bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Digital Presentation) Understanding the Impact of High-Nickel Cathode Microstructure on Battery Safety and Cycling Performance
Authors: Reid Hamish Thomas , Jervis Rhodri , Shearing Paul R 
Published: July 2022

To meet the increasing energy demands of portable devices and electric vehicles, high-nickel lithium-ion cathode materials with the general formula Li(NixMnyCoz)O2 (NMC) have been extensively researched. Currently NMC811 is used commercially for high-energy applications. The energy density of NMC also comes with concerns over cycle life and safety1,2. To improve the cycle life of NMC-based cells, single-crystal materials have recently gained attention to tackle the particle cracking issues found in polycrystalline cathodes3. However, for successful introduction to the lithium-ion battery market, inherent safety over a material’s lifetime also needs to be proven. Failure and degradation mechanisms both need to be fully understood to improve the stability of future cathode materials. Abusive testing, such as overheating, overcharge and nail penetration, has been used in conjunction with in-situ and ex-situ X-ray computed tomography (CT) 3D imaging to perform post-mortem studies and understand the relationship between thermal failure and cathode microstructure4,5. However, the interplay between safety characteristics, microstructural properties and material degradation remains unclear.
This work first aims to compare the safety performance of polycrystalline and single-crystal NMC811 in 200 mAh pouch cells. Accelerating rate calorimetry (ARC) with a heat-wait-search (HWS) technique is used to heat cells and determine the onset of self-heating, onset of thermal runaway and the peak thermal runaway temperature. Laboratory-based pre- and post-mortem in-situ and ex-situ X-ray CT is also used for non-destructive imaging at multiple length scales to determine how failure propagates through the cells and the impacts on the electrodes and microstructure. Pouch cells containing polycrystalline and single-crystal NMC811 cathode and graphite anode are electrochemically cycled to induce material degradation. EIS measurements and diagnostic cycles are performed to identify prevalent degradation modes in both types of cathode materials. Finally, the same ARC and X-ray CT characterisations are performed on the aged cells to determine how degradation and changes to the material structure affect the safety performance in high-nickel cathode materials.
The results of this work will improve the current understanding of capacity fade in high-nickel cathodes and the safety behaviour over the lifetime of a battery cell. This information can then be used to inform future materials development and strategies for mitigating thermal runaway in batteries.

References

L. Ma, M. Nie, J. Xia, and J. R. Dahn, J. Power Sources, 327, 145–150 (2016).

H. J. Noh, S. Youn, C. S. Yoon, and Y. K. Sun, J. Power Sources, 233, 121–130 (2013).

J. Langdon and A. Manthiram, Energy Storage Mater., 37, 143–160 (2021).

D. Patel, J. B. Robinson, S. Ball, and D. J. L. Brett, (2020).

D. P. Finegan et al., Phys. Chem. Chem. Phys., 18, 30912–30919 (2016).
Effect of a Heterogeneous Distribution of the Conductive Additives and Binder Domain on the Impedances of Lithium-Ion Battery Electrodes
Authors: Prasad Mrudula , Hein Simon , Danner Timo , Latz Arnulf 
Published: July 2022

The conductive carbon and binder are essential components of Lithium-ion battery electrodes. Their main task is to enhance the electrical connectivity and mechanical stability. Therefore, a homogeneous distribution of the carbon binder domain (CBD) throughout the electrode is desired. However, inhomogeneities can arise in the production process. At high drying rates of the wet coating, the CBD migrates to the surface of the electrode due to the drag of the evaporating solvent. This effect causes a gradient of the CBD through the thickness of the electrode. This process has two effects: (a) depletion of the CBD at the current collector, diminishing the electronic pathways and the adhesion of the electrode layer, and (b) accumulation of the CBD at the electrode surface, thus blocking pathways for Lithium transport. This is especially prominent in thick electrodes. Therefore, we investigate the effect of binder migration on the electrochemical performance of NMC622 electrodes of Lithium-ion batteries.
In our simulations we use virtual electrode microstructures of NMC622 electrodes which are informed by tomography data. As it is challenging to resolve the CBD using tomographic techniques, it is distributed on a model-basis at the contact points of active material particles using an in-house structure generator[1].
The valuable information derived from combining microstructure-resolved simulations with electrochemical impedance spectroscopy (EIS) on symmetric cells is used to characterize the Lithium-ion transport in the electrode pore space, including the contributions of the CBD. Additionally, half-cell discharge simulations are also conducted to analyze the effect of CBD heterogeneity on electrode performance.
Through our work, we demonstrate the significance of the CBD distribution and enable predictive simulations for future battery design.
[1] Hein S. et al, J. Electrochem. Soc. 2020, 167 013546

Figure 1
Reactive Spray Drying Approach Towards rGO As Matrix Material for the Cathode of Li-S Batteries
Authors: Müllner Sebastian , Roth Christina 
Published: July 2022

Lithium-sulfur batteries represent a promising alternative to the classical Li-ion technology, particularly due to the high specific energy density combined with the good environmental sustainability of sulfur. Compared to state-of-the-art cathode materials for Li-ion batteries (LiB), which usually contain cobalt and/or manganese, sulfur is less toxic and much more abundant [1]. Additionally, the theoretical capacity of 1.675 mAh g-1 is more than eight times higher than typical cathode materials as Lithium-Nickel-Mangan-Cobalt-Oxide (NMC), Lithium-Cobalt-Oxide (LCO) or Lithium-Iron-Phosphate (LFP) [1,2]. One of the main challenges of sulfur is the so-called “shuttle effect” [1,3]. During lithiation soluble intermediates (polysulfides) migrate to the anode side, further react and precipitate, resulting in a continuous loss of active material and capacity. Next to that, the poor electrical conductivity (5∙10-30 S cm-1) does not allow the utilization of pure sulfur as cathode material [1].
To improve the low conductivity, carbon-containing composites have been proposed as cathode material for Li-S batteries for several decades. One possible carbon matrix material is reduced graphene oxide (rGO) [4]. The reduced form of partially oxidized graphite (graphite oxide; GO) is a graphene-like material with high potential for a scale-up to mass production.
In our group, we have developed a new synthesis method to rapidly reduce GO using a reactive spray drying technique, where most functional groups can be removed from GO within seconds. The rapid thermal processing leads to a reduced and exfoliated rGO, which still contains small amounts of epoxy groups within the carbon lattice. These remaining oxygen atoms influence the conjugated π-bonds of the graphene-like matrix and thus change the polarity of the surface. A thermal post-treatment for 2 h in Ar/H2 can further reduce the remaining functional groups leading to a highly non-polar surface.
It is assumed that oxygen-containing groups (e.g. epoxy and hydroxy) result in a varying adsorption behavior of the polysulfides, affecting the unwanted “shuttle effect” and thus influencing the electrochemical performance [5]. Here, we show the impact of remaining functional groups in rGO on the electrochemical performance of S-rGO composites as cathode material vs. Li/Li+. We compare untreated GO to reactive spray dried and additionally (thermally) post-treated rGO. Furthermore, we analyze the composites in terms of asymmetric and symmetric bonding vibrations as well as crystallinity using FT-IR, RAMAN and XRD.
[1] Baikalov, N. et al., Frontiers Energy Research
2020, 8, 207
[2] Su, Y.-S. et al., Nature Communications
2013, 4, 2985
[3] Ren, W. et al., Energy Storage Materials
2019, 23, 707-732
[4] Shastri, M. et al., Ceramics International
2021, 47, 10, B, 14790-14797
[5] Ji, L. et al., Journal of the American Chemical Society
2011, 133, 18522-18525
5V Solid-State Lithium Batteries Using Garnet-Based Electrolytes and LiNi0.5Mn1.5O4 Spinel Cathode Composite
Authors: Niketic Svetlana , Filoso Gina , Houache Mohamed , Karkar Zouina , Yim Chae-Ho , Abu-Lebdeh Yaser 
Published: July 2022

There is an ever increasing demand to increase the gravimetric and volumetric energy density of Lithium batteries as well as enhancing their safety cycle life and lower safety. Solid-State batteries (SSB) enjoy a great attention nowadays due to their potential to meet all those requirements and power the EV revolution. The use of solid electrolytes (SE) in commercial batteries has been solely limited to polymer electrolytes based on poly(ethylene oxide), PEO, coupled with LiFePO4 (LFP) that are limited by the oxidative stability of PEO to < 3.6 V and the low potential of LFP at 3.4 V. The commercial cells are cycled at high temperature (45 ⁰C) to overcome the modest ambient ionic conductivity of the SE and under a stack pressure and a cathode composite to overcome the high interfacial resistances of the solid-solid interfaces. A cathode composite is made of conventional cathode components with a "catholyte" added to the formulation. The catholyte is made of an optimized amount of an ionic conductor that is mostly derived from the solid electrolyte formulation. Very recent studies by our research group (1) and others (2) have shown that higher voltage cells can be made by using garnet or perovskite-based ceramic/polymer composites and LiNi0.5Mn0.3Co0.2O2 (NMC532) or LiNi0.6Mn0.2Co0.2O2 (NMC 622) layered cathodes reaching 4.2 V and can operate for few cycles. Herein, we extend the work in order to further increase the voltage of the SSB cells by using LiNi0.5Mn1.5O4 (LNMO) spinel cathode with its high potential of 4.7 V. The Tantalum-doped Lithium Lanthanum Zirconate, Li6.4La3Zr1.4Ta0.6O12 (Ta-doped LLZO, LLZTO), of the garnet family of solid electrolytes has been selected as a SE due to their high ambient ionic conductivity, wide electrochemical stability window and good chemical stability against Li metal. PEO and other compatible polymers have been used to formulate composite SEs in thin films and their properties were studied and compared with LLZTO pellets. Cells have been made using composite cathode formulations composed of LNMO cathode as an active material, carbon black, conventional and novel binders and a SE-based and proprietary catholyte coupled with the SE films or pellets and thick/thin Li films. The short-term cycling performance of the cells assembled with selected SEs and composite cathodes along with other electrochemical results will be presented.

References:

(1) Hilal Al-Salih, Allan Huang, Chae-Ho Yim, Annica I. Freytag, Gillian R. Goward, Elena Baranova and Yaser Abu-Lebdeh, 2020, J. Electrochem. Soc. 167 070557.
(2) P. López-Aranguren, X. Judez, M. Chakir, M. Armand and L. Buannic, 2020, J. Electrochem. Soc. 167 020548.
(Invited) Second-Layer Growth Kinetics As a Decisive Factor for Non-Equilibrium Thin-Film Morphologies
Authors: Maass Philipp 
Published: July 2022

Understanding and control of cluster growth on solid surfaces is a subject of intensive research to develop materials with new properties. Of particular interest is the self-organized structure formation by deposition of atoms and molecules on surfaces, where the interplay of diffusion, nucleation, aggregation, segregation and superlattice ordering yields a rich variety of growth phenomena [1]. The resulting structures are often frozen-in non-equilibrium structures with properties distinctly different from the equilibrium bulk phases. Here I will discuss the role of second layer nucleation for three-dimensional cluster formation and its influence on cluster morphologies.
[1] M. Einax, W. Dieterich, P. Maass, Rev. Mod. Phys. 85, 921 (2013).
Minimum Thickness of Continuous Cu Layers on Mo from Fluoride Free Electrolytes
Authors: Ahmadi Kamyar , Quaye Peter , Dole Nikhil , Joi Aniruddha , Brankovic Stanko 
Published: July 2022

Mo as a refractory metal has physical properties which are of interest for applications in CIGS photovoltaic cells fabrication and for next generation of liners for Cu interconnects[1]. Therefore it is of fundamental and practical interest to develop a process for Cu metallization of Mo surfaces where contiguity and high coverage is achieved at minimum thickness. However, one of the obstacles that prevent readily use of Mo as substrate for Cu electrodeposition is tendency of its surface to form a high quality oxide[2]
,[3].The surface energy of Mo-oxide is much lower than Cu which results in sporadic 3D nucleation and low adhesion of Cu deposit[2]. The presented work addresses this fundamental problem by combining the knowledge/breakthroughs demonstrated in the field of electro-polishing of refractory metals such as Nb[4] with common pulse electrodeposition practice[1]
,[5]. A design of deposition pulse reverse potential/current function for Cu is presented which converts a Mo-oxide/Cu to a Mo/Cu interface. Elaborate measurements of the thin film impedance during the Cu growth complemented with Pb UPD decoration studies and AFM surface morphology analysis are presented. These data indicate that Cu layers reach full contiguity and coverage of the Mo substrate at the thickness level of 3-5 nm. Considering that common Cu electrodeposition bath chemistry for interconnects contains additives whose incorporation makes Cu deposit somewhat incompatible with photovoltaic layers[1], this work presents the Cu solution chemistry which is additive free and can serve as a base for further improvement of the specific Cu deposition processes depending on its application.
[1] . J. Bi et al, Journal of Power Sources, 326, (2011) 211.
[2] . D. Mercier et al, Journal of the Electrochemical Society, 160 (2013) 3103.
[3] . M. Pourbaix, Atlas of electrochemical equilibria in aqueous solutions. 2d English ed. 1974, Houston, Tex.: National Association of Corrosion Engineers.
[4] . Journal of The Electrochemical Society, 160 (9) E94-E98 (2013).
[5] . J.C. Puippe and F. Leaman, Theory and Practice of Pulse Plating, AESF, (1986).
(Invited) Structural Control of Molybdenum Silicide By Electrolytic Silicification of a Mo Substrate
Authors: Suzuki Yuta , Matsuo Yu , Shimizu Yosuke , Fukunaka Yasuhiro , Goto Takuya 
Published: July 2022

Metal silicides are attracting attention as environment-friendly functional materials because they are composed of abundant elements in the earth’s crust. However, conventional processes for preparing silicides from SiO2 as the starting material consume a lot of energy and utilize hazardous materials through the reduction process of SiO2. Against this background, the electrochemical process in molten salt become key technology for fabricating silicon materials in an environmentally friendly, simple, and inexpensive process. We have already reported the electrodeposition of metallic silicon films from SiO2 in high temperature molten salt. This process has the potential to develop environmentally friendly and sustainable systems for fabricating silicon materials by combining non-consumable oxygen-evolving anodes. In this study, we focused on the electrochemical formation of molybdenum silicide from SiO2 in molten chloride because the molybdenum silicide are promising materials for ultra-high temperature protective coating, heating element, and thermoelectric conversion element.
We report here the electrochemical formation of molybdenum silicide in CaCl2-based molten chloride containing SiO2 system. A Mo substrate was used as the working electrode. From the results of characterization by XRD, SEM, and EDS analysis, a metastable β-MoSi2 phase and stable α-MoSi2 phase were obtained by controlling applied potentials during potentiostatic electrolysis. In addition, since the nucleation and growth process of the silicide is very important to control its structure, composition and morphology, the electrolytic time transient between molybdenum substrate/molten chloride interface were carefully observed by SEM analysis. The fundamental research on formation process of silicides in molten salt will greatly contribute to materials science in high temperature environment and developing the novel rout for fabricating silicon materials.
Thermal, Mechanical, and Electrical Characteristics of the Lithiated PEO/LAGP Composite Electrolytes
Authors: Huang Hong , Lee Jeremy , Rottmayer Michael 
Published: July 2022

Lithium-ion batteries utilizing solid-state electrolytes have potential to alleviate safety issues, prolong discharge/charge cycle life, reduce packaging volume, and enable flexible design. Polymer-ceramic composite electrolytes are more attractive and recognized because the combination can remedy and/or transcend individual constituent’ properties. We have fabricated a series of free-standing composite electrolyte membranes consisting of Li1.4Al0.4Ge1.6(PO4)3 (LAGP), polyethylene oxide (PEO), and two different lithium-salts, i.e. LiBF4 and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI). It is determined that the type of lithium salt can prevail the ceramic LAGP loadings on altering the thermal, mechanical, and electrical properties of the composite electrolytes.
In this paper, we will present the results and discuss the differences in the aspects of melting transition, mechanical reinforcement, and ionic conduction resulting from the two different lithium salts together with the content of LAGP ceramic fillers in the lithiated PEO/LAGP composite electrolytes. The changes in these three aspects can be ascribed to the different interactions between the polymer matrix and lithium salt in the composite setting.
High Sensitivity Bimetallic Electrode Generation through the Study of Copper Electrocrystallisation on Metallic Substrates (Md/Ms) in Acidic Media
Authors: Abed Sherif , Gibilaro Mathieu , Chamelot Pierre , David Arnaud , Barus Carole , Abed Sherif 
Published: July 2022

The electrochemical nucleation of copper on metallic substrates in acidic media was investigated using cyclic voltammetry and chronoamperometry. The purpose is to optimize the operating conditions for preparing a high sensitivity bimetallic electrode. Indeed, optimizing the electrodeposition parameters whereby two different metals are present: deposited metal Md and substrate metal Ms, allows the generation of a large number of microelectrodes, correspondingly, yield the largest active surface, and so, increasing the electrode sensitivity.
The aim of this study is to highlight the positive impact of controlling the electrodeposition process of a metal on a substrate and determining the operation conditions towards the augmentation of the active surface area of an electrode.
This work is focused on studying the first instance of copper nuclei formation on the electrode surface and the growth of these nuclei over time. Factors influencing deposit quality and allow to yield the highest specific surface area were considered, principally the overvoltage and the deposit cutoff charge. The nucleation phenomena and the initial growth of the copper nuclei on three different metallic substrates was studied. The plot of the experimental results were compared to theoretical models for the two possible nucleation modes: instantaneous and progressive. The nucleation phenomena was overseen on cyclic voltammetry recorded and the electrodeposition overvoltage were determined for each couple (Md/Ms). Chronoamperometric measurements evidenced that copper electrodeposition process involves progressive nucleation on the substrates, which was confirmed by scanning electron microscopy (SEM). Afterward, the germination rates were determined.
The optimum theoretical cutoff charges were calculated from chronoamperograms using Faraday’s law and were experimentally verified.
Optimal operating conditions were determined for the preparation of bimetallic electrodes with the largest active surface area. Subsequently, copper deposition runs were carried out on the three electrode substrates. The formed bimetallic electrodes were tested using square wave voltammetry for their ability to detect species requiring high sensitivity identification tools such as nitrates in seawater. In open ocean, the concentration of nitrates can drop from few dozens of micromolars to as littles as few nanomolars.
The copper nuclei fount out to be unstable on the substrate in maritime area due to corrosion and attack by dissolved oxygen. A cathodic polarization by applying a direct current was applied to protect the deposited copper.
Streamlined Derivations and Explanations of the Scharifker-Hills Model
Authors: Sun Yunkai , Zangari Giovanni 
Published: July 2022

Despite being very popular in the analysis of experimentally measured potentiostatic transients during the initial stage of electrodeposition of metallic single-element coatings, the derivations and the assumptions of the Scharifker-Hills (S-H) model are not well understood. Important details and assumptions are scattered in different original papers. Meanwhile, some of the simplifications in derivations are somewhat intuitive, rather than being rigorously derived from a set of governing equations.
It is important to understand the derivations, the assumptions, and the successfulness of the S-H model first before moving forward to an advanced model for the potentiostatic transient at the initial stage of metal or alloy electrodeposition. In this presentation, we will provide rigorous derivation for each step and each assumption, thus achieving a complete demonstration of the physics of the S-H model.

References:

[1] G.J. Hills, D.J. Schiffrin, J. Thompson, Electrochemical nucleation from molten salts—I. Diffusion controlled electrodeposition of silver from alkali molten nitrates, Electrochim. Acta, 19 (1974) 657-670.
[2] B. Scharifker, G. Hills, Theoretical and experimental studies of multiple nucleation, Electrochim. Acta, 28 (1983) 879-889.
[3] G. Gunawardena, G. Hills, I. Montenegro, B. Scharifker, Electrochemical nucleation: Part I. General considerations, J. Electroanal. Chem., 138 (1982) 225-239.
[4] B.R. Scharifker, J. Mostany, Three-dimensional nucleation with diffusion controlled growth: Part I. Number density of active sites and nucleation rates per site, J. Electroanal. Chem., 177 (1984) 13-23.
[5] B.R. Scharifker, J. Mostany, Electrochemical Nucleation and Growth, in: A.J. Bard (Ed.) Encyclopedia of Electrochemistry2007, pp. 512-539.
[6] M. Sluyters-Rehbach, J.H.O.J. Wijenberg, E. Bosco, J.H. Sluyters, The theory of chronoamperometry for the investigation of electrocrystallization: Mathematical description and analysis in the case of diffusion-controlled growth, J. Electroanal. Chem., 236 (1987) 1-20.