bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental and Computational Study on SEI Composition and Electrochemical Performance of Lithium-Ion Battery with Silicon Oxide-Graphite Composite Electrode
Authors: Nakamoto Mitsunori , Inoue Nobuhiro , Kumita Hideyuki 
Published: September 2023

Demand on batteries with high energy density is surging. Conventionally, carbon materials have been used as an anode active material, but recently silicon materials are likely to be incorporated to form a composite anode in lithium-ion batteries (LIBs) for higher energy density. However, LIBs which include silicon materials in anode tend to show a low cycle performance especially the ratio of silicon materials in the anode increases. Commercial LIBs still have difficulty in incorporating large amount of silicon materials especially under the requirements where multiple aspects like safety, charging rate and energy density should be totally met.
One potential pathway to improve the cycle performance in LIBs with silicon materials is to tune the nature of solid electrolyte interphase (SEI), a thin film which forms at the interface between anode active material and electrolyte. The nature of SEI is particularly important for LIBs with silicon materials because such silicon active materials show large volume changes during battery operation and SEI is dynamically reconstructed. It has been qualitatively reported so far that LiF is an important component for better battery performance. Our work suggests that the ratio of LiF in initially formed SEI is a crucial factor to realize improved cycle performance in such LIBs.
In our work, anode with silicon oxide (SiOx)-graphite composite is considered. We investigated the relationship between electrochemical performance of the cell with such composite electrode and the nature of the film estimated by characterization and molecular simulation. We systematically changed the composition of liquid electrolyte to form various types of SEI on anode surface. For characterization, both fresh and aged cells with different electrolytes were dismantled, and SEI components were extracted by designated solvents, then NMR (nuclear magnetic resonance) was applied to identify the SEI species and quantify the amounts of major SEI components. Comparison between the evolution of SEI amount and an impedance element in electrochemical impedance spectroscopy during aging indicates that degradation of the cells is closely related to the growth of SEI. To further deepen understanding the role of LiF, molecular dynamics simulation was carried out, where the mixture of LiF and typical organic SEI was modelled. Correlation between calculated mechanical property and measured electrochemical performance of the cells were revealed. In our presentation, the requirements that SEI should satisfy will be discussed from the insight of electrochemical measurements, NMR characterization and modeling approaches.
Modeling the Anisotropic Transport Behavior for Axisymmetric 2D Electrode Particles Using a Modified Pseudo-2D Model Framework
Authors: Hoffman Robert M. , Evans Tyler A. P. , Taghikhani Kasra , Berger John R. , Kee Robert J. 
Published: September 2023

This presentation extends widely used pseudo-2D (P2D) Li-ion battery models to include electrode particles that have strong crystal-scale anisotropies and possibly non-spherical shapes. Typical P2D models predict Li transport with representative spherical electrode particles by solving a one-dimensional diffusion equation in spherical coordinates. However, battery electrodes (graphite, NMC, etc.) may have strong crystalline anisotropies, leading to transport and mechanical properties that vary by orders of magnitude depending on crystallographic orientations. The anisotropic transport can cause large concentration gradients, possibly leading to particle fracture associated with concentration-induced stress. The remainder of the P2D model, such as Li-ion transport within the electrolyte solvent, remains essentially unchanged. The charge-transfer boundary conditions at the particle surfaces do need to accommodate the crystallographic anisotropy.
The present model discretizes representative electrode particles in a two-dimensional finite-volume axisymmetric geometry, accounting for the anisotropic behaviors. The computational burden is greater than it is for the one-dimensional spherical solution. However, the P2D model with two-dimensional axisymmetric particle discretization still runs in only a few minutes on a typical personal computer.
The model shows how electrode-particle anisotropy affects the battery performance, such as charge-discharge characteristics and electrochemical impedance spectroscopy. The model also predicts the concentration gradients and correlated stress for various axisymmetric, non-spherical particles.
Low Temperature Research and Improvement on Lithium Ion Batteries
Authors: Fu Yanbao , Collins-Wildman Daniel , Higa Kenneth , Battaglia Vincent 
Published: September 2023

Lithium ion batteries have been the dominant power sources in portable electronics and electric vehicles due to their high energy density, long lifetime and environmental benignity. However, it is a big challenge for lithium ion batteries to be used at low temperature. Compared with the performance at room temperature, lithium ion batteries deliver much less capacity and energy at low temperature. The poor low temperature performance restricts the usage of lithium ion batteries for power electronics and electric vehicles in the winter. The results of previous research, suggest that the poor low temperature performance is attributed to the freezing of the liquid electrolyte which leads to low ionic conductivity and high interfacial resistance, especially on the anode side. Other researchers tried using a solvent with low melting point to partially replace ethylene carbonate or adding some additives to the electrolyte to enhance the ionic conductivity or modify the interface to reduce the resistance and then deliver more capacity and energy.
In this research, we investigated the discharge capacity, energy, pulse power and electrochemical impedance spectroscopy at different depths of discharge of NCM622/Graphite lithium ion batteries at varied temperatures. We found that the discharge energy and pulse power are sensitive to the temperature decreasing. For the NCN622/Graphite cell (2.5 mAh cm-2) with commonly used LiPF6-EC/EMC electrolyte, at -20 oC the cell is able to deliver 65% capacity of that at 30 oC with C/3 discharge current rate, while the delivered energy is only 60%. The 30 seconds pulse power became much worse at -20 oC compared with the power at room temperature. In our research the poor low temperature performance is not from the low ionic conductivity and interfacial resistance. The dominant factor is the charge transfer impedance from the cathode side of the cell.
To improve the low temperature performance, we explored the addition inexpensive nano-particles as the additive into the electrolyte. The cell composed of this electrolyte is able to release more than 70% capacity and energy at -20 oC of that measured at 30 oC. The charge transfer resistance in the fully charge state decreased almost 80% compared to a cell with baseline electrolyte. Meanwhile, the additive has no effect on the long-term cycling (1000 cycles) and stability at high temperature (55 oC)

Fig.1. Normalized capacity and energy. Fig.2. The EIS of the full cell at 30 oC and -20 oC.

Figure 1
Understanding the Energetics of Ion Intercalation in Lithium-Ion Batteries
Authors: Aggarwal Abhishek , Gordiz Kiarash , Zguns Pjots , Vivona Daniele , Baskin Artem , Grossman Jeffrey , Lawson John , Shao-Horn Yang 
Published: September 2023

Researchers around the world are working to increase the energy efficiency and the energy density of lithium-ion batteries. However, the mechanism and the factors influencing the charge transfer (CT) kinetics at the electrode-electrolyte interface remain poorly understood. Recently, Fraggedakis et al. [1] proposed the theory of coupled ion-electron transfer (CIET) to explain the process of charge transfer at the electrode-electrolyte interfaces. In this work, we provide deep atomistic understanding of the interfacial CT mechanism, the underlying microscopic steps, and the factors influencing the CT rates in a Li-ion battery. In addition, we connect our computational results with the experimental measurements and Marcus-like theories of charge transfer (viz. CIET [1]).
Using state-of-the-art computational techniques, such as metadynamics and molecular dynamics simulations, we model the electrode-electrolyte interface and compute the free energy profiles of Li-ion adsorption at the interface, subsequent ion-desolvation, and intercalation into the cathode. Specifically, we study the adsorption of Li+ ion on LixCoO2 surface for different (i) electrolytes, (ii) Li+ concentrations in electrolyte, (iii) salt compositions, and (iv) temperatures to uncover the trends governing charge transfer kinetics. Using the obtained free energy profiles of Li+ desolvation and intercalation at the solid-liquid interface, we provide estimation of the adsorption and desolvation energy at the interface and identify the key energy barrier which acts as the roadblock for ion transfer in Li-ion batteries. Based on this identified key kinetic barrier, we then propose strategies to tune the energy barrier for ion transport. In addition, we identify important thermo-physical observations that can explain the existing experimental trends. For instance, we find that increasing the salt concentration in the electrolyte increases the accessible solvation states to Li+ ion, thereby changing the energy barrier for the Li+ ion to intercalate into the electrode, and thus leading to higher currents. Moreover, we find that changing the salt from LiPF6 to LiClO4 further modifies the energy landscape of Li+ ion, leading to increased measured experimental kinetics as well. This work builds an understanding of the influence of various effects, such as salt concentration and electrolyte composition, on the Li+ transport properties at interfacial regions. Our computational framework can also provide descriptors to enhance the performance and stability of lithium-ion batteries.

References:

Fraggedakis, D., McEldrew, M., Smith, R.B., Krishnan, Y., Zhang, Y., Bai, P., Chueh, W.C., Shao-Horn, Y. and Bazant, M.Z., 2021. Theory of coupled ion-electron transfer kinetics. Electrochimica Acta, 367, p.137432.
Lithium Ion Battery Electrode Calendering Study By Combining X-Ray Computed Tomography and 3D-Resolved Physical Process Models
Authors: Xu Jiahui , Zapata Dominguez Diana , Demortiere Arnaud , Franco Alejandro A. 
Published: September 2023

Significant amount of research has been done recently on how to increase energy densities while maintaining or lowering costs in response to the growing demand for lithium-ion batteries (LIBs). In order to achieve optimization of the manufacturing process of batteries, it is essential to understand the influence of each process stage on the architectures of the electrodes, which affects the energy, power, lifetime and safety of the LIB cells. Our ERC-funded ARTISTIC project1 develops a digital twin that enables predicting the electrode architectures and their electrochemical performances from parameters at each stage of the LIBs manufacturing process.
In this work, we present our most recent research, which studies the manufacturing process of LiNixMnyCo1-x-yO2 (NMC)-based cathodes and especially focuses on the electrode calendering stage2. Our methodology encompasses coarse-grained molecular dynamics and discrete element method to simulate the calendering process of electrodes that are virtually produced after the drying and slurry simulations. In this new work, we account in our model for non-spherical NMC secondary particles with realistic 3D shapes derived by X-ray computed tomography (XCT), together with spherical particles representing the carbon binder domain. An in situ compressing micro-XCT experiment is carried out on the NMC electrode to monitor the change of the electrode morphology upon the calendering process. The findings from the simulation are validated by comparing our predicted electrode architectures with the experimental ones. Our approach captures the alterations in orientation of the secondary particles throughout the calendering processes and the relaxation process, as well as their possible deformation and spring back effect brought on by the pressure. Additionally, we discuss the comparison of variations in porosity, tortuosity factor, conductivity, different phases distribution and pore size distribution during the calendering process.

ERC Artistic : Home Artistic. http://www.erc-artistic.eu/.

Xu, J., Ngandjong, A.C., Liu, C., Zanotto, F.M., Arcelus, O., Demortière, A., and Franco, A.A. (2023). Lithium ion battery electrode manufacturing model accounting for 3D realistic shapes of active material particles. Journal of Power Sources 554, 232294. 10.1016/j.jpowsour.2022.232294.
(Invited) From Material Discovery Towards a Prototype Hydrogen Generator
Authors: Vaes Jan , Vereecken Philippe M. 
Published: September 2023

This contribution illustrates the approach that has been taken to develop a pre-commercial prototype of a water electrolyzer. The aim has been to develop and integrate novel nanostructured materials for both electrodes and membranes, demonstrating their upscaling potential by integrating them together in a water electrolysis cell with an active surface are of 50 cm² in order to proof their potential for further advancing the state of the art of green hydrogen generation.
Based on industrial experience with medium flow hydrogen generators, the boundary conditions for the new electrode and membrane components were set, safeguarding their integration potential in a scalable stack. A nano-porous intrinsically conductive membrane material has been developed, that allows to drastically reduce the thickness of the separator, reducing ohmic losses without compromising gas separation quality during operation at elevated pressures (up to 20 barg). This was combined with nanostructured electrodes of 4-10 μm thickness on both sides of the membrane. Given the vast range of dimensional scales, from 10-8 to 10-1
m, special attention was needed for the interconnections of the materials to establish the required electronic and ionic coupling together with adequate mechanical robustness. Two phase fluid flow modelling was done do have an optimal reactant distribution and gas evacuation from the electrode surfaces. Aspects like contact resistance, elasticity, stiffness, and overall electric field distribution inside the cell were considered. To characterize the cell in operation, a dedicated balance of plant has been built (Fig.1). The installation is automated and takes care of the electrolyte solution conditions and of the process window settings in terms of applied current, electrolyte flow and operational temperature at a pre-set pressure. The resulting cell potential, the gas purity of both oxygen and hydrogen streams and the differential pressure between anolyte and catholyte chambers are continuously monitored. The upscaled cell demonstrates a high hydrogen generation efficiency of 85% (HHV) that outperforms currently installed alkaline systems in terms of productivity and gas purity when operated at an elevated pressure 20 bar. The cell robustness, documented over 800 hours, reveals further areas of improvement for both the internal construction of the stack and the control logic of the balance of plant.

Figure 1
Driving Commercial Advancements in PEM Electrolysis – from Lab to Plant Floor
Authors: Ayers Katherine E. , Capuano Christopher , Carmo Marcelo 
Published: September 2023

Proton exchange membrane (PEM) electrolysis has advanced significantly in the last 10 years, scaling from units in the sub 100 kW range to installed systems at 10 megawatts and greater. This technology, among others, is likely to play a major role in decarbonizing the industry, transportation, and energy sectors, as both the cost of electrolyzer technology and the renewable energy to power it have decreased. Still, the capital cost of electrolysis needs to be further reduced to economically replace hydrogen from steam methane reforming in very large applications, especially as capacity factor goes down to take advantage of the lowest cost electricity. There is also significant potential to decrease cost, as electrolyzer manufacturing is still relatively undeveloped.
PEM electrolysis has been developed for many decades and is proven as a reliable, scalable technology. However, electrodes are overdesigned due to the manual methods used to produce them, as well as the aerospace legacy of these systems. Many advancements such as reductions in catalyst loadings, use of thinner membranes, novel porous transport layers, and alternate cell configurations have been shown to be feasible in the lab, but have been slow to transition to commercial products.
There are many factors in this lag, including the need to often change manufacturing methods when moving from the lab to a product environment. While this effort is sometimes viewed as “just engineering”, there is significant fundamental understanding required to translate a slow, manual process where finished parts can be individually scrutinized, to a fast, automated process that has to include automated inspection as well. For example, a catalyst ink that is hand painted onto a substrate will need different properties and formulation to deposit the catalyst by spray printing, or yet different properties for other methods such as slot die or gravure printing. Determining acceptability of the resulting parts can no longer rely on human judgment but must be well enough understood that the most important properties can be quickly measured and analyzed in real time. In addition, the scale over which high quality needs to be achieved increases by orders of magnitude when moving from lab scale to product scale. This talk will discuss these types of challenges and approaches to solve them.
Boundary-Directed Epitaxy of Block Copolymers Toward Sub-10 nm Fabrication
Authors: Su Katherine Anna , Jacobberger Robert , Stan Liliana , Arnold Michael Scott 
Published: September 2023

The directed self-assembly (DSA) of block copolymers (BCPs) can be used to produce nanometer-scale patterns without the cost and process complexity of state-of-the-art optical nanolithography. Thus, DSA is of potential use in a wide variety of semiconductor technologies, such as finFETs and biosensors. To control the position and orientation of BCP domains and create technologically useful patterns, conventional DSA mechanisms often rely on topographically complex structures or high-resolution chemical patterns that are difficult to fabricate. In comparison, a newly discovered mechanism for the DSA of BCPs – termed “boundary-directed epitaxy” – utilizes the chemical contrast at the boundaries between a substrate and relatively wide chemical stripe.[1] As a result, aligned and high density-multiplied BCP nanopatterns with half-pitch of 6.4 nm have been created using stripes as wide as 100 nm. By obviating the need for high-resolution chemical patterns, boundary-directed epitaxy offers exciting opportunities for the fabrication of sub-10 nm nanostructures.
[1] Boundary-directed epitaxy of block copolymers. R.M. Jacobberger, V. Thapar, G.-P. Wu, T.-H. Chang, V. Saraswat, A.J. Way, K.R. Jinkins, Z. Ma, P.F. Nealey, S.-M. Hur, S. Xiong, M.S. Arnold,
Nature Communications
11, 4151 (2020), 10.1038/s41467-020-17938-3.

Figure 1
A Ferroelectric Property Tailoring Method of Al0.7Sc0.3n Films by Sputter-Deposition Pressure
Authors: Tokita Yukimura , Tsutsui Kazuo , Kakushima Kuniyuki , Wakabayashi Hitoshi , Hoshii Takuya 
Published: September 2023

New ferroelectric materials have been extensively studied for scaled non-volatile memory [1]. Among materials, Al1-x
Sc
x
N (ASN) films are attracting attention owing to their high remnant polarization (Pr
) of over 100 µC/cm2 [2]. Although the material is started to be characterized, a high coercive field (E
c) with a relatively high leakage current has been an issue. As reactive sputtering used to deposit nitrides is known to be influenced by the condition, in this study, we have changed the sputtering pressure for ASN deposition and characterized the ferroelectric properties. The composition of the ASN films is Al0.7Sc0.3N.
Metal-insulator-metal (MIM) capacitors with 50-nm-thick ASN film capacitors with TiN electrodes were fabricated by a reactive sputtering process. We varied the sputtering pressure from 0.76 to 1.1 Pa. Figure 1 shows the leakage current (J-V) of the capacitors. The capacitor with a low-pressure ASN film shows a relatively low leakage current and a breakdown field (E
BD) of 8 MV/cm which is high considering the bandgap of the ASN film to be 3.2 eV. On the other hand, the capacitor with a high-pressure ASN film showed a high leakage current with a reduced E
BD of 5.2 MV/cm. As the leakage current is determined by the interface, stacking the ASN layers may result in reducing the leakage current while maintaining a high E
BD. The leakage current of a capacitor with a 5-nm-thick low-pressure ASN at each interface and a 40-nm-thick high-pressure ASN film is also shown in fig. 1. We see a slight suppression in the leakage current and improvement in the E
BD to be 6.2 MV/cm.

P
r of the capacitors were obtained by positive-up-negative-down (PUND) measurements. The pulse-height dependent P
r is shown in fig. 2. The capacitor with a low-pressure ASN film revealed a high E
c of 3.8 MV/cm, while the one with a high-pressure ASN film was 3.4 MV/cm. The capacitor with stacked ASN films showed the same E
c of 3.4 MV/cm. The capacitors with single film showed a gradual change in the P
r on the electric field. In the stacked one, in contrast, a sharp change in the electric field with a constant P
r of 100 μC/cm2 was obtained.
In conclusion, stacked ASN films deposited by different sputter pressures show reduced leakage current with a high breakdown field. Although the physical change by the pressure is still unknown, tailoring the interface and bulk regions has a possibility to further improve the ferroelectric properties.

References

[1] H. A. Hsain, et al., J. Vac. Sci. Technol., A 40, 010803 (2022). [2] S. Fichtner, et al., J. Appl. Phys.,
125, 114103 (2019).

Figure 1