bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrode Drying Metrology Via Light Microscopy with Supporting Techniques
Authors: Morrison Andrew R T , Dawson Will , Kendrick Emma , Shearing Paul R , Brett Dan 
Published: July 2022

An important way to improve the performance of mass-produced lithium-ion batteries is to develop a better understanding of the manufacturing process’s effects on the electrode structure, and thereby its performance. Drying of the electrode slurry is a key step in that process. The parameters that affect drying electrodes have been mainly studied through ex-situ methods. There are far fewer examples of in-line metrologies of drying electrode properties, with notable exceptions including stress measurement by bending beam and dynamic mechanical analyzer, and ultrasonic measurements revealing the evolution of acoustic reflecting surfaces in the electrode (1). With so few in-line metrologies having been investigated, the possibilities are quite wide. However, it is striking that perhaps the most obvious of in-line metrologies has not been systematically investigated in the literature – that of simple visual observation of the drying surface (specifically with a microscope).
Light microscopy can reveal a surprising amount of detail about the drying electrode. In Figure 1 micrographs of a drying electrode under two different lighting conditions – with ring lighting and with coaxial lighting – are shown. In the coaxial lighting condition, the surface of the drying solvent can be seen. In freshly coated electrode slurry, the surface of the drying solvent is uniform and unremarkable, then holes appear as the solvent evaporates eventually leading to a honeycomb-like structure. In the ring lit images, the active material particles themselves are visible directly, and their movement while drying can be tracked. Here, we will examine how microscopy supported by other techniques which yield averaged properties to complement microscopy’s local measurements, such as film stress, can elucidate the drying electrode more fully.
1. Y. S. Zhang, N. E. Courtier, Z. Zhang, K. Liu, J. J. Bailey, A. M. Boyce, G. Richardson, P. R. Shearing, E. Kendrick and D. J. L. Brett, Advanced Energy Materials, 2102233 (2021).

Figure 1
Improving Fundamental Understanding of Si-Based Anodes Using Carboxymethyl Cellulose (CMC) and Styrene-Butadiene Rubber (SBR) Binder for High Energy Lithium Ion Battery Applications
Authors: Kumar Kuldeep , Matts Ian L , Klementov Andrei , Sisco Scott , Simpson Dennis A. , Millero Edward R. , Kaleem Kareem , Terrago Gina M. , Lee Se Ryeon 
Published: July 2022

With increasing demand of high energy density lithium ion batteries, silicon (Si) based anodes are an obvious substitute of graphite based systems due to their high capacity. However, large volume changes of Si during lithiation and delithiation processes causes pulverization of silicon particles. The resulting reduction in electrical continuity and solid electrolyte interphase (SEI) growth within the anode leads to a fast depletion of lithium reservoirs and an accelerates battery failure. High energy lithium ion battery applications such as electrical vehicles and electronic devices require high capacity retention over extended cycling, so improving performance of Si-based anodes is a critical need for many applications.
Commonly, a combination of sodium carboxymethyl cellulose (CMC) and styrene-butadiene rubber (SBR) is used as a binder for waterborne Si anode slurries. In these systems, carboxyl (-COOH) groups on CMC form chemical bonding with hydroxyl (-OH) groups on Si active material surface and SBR addition provides enhanced flexibility in the anode layer. Several reports on electrode integrity improvement through adhesion promoters, increased crosslinking, different binding groups, etc. are available in the literature. Delving deeper into the weak mechanical integrity of Si based anodes, and understanding the parameters influencing the fabrication process and subsequent properties, is important. This presentation will focus on several variations in Si based anode slurries and electrodes using CMC-SBR binders. Physical, mechanical, and electrochemical properties are extensively studied as a function of these parameters and will be discussed.
3D Printing of Silicon-Based Anodes for Lithium-Ion Batteries
Authors: Rist Ulrich , Sterzl Yannic , Pfleging Wilhelm 
Published: July 2022

In order to meet the target for the next generation lithium-ion batteries, electrochemical performance such as energy and power density must be increased significantly at the same time. Optimized electrode architectures including 3D battery concepts and advanced materials are in development to achieve this goal. The use of silicon-graphite composite electrodes instead of graphite anodes is currently investigated. This is due to the fact that silicon can provide almost one order of magnitude higher specific energy density (3579 mAh/g) in comparison to natural graphite (330 - 372 mAh/g). However, during lithiation, i.e., lithium silicide formation, a volume expansion of about 300 % can take place, while during lithium intercalation in graphite about 10 % volume expansion can be observed. A huge volume expansion leads to a tremendous mechanical degradation of the anode resulting in a drop in capacity, and a limited battery lifetime.
In the presented study, laser induced forward transfer (LIFT) is applied as printing technology to develop sophisticated graphite and graphite-silicon electrode architectures with advanced electrochemical performances. LIFT was performed using a pulsed nanosecond UV laser with a repetition rate of up to 30 kHz and a maximal power of 10 W. To enable an accurate printing process during LIFT, the properties and compositions of the active material inks as well as the laser and process parameters have to be optimized. The printing process in combination with laser structuring provides a high flexibility regarding the final electrode design. In the presented study, the formation of multi-layer electrodes with spatial variation in electrode composition is achieved. As active materials silicon nanoparticles (SNPs) and various types of graphite, i.e., natural graphite, mesocarbon microbeads (MCMB), and artificial flake-like graphite with an average particle diameter of 1 µm up to 15 µm are utilized. The geometry and thickness of each printed layer is adapted with regard to an optimized electrochemical performance and cell lifetime. A single layer thickness of 5 µm up to 20 µm was achieved, while areal capacities of multi-layer anodes reaches values of 2 to 4 mAh/cm². In addition to the applied active materials and architecture concepts, different solvent and binder systems are investigated with regard to process scalability and an improved environmental compatibility. The printed electrodes are electrochemically characterized by rate capability measurements at C-rates of up to 5C. A correlation between capacity retention and electrode architecture is achieved. The results are discussed in terms of upscaling and impact on the next generation anode material.
Optimal Charging Protocols to Restrict Lithium-Ion Battery Degradation
Authors: Uppaluri Maitri , Kolluri Suryanarayana , Subramanian Venkat R. 
Published: July 2022

Lithium-ion batteries degrade due to several mechanisms that occur during cell operation. These mechanisms can be parasitic reactions that lead to loss of lithium inventory or loss of active material. Some examples of these side reactions include the growth of the solid-electrolyte interphase (SEI) layer, transition metal dissolution and deposition, lithium plating, solvent oxidation, etc. Thermal effects and mechanical fatigue on the electrodes also lead to cell aging and capacity fade.
For widespread implementation of lithium-ion batteries for electric vehicles, batteries should last approximately 10 years.1 Fast charging has also been heavily researched for accelerating this prevalent circumstance. However, charging at high currents can severely degrade the cell, affecting the cell’s lifetime. Algorithms that optimize charging can be effective to reduce cell aging. Physics-based battery models can be used to design these algorithms by restricting phenomena that occur in the cell that causes cell aging. For example, lithium plating can be prevented by restricting the overpotential of the reaction.
In our previous work, we have shown optimal charging profiles where the intercalation induced stresses, lithium plating and the SEI layer growth was restricted using reformulated physics-based models using model-based control 2
-
3 In this talk, we show different optimal charging protocols for restricting different mechanisms, and analyze the interplay between them to predict optimal charging profiles.

References

M. T. Lawder, P. W. C. Northrop, and V. R. Subramanian, J. Electrochem. Soc., 161, A2099–A2108 (2014).

B. Suthar, P. W. C. Northrop, R. D. Braatz, and V. R. Subramaniand, J. Electrochem. Soc., 161, F3144–F3155 (2014).

M. Pathak, D. Sonawane, S. Santhanagopalan, R. D. Braatz, and V. R. Subramanian, ECS Trans., 75, 51–75 (2017).
(Digital Presentation) Parameterization of a Commercial 18650 High-Power Lithium-Ion Cell for a Physico-Chemical Model
Authors: Ahamad Salahuddin , Sundaramaan K. V. , Singh Parmender 
Published: July 2022

Li-ion battery is an integral part for the electric or hybrid electric vehicles, as they provide high energy density and power density with extended cycle-life compared to their closest rivals, Ni-MH batteries [1]. Electric vehicles (EVs) require an advanced real-time based battery management system (BMS) that ensure a safe and efficient energy utilization, estimate state-of-charge (SOC) and state-of-health (SOH), and cell balancing [1]. A high performing BMS needs an accurate cell model that can precisely capture the cell dynamics in EVs. Due to the inherent complexity of the physics-based model, BMS are often based on equivalent circuit models [2-4] that are relatively easy to implement but lack the important underlying physico-chemical processes. In order to predicts an accurate cell response, a physico-chemical model based on fundamental governing equations of migration and diffusion processes as well as the kinetics of intercalation require precisely evaluated model parameters for the material under consideration [5].
In this work, a commercial 18650 cell is analyzed in order to parameterize a physico-chemical model. The parameters are estimated by the results of experiments performed on the cell material under investigation. For this, the fully discharged cell was opened in a glove box under inert environment with both moisture and oxygen level below 0.5 ppm. The material samples were collected in an air tight desiccator and analyzed using different methodology.
The results obtained based on the proposed methodology are presented as: electrodes, electrolyte, and separator composition; kinetic, transport, and thermodynamics parameters; electrodes and separator physical properties, e.g., porosity, microstructure, particle size distribution etc.; cell internal configuration, e.g., jelly roll dimension, electrode tab location and their dimension etc.; and full-cell electrode balancing determination. A range of electrochemical techniques were used to determine the kinetic and thermodynamic properties of the electrode materials, e.g., galvanostatic intermittent titration technique (GITT) was used to estimate the diffusion coefficient of Li-ion in anode and cathode at different state of charge (SOC) also, to ascertain the open circuit voltage (OCV) of the respective electrodes. In order to estimate the exchange current density, electrochemical impedance spectroscopy (EIS) was employed. The SEM images to illustrate the microstructures of cathode, anode and separator and the particle size distribution of cathode and anode are shown in Figure.

References:

D. Rahn, and C. Y. Wang, Battery Systems Engineering, Wiley, State College, PA (2013).

L. Plett, J. Power Sources, 134, 252 (2004).

W. Verbrugge, and R. S. Conell, J. Electrochem. Soc., 149, A45 (2002).

L. Moss, G. Au, E. J. Plichta, and J. P. Zheng, J. Electrochem. Soc., 155, A986 (2008).

S. Ahamad, and A. Gupta, Electrochim. Acta, 297, 916 (2019).

Figure 1
Automated Data Gathering, Classification, Standardization and Evaluation Connected with AI in Smart Li-ion Battery Cell Production
Authors: Hagen Markus , Ngyuen Josef Quan , Lau David Hui Shyan , Nave Eran , Tübke Jens 
Published: July 2022

The production of lithium-ion batteries is characterized by high scrap rates. With material costs of 70-80% of the cell price, these are a significant cost factor. By using AI, correlations of process data and cell properties can be determined and particularly quality-relevant process steps can be identified.
However, the prerequisite for the use of AI is a clean collection, description and allocation of data which is very time-consuming.
In the BMBF-funded projects “KontElPro”, for solvent-free electrode production and “AgiloBat2”, for the agile production of format-flexible cells, software is being developed to solve this problem.
The corresponding software system "Batalyse" is capable of automatically collecting, categorizing, linking and evaluating test, analysis and production data. Quality-relevant parameters of the produced (lab) cells such as capacity, resistance and power can thus be directly correlated with process parameters and data. The complete process chain of input materials, (intermediate) products, sensors, equipment, process parameters and all evaluated result data of the produced cells is stored in the database. All data, correlations and logic is provided by this database via an interface for AI applications.
The aim is to use this data to generate digital twins of each individual process step and to optimize them step by step. Later, the processes are to be controlled autonomously by AI applying optimized process parameters to avoid or at least to reduce scrap.
In the talk we present the structure, status and use of the software for research data management and in the use of in the research production of Li-ion cells.
(Invited) Nanoscale Wetting and Its Connection with Macroscopic Young's Equation
Authors: Yamaguchi Yasutaka , Kusudo Hiroki , Bistafa Carlos , Surblys Donatas , Omori Takeshi , Kikugawa Gota 
Published: July 2022

Wetting plays a key role in the cleaning process to remove impurities as one of the essential processes for the fabrication of semiconductor device, where cleaning of trenches with water, replacement with IPA (isopropyl-alcohol) and its removal are iteratively carried out. This process is still required upon recent reduction of the line width under 10 nm; however, this size is already at the border of the continuum limit where the theories of fluid mechanics can be applied. The authors adopted molecular dynamics (MD) simulations to examine the liquid behavior, especially regarding wetting at the nanoscale with respect to simple Lennard-Jones fluid [1-3], water [4,5], methanol as well as IPA as the liquids [6,7], while simple non-polar crystal [1-3,6], silica partially terminated with OH as the solids [4,5,7]. In these series of studies, we have shown how the solid-liquid, solid-vapor and liquid-vapor interfacial tensions can be defined in nanoscale to be consistent with Young’s equation as the macroscopic description about wetting.
In the presentation, we will discuss how the interfacial tensions as the free energy can be properly calculated by MD simulations from mechanical and thermodynamic viewpoints.
[1] Y. Yamaguchi, H. Kusudo, D. Surblys, T. Omori and G. Kikugawa, J. Chem. Phys. 150 (2019), 044701.
[2] H. Kusudo, T. Omori, Y. Yamaguchi, J. Chem. Phys. 151 (2019), 154501.
[3] Y. Imaizumi, T. Omori, H. Kusudo, C. Bistafa, Y. Yamaguchi, J. Chem. Phys., 153 (2020), 034701.
[4] D. Surblys, F. Leroy, Y. Yamaguchi, F. Mueller-Plathe, J. Chem. Phys. 148 (2018), 134707.
[5] C. Bistafa, D. Surblys, H. Kusudo, Y. Yamaguchi, J. Chem. Phys., 155 (2021), 064703.
[6] D. Surblys, Y. Yamaguchi, K. Kuroda, M. Kagawa, T. Nakajima, and H. Fujimura, J. Chem. Phys. 140 (2014), 034505.
[7] Y. Yamaguchi, S. Nakaoka, T. Hayashi, M. Kawakami, D. Yano, ECS Trans. 92 (2019), 87.
A Gradual Change in Al1-XScX N Ferroelectric Film upon Switching Reversal
Authors: Tsai Sung-Lin , Hoshii Takuya , Wakabayashi Hitoshi , Tsutsui Kazuo , Kakushima Kuniyuki 
Published: July 2022

Ferroelectric materials have been utilized for non-volatile memory applications [1]. Recently, Al1-x
Sc
x
N (ASN) films were reported to exhibit ferroelectricity with a high remnant polarization of over 100 µC/cm2 which is attractive for future non-volatile memory [2]. The feasibility of FeRAM application has been confirmed based on material and electrical properties [3]. One of the issues of ASN films is the lack of reliability and endurance properties, as the number of switching cycles of 104 to 105 is the typical endurance of the ASN films before breakdown [4]. In this study, we infer the gradual change in the ASN film upon switching cycles.
A 50-nm-thick ASN film with x of 0.22 was characterized with TiN electrodes at top and bottom. The as-fabricated film is self-polarized in an upward direction; the negative voltage applied to the top electrode triggers the switching reversal. Capacitance-voltage (C-V) characteristics, double sweeping the voltage to the negative, and then to the positive directions, were used to observe the switching voltage. A sinusoidal wave with an amplitude of 28 V at 2 kHz was used to switch the capacitor, ending with a positive voltage applied to the top electrode.
The C-V curve for the as-fabricated sample (fresh), shown in figure 1, showed only a single peak capacitance for each sweep. The voltage at the peak capacitance during the negative sweep shifted from -20.8 to -17.4 V from the first to third sweep, larger than the shift during the positive sweep. This indicates that the switching voltage, or the coercive field, was reduced during the first negative sweep. After stressing the sample by 103-cycle switching, the C-V curve revealed two capacitance peaks in the negative direction, as shown in figure 2; the peak at -20.2 and -15.2 V are referred to as the peaks obtained in the first and third sweeps for the fresh device. The capacitance peak at -20.2 V gradually decreased moving to merge to the peak at -15.2 V. During this transition, little change of the peak in the positive region was observed, indicating that a gradual transformation in the ASN film upon switching reversal is happening only when the film is switched from upward to downward direction. We hypothesized the creation of nitrogen-vacancy (VN) during the switching, facilitating the movement of N atoms to reduce the coercive field. One can understand that the transformation is completed during the C-V measurement for the fresh sample as the time for the measurement is long.
In conclusion, we observed a gradual change in the switching voltage upon switching reversal. A lower coercive field was found to gradually appear after switching, decreasing, and shifting the initial coercive field.

References

[1] T. S. Böscke, et al., Appl. Phys. Lett., 99, 102903 (2011). [2] S. Fichtner, et al., J. Appl. Phys., 125, 114103 (2019). [3] C. Liu, et al., IEDM Tech. Dig. (2021). [4] S.-L. Tsai, et al., Jpn. J. Appl. Phys. 60, SBBA05 (2021).

Figure 1
(Invited) Breakthrough Avalanche and Short Circuit Robustness in Vertical GaN Power Devices
Authors: Zhang Yuhao , Zhang Ruizhe , Song Qihao , Li Qiang , Liu J. 
Published: July 2022

After decades of relentless efforts, GaN power devices, specifically, the lateral GaN high-electron mobility transistor (HEMT), have been commercialized in the 15-650 V classes. Owing to GaN’s competitive physical properties over Si and SiC for power electronics, GaN HEMTs allow for higher switching frequency and therefore, have already seen wide adoptions in fast chargers, wireless charging, data centers, and electrified transportation. Despite the success of lateral GaN HEMTs, a vertical device structure is usually believed to be more favorable for high-voltage, high-power devices. In the last few years, with the advent and maturity of large-diameter, low-dislocation GaN wafers on freestanding GaN substrates, a new generation of vertical GaN power devices have been developed to extend GaN’s application space beyond 650 V. Very recently, several industrial vertical GaN devices in the voltage classes of 1.2-1.7 kV have been demonstrated, which are close to commercialization.
This presentation will review the key advancements in vertical GaN power devices in the past decade, with a focus on the device technologies that are being commercialized, and provide a prospective for research and development in the next decade. The devices to be covered will include two-terminal power rectifiers including the p-n diodes, Schottky barrier diodes, junction barrier Schottky diodes, and trench MIS/MOS barrier Schottky diodes. The transistors will include the trench and planar MOSFETs, current-aperture vertical electron transistors, fin-channel MOSFETs, and fin-channel JFETs. Particular emphasis will be on large-area rectifiers and transistors with a device performance superior to similarly-rated Si and SiC transistors. The newly demonstrated avalanche and short-circuit robustness in vertical GaN devices, which are lacking in lateral GaN HEMTs, as well as their underlying device physics, will also be introduced. The presentation will be concluded by a discussion of current challenges and future application spaces of vertical GaN devices, as well as emerging vertical GaN devices (e.g., superjunction) under development.
Power Cycling Test Failure Analysis of SiC MOSFET Devices
Authors: KIM Mijin , Kang Inho , SEO Jae HWA , Hong Tae-eun , Jeong Jee-Hun , Yoo Dahui , Lee Ho-Jun 
Published: July 2022

In recent years, gradual development in industry and automobiles and the field of renewable energy production has been achieved led to significant growth in the field of power semiconductors.
In particular, operation and non-operation are repeated in such a field, so reliability issues such as delamination and cracking are critical factors.
Therefore, there is an increasing demand for reliability verification such as power cycling tests(PCT).
In this study, reliability was evaluated using PCT (Mentor Graphics’ Power Tester 1500A), which repeats the heating and cooling of the device by applying continuous gate pulses in the same way as in the actual operating environment.
Keysight's B1506A was used to compare the electrical characteristics before and after the PCT.
It was found that this increased the turn-on resistance(Ron) on the output curve.
The components of the turn-on resistance are:
Ron = Rpack + Repi + Rch + R*

Where, Rpack is the packaging resistance due to bond wire, metallization, etc., Repi is the drift layer resistor, Rch is the channel resistance, and R* is the other components resistance e.g., the substrate.
If there is an increase of Ron, it might be due to Rpack, which is typical power cycling aging [1].
We also performed Scanning Electron Microscopy (SEM) analysis for failure analysis and confirmed that the bond wire cracked after PCT.
We performed a Scanning Acoustic Microscopy (SAM) analysis for further failure analysis and confirmed that voids were formed in the solder after PCT.
Both results are due, as is previously known, to bond wire degradation resulting from thermal-mechanical stress due to the coefficient of thermal expansion (CTE) mismatch between packaging materials [2].

Figure 1