bluuebunny/crossref_metadata_2025_split huggingface dataset:
Monitoring the Solid-Electrolyte Interphase Formation in Bis(fluorosulfonyl)Amide Ionic Liquid Electrolyte Using a Redox Probe Method
Authors: Katayama Yasushi , Okazaki Sho , Serizawa Nobuyuki 
Published: August 2024

The solid-electrolyte interphase (SEI) has been considered to be formed on the negative electrode surface by reductive decomposition of electrolyte components. In the case of the electrolytes containing lithium ions, the SEI can be regarded as the Li+ conductor that enables the negative electrode reactions and prevents the further decomposition of the electrolytes. The structure of the SEI is often explained by the mosaic model, in which the SEI is a composite of several different inorganic and organic domains [1]. On the other hand, we have proposed the formation of the gelled SEI in bis(fluorosulfonyl)amide (FSA–) ionic liquid electrolytes containing a high concentration of LiFSA [2,3]. Furthermore, we have reported that the SEI formation can be detected by monitoring the redox reaction of ferrocene (Fc) and ferrocenium (Fc+) [4,5]. In the present study, the time-dependent transition of the SEI formed on a Pt electrode was investigated by the redox probe method in BMPFSA (BMP+ = 1-butyl-1-methylpyrrolidinium) containing LiFSA.
The formation of SEI by holding a Pt electrode at a negative potential was confirmed by a shift in the anodic peak potential of the cyclic voltammogram for Fc+/Fc couple in LiFSA/BMPFSA. The anodic peak disappeared when the electrode was held at the negative potential for a few hours, indicating the formation of a thick SEI. However, the anodic peak was observed again after keeping the electrode at the open circuit potential for a few hours, indicating the disappearance of the SEI. These results suggest that the SEI is formed by dissolution and/or dispersion of the decomposed products, which form at the electrode surface and diffuse into the electrolyte. Thus, the SEI formed at the potential is considered to exist as a metastable phase in the balance between the formation and diffusion of the decomposition products.
This work was partly supported by GteX Program Japan Grant Number JPMJGX23S0.
[1] E. Peled, D. Golodnitsky, and G. Ardel, J. Electrochem. Soc., 144, L208 (1997).
[2] R. Furuya, T. Hara, T. Fukunaga, K. Kawakami, N. Serizawa, and Y. Katayama, J. Electrochem. Soc., 168, 100516 (2021).
[3] N. Serizawa, R. Yamashita, and Y. Katayama, J. Phys. Chem. C, 127, 10434 (2023).
[4] S. Kato, N. Serizawa, and Y. Katayama, J. Electrochem. Soc., 169, 076509 (2022).
[5] S. Kato, N. Serizawa, and Y. Katayama, J. Electrochem. Soc., 170, 056504 (2023).
(Invited) Atomic-Scale Modeling of Charge-Transfer Kinetics at LixCoO2 Cathode-Electrolyte Interfaces
Authors: Halldin Stenlid Joakim , Lawson John W 
Published: August 2024

In the search for Li-ion batteries with improved performance, interface engineering is a comparably underexplored area with significant opportunities for innovation. Ion transport across interfaces is, for instance, a significant bottleneck for fast charging/discharging. At electrode interfaces, it is often essential to capture the coupled motion of ions and electrons in order to provide accurate computational input for interfacial design. In this work we employ the recently proposed theory of coupled ion-electron transfer kinetics[1,2] in conjugation with constrained and constant-potential density functional theory to examine Li+ transfer across battery electrolyte-cathode interfaces at the atomic scale. Here, we focus on the common Li
x
CoO2 intercalation-type cathode material and liquid-state organic electrolytes. We establish trends in transport kinetics for different states-of-charge (SOC, i.e., varied degree of lithiation, x), types of electrolytes, and counterions that closely reproduces experimentally observed trends. From our modeling, we can identify a few key descriptors to predict performance metrics in Li-ion transport of a given electrolyte-cathode combination. These include the Li-ion free energy of adsorption, the free energies of reorganization of the cathode material and electrolyte upon the addition/removal of electrons, as well as the electronic coupling between electron acceptor and donor states. As these quantities can be relatively straightforwardly estimated for any given electrode-electrolyte pair, we envisage broad applications of our modeling approach in the interfacial design for batteries and related fields.
[1] Fraggedakis et al., Electrochimica Acta, 367, 137432 (2021)
[2] Bazant, Faraday Discussion, 246, 60 (2023)
Fluorination Promotes Lithium Salt Dissolution in Borate Esters for Lithium Metal Batteries
Authors: Ma Peiyuan , Amanchukwu Chibueze 
Published: August 2024

Lithium metal batteries promise higher energy densities than current lithium-ion batteries but require novel electrolytes to extend their cycle life. To promote electrolyte stability against lithium metal and improve the reversibility of lithium deposition/stripping, several electrolyte design strategies have been pursued. For example, high concentration electrolytes (HCEs) and localized high concentration electrolytes (LHCEs) produce solvation structure rich in salt aggregates and ion pairs, which can increase lithium metal cycling Coulombic efficiency to as high as 99.5%. Recently, molecular design of fluorinated ether solvents also leads to high lithium metal Coulombic efficiency of up to 99.9% in single-solvent-single-salt ~ 1 M electrolytes. In addition, fluorinated acetals, fluorinated carbonates, and fluorinated sulfonamides are also reported to enable efficient lithium metal cycling. Among those novel electrolytes, fluorinated solvents or diluents are frequently used because fluorinated moieties are known to yield LiF as a preferable component in solid electrolyte interphase (SEI). However, fluorinated groups are believed to weaken ion solvation as most fluorinated solvents show poorer solvation ability or lower ionic conductivity compared to their nonfluorinated counterparts. The trade-off between SEI passivation and ion solvation limits further optimization of fluorinated electrolytes.
In this work, we synthesize tris(2-fluoroethyl) borate (TFEB) as a new fluorinated borate ester solvent. Interestingly, moderately fluorinated TFEB shows unexpectedly high lithium salt solubility (~1 M LiFSA) while the nonfluorinated triethyl borate (TEB) and heavily fluorinated tris(2,2,2-trifluoroethyl) borate (TTFEB) can hardly dissolve lithium salt. Through density functional theory (DFT) calculations and ab-initio molecular dynamics (AIMD) simulations, we show that the partially fluorinated -CH2F group in TFEB acts as primary coordination site that promotes lithium salt dissolution. The electrochemical property of TFEB electrolyte is then compared to the methoxy polyethyleneglycol borate esters reported in literature. Owing to the fluorinated solvent structure, TFEB electrolyte passivates lithium metal with LiF-rich SEI and supports compact lithium deposition morphology, high lithium metal Coulombic efficiency, and stable cycling of lithium metal/LiFePO4 cells. This work ushers in a new electrolyte design paradigm where partially fluorinated moieties enable salt dissolution and can serve as primary ion coordination sites for next-generation electrolytes.

Figure 1
Realizing of Earth-Abundant, Mn-Rich Cathodes for Lithium-Ion Batteries
Authors: Chen Jiajun , Gutierrez Arturo , Balasubramanian Mahalingam , Croy Jason R. 
Published: August 2024

The development of sustainable materials for lithium-ion batteries (LIB) is of critical importance, especially considering the significant, ever-growing demand for energy storage technologies. Lithium- and manganese-rich (LMR) oxides are of great interests because of their inherently high capacities/energies and the potential economic benefits associated with earth-abundant manganese-based compositions. However, despite their attractive properties, LMR commercialization has been hindered by several challenges.
In this presentation we will explore these challenges across length-scales, spanning from the atomic to the cell level, and consider the correlated effects observable in electrochemical cells. Detailed synthesis studies will be presented concerning morphological control of LMR cathode precursors; complex local structure will be discussed and linked to properties that are unique to this class of cathodes; and finally, techno-economic modeling will be used to evaluate the potential of an LMR system – developed at Argonne National Laboratory – for practical implementation in large-format EV cells.
The work presented herein represents research and development efforts led by Argonne National Laboratory within the Vehicle Technologies Office, Earth-abundant Cathode Active Materials (EaCAM) consortium. This effort endeavors to bridge the knowledge gap across various length-scales, from atomic-level intricacies to broader cell-level implications, to innovate, and enhance the sustainability of energy storage technologies.
Model-Based Interpretation of Thermal-Gradient Effects in Li-Ion Cells
Authors: Evans Tyler A. P. , Ishtiaque MD Mahdi Ul , Harkaway Andrew , Pint Cary L. , Kingston Todd A. , Kee Robert J. 
Published: August 2024

The present study develops a combined experimental and modeling approach to study temperature gradients in Li-ion batteries. Although through-plane temperature differences may be small (ΔT ≈ 1-10 °C), large interelectrode thermal gradients (∇T ≈ 1,000-10,000 °C/m) can be present and have been found to significantly affect Li-ion battery performance and degradation [1,2]. Figure 1 illustrates a thin pouch cell (order of 300 microns thick) sandwiched between cool and warm plates. The cell uses a graphite anode and a NMC622 cathode. By maintaining the temperature of the cool and warm blocks, a thermal gradient can be enforced across the cell. Depending on how the cell is positioned, the cell’s cathode or anode can be on the cool or warm side. Experiments include overpotential analysis and galvanostatic intermittent titration technique (GITT) at different states of charge. Results show different behaviors as the thermal gradient is applied and the directionality of the thermal gradient changes.
This presentation presents a pseudo-two-dimensional (P2D) model [3] that has been modified to represent the experimental conditions, including the thermal gradients. The model considers the temperature dependencies of thermodynamic properties, electrolyte conductivities, electrode diffusion coefficients, intercalation rates, etc. [4]. The model captures some, but not all, of the measured behaviors. Thus, an important objective is to investigate physical and chemical behaviors that are not included in typical P2D models. For example, off-diagonal Onsager contributions could be significant in the presence of high temperature gradients. The results predict how thermal gradients can contribute to Li-ion concentration fluxes (Soret contribution), and thus affect battery performance. The scientific intent is to understand the thermal gradient behaviors and thus assist battery design guidelines and battery-management control considerations.

Acknowledgments

The authors thank the Office of Naval Research (Dr. Michele Anderson) for financial support (ONR award numbers: N00014-23-1-2694 and N00014-22-1-2411) of this work.

References

[1] C. Fear et al., Journal of Energy Storage Materials, 35, 500-511 (2021)
[2] R. Carter et al., Cell Reports Physical Science, 2, 100351 (2021)
[3] T.F. Fuller et al., J. Electrochem. Soc., 141, 1 (1994)
[4] A.M. Colclasure et al.,
J. Electrochem. Soc.,
166, A1412 (2019)

Figure 1
Design and Preparation of One-Dimensional Cathode By Electrophoretic Deposition Method for Flexible Knitted Batteries
Authors: Zhalgas Nuray , Bakenov Zhumabay , Mentbayeva Almagul , Tatykayev Batukhan 
Published: August 2024

Rechargeable batteries are highly promising energy storage systems that can convert and store electrical energy. Effective energy storage systems should have high energy density, high power, safety, environmentally friendliness, and long cycle life. To meet the aforementioned objectives, researchers have attempted to use different morphologies of nanomaterials as electrodes to improve the electrochemical performance of batteries. Among the materials available, one-dimensional structures have unique properties over traditional ones and extensive applications in wearable devices due to their flexibility [1]. Flexible batteries have several advantages such as mechanical flexibility, good energy storage capabilities, affordability, and environmental safety [2]. They knitted or sewed into textiles, folded into random forms, and wrapped around body parts like the neck or wrist [3]. However, there is little research that covers Li-ion batteries that have a one-dimensional flexible structure.
Achieving simultaneous high electronic/ionic conductivity and electrochemical stability is difficult in a homogeneous single-component electrode material. Consequently, the development of precisely defined functional one-dimensional (1D) hetero-nanostructures that effectively integrate the advantages and address the limitations of various electrochemically active materials becomes critical [1].
The proposed methodology involves the electrophoretic deposition of lithium iron phosphate on conductive nickel wire, providing a one-dimensional cathode structure. As an anode, nickel-tin is deposited on nickel wire by electrochemical deposition. The deposition method allows greater precision and control over the deposition of active material on the current collector and also has possible applications on different structures such as 1D and 3D. Also, the electrolyte was obtained by layer-by-layer method, by dipping the cathode and anode, separately, in polymers to coat the cathode material as an electrolyte-separator film. The full cell was assembled and the better results will be presented in the meeting.

Acknowledgments

This research was funded by the Science Committee of the Ministry of Education and Science of the Republic of Kazakhstan (Grant No. АР19679855).

References

[1] L Mai et al., Acc. Chem. Res. 51(2018) 950–959
[2] S. Zhai et al., J. Mater. Chem. A. 9(2021) 26573-26602
[3] K.Wang et al., ACS Applz. Mater. Interfaces. 10(2018) 24573–24582
AI-Powered 3D Image Reconstruction for Analyzing Lithium Ion Battery Microstructures at the Nanoscale
Authors: Kelly Stephen T , Trenikhina Yulia , Harris William 
Published: August 2024

A clean energy future will rely heavily on lithium-ion batteries to shift away from carbon-based energy sources. These devices are closed off from the outside world and operate under highly non-ambient conditions (e.g., liquid electrolytes, air-free environments). Their performance is largely driven by the 3D microstructures of the internal components and their evolutions. For example, breached layers in batteries due to lithium dendrite growth can lead to catastrophic failures and safety concerns. As such, imaging the internal microstructures and processes is important for observing and measuring device construction details and understanding how defects are distributed and change performance during operation. In particular, 3D imaging allows for analysis of features and parameters that can only be fully understood in 3D, like porosity and tortuosity, and can also provide realistic microstructural input for 3D modelling and simulation approaches.
Within this scope, X-ray microscopy provides a unique method to image electrochemical devices because of the non-destructive nature of the technique. Modern x-ray microscopes enable 3D imaging even at the nanoscale, bringing capabilities once reserved for the synchrotron into the laboratory. Advances in tomographic image reconstruction have allowed researchers to increasingly maximize the impact of x-ray microscopy data through higher image quality and enabling faster data acquisition schemes. Recently, artificial intelligence (AI) has been incorporated into these algorithms, dramatically increasing the performance and capability of the technique. Here, we apply multiple novel reconstruction technologies that leverage AI to dramatically improve the performance of laboratory-based nanoscale x-ray microscopes, showing examples of improvements in imaging lithium-ion battery electrode materials.
We show how AI-powered tomographic reconstruction can reveal new levels of detail in lithium-ion battery materials and enable up to 10 times faster data collection across the micrometer and nanometer length-scales. These capabilities shift the paradigm in volume analysis for electrochemical devices and give researchers unprecedented insight into the detailed microstructures that drive device performance, enabling new levels of understanding and helping to power the drive to a clean energy future.
A TEM Study of Structural Degradation in LiFePO4 Batteries after Hybrid Vehicle Use
Authors: Ramirez-Meyers Katrina , Dickey Elizabeth C 
Published: August 2024

Establishing a robust, efficient circular economy for batteries hinges on understanding how they decay over time under various conditions. This understanding is crucial to maximize material use before recycling or disposal. A key aspect of this endeavor is the study of lithium iron phosphate (LiFePO4), a pivotal battery technology whose structural integrity over time remains a subject of inquiry.1 Known aging mechanisms in LiFePO4 (LFP) batteries include electrode degradation, SEI growth, and electrolyte decomposition.1 These processes extend to the cathode, where degradation can manifest as Fe dissolution, Li inventory loss, Fe/Li anti-site defects, and LFP amorphization.1–3 However, these mechanisms are typically studied in lab-aged cells under controlled conditions, leaving a gap in our understanding of their behavior in real-life, commercialized applications.
Our research aims to bridge this gap by characterizing the degradation mechanisms of LFP cathode material in various states of health (SOH) after use in a hybrid vehicle. We sourced our cathode samples from 26650 cells extracted from a BAE ESS-A123 hybrid bus battery pack. After selecting cells with drastically different SOHs based on previous analyses,4 we employed transmission electron microscopy (TEM) for detailed characterization.
In this talk, we will share insights gained from high-resolution TEM characterization, alongside chemical analysis using energy-filtered TEM and electron energy loss spectroscopy (EELS). Our focus will be on changes in the olivine structure, including lattice parameter alterations, Li and Fe migration, and Fe oxidation. By combining cell-level SOH analyses with TEM characterization, we will highlight how electrochemical test results correlate with material degradation mechanisms, enhancing our understanding of battery health, longevity, and diagnostics.

Wang, L. et al. Insights for understanding multiscale degradation of LiFePO4 cathodes. eScience
2, 125–137 (2022).

Li, X. et al. First Atomic-Scale Insight into Degradation in Lithium Iron Phosphate Cathodes by Transmission Electron Microscopy. J. Phys. Chem. Lett.
11, 4608–4617 (2020).

Xu, P. et al. Efficient Direct Recycling of Lithium-Ion Battery Cathodes by Targeted Healing. Joule
4, 2609–2626 (2020).

Ramirez-Meyers, K., Rawn, B. & Whitacre, J. F. A statistical assessment of the state-of-health of LiFePO4 cells harvested from a hybrid-electric vehicle battery pack. J. Energy Storage
59, 106472 (2023).
Modifying Li-Rich Cathodes and Investigation into Fully Earth-Abundant Cathode Materials
Authors: Mallick Subhadip , Kwok Chun Yuen , Pollock Christopher , Dixit Marm , Gutierrez Arturo , Balasubramanian Mahalingam , Croy Jason R. 
Published: August 2024

The growing demand for electric vehicles and grid storage devices entails the search for materials to further enable these technologies. In this regard, the development of cost-effective, and energy-efficient lithium-ion battery cathodes is of the essence. In recent times, Ni-rich NMC oxides (LiNi
x
Mn
y
Co
z
O2, x+y+z = 1) have emerged as the latest and most advanced materials for use as Li-ion cathodes. However, increasing concerns over sustainability, supply chain issues, and cost-effectiveness of critical elements like Co and Ni have accelerated the search for earth-abundant, Mn and Fe-rich cathode materials.1

Lithium and manganese rich oxide materials (LMR), with general formula xLi2MnO3 • (1-x)LiMO2, can achieve higher energy densities compared to conventional NMC oxides, and thus represent attractive alternatives.2-3 Although issues like voltage fade and hysteresis are concerns with respect to practical application of LMR cathodes and have been well studied, the anomalous increase of area specific impedance (ASI) at low states of charge (SOC), has been comparatively overlooked. This presentation will discuss recent attempts to modify the low SOC ASI behavior of LMR materials by targeted substitution using Sn4+ as an example.
The second part of this presentation will focus on investigations into the synthesis, structure, and electrochemical properties of layered-rock salt composites: xLi2MnO3 • (1-x)LiFeO2. Electrochemical performance of Mn-Fe rich systems is also fundamentally linked to the debated and conflicting theories of oxidation state, local structure, and migration behavior of the Fe3+/4+ red-ox couple. X-ray spectroscopic techniques have been used to address this issue. A composition-structure-property relationship is established within these systems and novel approaches are underway to further improve their electrochemical performance.
References

Communications Materials
2020, 1 (1), 99.

Accounts of Chemical Research
2015, 48 (11), 2813-2821.

Journal of The Electrochemical Society
2023, 170 (3), 030509.