bluuebunny/crossref_metadata_2025_split huggingface dataset:
State-of-Charge Dependent Change of the Young’s Modulus in Lithium-Ion Batteries
Authors: Daubinger Philip , Feiler Simon , Gold Lukas , Hartmann Sarah , Giffin Guinevere A. 
Published: July 2022

One way to increase the sustainability of lithium-ion batteries (LIB) is to extend the cycle life, e.g., in electric vehicles. To do this, the effects within a LIB must be understood and tracked over its lifetime. In addition to electrical (e.g. IR-drop) and thermal measurements (e.g. temperature inhomogeneities), a new approach for such studies is the use of ultrasound to investigate the mechanical changes inside a LIB [1]. With this low-cost technology, it is possible to detect mechanical degradation (e.g. local thickness change due to lithium plating) or Young’s moduli changes over lifetime and possibly counteract them by the battery management system.
In this work a self-built device containing a LIB between two opposing transducers is used to study the impact of state-of-charge (SOC), current rate and frequency on the ultrasound signal inside the LIB. Based on the time the ultrasound signal takes to pass through the LIB (time-of-flight (TOF)), the speed of sound and the Young’s moduli can be determined. The influence of the applied current rate and the frequency of the transducer to the TOF/ speed of sound in the LIB is relatively small. However, the SOC has an impact on the TOF/ speed of sound, where the speed of sound is around 4.5% higher in the fully charged state with ~1740 m s-1 compared to the discharged state with ~1660 m s-1 (see Figure 1 (a)). One explanation for this phenomenon is the change in the lithium staging within the graphite anode. In a charged battery, the graphite anode is filled with lithium ions, which enhances the transmission properties of ultrasound. By knowing speed of sound, the Young’s modulus of the whole battery can be estimated as ~4.2 GPa in discharged state and ~5.6 GPa in the charged state (Figure 1 (b)). This significant increase can also be explained with the lithiation stages of the graphite anode, as the graphite particles themselves exhibit a threefold increase of the Young’s modulus during lithiation [2]. Additionally, the evolution of the speed of sound and Young’s moduli is studied during aging of the LIB.

References:

[1] Gold, L., Bach, T., Virsik, W., Schmitt, A., Müller, J., Staab, T. E., & Sextl, G. (2017). Probing lithium-ion batteries' state-of-charge using ultrasonic transmission–Concept and laboratory testing. Journal of Power Sources, 343, 536-544.
[2] Qi, Y., Guo, H., Hector Jr, L. G., & Timmons, A. (2010). Threefold increase in the Young’s modulus of graphite negative electrode during lithium intercalation. Journal of The Electrochemical Society, 157(5), A558.

Figure 1
Chemical and Morphological Changes of Graphite Electrodes at Low Cathodic Potentials and Its Relevance to Li-Ion Batteries
Authors: Wong Raymond , Yokota Yasuyuki , Kazuma Emiko , Oniki Motoyuki , Kim Yousoo 
Published: July 2022

Lithium-ion (Li-ion) batteries have become ubiquitous to modern-day electronics and electric vehicles. A detailed understanding regarding the reversible and irreversible nature of Li-ion electrode processes is a prerequisite to rationally delineate the factors affecting device performance and clarify degradation mechanisms. This includes, for instance, the role of electrode cracking and solid solid-electrolyte-interphase (SEI) formation which can contribute toward irreversible capacity loss. In terms of experimental approaches, aside from the high surface area electrodes used in practical systems, one powerful approach is to incorporate the study of well-defined electrodes and surface science techniques.1

Herein, we employ highly oriented pyrolytic graphite (HOPG) as a well-defined model anode in Li-ion batteries and reveal the chemical and morphological changes at low cathodic potentials prior to the potentials of bulk SEI formation.2 To achieve this, we employ the use of X-ray photoelectron spectroscopy (XPS) and ultrahigh vacuum scanning tunneling microscopy (UHV-STM). We utilize a so-called UHV-EC setup to provide a snapshot-like analysis of the electrode surface without the involvement of electrode washing or exposure to air.
Upon cathodic polarization at ca. 1.75V (Figure 1), STM imaging shows the onset and occurrence of graphite exfoliation which can originate from the intercalation of solvated Li+ ions. Meanwhile, XPS shows a minimal amount of residual electrolyte along with the observation of LiF indicating the decomposition of the Li salt (LiPF6). The future extensions of our methodology and additional details will be provided at the presentation.

Figure 1. (a) Cathodic linear sweep voltammogram in 1.1 M LiPF6 EC/DMC. Following polarization at ca. 1.75 V (b) STM imaging, and (c) XPS F 1s and Li 1s spectra.
References
[1] T. Minato, T. Abe, Prog. Surf. Sci.
92, 240-280 (2017).
[2] R. A. Wong, Y. Yokota, E. Kazuma, M. Oniki, Y. Kim, J. Phys. Chem. C
125, 21093-21100 (2021).

Figure 1
Understanding of Structural, Dynamic and Ionic Diffusion Characteristics of Li6(PS4)SCl Superionic Conductor from Classical Molecular Dynamics
Authors: Das Tridip , Merinov Boris V , Yang MoonYoung , Goddard William 
Published: July 2022

Solid-state batteries are preferred over commercial Li-ion batteries, due to their higher thermochemical stability, higher safety, and longer cycle life. Successful applications of solid-state batteries largely depends on electrode-electrolyte interfacial stability and fast Li-ion transport in the electrolyte.1 Among different electrolyte candidates from polysulfide, oxide, argyrodite, perovskite families - Li6(PS4)SCl looks very promising due to its lithium superionic conductivity at room temperature and very wide electrochemical stability window (0−7 V versus Li/Li+).2

We report here our results on molecular dynamics simulations with applied electric fields (LAMMPS+UFF)8 to explain both cationic and anionic diffusion mechanisms leading to the Li-superionic conductivity of a Li6(PS4)SCl single crystal. Charges on ionic species were scaled from DDEC6 calculated charges and the Li-ion charge is comparable to that calculated for Li-ions in Li-P-S systems using ReaxFF. We find that Li migration occurs via conjugated substitutional type diffusion involving rearrangements of three or more Li-ions in a 3D matrix of anions that are essentially stationary around room temperature. Figure 1 shows mean-square displacements (MSDs) of the ions in Li6(PS4)SCl in our 20 ns MD simulation. The MSD of the Li-ions reaches the Fickian regime for Li-diffusion after 1 ns of the simulation.
The predicted Li-ion diffusivity (4x10-12 m2/s) and conductivity for single phase Li6(PS4)SCl is 6.7 mS/cm is in good agreement with solid state NMR measurements of 5.7 mS/cm.4 Our calculated activation energy of 0.26 eV is within experimentally reported range. 0.27 – 0.29 eV, from NMR measurements (Figure 2).3–6 We further used the two phase thermodynamic (2PT) method7 to predict the melting point. Also, a detailed study was performed to examine the directional electric field effect of different field strengths on the Li-ion diffusion in Li6(PS4)SCl.
Financial support of this research from the Centre of Hong Kong Quantum AI Lab Ltd established by the University of Hong Kong (the InnoHK initiative) is gratefully acknowledged.
References:

L. Ye and X. Li, Nature, 593, 218–222 (2021).

J. C. Bachman et al., Chem. Rev., 116, 140–162 (2016).

C. Yu, L. van Eijck, S. Ganapathy, and M. Wagemaker, Electrochimica Acta, 215, 93–99 (2016).

R. Schlenker et al., Chem. Mater., 32, 8420–8430 (2020).

S. Ganapathy, C. Yu, E. R. H. van Eck, and M. Wagemaker, ACS Energy Lett., 4, 1092–1097 (2019).

I. Hanghofer, B. Gadermaier, and H. M. R. Wilkening, Chem. Mater., 31, 4591–4597 (2019).

S.-T. Lin, M. Blanco, and W. A. Goddard, J. Chem. Phys., 119, 11792–11805 (2003)

A. K. Rappe et al., J. Am. Chem. Soc.
114, 10024–10035 (1992)

Figure 1
Effect of Post-Grinding and Heat Treatment on the Electrochemical Performance of NMC622 Li-Ion Battery Cathode Materials
Authors: Tahmasebi Mohammad Hossein , Obrovac Mark 
Published: July 2022

Given the increasing demands for high energy density lithium-ion batteries (LIBs), all cell components, particularly cathode materials, will need significant improvement in the future. Among the possible cathode materials for LIBs, NMC-based materials (LiNixMnyCozO2) have been receiving more attention due to their high energy density and low price. However, NMC-based cathode materials still suffer from degradation and capacity fading due to polarization and structural change over charge-discharge cycling which may be associated with, for example, cation mixing and particle morphology. Among these, the particle size of NMC-base cathodes plays an important role in degradation mechanism during long-term electrochemical cycling [1,2].
The present study comprehensively highlights the effect of post-grinding methods and re-heating on electrochemical performance of Li-NMC622 cathode materials. For this purpose, NMC622 samples were synthesized using commercial precursors and different grinding methods were employed to break up the agglomerated secondary particles into smaller sizes. Accordingly, the microstructural, morphological, and electrochemical evolution of unground and ground samples were studied. Microscopy observations, along with electrochemical data, suggest that marked performance improvements can be achieved by controlling the particle size of NMC622 through post-grinding and heat treatment.

References

B. Huang et al., Solid State Ionics, 345, 115200 (2020).

A. Liu et al., J. Electrochem. Soc., 168, 050506 (2021).
(Digital Presentation) Mapping of Degradation Processes in Ni-Rich Layered Oxide Cathode Materials in State-of-the-Art Commercial Li-Ion Cells Based on Battery Usage Conditions
Authors: Mikheenkova Anastasiia , Roy Chowdhury Niladri , Smith Alexander James , Tesfamhret Yonas , Pay Gómez Cesar , Wreland Lindström Rakel , Thiringer Torbjörn , Berg Erik J. , Lacey Matthew , Hahlin Maria 
Published: July 2022

Ni-rich oxide cathode active materials are today key components in Li-ion batteries used for electric vehicles (EV). The high capacity of LiNixCoyMnzO2 and LiNixCoyAlzO2 (NCA) with x≥0.6 has enabled a continued increase in energy density and decrease in cost at the pack level, enabling the rapid growth of the EV market in recent years. Despite a wide use, rather fast material ageing results in the batteries being a source of considerable environmental impact [1]. Various degradation sources are highlighted in the literature, these include transition metal dissolution, surface layer reconstruction, particle cracking, etc [2]. However, when extrapolating the knowledge from a model cell to a commercial battery the relevance and the degree of degradation impact can drastically change [3]. The importance of approaching real conditions is a key to a full understanding of the ageing processes occurring in commercial cells. In the given work, we analyse commercial state-of-art 2170 cylindrical cells. The cells were aged at various temperatures and state of charge windows, targeting divergent usage scenarios. The degradation processes were accessed with a wide range of analytical techniques applied to extracted electrodes (x-ray diffraction, inductively coupled plasma atomic emission spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, cycling voltammetry, incremental capacity analysis, electrochemical impedance spectroscopy and intermittent current interruption). In the current work we show that depending on the operating conditions, influence of ageing sources varies. Additionally, ageing mapping within cell geometry is presented highlighting “hot spots” of the cell [4].

References

[1] W. Liu et al., “Nickel-Rich Layered Lithium Transition-Metal Oxide for High-Energy Lithium-Ion Batteries,” Angew. Chemie Int. Ed., vol. 54, no. 15, pp. 4440–4457, Apr. 2015.
[2] T. Li, X.-Z. Yuan, L. Zhang, D. Song, K. Shi, and C. Bock, Degradation Mechanisms and Mitigation Strategies of Nickel-Rich NMC-Based Lithium-Ion Batteries, vol. 2018, no. January 2017. Springer Singapore, 2019.
[3] M. Lucu et al., “Data-driven nonparametric Li-ion battery ageing model aiming at learning from real operation data – Part A: Storage operation,” J. Energy Storage, vol. 30, p. 101409, Aug. 2020.
[4] Mikheenkova et al., in manuscript.
Impact of Ni Content on the Structure and Electrochemical Performance of the Co-Free, Li/Mn-Rich Layered Cathode Materials
Authors: Qi Gongshin , Hu Jiazhi , Balogh Michael P , Wang Lei , Nageswaran Shubha , Pieczonka Nicholas , Li Wei 
Published: July 2022

Since early 1990s lithium-ion batteries (LIBs) have become the most important secondary/rechargeable battery technology for portable electronic devices; and more recently for battery powered vehicles. Extensive research has been conducted on high-capacity electrode materials for LIBs due to the emerging demands for high energy density batteries for electric vehicles. Compared with the conventional cationic redox-based cathode materials, such as NMC, LMO and LFP, Li-excess, Manganese rich layered cathode (LLC) materials containing cationic and anionic redox process, show great potential as the next generation cathode materials because of their higher theoretical specific capacity and lower raw material cost.
Our work has shown that Ni content of the Co-free, LLC materials, Li1.2NixMn0.8-xO2 (x = 0.12, 0.24, 0.30 and 0.36) prepared by a citric acid method, has a significant impact on the material structure, electrochemical performance, and thermal stabilities. Generally, the primary particle size increased as the Ni content increased with a primary particle size distribution in the range of 200–600 nm for the samples investigated. Monoclinic phase (C2/m) and spinel (Fd3m) phase depending on the content of Ni have been identified by XRD. With increasing Ni content, the fraction of the spinel phase decreased and eventually the pure layered structure was obtained on the samples at x = 0.30 and 0.36. Our work demonstrates that the charging and discharging capacities are determined by the Ni or Mn content. The highest charging and discharging capacities were achieved when x = 0.24. As Ni content increased, the first cycle coulombic efficiency decreased, and the thermal stability deteriorated. But, an increase in Ni content results in an increase in average discharge voltage, higher electrochemical stability of the layered structure, fast Li ions diffusivity. Li1.2Ni0.12Mn0.68O2 sample exhibited the best capacity retention and thermal stability among the tested samples. However, its specific energy density was limited due to the lowest average discharge voltage. The Li1.2Ni0.36Mn0.44O2 sample which contained the highest Ni content exhibited the worst thermal stability, but relatively higher specific energy density due to the highest average discharge voltage.
(Digital Presentation) Lithiation/De-Lithiation of a Unique C-S Species in Amorphous FeS4/C Cathodes for Li Batteries
Authors: Wygant Bryan R. , Kolesnichenko Igor V. , Schorr Noah B. , Lambert Timothy N. 
Published: July 2022

When paired with Li metal anodes, Fe-based conversion cathodes like iron sulfide present a promising material for creating energy dense rechargeable batteries for energy storage. While iron sulfide cathodes (e.g. FeS2) typically suffer from deleterious polysulfide formation, recent work with a class of amorphous iron sulfide-carbon composites (e.g. FeS4/C) has shown minimal evidence of polysulfide formation during lithiation and de-lithiation, and thus it may represent a pathway to stable, polysulfide-free iron sulfide batteries. Prior reports indicate that the active component of the composite is the FeS4 and that the amorphous carbon does not exhibit any electrochemical response. While studying this material, however, we have found evidence to suggest that the cycling of FeS4 alone does not fully explain the electrochemical and chemical behavior observed for the FeS4/C cathode, and that the carbon plays a significant role in the overall electrochemistry of the composite.
In this presentation, we will present a study of this amorphous FeS4/C composite as a cathode for use in Li batteries and provide evidence of the electrochemical lithiation and de-lithiation of a previously unstudied and unreported C-S compound found in the composite material. Our results indicate that this C-S species is amorphous and is (electro)chemically similar to sulfurized poly(acrylonitrile) (SPAN) and carbyne polysulfide (C-PS). By coupling ex situ Raman and X-ray photoelectron spectroscopy (XPS) to galvanostatic battery cycling, we show how chemical changes in the FeS4/C cathode correspond to electrochemical features associated with the lithiation and de-lithiation of both iron sulfide and the C-S species. Our results indicate that the C-S species is electrochemically active at all stages of cycling, while the FeS4 loses activity within approximately 15-20 cycles. This differs significantly from earlier reports and suggests that the lack of polysulfide formation when testing the FeS4/C composite may in fact be due to the cycling of this C-S species rather than iron sulfide. These results serve as an initial foray into the electrochemistry of this new material and should provide a basis for additional study of this new and promising C-S based cathode material for Li batteries.
This work was supported by the Laboratory Directed Research and Development program at Sandia National Laboratories, a multi-mission laboratory managed and operated by National Technology and 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-NA-0003525. The views expressed herein do not necessarily represent the views of the U.S. Department of Energy or the United States Government.
Lithium-Ion Battery Degradation: How to Diagnose It
Authors: O'Kane Simon E. J. , Kirkaldy Niall , Offer Gregory James , Marinescu Monica 
Published: July 2022

Many different degradation mechanisms occur in lithium-ion batteries, all of which interact with one another [1]. However, there are few fewer observable consequences of degradation than there are mechanisms [2]. It is possible to measure the different degradation modes: loss of lithium inventory (LLI), loss of active material (LAM), impedance change and stoichiometric drift [3].
It is not always possible to link these observable consequences of degradation to any particular mechanism or combination of mechanisms. Many models of degradation exist [4], but these models have many parameters that cannot be measured directly. A recent modelling study [5] found the number of parameters that the model is sensitive to is greater than the number of observable degradation modes.
However, the same model [5], despite including just four degradation mechanisms, found five possible degradation pathways a battery can follow. The model was built so that more mechanisms can easily be added later, so more pathways will be found.
In this work, a new approach to diagnosing battery degradation is proposed, based on these pathways. Experimental data for the degradation modes can be identified as being consistent with a particular pathway. Once the correct pathway is found, the parameters that particular pathway is sensitive to can be fit to the data, feeding back into the model.
[1] Jacqueline Edge et al., Phys. Chem.: Chem. Phys. vol. 23, pp. 8200-8221, 2021.
[2] Christoph Birkl et al., Journal of Power Sources vol. 341, pp. 373-386, 2017.
[3] Matthieu Dubarry et al., J. Electrochem. En. Conv. Stor. vol. 17, pp. 044701, 2020.
[4] Jorn Reniers et al., J. Electrochem. Soc. vol. 166 pp. A3189-A3200, 2019.
[5] Simon O’Kane et al., Phys. Chem.: Chem. Phys., submitted, 2022. https://arxiv.org/abs/2112.02037
(Digital Presentation) Systematic Cycle and Calendar Aging of Commercial 18650 LFP Lithium-Ion Cells
Authors: Wittman Reed M , Fresquez Armando , Chalamala Babu , Preger Yuliya 
Published: July 2022

In recent years lithium-ion (Li-ion) batteries with a lithium iron phosphate (LFP) cathode have become popular for grid storage and electric vehicle applications. To address uncertainty in their performance and lifetime, we initiated a multi-year cycle and calendar aging study of commercial LFP cells under systematically varied conditions. Here, we present an update of cycling data from these cells at their current state where most have reached 80% capacity retention. Cells were cycled at different state of charge (SOC) ranges (0-100%, 20-80%, and 40-60%), temperatures (15, 25, and 35 °C) and discharge rates (0.5C, 1C, 2C, and 3C). Additionally, we present data from a concurrent calendar aging study at different temperatures (15, 25, and 35 °C) and SOCs (25, 50, and 90%).
To date, higher ambient temperatures have most significantly reduced the cycle and calendar life of LFP cells. A higher SOC range or single SOC value during cycle and calendar aging, respectively, also increased the capacity fade rate, but to a lesser extent. The rate of discharge during cycling showed a mixed influence on capacity fade, with the highest and lowest rates producing the most rapid fade. This data provides a foundation to identify the distinct contributions of calendar and cycle aging. We will also discuss changes in other metrics that are of interest to system integrators, such as round-trip efficiency, cell skin temperature during cycling and discharge energy throughput. Finally, we will discuss future work that will center around materials cycling of cells disassembled at 80% capacity and cycling the remaining cells down to an end of life of 40% capacity, at which point materials characterization will be conducted again. This will help determine why capacity fade varies in the cells and what is their useful life under these aging conditions.
This work was funded by the DOE Office of Electricity under the direction of Dr. Imre Gyuk.
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. SAND2021-15833 A