bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ultrasound Spectroscopy of Lithium-Ion Batteries: Insights into Layering Distances
Authors: Feiler Simon , Daubinger Philip , Gold Lukas , Hartmann Sarah , Giffin Guinevere A. 
Published: February 2024

Improving diagnostics of lithium-ion batteries (LIBs), and in particular the measurement and prediction of the remaining capacity, can lead to a longer lifetime and safer use. One promising approach to LIB diagnostics is the use of ultrasound. Ultrasound signals can measure stiffness changes of the active materials occurring during cycling and aging and can be used to predict state-of-charge (SoC) and state-of-health (SoH) of the cells [1,2]. Traditionally, ultrasound signals have been analyzed in the time domain by studying the time of flight. However, a novel approach is to study the signals in the frequency domain.
The aim of this study was to investigate the potential of ultrasound spectroscopy to provide insights into the layering distances, sound velocity of the layer constituents, and homogeneity of layer thickness of LIBs. A key consideration in analyzing ultrasound signals is the interference effect resulting from reflections at different layer interfaces in the battery. The most relevant reflections occur at the copper and aluminum current collectors, so one unit of (Copper-Anode-Separator-Cathode-Aluminum) can be considered as the basic resonator. In transmission, the first destructive interference (Antiresonance) occurs when the width of the resonator is a quarter of the wavelength, which results in a dip in the frequency response. The frequency of the dip can be found by sweeping the measurement frequency (i.e., ultrasound spectroscopy) and can providing insights into the resonator width and therefore layering distances.
This work presents a study of a commercial LIB (nickel-rich NCM/Graphite) with a nominal capacity of 12 Ah from Kokam (SLPB065070180, Kokam Co., Ltd.) using ultrasound spectroscopy. The results exhibited an antiresonance at 2.26 MHz in the commercial LIB (Figure 1). This frequency and sound velocity (measured to be 1640m/s) were then used to calculate the wavelength at 726 µm, and the resonator width was calculated to be 726 µm/4 = 181 µm. This result is in good agreement with the measured width of one unit from post mortem analysis at ~187 µm. The changes in the antiresonance were then studied over the course of 1000 cycles.
References
[1] A.G. Hsieh, S. Bhadra, B.J. Hertzberg, P.J. Gjeltema, A. Goy, J.W. Fleischer, D.A. Steingart, Electrochemical-acoustic time of flight: in operando correlation of physical dynamics with battery charge and health, Energy Environ. Sci. 8 (2015) 1569–1577. https://doi.org/10.1039/C5EE00111K.
[2] Feiler, S., Daubinger, P., Gold, L., Hartmann, S., Giffin, G. A., Interplay between Elastic and Electrochemical Properties during Active Material Transitions and Aging of a Lithium-Ion Battery, Batteries & Supercaps 2023, 6, e202200518., https://doi.org/10.1002/batt.202200518

Figure 1
(Invited) High-Nickel Layered Oxide Cathodes: Crack Vs. Surface Reactivity
Authors: Manthiram Arumugam 
Published: February 2024

The appetite for long driving range and high energy density is pushing the nickel content in layered oxide cathodes for lithium-ion batteries. The lying of Ni3+/4+:3d band slightly above the Co3+/4+:3d band enables to extract more lithium during charge without encountering oxygen release from the lattice in high-nickel cathodes compared to that in LiCoO2. However, as the nickel content increases in the lattice, the cells suffer from cycle and thermal instability. The cycle instability has largely been attributed in the literature to the formation of cracks caused by the occurrence of H2-H3 phase transition with large lattice parameter changes during high degree of charge. Several approaches, such as doping with other cations and microstructural control of the primary and secondary particles, have been extensively pursued to overcome the challenges and improve the cycle life.
With a systematic investigation of a number of cathode compositions and their characterization after extensive cycling, this presentation will illustrate that surface reactivity of high-nickel cathodes with electrolyte plays a dominant and decisive role on cycle life. Even cathodes like LiNiO2 with 100% Ni without any cation doping or surface coating could be cycled with high capacities over a large number of cycles with an appropriate choice of electrolyte that suppresses surface reactivity. Electrolytes that are stable to slightly higher voltages, even by as low as 100 mV, compared to the conventional electrolytes alter the surface reconstruction pathway on cathode surface in contact with electrolyte. Electrolytes with better high-voltage stability favor the formation of mildly reduced LiNi2O4 spinel on the surface without much oxygen release from the surface. In contrast, electrolytes that have inferior stability to higher voltages lead to a drastic reduction of the cathode surface to highly reduced Ni3O4 spinel and NiO rock salt phases with significant oxygen loss from and volume change on the surface, which could cause crack initiation on the surface, followed by their propagation into the bulk. Interestingly, the fast 3-dimensional lithium-ion and electron transport in spinel LiNi2O4 supports a facile charge transfer through the cathode-electrolyte interphase (CEI), resulting in better cycle life, in contrast to the poor lithium-ion transport in both spinel Ni3O4 and rock salt NiO phases, resulting in poor charge-transfer through the CEI and inferior cycle life. With robust electrolyte formulations with better high-voltage stability, long cycle life could be achieved even with the repeated occurrence of the H2-H3 phase transitions over a large number of cycles.
(Invited) Effects of LiPF6 Salt Concentration on the Cycling Performance of NMC532 Cell Containing Organic Carbonate Solvents
Authors: Wu She-huang , Lee Po-Han 
Published: February 2024

Pouch-type cells with NMC532 cathode, MCMB anode (A/C loading ratio of 1.1) and electrolytes containing various LiPF6 concentrations in EC/EMC (3:7 by volume) + 2wt% VC were prepared for investigating the effects of lithium salt concentration on the cycling performance of NMC532 cells. These cells were cycled at 0.5 C rate within 3.0 and 4.2 V until their residual capacity become lower than 70% of their initial capacities, respectively, as shown in Figure 1. After end of life, these cells were disassembled for post-mortem study. The cycled electrodes were used to assemble into coin-type cells with lithium metal for estimating their losses of lithium inventory (LLI), losses of cathode material (LAMC) and losses of anode material (LAMA) by comparing their specific capacities of first and second cycles of the coin-cells with those of the coin-cells prepared with fresh electrodes, respectively. XRD, SEM, HRTEM and XPS were also used to reveal the phase evolution, structure and morphology changes of the electrode materials after cycling. Results suggest that the fast capacity fade of the cell prepared with the electrolyte containing 1 M LiPF6 salt concentration can be attributed to the carbonate solvent oxidation via dehydrogenation on the cathode surface at voltages higher than 3.8 V as reported by Zhang et al.(1) The oxidation can not only accelerate the increase of impedances at anode side, the losses of lithium inventory and anode material by the SEI formation from the reactions between the oxidation products and lithium ions, but also cause the loss of cathode active material and resistance growth at the cathode side, though they are less significant. They can be caused by the phase evolution of spinel and rock-salt phases on the surface of cathode particles, which had been observed from the HRTEM and SAD studies of the cathode particle collected from the cycled cell prepared with 1 M LiPF6 in EC/EMC electrolyte after 600 cycles. It was also found that the amounts of spinel and rock-salt phases formed on the NMC particle surface, rates of capacity fading and resistance growth of the aged cells decreased with the increased LiPF6 salt concentration contained in the electrolytes of the cells. It can be due to the higher salt concentration can induce the less free solvent for being oxidized on the cathode particle surface at voltages higher than 3.8 V. Whereas the layered NMC phase only can be found on the surface of NMC particle collected from the cathode of the cycled cell prepared with 3 M LiPF6 electrolyte after 1100 cycles. This cell shows lower LLI, LAMC, LAMA and impedances growth after 1100 cycles than those of the cell with electrolyte of 1 M concentration after 600 cycles.
Reference:

Zhang, Y. Katayama, R. Tatara, L. Giordano, Y. Yu, D. Fraggedakis, J. G. Sun, F. Maglia, R. Jung, M. Z. Bazant and Yang Shao-Horn, Energy Environ. Sci., 2020, 13, 183-199.
Optimizing the Potential Diagram for a Highly Sustainable and High-Energy-Density SiOx/LiNi0.5Mn1.5O4 Battery
Authors: Ko Seongjae , Han Xiao , Shimada Tatau , Takenaka Norio , Yamada Yuki , Yamada Atsuo 
Published: February 2024

In the transition towards a sustainable society, developoing a battery system that meets various social requirements, such as high energy density, cost-effectiveness, environmental sustainability, and elemental abundance, is urgent. Elminating cobalt (Co) from cathodes due to its economically/geopolitically constrained supply chain and child labor issues is particularly important.1 In this regard, considerable efforts have been conducted in the past decade to realize an ideal full cell combined with a high-capacity and earth-abundant SiOx anode (theoretically 1965~4200 mAh g-1 with 2≥x≥0 at ≤0.4 V vs. Li/Li+) and a high-potential Co-free spinel LiNi0.5Mn1.5O4 cathode (theoretically 147 mAh g-1 with an average operating potential of 4.7 vs. Li/Li+).2 However, its stable cycling has rarely been achieved because the reaction potentials of SiOx and LiNi0.5Mn1.5O4 are located outside the operating potential windows of traditional electrolytes, thus giving rise to severe electrolyte decomposition at both anodes and cathodes.
Herein, we report a long-awaited extremely stable SiOx/LiNi0.5Mn1.5O4 battery over 1000 cycles with an upper cut-off voltage of 4.9 V by carefully optimizing its overall potential diagram with a specifically designed electrolyte, 3.4 mol L-1 (M) LiN(SO2F)2/methyl (2,2,2-trifluoroethyl) carbonate (LiFSI/FEMC).3 The developed electrolyte provides remarkably high redox stabilities by: 1) destabilizing Li+ in the electrolyte4, which is a key to reducing the thermodynamic driving force of electrolyte reduction with an upshift of the reaction potential of the SiOx; 2) offering a large amount of anions with modified electronic states5, which enables the formation of a highly Li+-conductive and chemically/electrochemically stable anion-derived SEI at the negatively charged SiOx surface; and 3) increasing the oxidation potential of the electrolyte while retarding Al and trasition metal dissolution, thus guranteeing the high reversibility of the LiNi0.5Mn1.5O4. We belived that the electrolyte-design rationale highlighted in this work will provide a new chance to develop and design highly sustainable high-energy-density Li-ion batteries.
Reference

Olivetti, E. A., Ceder, G., Gaustad, G. G. & Fu, X. Joule 1, 229–243 (2017), Banza Lubaba Nkulu, C. et al. Nat. Sustain. 1, 495–504 (2018), Lee, S. & Manthiram, A. ACS Energy Lett. 7, 3058–3063 (2022).

Liu, Z. et al. Chem. Soc. Rev. 48, 285–309 (2019), Fan, X. & Wang, C. Chem. Soc. Rev. 50, 10486–10566 (2021).

Ko, S., Han, X., Shimada, T., Takenaka, N., Yamada, Y. & Yamada, A. doi:10.21203/rs.3.rs-2536539/v1 (2023).

Takenaka, N., Ko, S., Kitada, A. & Yamada, A. doi:10.21203/rs.3.rs-1830373/v1 (2022).

Sodeyama, K., Yamada, Y., Aikawa, K., Yamada, A. & Tateyama, Y. J. Phys. Chem. C 118, 14091–14097 (2014).
Improving Extreme Temperature and Charge Rate Performance in Li-Ion Batteries through Addition of Fluorinated Electrolyte Additives
Authors: Kerber Brian M , Guillot Sarah Lucienne , Du Peng , Zhou Liu (Amy) , Garg Shipra , Usrey Monica Lee 
Published: February 2024

Despite advances in Li-ion battery electrolytes, commercial electrolytes continue to include organic solvents that are unable to withstand many of the arduous conditions demanded by the industry today, such as extreme temperatures and charge rates. The stability limits of these solvents damper the advancement of Li-ion batteries needed to sustain automotive electrification and other industrial applications. Further efforts are needed to enable electrolyte formulations to withstand the operational demands of Li-ion batteries in the market today.
Koura has developed a series of fluorinated materials for use in lithium-ion electrolytes that demonstrate improved stability and safety over conventional commercial electrolytes. In a recently completed study, the impact of Koura’s fluorinated solvents on performance in 4.3V Gr/NMC811 was examined, with a particular focus on benefits seen on extreme temperature and rate performance. Testing included cycling and rate performance across a range of temperatures from -20 °C to 45 °C and cycling conditions from C/2 to 4C. It has been found that these materials exhibit improved performance in low temperature testing, as well as reduced gassing and increased performance in high-temperature and fast charge cycling. To investigate the mechanisms responsible for the observed improvements, comprehensive post-test analysis has been conducted, including gas identification and quantification via gas chromatography, bulk electrolyte composition analysis via NMR spectroscopy, and surface layer characterization via XPS and SEM. Bulk properties of the materials and electrolytes are correlated to performance benefits where appropriate.
This presentation will summarize Koura’s efforts to fill a major gap in the demands of the battery industry today through the development of fluorinated electrolyte materials. Specifically, we will present data highlighting the performance of fluorinated compounds on improving battery performance under strenuous conditions with respect to both temperature and cycling rate. Results from post-test analyses will be discussed highlighting the mechanisms underlying the observed performance improvements.
Nonflammable Fluorinated Ester-Based Electrolytes for High Voltage Li Batteries with LiCoO2 Positive Electrode
Authors: Ugata Yosuke , Yukishita Kazuki , Yabuuchi Naoaki 
Published: February 2024

LiCoO2 is widely used as a positive electrode material for LIBs. The theoretical capacity of LiCoO2 is calculated to be 274 mA h g–1 upon full delithiation, but the practical reversible capacity is generally restricted to approximately 140 mA h g–1 to avoid capacity deterioration when cycled at higher voltages (>4.2 V vs Li/Li+). To solve this limitation, functional electrolytes that possess a high oxidative stability and form a stable and effective passivation layer on the LiCoO2, are desired.
In this study, we report that the cyclability of LiCoO2 under high-voltage operation is drastically improved by using a fluorinated ester, methyl 3,3,3-trifluoropropionate (MTFP), as an electrolyte solvent.1 Notably, the combined use of MTFP-based electrolyte and mixed sodium carboxymethyl cellulose/styrene-butadiene rubber binder synergistically stabilize the LiCoO2 electrode surface, resulting in the almost no capacity fading for 50 cycles even with the upper cutoff voltage of 4.5 V. Note that, in general, LiCoO2 shows significant capacity deterioration when cycled at higher voltages over 4.2 V vs Li/Li+. Moreover, our study reveals that superior low-temperature performance and higher thermal stability is evidenced for the LiCoO2 with MTFP-based electrolyte when compared with that with conventional electrolyte. XPS analysis reveals that thinner and uniform passivation layer derived from PF6
– anion and MTFP is formed on the LiCoO2 electrode surface, which is the origin for improved cyclability and thermal stability of high-voltage LiCoO2 with MTFP-based electrolyte.
Reference
[1] Y. Ugata et al., and N. Yabuuchi, Chemistry of Materials, in press.
Quantifying the Inactivation of Battery Electrode Material Particles
Authors: Wiemers-Meyer Simon , Vahnstiege Marc , Kroeger Till-Niklas , Harte Patrick , Beuse Thomas , Wölke Mathis Jan , Klein Sven , Börner Markus , Winter Martin , Nowak Sascha 
Published: February 2024

Lithium ion batteries, like any other battery technology, tend to lose capacity with continued charging and discharging. One of the effects contributing to the decline in capacity is the inactivation of positive electrode material particles. The electrodes typically consist of polydisperse active material particles, a conductive agent and a binder. By charging and discharging of the battery the active material particles are lithiated and delithiated. If a particle becomes inactive, e.g. by losing the electronical contact or by the formation of ion blocking surface films, it stops following the lithiation and delithiation of the rest of the electrode. Analyses of the degree of lithiation (DOL) of single particles therefore provide valuable information on the capacity loss attributed to inactive particles.[1-3]
Since TOF-SIMS and synchrotron-based techniques which are usually used to determine the lithium content of single electrode particles only analyze small areas of the electrodes and are not well suited for measuring large numbers of samples, a method has been developed applying common ICP-OES instrumentation. For the determination of the DOL of single particles, the most important advantage of many ICP-OES instruments is the simultaneous detection of several elements. In case of common positive electrode materials such as Li(NixMnyCoz)O2 (x+y+z=1) (NMC) the ratio of e.g. Li to Mn signal intensities can be used to determine the DOL. As an aqueous sample introduction cannot be used because these materials would undergo Li+/H+ exchange reactions, a sample introduction using argon gas that furthermore enables a classification of particle sizes was developed.
This presentation will focus on the method development and application of single particle ICP-OES for battery materials. It will be shown how this method helps to elucidate the mechanisms of capacity fading, and the advantages and disadvantages of ICP-OES will be compared with those of alternative methods for this application. Different parameters affecting the inactivation of poly- and single-crystallin NMC particles will be discussed.
[1] T. N. Kroger, S. Wiemers-Meyer, P. Harte, M. Winter, S. Nowak, Analytical Chemistry
2021, 93, 7532-7539.
[2] T.-N. Kröger, P. Harte, S. Klein, T. Beuse, M. Börner, M. Winter, S. Nowak, S. Wiemers-Meyer, J. Power

Sources
2022, 527, 231204.
[3] Kröger, T.-N.; Wölke, M. J.; Harte, P.; Beuse, T.; Winter, M.; Nowak, S.; Wiemers-Meyer, S. Chemsuschem
2022, 15, e202201169.

Figure 1
(Invited) A Novel Dems Approach for Studying Gas Evolution in Pouch Cells
Authors: He Meinan , Cai Mei 
Published: February 2024

In this study, we designed a novel differential electrochemical mass spectrometry (DEMS) system to in-situ quantify the gas generation in batteries. While a lot of battery gas analyses were carried out by DEMS previously, most of those studies were based on small coin cells or EL cells. The fluid electrolyte and limited amount of active material may make it challenging to quantify the gas generation. The DEMS we designed here can continually sample gas from a small 2.5Ah pouch cell, and it has a similar electrolyte to capacity ratio, 1.8g/Ah, with our production cell. To the best of our knowledge, this is the first DEMS design based on a pouch cell.
Moreover, by using flowrate-controlled Ar carrier gas and a reasonable residence time setup, our DEMS design not only can identify volatile electrolyte degradation products throughout battery cycling but also quantify the gaseous species production rates as a function of the state of charge. We found that cell chemistry and operation protocol greatly impact gas product species, the production profile of different gases during cycling, and the total gas quantity. For example, the gas evolution of oxidation products, such as CO2 and CO, is exacerbated by the elevated upper cutoff voltage, while reduction products are only minimally affected. Furthermore, changing the electrolyte SEI former, from EC to FEC, or adding different electrolyte additives can affect the gas product species generation dramatically as well.
Therefore, we successfully demonstrated DEMS as a powerful tool to probe the gas evolution behavior in different applications-based batteries, provided valuable data for battery reactivity simulation, and most importantly, provided guidance for electrolyte optimization.
Single-Crystal Li1+x[Ni0.6Mn0.4]1-xO2 Made By All-Dry Synthesis
Authors: Garayt Matthew D. L. , Zhang Ning , Yu Svena , James Abraham Jeffin , Murphy Aidan , Omessi Roee , Ye Ziwei , Azam Saad , Johnson Michel B. , Yang Chongyin , Dahn Jeff R. 
Published: February 2024

Single-crystal LiMO2 (M = 3d transition metal such as Ni, Mn, Al, and Co) has received much attention as a positive electrode material over the last few years due to its superior cycling stability over conventional polycrystalline materials1. Moreover, Co has fallen out-of-favour as a transition metal of choice due to its relatively high cost2 and the human rights abuses associated with its mining3. As well, the synthesis of conventional LiMO2 materials requires complex co-precipitation equipment that not only increases the cost of manufacture, but also produces waste such as Na2SO4. Furthermore, coating W on the particles’ surface in a separate step after co-precipitation improves the electrochemical performance of these materials4. Therefore, Co-free, W coated, single-crystal LiMO2 materials, made in a simple synthesis process like LiNi0.6Mn0.4O2 (NM64) are of most interest.
In this presentation, a simple, solvent- and waste-free synthesis method is shown to create NM64 materials with and without a W coating. This all-dry synthesis uses a mixture of metallic Ni, MnO2, LiOH·H2O, and an optional W precursor, along with two to three heating steps, and an agglomeration separation step to produce single-crystal NM64. The resulting material is R-3m phase pure with ≤4% Ni in the Li layer and contains only trace residual lithium. Additionally, the NM64’s grain size is between 2 to 5 µm, as shown in Fig. 1a), which can be tuned by the addition of W during the initial synthesis rather than with a separate coating step. While W inhibits grain growth during synthesis4, the Ni, Mn, and Li interdiffusion is largely unaffected according to the unit cell parameters and the Ni in the Li layer obtained from Rietveld refinement of their XRD patterns. Fig. 1b) illustrates that while NM64 materials without W retain 91% of their original capacity after 100 cycles at C/5, matching the vendor material, when W is added they outperform it with 93% retained capacity. It is believed that this incredibly simple process could be adopted relatively easily into current commercial positive electrode manufacturing facilities to reduce the complexity, cost, and time of manufacture.

Figure 1. (a) shows SEM micrographs of the all-dry synthesized NM64 material without and with W. (b) shows half coin cell cycling of NM64 materials with and without W as compared to a vendor material.

References

J. Li et al., J Electrochem Soc, 164, A1534–A1544 (2017).

Mining.com https://www.mining.com/markets/.

J. P. Otamonga and J. W. Poté, J Geochem Explor, 208, 106394 (2020).

D. Rathore et al., ACS Energy Lett, 7, 2189–2195 (2022).

Figure 1