electrochemical synthesis of calcium silicates. We will discuss connections between the charging of convention Li-ion cathodes and electrochemical cement production.
(Invited) Enabling Rechargeable Conversion Cathodes By Modeling the Coupling between Structure, Electrochemistry, and Mechanics
Authors: Roberts Scott A. , Horner Jeffrey Scott
Published: September 2023

While traditionally used as a primary battery chemistry, there is current interest in using FeS2 as a high-energy density cathode material for specialized rechargeable battery applications. However, the combination of intercalation and conversion processes, large volume change upon reaction, and the formation of polysulfides complicate its cycling behavior and therefore wider adoption. We present computational models at both the mesoscale (particle-resolved) and macroscale (homogenized) that look at the coupled interplay between mechanical stress and strain and electrochemistry to determine the performance and degradation of FeS2 electrodes. These models are used to explore the role of particle size polydispersity and additively manufactured 3D-structured electrode designs (e.g. pillars) to appropriately balance mechanics, transport, and kinetic limitations and optimize electrode performance. SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525.
(Invited) Kinetic Modeling of Ethanol Electro-Oxidation on Co-Ni-Mo-P Electrocatalyst
Authors: Kalu Egwu Eric , Chaitree Wasu , Ike Innocent S
Published: September 2023

A rotating disk electrode technique was used to study the kinetics of ethanol electro-oxidation on multi-alloy composition of CoNiMoP deposited on catalyzed carbon substrate (CCS). A simple kinetic model for ethanol oxidation on CoNiMoP/CCS was developed with the assumption of a simultaneous generation of two main products – CH3CHO (acetaldehyde) and CH3COOH (acetic acid) and the experimental result was used to evaluate the kinetic parameters of the model. In the developed model, if only one of the two products- CH3CHO or CH3COOH was generated, the result showed that at high ethanol concentration, the ethanol reaction mechanism followed the acetaldehyde route while at low ethanol concentration, the mechanism led to acetic acid and carbon dioxide route. However, a modified model in which a simultaneous production of both CH3CHO and CH3COOH occurred, showed that ethanol oxidized rapidly to CH3COOH. Additionally, the effect of the rotation speed (400 or 900 rpm) on the reaction was investigated and the result showed that the speed did not affect the mechanism because the experimental results were closer to the CH3COOH curves for both cases (400 and 900 rpm), but rotation speed affected the mole fraction of CH3COOH and CH3CHO.
Numerical Modeling Unlocks Remarkable Ion Selectivity of Capacitive Deionization
Authors: Suss Matthew , Shocron Amit N. , Uwayid Rana
Published: September 2023

Ion-selective water treatment is an important frontier in water research, as for many applications removing all ions indiscriminately leads to significant extra energy and downstream re-ionization costs. Capacitive deionization (CDI) is under intensive investigations for ion-selective treatment of polluted feedwaters [1]. CDI has the remarkable feature of being not only highly selective, but additionally dynamically tuneable to adjust, real-time, to varying feedwater composition and produced water targets [1]. However, we will show that to further develop CDI technologies to achieve desired separations, in feedwaters of several competing anions and cations, requires detailed numerical models. Such models couple ion transport theory to nanopore electrosorption, and often include pH dynamics. We here describe our recent work exploring the limits of ion-ion selectivity by capacitive deionization with inexpensive nanoporous carbon electrodes. We show how theory enabled us to achieve in the lab remarkable selectivity and a diverse set of separations, such as “perfect” divalent cation selectivity[2], monovalent ion selectivity[3], and removal of amphoteric pollutant species such as boric acid and nutrient species[4]. We show using strong-acid functionalized electrodes that the same two-electrode system can be used for either excellent divalent selectivity, or long-lasting monovalent ion selectivity, depending on cell operational parameters [2,3]. Our work furthers the argument that membraneless CDI, based on inexpensive and easily-scalable porous carbon electrodes, can address a wide variety of important applications in water treatment.

References:

[1] J.G. Gamaethiralalage, et al. “Recent advances in ion selectivity with capacitive deionization”, Energy &Environmental Science, 2021.

[2] R. Uwayid, E.N. Guyes, A.N. Shocron, J. Gilron, M. Elimelech, M.E. Suss. “Perfect divalent cation selectivity with capacitive deionization”, Water Research, 2022.

[3] E.N. Guyes, A. Shocron, Y. Chen, C. Diesendruck, M.E. Suss. “Long-lasting, monovalent selective capacitive deionization electrodes.” NPJ Clean Water, 2021.

[4] A.N. Shocron, E.N. Guyes, H.H. Rijnaarts, P.M. Biesheuvel, M.E. Suss, J.E. Dykstra, “Electrochemical removal of amphoteric ions”,

Proceedings of the National Academy of Sciences, 2021.

Figure 1

From Ref. 3. CDI concept for treatment of water for direct use towards irrigation. a) Schematic of a CDI cell fed with water containing excessive Na+ which must be removed for direct use in irrigation. The cell is charged at an applied cell voltage Vch at or above 1 V and for a time tch significantly shorter than the time to reach equilibrium, teq. b) The cathode nanopore is functionalized with strong-acid sulfonic groups, which enhances the preferential storage of monovalent Na+ over divalent Ca2+ at short charging times. c) The treated water has significantly reduced sodium absorption ratio (SAR) and ionic conductivity, rendering it

Figure 1
Modeling Charge Transport in Flowable Suspension Electrolytes
Authors: Majji Madhu V. , Brushett Fikile R.
Published: September 2023

Abstract

Flowable suspension electrolytes (FSEs) consist of electrically conductive, redox-active, and/or energy-storing particles suspended in aqueous or non-aqueous electrolyte solutions (supporting salt + solvent). These particles, which can range in size from nanometers to micrometers, are subjected to Brownian forces, hydrodynamic forces, hydrophobic interactions, and van der Walls interactions among others. FSEs may enable electrochemical processes where solid reactants can be integrate with flow cells potentially unlocking new approaches to materials processing (e.g., synthesis, extraction/recovery). For example, FSEs has been demonstrated in redox flow batteries, facilitating higher energy densities without sacrificing independent power and energy scaling However, understanding and controlling charge transport through the deformable particle microstructures, especially under shear, is key to enable desirable current distributions and thus effective electrode utilization.

In this presentation, we investigate the impact of interparticle interactions, particle volume fractions, and applied shear rate on charge transport through FSEs. At sufficiently large volume fractions above the percolation threshold and stationary conditions, particle interactions in an FSE can drive the formation of networks that span the cell dimensions and provide electronic transport similar to stationary freestanding porous electrodes. However, under flowing conditions, shear forces can break these networks, hampering charge transport. Conversely, increasing attractive particle interactions or particle concentration can strengthen the particle networks and fortifying charge transport, albeit at the expense of fluid viscosity. To better understand these processes, we model the charge transport through these dynamic particle networks, using a combination of local charge transport models and discrete particle simulations, considering the Peclet number (ratio of shearing to Brownian forces) and Mason number (ratio of shearing to attractive forces). Our results contribute to the development of continuum models for charge transport in FSEs, which, in turn, can facilitate efficient and accurate system-level analysis.

Acknowledgments

This work was funded by the Skoltech – MIT Next Generation Program.
In-Situ Microscale Compression Testing of Li-Si Micropillars
Authors: Yeom Junghoon , Lefler Matthew Jacob , Rudolf Chris , Love Corey T.
Published: September 2023

Silicon is considered as an ideal anode material for high-capacity Li-ion batteries (LIB) thanks to its high theoretical capacity, but the commercial viability is severely hampered by considerable volume expansion of Si upon lithiation that can lead to mechanical failure (e.g., cracks and delamination). Hence, understanding the mechanical behaviors of the Li-Si system is of high interest, but the experimental studies have been limited to thin film electrodes by means of wafer curvature measurements or nanoindentation. In this work, we for the first time present in-situ microscale compression testing of Li-Si micropillars and extract the key mechanical properties (e.g., Young’s modulus, yield strength, and fracture energy) from the resulting stress-strain curves. Prior to testing, Si micropillars of various sizes/shapes and oriented at different crystal directions were lithiated/delithiated at room temperature. We then performed the microscale compression testing on these lithiated Si micropillars using a flat-head indenter in environmental scanning electron microscope (ESEM) while obtaining live video images for data-image correlation. The results suggest that the measured elastic moduli of the Li-Si system agree with the values obtained from the standard nanoindentation experiments but with much smaller variance. The precise nature of these experiments allows us to observe the mechanical properties dependent on the crystal orientation of Si and lithiation rate. In addition, various failure behaviors of Li-Si under compressive stresses will be presented, which is difficult to be obtained through the existing experimental techniques.
Dry Extrusion Process for Manufacturing of High-Energy Cathodes for Lithium-Ion Batteries
Authors: Sperling Tom , Hoffmann Alice , Wohlfahrt-Mehrens Margret
Published: September 2023

For a sustainable production of lithium ion batteries, more environmentally friendly, energy saving and faster strategies are required. For cathode production NCM/NCA layered oxides are commonly used as active materials. Nevertheless, application of the very toxic and teratogenic solvent N-methylpyrrolidone (NMP) is still common for the industrial production of these cathodes. Besides the high toxicity, the NMP recovery after coating is very energy-, time- and cost-intensive.

As an alternative, to conventional NMP-based cathode production, we developed a dry extrusion process coupled with slot-die coating, to manufacture high-energy cathodes. The extrusion process offers continuous production, alongside a very good scalability to industrial demands and a significant reduction of mixing time. Since the process is NMP-free and the drying step is saved, it overcomes typical shortcomings of the wet coating as crack formation or binder migration occurring during solvent evaporation. In addition, producing high-energy electrodes leads to lower material costs and space savings, since less layers of Al/Cu foil and separator are required on cell level, compared to a battery of the same capacity and lower electrode mass loading.

Herein, we present the development of a dry cathode manufacturing process, a suitable recipe for dry processing, consisting of NCM622, PVdF, carbon black and a superplasticizer, as well as the optimization of the formulation in terms of processability and active material content. We also discuss the influence of process parameters such as temperature or rotation speed on the viscosity of the cathode paste. As a proof of concept, we processed powder mixtures, corresponding to our optimized formulation with about 90 % of NCM, in a pilot scale twin-screw extruder. By melt extrusion through a slot die, we create a thin film from the cathode composite that we directly apply on an Al current collector. We show a schematic representation of the process in the attracted graphic. By repositioning of the electrode coil, we also produce double-sided coatings. After calendaring, we characterize the dry processed electrodes electrochemically in half-cells. The electrochemical performance data is comparable to state of the art cathodes and results are promising that even higher active material contents can be reached. Therefore, the solvent free extrusion of cathodes is highly relevant for industrial applications.

Acknowledgement

The presented work was financially supported by BMBF within the project Tropex under the reference number 03XP0235C.

Figure 1
(Invited) Opening Twisted Molecular Chains of High Solid Content Screen Printable Ink for Screen-Printed Low-Tortuosity Electrodes
Authors: Wang Ying , Zhu Hongli
Published: September 2023

Reducing the tortuosity of electrodes is an efficient technique for enhancing the charge transfer inside electrodes and boosting the fast-charging capabilities of lithium-ion batteries for electric vehicles. Compared to reported complex methods, screen printing is facile, economical, and printing pattern controllable. More importantly, the roll-to-roll screen printing equipment can be integrated into the existing electrode production system, allowing for the industrialization of low-tortuosity electrodes. However, the absence of screen-printable inks with a high solid content restricts the ink transfer volume per printing, lowering production efficiency and raising the price of screen-printed electrodes. By integrating rheological characteristics analysis, X-ray computed tomography characterization, and coarse-grained molecular dynamics (CGMD) simulation, we are able to recognize and illustrate the relevance of the molecular chain state in high-solid-content ink for screen printability. Additionally, we propose and develop a unique preparation procedure for producing high-solid-content screen-printable inks. In addition, the electrochemical performance of screen-printed electrodes was evaluated in order to enclose the importance of electrode micromorphology. This finding lays the door for the industrialization of screen-printable inks with high solid content and encourages additional research into screen-printed architectures with functional electrodes.

In this work, we demonstrated for the first time that the molecular chains within high-solid-content inks should be untangled to obtain outstanding screen printability. Specifically, the twisted molecular chains serve as extra networks that drag certain particles within the electrode ink onto the mesh, hence diminishing its screen printability. Therefore, we suggest a two-step approach for opening the twisted molecular chains of inks with a high solid content of 60%. Employing this type of ink, the mass loading per printing layer elevates to about 5 times greater than the existing cathode inks. After opening the twisted chains, the LiNi0.6Mn0.2Co0.2O2 cathode ink exhibited a lower viscosity, a faster thixotropic recovery, and superior screen printability than the ink containing twisted chains. Furthermore, due to the improved internal architectural integrity of screen-printed electrodes printed by the excellent screen-printability of ink, the electrode printed with optimized inks displayed a 33% larger charge capacity at 6C with a mass loading of 6.5 mg/cm2 than that produced with chains-twisted ink. In addition, based on the fundamental of the two-step approach, we present optimization approaches for altering screen-printable inks for a variety of circumstances. This idea could promote the coupling of screen printing with the production of functional electrodes and could be utilized for the production of screen-printable inks for all fields.
Multifunctional Zeolite Coated Separators for Improved Performance and Safety of Lithium Metal Batteries
Authors: Sharma Bhamiti , Tan Bing , Shepard David , Li David , Liao Yuhao , Cheng Yang-Tse
Published: September 2023

Lithium (Li) metal batteries are attractive due to their high gravimetric and volumetric energy densities. However, they can fail catastrophically due to dendritic nucleation, growth, and penetration through the polypropylene (PP) or polyethylene (PE) separators. Poor electrolyte wetting and non-uniform Li ion flux are known to affect Li dendrite formation, especially since the PP/PE separators have broad gaussian pore size distribution and typically organic electrolytes do not wet them well. In this work, we demonstrate that a multifunctional zeolite coating on a commercial PP separator (Z-PP) can improve electrolyte wettability and in-plane ionic conductivity, giving rise to more uniform Li flux. Consequently, Z-PP can effectively delay dendrite penetration and enhance cell performance and safety. Firstly, electrochemical impedance spectroscopy (EIS) was used to establish that the thin zeolite coating on PP separator had little effect on through-plane ionic conductivity. For electrochemical cycling behavior, PP and Z-PP separator based symmetric cells and half-cells were studied by monitoring the cell overpotential (symmetric cell) and discharge capacity (half-cell). For the Z-PP separator, lower overpotential and better discharge capacity retention were observed in the respective symmetric and half-cell studies, suggesting improved electrolyte wetting and relatively uniform Li flux. Scanning electron microscopy (SEM) equipped with energy dispersive x-ray spectroscopy (EDS) studies helped in understanding coating microstructure and cycled electrode morphologies. SEM images of cycled Li metal harvested from the Z-PP cells show much smoother Li surface for Z-PP cell as compared to PP cells. This work suggests that overall cell performance and safety can be improved by employing Z-PP separators.
Co-Intercalation-Free Fluorinated Ether Electrolytes for Lithium-Ion Batteries
Authors: Ma Peiyuan , Mirmira Priyadarshini , Amanchukwu Chibueze
Published: September 2023

Lithium-ion batteries are widely used to power portable electronics because of their high energy densities and have shown great promise in enabling the electrification of transport. However, the commercially used carbonate-based electrolytes are limited by a narrow operating temperature window and suffer against next generation lithium-ion battery chemistries such as silicon-containing anodes. The lack of non-carbonate electrolyte alternatives such as ether-based electrolytes is due to undesired solvent co-intercalation that occurs with graphitic anodes. Recently, fluorinated ether solvents have become promising electrolyte solvent candidates for lithium metal batteries but their applications in other battery chemistries have not been studied. In this work, we synthesize a group of novel fluorinated ether solvents and study them as electrolyte solvents for lithium-ion batteries. Using X-ray diffraction (XRD) and solid-state nuclear magnetic resonance (ssNMR), we show that fluorinated ether electrolytes support reversible lithium-ion intercalation into graphite without solvent co-intercalation at conventional salt concentrations. To the best of our knowledge, they are the first class of ether solvents that intrinsically suppress solvent co-intercalation without the need for high or locally high salt concentration. In full cells using graphite anode, fluorinated ether electrolytes enable much higher energy densities compared to conventional glyme ethers, and better thermal stability over carbonate electrolytes (operation up to 60°C). As single-solvent-single-salt electrolytes, they remarkably outperform carbonate electrolytes with fluoroethylene carbonate (FEC) and vinylene carbonate (VC) additives when cycled with graphite-silicon composite anodes. Using X-ray photoelectron spectroscopy (XPS), NMR and density functional theory (DFT) calculations, we show that fluorinated ethers produce a solvent-derived solid electrolyte interphase, which is likely the key to suppressing solvent co-intercalation. Rational molecular design of fluorinated ether solvents will produce novel electrolytes that enable next generation lithium-ion batteries with higher energy density and wider working temperature window.
Mechanical Impacts from Cycling on Silicon Calendar Aging Measurements
Authors: McBrayer Josefine , Harrison Katharine L , Fenton Kyle , Minteer Shelley
Published: September 2023

Much of the silicon anodes for lithium ion batteries literature concentrates on the volume expansion of silicon leading to poor cycle life. Recently, the poor calendar life of silicon has become more of a focus. Calendar aging is typically measured by long periods of open circuit voltage (OCV) that are intermittently interrupted with a reference performance test (RPT) to quantify performance and capacity fade. The United States Advanced Battery Consortium LLC protocol calls for an RPT once a month with daily voltage pulses to keep the state of charge the same during the rest. If the solid electrolyte interphase (SEI) is unstable and there is substantial volumetric changes during cycling, as is the case with silicon, the frequency and amount of cycling interruption may impact how calendar life is quantified. It was hypothesized that an SEI that equilibrates during a rest may be disrupted enough during RPT cycling that the SEI passivation is decreased and the start of the next rest will result in greater irreversible lithium inventory consumption to rebuild the SEI that was lost during cycling. To test this, a specially designed variable OCV-RPT protocol was applied to silicon – NMC622 full cells. It was found that for all rest durations, time since assembly, rather than cycling, dominated capacity fade, indicating that calendar aging is likely primarily governed by chemical SEI degradation during rest rather than mechanical SEI degradation during RPTs.

This research was supported by the U.S. Department of Energy’s Vehicle Technologies Office under the Silicon Consortium Project, directed by Brian Cunningham, and managed by Anthony Burrell. This work was conducted in part by the Alliance for Sustainable Energy, LLC, the manager and operator of the National Renewable Energy Laboratory for the U.S. Department of Energy (DOE) under Contract No. DE-AC36-08GO28308. Sandia National Laboratories is a multimission Laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.
Understanding on Kinetics Change of Li-S Battery with Fluorinated Additives Using in-Situ/Operando Raman and X-Ray Absorption Spectroscopy
Authors: Dai Huidong , Pandey Gaind , Mukerjee Sanjeev
Published: September 2023

Li-S battery concept is promising for the next generation energy storage due to its distinct advantage of high theoretical capacity (1675 mA/g) and energy density (2600 Wh/gm). Yet the formation of polysulfides as intermediate discharge products (Li2Sn, 4<n<8) and their dissolution result in the loss of active material and ultimate deposition at the anode. This shuttle phenomenon gives rise to irreversible loss of active material, rapid capacity fading, low coulombic efficiency and short cycle life with an ambiguity of its mechanism. To our best knowledge, we will be the first to employ the in-situ characterization techniques including Raman spectroscopy and X-ray absorption spectroscopy (XAS) to investigate the kinetics evolution with various electrolyte systems. This work presented the formation change of polysulfides intermediates at various fluorinated additives environment with different formula and composition based on in-situ/operando Raman spectroscopy. The Raman results clearly revealed the long-chain polysulfide conversion (400 cm-1) was pushed forward and an increasing concentration of short-chain polysulfide (453 cm-1) was appeared when fluorinated carboxylate ester-based electrolyte was used at its optimized formula compared to the baseline. Cyclic voltammetry results correspond to the chemistry evolution proposed by Raman. In-situ X-ray absorption spectroscopy was also conducted on sulfur K-edge to monitor the polysulfide intermediates formation. X-ray fluorescence mapping (XRF) on cathode and anode also confirmed that the sulfur shuttle phenomenon was significantly suppressed in fluorinated carboxylate ester-based electrolyte by changing the sluggish kinetics.

Figure 1
Electrochemical Performance According to High-Capacity Silicon Active Materials in Lithium Ion Batteries
Authors: Park Ji Hye , Kang Sung Hwan , Kim Chang Beom , Kwon Se Man
Published: September 2023

Carbon has been used as stable anode material for lithium-ion secondary batteries. However, instead of graphite with a low capacity, a new material with a high capacity that can increase the energy density per volume or mass of a lithium ion secondary battery is required. Among the various candidates, silicon has a high capacity of about 4000 mAh/g, making it a major research subject. Graphite is a combination of 6 carbon atoms and 1 lithium ion, but silicon accepts 4.4 lithium ions per atom, resulting in high volume expansion. In this way, excessive volume expansion causes cracks in the electrode and electrochemical disconnection, which eventually leads to a decrease in battery capacity. The large volume change and low electrical conductivity of silicon limits its application to anodes. Potential silicon-based materials include silicon oxide-based (SiOx), carbon-silicon composite (SiC), and pure silicon (pure Si). Silicon-based oxides have the advantages of high capacity and stable battery life, but have the limitations of low initial efficiency and low electrical conductivity. Carbon-composite silicon has high initial efficiency, high ionic conductivity, high capacity, and can be applied in the same slurry system as existing graphite electrodes. Selection of a stable binder and conductive material is important for active use of silicon-based materials. Promising binders include polyvinyl alcohol (PVA), polyacrylic acid (PAA), and polyacrylamide (PAM), and conductive materials include single-walled carbon nano tube (SWCNT), multi-walled carbon nano tube (MWCNT), and carbon-based conductive materials. In this study, we applied poly(vinyl alcohol-co-acrylic acid) random copolymer polymer as a binder and analyzed the characteristics of silicon-based batteries with various conductive materials. Slurry analyzes such as slurry dispersibility, phase stability, and rheology were performed. The initial efficiencies and cycle performances of different types of silicon-based materials were compared. It was confirmed that the type of silicon-based negative electrode material and the type of conductive material affect battery performance.
High-Energy Li−S Batteries Achieved by Compact S Cathode and Polysulfide Adjoining Interface Engineering
Authors: Kim Hun , Lee Su-Hyun , Kim Jae-Min , Sun Yang-Kook
Published: September 2023

To maximize the energy density of Li−S batteries, it is crucial to increase the loading level of sulfur cathode and minimize the electrolyte content. However, excessive amounts of lithium polysulfides (LiPSs) generated in the high loading Li-S batteries limit the stable cycling. In this study, a high-loading S cathode with a three-dimensional (3D) network structure is fabricated using a simple pelletizing method, and the exhausting overcharging phenomenon, which occurs in the high loading Li−S cell, is successively prevented by pre-treating the lithium metal anode. Moreover, adding a diluent to the electrolyte containing viscous LiPSs enables the facile conversion between S species during the cycling of high-loading Li−S cells under lean electrolyte conditions. Finally, a prototype Li−S pouch cell with high energy density (427 Wh kg−1) was realized by combining a compacted 3D cathode with a high-loading, pretreated thin lithium metal and diluent-modified electrolyte. We believe that the results reported herein will be a good guideline to establish proper strategies to achieve high energy density Li−S batteries.
Enhanced Cycling Performance by Transition Metal Substitution on Li2CuO2 Cathode Additive for Advanced Lithium-Ion Battery
Authors: You Min Jae , Kim Taehee , Park Min-Sik
Published: September 2023

Lithium-Ion batteries (LIBs) have made remarkable progress in the last decade and have been employed so far as the most popular power source for electric vehicles (EVs). However, the energy density issue still remains a drawback for LIBs on long-range driving of EVs for the reason of significant irreversible Li+ loss in the initial charging process of LIBs, induced by a spontaneous formation of solid electrolyte interphase (SEI) on the anode surface. Therefore, strategic studies are required to maximize the energy density of LIBs as compensation of the initial loss of Li+ during cell operation. The utilization of a Li-excess cathode additive in commercial cathodes is an ideal approach to minimize the loss of energy density of LIBs. Recently, Li2CuO2 has been proposed as a potential cathode additive with many advantages over other candidates, including the following: (i) high charge capacity (~ 490 mAh g-1), (ii) comparable operating voltage window (2.5 ~ 4.3 V vs. Li/Li+) to commercial cathode materials, and (iii) abundance of copper (Cu) on the earth. But, its practical use is still restricted by the structural instability and spontaneous oxygen (O2) evolution (> 3.8 V vs. Li/Li+), which results in loss of reversibility during subsequent cycling. It is thus crucial to reinforce the structure of Li2CuO2 to make it more reliable as a cathode additive for charge compensation. In a pursuit of improving the structural stability of Li2CuO2, herein, we demonstrate structural modification via co-substitution by heteroatoms, such as nickel (Ni) and manganese (Mn), for improving the structural stability and electrochemical performance of Li2CuO2. Such an approach effectively enhances the reversibility of Li2CuO2 by suppressing continuous structural degradation and O2 gas evolution during cycling. Our findings provide new conceptual pathways for developing advanced cathode additives for high-energy LIBs.
Lithium Iron Manganese Oxyfluoride High Energy Density Cathode
Authors: Adams Jada I. , Green Asa , Irvin Monet , Bradbury Kameron , Richardson Trenton , Watson David , Meda Lamartine
Published: September 2023

Ball-milling has also been used to add fluorine atoms into rock-salt structures to take advantage of fluorine’s high electronegativity to raise the working voltage of oxide materials to create high power and energy density cathodes. New composite structures of metal oxides and LiF synthesized using this method have been studied as conversion reactions. In this study, LiF-FeMnO3 composites are synthesized by the solid-state method after mechanochemical-ball milling 3 mol LiF, 1 mol FeO, and 1 mol MnO for 12 h. The synthesized composites are characterized by powder X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy techniques as well as the electrochemical properties. The lithium ion storage property is evaluated by galvanostatic discharge/charge experiments. Initial discharge capacity of 418 mAh/g at 10 mA/g was obtained. The coulombic efficiency almost remains 100%, demonstrating good high-rate performance and good cyclability. The high electrochemical performance is attributed to unique lithium storage mechanism, including conversion and intercalation/de-intercalation mechanism. Small particle size also provides some benefits to lithium ion storage property. This mixture of 3LiF-FeMnO3 composites is a promising cathode material for lithium-ion batteries with high power and energy densities.

Figure 1
Bi2O3 Intercalated SWCNT/Sulphur (S) Composite Electrodes for Stable & High Performance Li-S Batteries
Authors: Tripathi Balram , Zuluaga Gomez Claudia C. , Castillo Ivan , Katiyar Rajesh , Morell Gerardo , Weiner Brad , Katiyar Ram S.
Published: September 2023

In the present work, bismuth oxide (Bi2O3) nanoparticles have been coupled chemically with SWCNT/sulphur (S) composites. Here an architecture constructed by rooting bismuth oxide into SWCNT/sulphur composites could enhance the electrochemical performance of the system. X-ray diffraction (XRD), Raman & Scanning electron microscopy (SEM) measurements of prepared composites were executed to study structural and morphological properties. High theoretical discharge capacity (690 mAh/g) and rate capability expected due to favourable surface structures of SWCNT/S composites which may cause fast redox reaction and high immobilization ability towards intermediate polysulphides. The detailed results of the study will be discussed during the presentation of meeting.

Keywords: Bi2O3, SWCNT-S composites, Structural & surface morphology, Electrochemical performance
Lithium Metal Anode Using Fluorination on Iron Powder for Lithium Metal Batteries
Authors: Choi Yusong , Lee Junghun , Yu Hye-Ryeon , Ahn Tae-Young
Published: September 2023

High-energy-density batteries have been gaining considerable attentions in renewable energy, and Li metal anodes are potential candidates for developing such batteries. Therefore, many attempts were carried out to find alternative ways to use Li by mixing it with tiny metal powders or impregnating the porous media. However, most materials used in battery fabrication are lithiophobic to molten Li; hence, infusion of Li into porous structures or powders with an intrinsically lithiophobic surface presents challenges in developing Li metal batteries. Optimizing and improving molten Li's wettability is one approach to address this. Herein, we propose an efficient and straightforward direct fluorination method for achieving an ultra-lithiophilic fluoride layer on the surface of the Fe powder. Fluorination of Fe powders resulted in a remarkable increase in the wettability of molten Li by a growth of Fe-F layer on the surface of Fe powder. This layer was lithiophilic and showed high wettability. Moreover, an anode prepared using fluorinated Fe-Li metal showed no evidence of short circuits or dendrite formation after the cycle test at 0.1 and 0.2 mA cm-2. In contrast, a pure Li anode and pristine Fe powder showed unstable charge-discharge characteristics in cycle tests. The proposed fluorination is the most practical and straightforward method among those reported. Thus, the proposed method will further develop rechargeable lithium-metal battery technology.
Regulation of Ionic Conductivity and Lithium Affinity of Porous Carbon Framework in Li Metal Anode through Oxidized Nitrogen Groups
Authors: Suh Joo Hyeong , Qutaish Hamzeh , Kim Jung Ho , Park Min-Sik
Published: September 2023

For decade, lithium-ion batteries (LIBs) have become a promising power source for a wide range of electrical application. However, current LIBs still suffer from their limited capacity to store electrochemical energy because of the limitations in their storage mechanism (i.e., intercalation). Unfortunately, they are unsuitable for powering long-range electric vehicles (EVs) at this moment because of their lengthy charging cycle and short operating time. To improve energy density of LIBs, it is essential to develop advanced materials that provide higher specific capacity and operating voltage. Lithium (Li) is considered as one of the most prospective anode materials for LIBs owing to its lightweight (0.53 g cm−3), much high theoretical specific capacity (3860 mAh g−1), the lowest standard reduction potential (−3.04 V vs. standard hydrogen electrode). The technical issues like uncontrollable dendritic growth and infinite volume changes, however, have yet to be resolved. To address these issues, porous carbon 3D host materials to accommodate metallic Li during cycling, thus enhancing the safety and stability of the anode. While porous carbon is widely used as a metallic lithium host framework, the inadequate wettability of the carbon hinders its usage. For this purpose, herein, we functionalized the porous carbon with oxidized nitrogen groups by utilizing nitric acid. We found that the functionalized porous carbon demonstrated an improved wettability compared to its non-functionalized counterpart. Moreover, by functionalizing the carbon surface with oxidized nitrogen during lithium plating and stripping, catalyzed lithium nitride (Li3N) formed in the solid electrolyte interphase which much enhanced the surface morphology of lithium deposition. The functionalized porous carbon is effective for improving the capacitive behavior as well as enhancing electrochemistry performance in terms of cyclability and reversibility.
In-Situ Crosslinked Single-Ion Conducting Gel Polymer Electrolyte for Lithium Metal Batteries
Authors: Hong Da Young , Lim Da-ae , Shin Young-Kyeong , Seok Jinhong , Kim Dong-Won
Published: September 2023

Lithium metal batteries (LMBs) have been considered as promising candidates for energy storage device due to their high energy density. However, high reactivity of lithium metal with liquid electrolyte and continuous growth of dendrite lead to degradation of cycle performance and cell failure. To overcome these problems, the strategy of employing gel polymer electrolytes (GPE) was investigated. GPE can effectively encapsulate organic solvents and facilitate uniform contact with electrodes. Both cations and anions migrate in conventional GPE, which gives rise to low Li+ ion transference number (tLi+). Low tLi+ causes inhomogeneous Li+ ion flux and continuous dendrite growth. Compared to conventional GPE, single-ion conducting gel polymer electrolytes (SIC-GPE) have superior tLi+ value close to unity, since the movement of anions is suppressed. In this work, we synthesized a novel sulfonamide based single-ion conductor and prepared the chemically crosslinked SIC-GPE. The electrolyte was obtained by a facile in-situ crosslinking that further improves interfacial contact with electrodes. The resulting SIC-GPE exhibited high tLi+, which led to homogeneous deposition of Li+ ion and enhanced electrochemical stability. The LMB cell employing SIC-GPE exhibited stable cycle performance, proving ability to suppress the growth of lithium dendrite.
Spherical LiMn0.7Fe0.3PO4/C Cathode Materials for Lithium-Ion Batteries
Authors: Yamashita Hiroki , Shiozaki Mayu , Oikawa Mutsuki , Hirayama Yuko , Ogami Takaaki , Kanamura Kiyoshi
Published: September 2023

Lithium manganese iron phosphates (LiMnxFe1-xPO4) [1] are attractive as next-generation cathode materials for lithium-ion batteries because they are safer than conventional lithium transition metal oxides (e.g. LiCoO2) [2] and are Co- and Ni-free. However, due to their low electronic conductivity [3], they can deliver much lower electrochemical properties than theoretically expected one. Therefore, many researchers have focused on chemical composition, reducing primary particle size, and carbon coating. On the other hand, granulation of LiMnxFe1-xPO4 primary nanoparticles is effective in improving poor handling of LiMnxFe1-xPO4 primary nanoparticles during cathode slurry preparation. However, electrochemical properties of granulated LiMnxFe1-xPO4 have not been well studied in previous reports. In this study, the electrochemical properties of the spherical LiMn0.7Fe0.3PO4/C composed of primary nanoparticles are reported. Spherical LiMn0.7Fe0.3PO4/C was synthesized by hydrothermal method followed by granulation and carbon coating. The synthesized spherical LiMn0.7Fe0.3PO4/C was characterized using X-ray diffraction (XRD) and scanning electron microscope (SEM). Electrochemical properties of spherical LiMn0.7Fe0.3PO4/C were examined using CR2032 coin-type cells. Fig. 1 (a) shows the SEM images of spherical LiMn0.7Fe0.3PO4/C. As shown in Fig. 1 (a), spherical particle 10 μm in diameter composed of homogeneously sized primary nanoparticles were observed. Fig. 1 (b) shows the galvanostatic charge-discharge curves for spherical LiMn0.7Fe0.3PO4/C at discharge current rates of 0.2, 1, 5, and 10 C in a voltage range of 1.5–4.5 V at 30 °C. Spherical LiMn0.7Fe0.3PO4/C delivered a 0.2 C discharge capacity of 153 mAh g−1. At the 10C rate, spherical LiMn0.7Fe0.3PO4/C also delivered a high discharge capacity of 137 mAh g−1, which was 89 % of the 0.2C discharge capacity. Detailed data of our study including blended cathode of LiNiaMnbCocO2 and spherical LiMn0.7Fe0.3PO4/C will be presented in the meeting.

References:

A.K. Padhi, J. Electrochem.Soc. 144 (1997) 1188.

C. Delmas et al., Nat.Mater. 7 (2008) 665.

A. Yamada et al., J. Electrochem. Soc. 148 (2001) A224.

Figure 1
Understanding Water Dissociation in Bipolar Membranes for Applications in CO2 Electrolyzers
Authors: Chen Lihaokun , Xu Qiucheng , Fabrizio Kevin , Boettcher Shannon W.
Published: September 2023

Bipolar membranes (BPMs) offer a unique way to manage local pH and control ion crossover in diverse devices for electrodialysis, water and CO2 electrolysis, and for water purification and metals recycling. Current commercial BPMs, however, are limited to low current densities and with low energy efficiencies. The water dissociation (WD, H2O → H+ + OH−) reaction under reverse bias, is the core process in BPMs that limits efficiency. A deeper understanding of WD in BPMs, and improving the WD rate, will enable broad use of BPMs in novel CO2 electrolyzers designs. Both electric-field and catalytic effects have been invoked to describe WD, but the interplay of the two and the underlying design principles for WD catalysts remain unclear. Using precise layers of metal-oxide nanoparticles, membrane-electrolyzer platforms, materials characterization, and impedance analysis, we illustrate the role of electronic conductivity in modulating the performance of WD catalysts in the BPM junction through screening and focusing the interfacial electric field. BPM electrolyzers, optimized via these findings, use ~30-nm-diameter anatase TiO2 as an earth-abundant WD catalyst, and generate O2 and H2 at 500 mA cm−2 with a record-low total cell voltage below 2 V. Furthermore, integrating reference electrodes into electrolyzers allows the precise study of WD kinetics. Using TiO2-P25 as a model WD catalyst, we discovered an apparent activation energy of 25–30 kJ mol−1, only weakly dependent on the driving force (WD overpotential, η
wd), while the pre-exponential factor is proportional to η
wd. We proposed a new field-enhanced catalytic WD mechanism including the proton transport on the catalyst surface with the local electric field, which works to organize water molecules for proton transfer elementary steps comprising WD. These understandings of WD in BPMs will accelerate deployment of new electrodialysis, carbon-capture, and carbon-utilization technology.