bluuebunny/crossref_metadata_2025_split huggingface dataset:
Exploring Surfactant Electrolyte-Porous Electrode Interactions
Authors: Barth Brian , Zawodzinski Thomas A. 
Published: September 2023

Microemulsions are an alternative to aqueous organic electrolytes for redox flow batteries (RFB) that can be modified without synthesis. Water, oil, and emulsifiers, when combined using optimized chemistries and compositions, produce stable mixtures with aggregate structures (microemulsions). Design limitations imposed by the interdependency of redox solubility and electrolyte conductivity are circumvented by solubilizing redox active molecules in the oil phase and supporting ions in the aqueous phase. While macroscopically homogeneous, microemulsions are biphasic at the nanometer scale, effectively decoupling solubility from conductivity. Recently, the first microemulsion RFB was demonstrated using ferrocene solubilized in an anionic surfactant system. Polarization curve analysis revealed performance limitations seemingly arising from electrolyte interactions with the cell components including porous electrodes. Further optimization requires a deeper understanding of microemulsion-porous electrode interactions.
Due to the complexity of microemulsion electrochemistry, a first step towards understanding these interactions is made by investigating the relationship between surfactants and porous electrodes. Vanadium redox flow battery (VRFB) electrolytes with surfactant additives are used as a model system to explore fundamental interactions, in situ, between a surfactant-containing electrolyte and a porous electrode. Transport and kinetics are evaluated as a function of electrode, electrolyte, and surfactant properties. Redox species transport is quantified through mass transfer coefficients, using a generalization of an existing porous electrode model fit to experimental polarization curve data. Electrochemical impedance spectroscopy, interpreted using existing kinetic models, is also employed to gain insight into the effects of surfactant on electron transfer rates.
Bipolar Anodization for the Synthesis of TiO2 Nanotube Layers: New Concepts and Cell Designs
Authors: Sopha Hanna , Sepúlveda Sepúlveda Lina Marcela , Macak Jan M. 
Published: September 2023

Self-organized TiO2 nanotube (TNT) layers have attracted considerable scientific and technological interest over the past almost 20 years, due to their wide range of applications, including (photo-) catalysis, hydrogen generation and biomedical uses [1,2]. The synthesis of these TNT layers is usually carried out by electrochemical anodization of valve Ti metal substrates in various F--containing electrolytes using a conventional 2-electrode set-up with the Ti substrate as anode and a Pt-foil as cathode.
By now, the TiO2 nanotube layer modification of Ti substrates is mainly focused on planar substrates, such as Ti foils and 2D Ti meshes, as these substrates can easily be connected to the potentiostat during anodization. However, for the real application in photocatalytic cleaners, 3D Ti substrates, such as 3D meshes or Ti spheres, are of high interest due to their significantly increased surface area compressed in a small volume.
To anodize such 3D Ti substrates towards TiO2 nanotube layers, bipolar electrochemistry can be employed instead of using a conventional set-up [3-5]. In such a bipolar set-up, the Ti substrate is not directly connected to the potentiostat but placed in an electrolyte between two so-called feeder electrodes. Due to the electric field between the feeder electrodes, the Ti substrate is polarized and can be anodized if the applied potential between the feeder electrodes is high enough. This method opens the door for the preparation of TNT layers with gradients in dimensions (i.e. diameter and length of the nanotubes) [3-5] as well as for the preparation of TNT layers on Ti substrates, which cannot be directly connected to the potentiostat, e.g. small Ti spheres [6] and complicated 3D printed structures [7].
In this presentation, the preparation of TNT layers on small Ti spheres [6] as well as on 3D printed Ti substrates [7] using bipolar electrochemistry will be shown. Their application in liquid and gas phase photocatalysis will be discussed. Furthermore, we will also show the possibility of using closed bipolar electrochemical cells, consisting of two closed half-cells with the Ti substrate as obstacle between the cells for the preparation of TiO2 nanotube layers with different dimensions on the two sides of a classical Ti foil [8].
References:
[1] J.M. Macak et al., Curr. Opin. Solid State Mater.
2007, 11, 3.
[2] Lee, K. et al., Chem. Rev.
2014, 114, 9385.
[3] G. Loget et al, J. Mater. Chem A
2014, 2, 17740.
[4] G. Loget et al., Langmuir
2014, 30, 15356.
[5] W. Wei et al., Electrochim. Acta
2015, 176, 1393.
[6] H. Sopha et al., Electrochem. Commun.
2020, 111, 106669.
[7] H. Sopha et al., Nano Lett.
2021, 21, 8701.
[8] H. Sopha et al., ChemElectroChem
2021, 8, 3827.
Wide and Thin Li Metal Powder Electrodes and Their Electrochemical Performances
Authors: Lee Yong Min 
Published: September 2023

Li metal powders are very useful in fabricating wide and thin Li metal electrodes due to its ease applicability to slurry-coating process. Furthermore, not only microstructure but also functional components can be controlled or added in Li metal power electrode. These beneficial characteristics can lead to more stable and robust Li metal electrode comparing to the conventional extrusion/roll-pressed, electroplated, or vacuum evaporated Li metal electrodes. In this work, we introduce how thin and wide the Li metal electrode can be fabricated using the conventional slurry-coating method. And then, it is also included how binder-induced scaffold-like electrode structure can improve the electrochemical performances of Li metal electrode. Furthermore, the role of some inorganic additives like CNTs, LiNO3 or AgNO3 will be also discussed with significant electrochemical performance enhancements. Finally, these Li metal powders are being investigated to lithiate diffusion-dependent electrodes especially for all-solid-state batteries.

[References]

1. D. Kang†, D. Jin†, H. Lee*, S.-Y. Ryou*, Y. M. Lee* et al., Chemical Engineering Journal, 452 (2023) 139409
2. C. B. Dzakpasu, H. Lee*, S.-Y. Ryou*, Y. M. Lee* et al., Electrochimica Acta, 430 (2022) 141093
3. J. Kim†, S. Jung†, Y. M. Lee* et al., Advanced Energy Materials, 12 (2022) 2103108
4. D. Jin, M.-H. Ryou*, H. Lee*, Y. M. Lee* et al., Advanced Energy Materials, 11(18) (2021) 2003769
5. D. Jin, M.-H. Ryou*, Y. M. Lee* et al., Chemical Engineering Journal, 406 (2021) 126834
6. D. Jin, Y. M. Lee*, M.-H. Ryou* et al., Electrochimica Acta, 364 (2020) 136878
Development of Graphite Anodes from Coal Derived Carbon from Pitch
Authors: Paul Abigail , Magee Regan , Wichert Nathan , Wilczewski Warren , Mollah Rafid , Jones Matthew , Trembly Jason , Staser John A. , Garrick Taylor R. 
Published: September 2023

Lithium ion battery demand is expected to increase 10x over the next decade. Much of the materials for lithium ion batteries are sourced from overseas. The United States possesses vast coal reserves that have historically been used to generate electricity. That application is on the decline as cleaner sources of electricity are brought online, which leads to economic impact in coal-producing regions. Coal could also serve as a carbon source for battery-grade graphite if sufficient production procedures are developed. This group has been developing coal-derived graphite for these applications.
This presentation will discuss our efforts to develop coal-derived graphite and integrate it into lithium ion batteries. Typical formation cycles, charge/discharge cycling, and HPPC profiles will be presented. The performance of lithium ion batteries containing coal-derived graphite will be compared to those containing only typical battery-grade graphite. Future directions will be discussed, including possible performance impacts and preliminary techno-economic assessments.
Tailored Pre-Lithiation of Carbon Anodes Using Melt Deposited Thin Lithium
Authors: Schönherr Kay , Pöthe Markus , Schumm Benjamin , Althues Holger , Leyens Christoph , Kaskel Stefan 
Published: September 2023

The user demands for Lithium ion batteries in mobile applications and electric vehicles request steady improvement in terms of capacity and cycle life. State-of-the-art lithium ion batteries irreversibly loose about 10 % of the capacity during the first cycles due to SEI formation. Therefore, 10 % of the cathode material is not used during the rest of the cells life which results in a waste of cathode material and leads to a lowered range of battery electric vehicles. Therefore, these losses must be compensated to ensure efficient resource utilization and to further increase the capacity of the lithium ion battery.
We have developed a method to compensate these capacity losses by pre-lithiation: A fast and simple approach of electrolyte-free direct contact pre-lithiation leads to targeted degrees of pre-lithiation in a range of 7-50 % for state-of-the-art graphite electrodes. The parameters pressure (0-40 MPa), temperature (20-150°C) and time (0-60 min) are used to transfer lithium from a temporary substrate to the graphite anode. This process uses 1-5 µm thin lithium films made by the Fraunhofer IWS lithium melt deposition process as a lithium source.[1] The degree of pre-lithiation can be controlled by the lithium loading of the temporary substrate. NCM full cells built with pre-lithiated graphite electrodes where electrochemically evaluated in comparison to unlithiated electrodes. They show 6.5 % capacity increase after the first cycles using the additional lithium to form the SEI during the first cycles. The parameter influence of the pre-lithiation process on the initial coulomb efficiency of cells with pre-lithiated graphite electrodes is examined in half cells showing an ICE of 99.91 % for the best parameters.
This method of electrolyte-free direct contact pre-lithiation shows an efficient way to further increase the capacity of state-of-the-art LIBs with graphite electrodes by increasing the cathode material utilization. It can potentially be scaled up to a roll-to-roll process using a heated calender nip. The temporary substrates with tailored lithium loading can be processed by lithium melt deposition in an efficient way with high lithium yield and high precision.
[1] K. Schönherr, B. Schumm, F. Hippauf, R. Lissy, H. Althues, C. Leyens, S. Kaskel, Chemical Engineering Journal Advances
2022, 9, 100218.

Figure 1
Understanding the Degradation Mechanisms in Lithium Manganese Oxyfluoride Cathodes
Authors: Pi Liquan , Björklund Erik , Rees Gregory , House Robert , Bruce Peter 
Published: September 2023

The development of next-generation nickel and cobalt-free Li-ion batteries with significantly greater energy density for electric vehicles is largely contingent on the discovery of new cathode materials. A number of novel candidates with a disordered rocksalt crystal structure have recently been reported to exhibit high capacities, offering a highly promising new avenue for cathode research.1–5 However, disordered rocksalt cathode materials generally suffer from voltage and capacity fade over cycling. For example, the Mn-based archetypal oxyfluoride Li2MnO2F shows 254 mAh g-1 discharge capacity in the first cycle but fades to 104 mAh g-1 after 100 cycles. For improving these materials leading to practical devices, it is vital to develop an understanding of the fading mechanisms.
Various explanations have been proposed for the gradual deterioration in performance of disordered rocksalt oxide and oxyfluoride cathodes. These include O-loss and surface densification4,6, growth of a CEI layer7, phase segregation6,8. In this study, we examine the main degradation mechanisms in Li2MnO2F over cycling and demonstrate that the capacity and voltage retention can be improved through compositional control, figure below. This understanding points the way to manganese oxyfluorides with better cycling performance.

House, R. A. et al. Lithium manganese oxyfluoride as a new cathode material exhibiting oxygen redox. Energy Environ. Sci.
11, 926–932 (2018).

Lee, J. et al. Reversible Mn2+/Mn4+ double redox in lithium-excess cathode materials. Nature
556, 185–190 (2018).

Yabuuchi, N. et al. Origin of stabilization and destabilization in solid-state redox reaction of oxide ions for lithium-ion batteries. Nat. Commun.
7, 1–10 (2016).

Li, L. et al. Fluorination‐Enhanced Surface Stability of Cation‐Disordered Rocksalt Cathodes for Li‐Ion Batteries. Adv. Funct. Mater.
2101888, 2101888 (2021).

Chen, R. et al. Disordered lithium-rich oxyfluoride as a stable host for enhanced Li+ intercalation storage. Adv. Energy Mater.
5, (2015).

Chen, D., Kan, W. H. & Chen, G. Understanding Performance Degradation in Cation-Disordered Rock-Salt Oxide Cathodes. Adv. Energy Mater.
9, 1–15 (2019).

Källquist, I. et al. Degradation Mechanisms in Li2VO2F Li-Rich Disordered Rock-Salt Cathodes. Chem. Mater.
31, 6084–6096 (2019).

Chen, D., Ahn, J., Self, E., Nanda, J. & Chen, G. Understanding cation-disordered rocksalt oxyfluoride cathodes. J. Mater. Chem. A
2, 7826–7837 (2021).

Figure 1
Critical Barriers to Successful Implementation of Earth-Abundant, Mn-Rich Cathodes: Low SOC Impedance
Authors: Chen Jiajun , Gutierrez Arturo , Saray Mahmoud Tomadoni , Shahbazian-Yassar Reza , Balasubramanian Mahalingam , Wang Yan , Croy Jason R 
Published: September 2023

The ever-growing demand for electric vehicles and grid storage systems has pushed the development of sustainable cathode materials for Li-ion batteries. Lithium- and manganese-rich (LMR) oxides are a promising class of cathode materials in this regard because of their high capacities/energies and reliance on low-cost, earth-abundant manganese (>50%). However, several outstanding issues remain that hinder the performance of these cathodes. While the mechanisms of the now well-known phenomena of voltage fade, hysteresis, and oxygen activity have been intensively studied, relatively little attention has been given to understanding the impedance characteristics of LMR electrodes. Specifically, the anomalous rise in area specific impedance (ASI) at low states-of-charge (SOCs), and the overall impedance rise on extended cycling due to surface issues, are critical barriers to implementation that still need to be further understood and mitigated.
This presentation will discuss a comprehensive study at Argonne National Laboratory on understanding impedance behavior in cobalt-free, LMR cathode-electrodes. In this study, we use a unique surface-treatment/electrolyte-additive combination that allows us to separate the major contributions of bulk and surface to the impedance behavior over long-term cycling. The results indicate that the anomalous rise in impedance at lower SOCs is directly associated with the correlated, bulk processes of voltage fade and voltage hysteresis. A conceptual model is presented to understand the impedance behavior of these complex materials.
How Graphite Particle Sizes Affect Fast Charging Performance of Ultra-Thin Layer Electrodes for Li- Ion Batteries
Authors: Luo Mei , Wang Guanyi , Mijailovic Aleksandar S , Yang Jian , Sheldon Brain W. , Wu Qingliu , Lu Wenquan 
Published: September 2023

Extreme fast charging (XFC, ≤15 min) of lithium-ion batteries is highly desirable to accelerate mass market adoption of electric vehicles.[1] However, great capacity fading, as well as safety issues due to the lithium plating, limit its implementation. In this study, we investigated the fast-charging capability of graphite materials with various particle sizes under different charging currents up to 6C. To eliminate Li+ ion gradients effects across the thickness of electrode[2], ultra-thin layer graphite electrodes were developed to investigate the “real" fast-charging capability of graphite at particle level by assessing its lithium plating limit. Observations derived from the electrochemical results as well as microscopy characterization revealed that smaller particles exhibited a superior fast-charging performance including better capacity reversibility, less polarization and less lithium plating. Moreover, smaller particles are observed to be able to handle higher C rate charging without Li plating, graphite electrodes with particle size of ~5μm can be safely charged to 80% SOC at 4C. While with particle size of ~15 μm, Li plating occurred on the graphite electrode at 2C. According to pseudo-2-dimensional (P2D) model, the superiority of the small particles might be due to the faster diffusion and intercalation through the particle because of their smaller size and faster rate kinetics due to their larger surface area. This work can help us to better understand the fast-charging behavior and provide the guidance to design the optimum electrode architecture for high-rate of lithium-ion batteries.
Keywords: Ultra-thin electrode, Graphite Electrode, Particle Size, Fast Charging, Li-Ion Batteries
[1] D. Howell et al., “Enabling Fast Charging: A Technology Gap Assessment,” 2017.
[2] K. P. C. Yao, J. S. Okasinski, K. Kalaga, I. A. Shkrob, and D. P. Abraham, “Quantifying lithium concentration gradients in the graphite electrode of Li-ion cells using operando energy dispersive X-ray diffraction,” Energy Environ Sci, vol. 12, no. 2, pp. 656–665, Feb. 2019, doi: 10.1039/C8EE02373E.
(Keynote) Inferring Degradation Modes from Battery Cycling Data
Authors: West Alan , Mayilvahanan Karthik , Hui Zeyu , Takeuchi Esther S. , Marschilok Amy C. 
Published: September 2023

Battery research and development efforts necessarily involve large-scale experimental studies where cells are cycled under different conditions. Physics based models (PBM) of the type pioneered by John Newman, Ralph White, and others can play a key role in interpreting the resulting cycling data, and of course can be used to improve performance by modifications of cell design to optimize for a specific application.
Long-term studies that characterize degradation in cell performance are an important type of cycling experiment that can be used to estimate useful battery life in a real-world application. The establishment of correlations between duty cycle and life is valuable and can inform battery management systems with a goal to extend life. During the course of such experiments, large data sets are created and we explore how a PBM might be used to infer the modes of cathode degradation. From degradation modes, mechanisms of degradations might be hypothesized, and this may lead to insights to further improve design and operation.
Here, two PBM are reformulated to determine how cell parameters such as the amount of active cathode material appears to change with cycle number. Parameter estimation is applied to cycling data, and parameter changes are tracked for cycling data at different C-rates and different cutoff voltages. Parameter estimates are challenged with complementary experimental data for NMC and for a second cathode material that has been characterized extensively. The comparisons suggest that the methodology is effective and can provide physical insights into degradation mechanisms.
To facilitate the “workflow,” inverse surrogate machine-learning techniques, in which simulation data are used for training neural networks to rapidly estimate parameters from experimental data, were utilized. To allow for both imperfect PBM and for non-ideal experimental data, data augmentation methods were introduced to improve the accuracy of parameter estimation algorithms. Examples are shown, with an emphasis on the physics over the mathematics and with an eye towards next steps.
Simulation-Driven Enhancement of an Alkaline CO2 Capture Electrochemical Cell
Authors: Masiello Davide , Gubler Lorenz , Muroyama Alexander 
Published: September 2023

Electrochemical cells using anion exchange membranes (AEM) have been previously demonstrated to regenerate aqueous K2CO3 solutions obtained via CO2 absorption from air with aqueous KOH [1]. Preliminary results suggest this technique might significantly outperform currently employed methods in terms of specific energy expenditure (MJ/kgCO2). In order to accomplish this, we propose a computational study of an electrochemical cell designed and operated at the Paul Scherrer Institut. A multi-phase multi-component model has been developed and implemented via appropriate customization of the commercial CFD software Ansys Fluent. The model accounts for all the physical and chemical phenomena relevant to the electrochemical process, i.e. fluid flow mechanics, heat and mass transfer, electrical potential propagation and chemical and electrochemical reactions. The results of the simulations suggest two possible causes of cell overpotential. Firstly, the formation of hydrogen bubbles by the hydrogen evolution reaction in the cathode electrode, which partially cover the liquid-solid interface where the electrochemical reaction occurs. This is clearly shown by direct comparison with idealized single-phase simulations. Secondly, the flow structure of the catholyte is not optimized to favor the diffusion/migration of carbonate rather than hydroxide anions towards the membrane. This requires increasing the gap between the electrode and the membrane in order to maximize the faradaic efficiency, but it also increases the cell specific resistance. Although we show that there exists an optimal ratio of electrode-membrane gap to cell height, our simulations indicate that a topological optimization of the electrode fine structure might be beneficial to eliminate the undesired effects mentioned above.
[1] Muroyama, A. P., & Gubler, L. (2022). Carbonate Regeneration Using a Membrane Electrochemical Cell for Efficient CO2 Capture. ACS Sustainable Chemistry & Engineering.
Strategies of Practical Implementation of Chemical Pre-Lithiation Using Lithium Arene Complex Solutions: A Systematic Study on Silicon-Based Anodes
Authors: Frankenstein Lars , Mohrhardt Marvin , Peschel Christopher , Gomez Martin Aurora , Placke Tobias , Kasnatscheew Johannes , Winter Martin 
Published: September 2023

Currently, Lithium ion batteries (LIBs) are state-of-the-art (SOTA) energy storage systems. There is an urgent need for further improvements in terms of gravimetric and volumetric energy of LIBs, for a successful market penetration of electric vehicles. Therefore, development of advanced negative electrode materials is of high interest. Here, silicon (Si) is a promising active material to replace SOTA graphite due to its ~10-fold higher specific capacity and being also high abundant.
However, Si undergoes severe volume changes up to 280% during (de-)lithiation, resulting in fast capacity fading and short cycle life due to the continuous re-formation of the solid electrolyte interphase (SEI), leading to active lithium losses (ALL). In order to counteract ALL, research is focusing on suitable pre-lithiation processes. Among different pre-lithiation methods, chemical pre-lithiation by application of lithium arene complex (LAC) solutions is promising as it is a fast, easy and cost-effective method.
In this work, the stability of three different solvents to produce a 4,4’-dimethylbiphenyl (4,4’-DMBP) LAC is investigated via solid phase microextraction gas chromatography-mass spectrometry method (SPME-GC-MS). The optimized LAC solution is used to evaluate the stability of different binder systems with respect to electrode manufacturing. Based on these fundamental insights, different parameters such as the reaction temperature (T) and pre-lithiation time (PL-t) are systematically investigated regarding suitable degrees of pre-lithiation (DOPL) of the negative electrode. DOPLs up to a plateau of 55% can be obtained by using 0.5 M 4,4’-DMBP in tetrahydrofuran (THF) as LAC solution. Higher temperature during the reaction reduces the PL-t until achieving a pre-lithiation plateau. The impact of the parameters T and PL-t towards the electrochemical performance of Si-based LIB full cells is thoroughly investigated. It is shown that this approach improves the cycle life of a silicon nanowire graphite composite negative electrode up to 600% compared to the pristine electrodes