bluuebunny/crossref_metadata_2025 huggingface dataset:
Micro Droplet Corrosion: Measuring Changes in Wetting and Surface Area during Electrochemical Measurements
Authors: Gateman Samantha , Gharbi Oumaïma , Turmine Mireille , Vivier Vincent
Published: July 2022

Dynamic surface wetting that occurs during electrochemical droplet cell corrosion measurements on an Al alloy and Cu galvanic couple was monitored using the combination of a goniometer and potentiostat. The in situ observation of wettability during polarization of each metal and at the interface in 0.4 μL, 0.05 M NaCl aqueous droplets was performed. Droplet spreading was heterogeneously dynamic for measurements at the interface of the two metals due to the diffusion of oxygen from the surrounding environment into the droplet edges that was reduced on the cathodic metal, thus increasing the wettability on this region. The anodic metal served as a sacrificial anode and remained in a constant wetted state. Performing measurements under anaerobic conditions, where minimal changes in voltammetric response were observed, inhibited such dynamic wetting. All voltammetry was normalized by the surface area of the droplet footprint, which was measured after droplet evaporation instead of overestimating the corrosion current densities by assuming the droplet size to be same diameter as the pipette aperture. This work highlights the potential for the combined goniometer-electrochemical setup to further enhance the corrosion community’s knowledge about interfacial chemistry, the influence of surface preparation on droplet footprint size, and the importance of considering the dynamic evolution of micro/nanoscale droplets on heterogeneous substrates when estimating corrosion rates.
Multimodal Synchrotron X-Ray Tools for Studying Spinel Oxide Nanocrystals-Based Mg Cathodes
Authors: Li Hui , Yang Feipeng , Guo Jinghua
Published: July 2022

Magnesium battery has huge potential to meet the future needs of large-scale energy storage due to the high abundance of Mg element, high volumetric and gravimetric capacities, and improved safety compared to Li metal battery. The complex solid-electrolyte interface (SEI) formed on Mg anode surface and slow diffusion rate of magnesium ion in cathode bulk are two critical challenges to achieve high capacity and energy density of Mg battery. Nanostructured spinel oxides with well-defined morphology and crystalline structures are promising candidates for Mg battery cathodes, but their dynamic evolutions of chemical composition and electronic/geometric structure during charging and discharging are still on the early stage, which hinders understanding of the interaction and degradation mechanisms on spinel oxide-based cathodes. Herein, in-situ/or ex-situ soft X-ray absorption spectroscopy (sXAS) and small/wide-angle X-ray scattering (SAXS/WAXS) to track the changes of structure and surface/bulk chemistry of spinel oxide nanocrystals during Mg intercalation/deintercalation processes at both local and macroscopical levels. The Mg0.5Fe2.5O4 (MFO) nanocrystals were tested in a Swagelok cell with an electrolyte of 0.3 M Mg(TFSI)2 and 0.15 M MgCl2 at room temperature. An initial discharge capacity of 187 mAh g-1 was achieved and 83% capacity was retained after 20 cycles. sXAS results reveal that Fe3+/Fe3+ redox is highly reversible during charge/discharge process, and MgF2 slowly formed on the surface as well. In-situ WAXS shows that rocksalt phases of FeO and MgO were both observed during discharge process, and the former one quickly disappeared and the latter one slowly converted to pristine phase during charge process. Moreover, MFO with small size (~5 nm) delivered double specific capacity but poorer cyclability compared to large size (~18 nm), which is ascribed to the nanocrystal aggregation and decrease of active surface area and formation of interfacial crystal boundary based on in-situ SAXS and ex-situ STEM. More structural features of shape and crystallinity degree of MFO were also investigated and correlated to their battery performance. This work highlight the powerful role of multimodal in-situ synchrotron X-ray techniques in understanding the structure-performance of spinel oxide nanocrystals-based Mg cathodes.

Figure 1
Calcium Solvation Dynamics Probed By in-Situ/Operando Soft X-Ray Absorption Spectroscopy
Authors: Yang Feipeng , Feng Xuefei , Li Hui , McClary Scott A , Matias Ana Sanz , Hahn Nathan T , Prendergast David , Zavadil Kevin R , Guo Jinghua
Published: July 2022

Calcium is considered a promising candidate in multivalent battery technologies due to its safe, economic, and nontoxic nature. It has received considerable attention since the recent work showing that calcium can be plated and stripped at room temperature with good stabilities and capacities. It offers the promise of a more than two-fold increase in the volumetric capacity compared to the monovalent lithium-ion batteries. Additionally, because of the higher mobility of Ca2+ compared to that of Mg2+ because of the lower charge density of Ca2+, the interest in calcium batteries has been growing rapidly. The understanding of the solvation and charge transfer mechanism at the electrolyte/electrode interface and how different types of cations and anions will affect the calcium solvation at this interface is the key to develop novel calcium batteries. To probe the Ca2+ coordination at the electrolyte/electrode interface as a function of the type of anions, total electron yield (TEY) mode soft X-ray absorption spectroscopy (XAS) sensitive to the interfacial speciation has been used under operando electrochemical conditions. Meanwhile, total fluorescence yield (TFY) mode XAS is sensitive to bulk speciation. By comparing the operando TEY and TFY mode XAS from 0.5 M calcium bis(trifluoromethanesulfonyl)imide (CaTFSI2) in THF, the Ca L3,2-edge TEY-XAS intensity increased at positive potentials while the Ca L3,2-edge TFY-XAS intensity decreases at these positive potentials. Such a comparison clearly shows the solvation and desolvation dynamics of calcium at the electrolyte/electrode interface, which will benefit the future development of next-generation multivalent batteries.
(Invited, Digital Presentation) Nanostructured Perovskite Resistive RAM for Next Generation Data Storage
Authors: Poddar Swapnadeep , Zhang Yuting , Fan Zhiyong
Published: July 2022

Resistive RAMs (Re-RAMs) have emerged as a propitious candidate among next generation non volatile memories because of their strikingly fast speed, prolonged data retention ability and high storage density. Herein, we developed an electrochemical metallization (ECM) based Re-RAM with three-dimensionally integrated single-crystalline perovskite (methyl ammonium lead halide or MAPbX3 where X=I, Br and Cl) quantum wire (PQW)/ nanowire (PNW) array embedded in a nano-engineered porous alumina membrane (PAM) serving as the switching medium. The PQWs and PNWs were grown inside the PAM template by a vapor-solid-solid-reaction (VSSR) process and were clubbed between silver (Ag) and aluminum (Al) contacts. The nanostructured perovskite Re-RAM exhibited 100 ps switching speed which is a record for perovskite Re-RAMs and also among the fastest for all types of Re-RAMs reported. The fast switching was attributed to the increased ionic (Ag+) and electronic mobility and subsequent accelerated filament formation within the body of the monocrystalline PQWs/PNWs. The PAM scaffolding imparted material and electrical stability to the environmentally delicate perovskite. As a consequence, we were able to obtain a record long (among perovskite Re-RAMs) estimated retention time > 28 years and record-high (among perovskite Re-RAMs) uninhibited cyclic endurance of 6×106 cycles. Also, utilizing the ultra-high density (2×1011/cm2) of the PQWs, a 14 nm lateral dimension ultra-small memory cell was built. In conjunction with multi-bit switching, an effective device footprint of 76.5 nm2 was achieved for a single bit storage. Further, as a concept proof, an 8×8 Re-RAM crossbar array device was fabricated which demonstrated temporally robust alphabetic data storage, with a unique metal-semiconductor-insulator-metal (MSIM) architecture to alleviate the sneaky path problem. The MSIM scheme based on quasi-self-selecting elements, demonstrated a strong potential for unhindered scalability in the future, a problem often encountered with integrating external selecting diodes and transistors. The PQW/PNW Re-RAMs also responded to light stimuli, exhibiting optical programmability among the low resistance states. In summary, these intriguing results propel perovskite Re-RAMs to the state-of-the-art standard and demonstrate an attractive potency for PQW/PNW devices to be used as an alternative technology in future storage and computing modules.
(Invited) New Challenges in Early Diagnosis of Gastric Cancer
Authors: Van Staden Raluca , Gheorghe Damaris Cristina , Bratei Alexandru A A , Mibai Ruxandra Maria
Published: July 2022

Graphene proved to be an excellent material for sensors’ design. Therefore, we decorated it with different heteroatoms (e.g., N, B, S) and use it as electrode material for the design of new stochastic sensors. The graphene paste was modified with oleamides, inulins, dextrins in order to get the stochastic response of the sensor. Biomarkers like MSH6, MLH1, KRAS, p53 were analysed by screening the whole blood, urine, saliva, and tissue samples with the proposed sensors. High sensitivities and low limits of determination were obtained. Excellent correlations between the results obtained using the proposed screening method and the standard method were obtained.
Low-Temperature Rough-Surface Wafer Bonding with AlN/AlN Via Oxygen Plasma Activation
Authors: Huang Wei-Chi , Nien Shao-Ming , Ruan Jian-Long , Kuo Yang-Kuao , Lee Benjamin T.-H.
Published: July 2022

In this study, we demonstrate breaking through the main obstacle to achieve perfect wafer bonding: the requirement of the surface needs to be very flat and smooth. Strictly, the roughness must be less than 0.5 Å. We use sintered aluminum nitride as an example. AlN is a ceramic material with excellent dielectric and thermal properties and is usually used in the fields of microelectronics and energy. Despite CMP polishing, the high roughness (rms> 10 nm) of AlN wafers due to voids formed in sintering cannot meet the surface requirements for direct wafer bonding (rms < 5 Å). We present that bonding an AlN to another AlN with a high roughness surface can be achieved by design bonding processing. First, we used oxygen plasma to activate the hydrophobic rough surface to become a hydrophilic surface to introduce strong capillary action. Then, both surfaces of the bonded AlN/AlN pair were reacted with bonding species (OH-). The reaction was strengthened via electron transfer caused by clamping the bonded AlN/Al pair. Finally, low-temperature annealing (<150°C) was performed on the bonded AlN/AlN pair to synthesize Al2O3 at the bonding interface. After annealing at 150°C for 4 hours, the bonding interface of the AlN bonding pair was observed with scanning electron microscopy (SEM), as shown in Figure 1. The bonding interface showed that the two surfaces were perfectly fused without cracks and nothingness. TEM and XPS results also showed that there is a transition layer between the bonding surfaces, in which the nitrogen concentration decreases and the oxygen concentration increases significantly. It can be inferred that after annealing, an Al2O3 layer is formed by hydrolysis and dehydration, which acts as a bridge to firmly connect the two AlN wafers.

Figure 1
Passive Components in Next Generation Li-Ion Batteries
Authors: VahidMohammadi Armin , Gogotsi Yury
Published: July 2022

Most of the research in development of next generation and high-performance Li-ion batteries has focused on active materials (either in the cathode or anode side). This might sound obvious as active materials are the main component responsible for storing charge in batteries, and therefore, any improvement in them, will directly impact the overall performance of the battery. However, when looking at the cell level, passive components such as current collectors, conductive additives, binders, and separators constitute around 20 wt.% of each battery cell. These so-called passive components while do not directly contribute to the charge storage, their ratio, composition, and structure has a profound effect on the overall performance of the active material and therefore the battery cell. This is mainly due to their importance in charge transport inside the electrode, processing of electrodes, and also cycle life the battery cells. Despite this, they usually receive less attention in development of high power and energy density batteries. If these components are engineered properly or substitute with alternative new materials, potentially, one can improve the performance (energy and power metrics) of a Li-ion battery cell by up to 20%; a number that industry still strives to achieve through modification of active materials which usually is a more complex issue with slower development timeframes. In this talk, we take a closer look at the role of passive components in Li-ion batteries and discuss the possibilities that novel nanomaterials can offer as next generation passive components, both from the standpoint of improvements in metrics of battery cells as well as electrode processing and manufacturing in Li-ion batteries. We will also discuss the cost and safety advantages these materials can offer when used as passive components of the cells and present results and give examples that demonstrate how nanomaterials can in fact act as semi-passive components where they can substitute multiple conventionally used passive components and serve multiple purposes even if directly do not contribute to charge storage. Taking such an approach in development of battery electrodes/cells can potentially pave the way for development of batteries with higher power and energy densities using the current commercially available active materials, and further enable the use of high-capacity materials that degrade quickly and therefore, cannot be used in commercial cells using current technologies.
Incorporation of Functionalized Graphene and Its Derivates into Electrolyte: A Facile Approach to Improve the Electrochemical Performance of Lithium-Sulfur Batteries
Authors: Shah Vaidik , Joo Yong Lak
Published: July 2022

The impending global energy crisis and the severe environmental problems in the recent years has bolstered the research for sustainable electrochemical energy storage. With the lithium-ion technology reaching its theoretical limit, lithium sulfur (Li-S) batteries have garnered extensive attention owing to their ultrahigh theoretical capacity and the low-cost, Earth abundant and environmentally friendly nature of the sulfur cathode. Despite all the advantages, the development of Li-S technology is hindered by several inherent challenges namely, the large capacity drain due to the dissolution of the intermediate polysulfides in the electrolyte leading to polysulfide shuttling and low conductivity in the cell.

To overcome these issues, graphene and its derivatives have been extensively explored to mitigate polysulfide shuttling and enhance conductivity in the cell. However, at present, most of this research is limited to cathode modification which despite improving capacity retention is unable to curb the deleterious impact of polysulfide shuttling once the polysulfides dissolve in the electrolyte.

In this work, we have probed the impact of implementing graphene and its derivatives as additives to the Li-S electrolyte. We have extensively characterized various commercially available rGO and graphene samples to determine their morphology, functionalization, and other key ancillary properties such as defects and ionic resistivity and have studied their impact towards the electrochemical performance of the electrolyte-modified Li-S cell. Results showed a marked improvement in initial capacity of 1323 mAh/gs and a capacity retention of 83% at 0.2 C over 105 cycles with single layer graphene additive. Further, it was shown that increasing functionalization led to improved mitigation of polysulfide shuttling and about 20% higher capacity retention (than reference) over 105 cycles. The impact of different functional groups on graphene was also probed to compare their polysulfide shuttling mitigation capacity in the electrolyte.

Overall, we successfully achieved superior electrochemical performance of the Li-S cell simply by addition of graphene to the electrolyte. It was successfully shown that functionalized graphene dispersed in the electrolyte can enhance polysulfide encapsulation and improve the ionic conductivity in the cell.
(Digital Presentation) Self-Discharge in Electrochemical Capacitors: Beyond Conway’s Diagnostics
Authors: N V N Deeksha , Madabattula Ganesh , Kumar Sanjeev
Published: July 2022

Electrochemical double-layer capacitors (EDLCs), also known as supercapacitors, are energy storage devices. Charge-discharge in EDLCs occurs through electrostatic interactions between electrodes and oppositely charged ions. Self-discharge is the gradual loss of energy when a charged EDLC is left in open circuit state. A comparatively higher rate of self-discharge (SD) than in the batteries prevents the use of EDLCs in stand-alone devices or those charged only infrequently. The process of self-discharge, to the best of our knowledge, is far from being fully understood. It manifests as decrease in open-circuit potential which, depending on the charging protocol, can be dominated by charge-redistribution [1-3] induced rapid decrease in the initial stages.

Conway [4] proposed model-based diagnostics to identify activation, diffusion, and leakage-resistance controlled mechanisms from voltage vs. time measurements. We show that for the limited voltage range window available, the method is subjective and ambiguous for real measurements. We have proposed and carried out an alternative set of extensive experiments to gain insights into the self-discharge process for an in-house capacitor with sulfuric acid as electrolyte and activated carbon as electrodes. We varied electrode thickness, the distance between the electrodes, and the state of mixing in the electrolyte. We also measured self-discharge of electrochemically isolated charged half-cells (Figures 1a,b). The results bring out interesting and unambiguous findings, independent of the degree of fit with the expected variations for various controlling mechanisms. They rule out leakage resistance as the cause of self-discharge and disprove the shuttle mechanism [2,3] (Figure 1c,d). The analysis of measurements with electrodes of different thicknesses establishes that activation process controlled self-discharge does not dominate either. And the predicted effect of charge-redistribution is in the opposite direction. The role of the complex interplay of diffusion and electrochemical reactions holds promise.

Figure 1
(Digital Presentation) On the Origin of High Resistance at the Interface between Lithium Metal and Sulfide Solid Electrolytes
Authors: Hao Wei , Hwang Gyeong S.
Published: July 2022

Sulfide materials have been extensively studied as solid-state electrolytes (SSEs) for all-solid-state lithium metal batteries (ASSLMBs) because of their high ionic conductivity, wide electrochemical window, and appropriate mechanical properties. However, they suffer from the high interfacial resistance with Li metal anode, besides poor stability when exposed to air, hindering the application of sulfide-based SSEs in ASSLMBs. Sulfide materials are well known to undergo reaction with Li metal, leading to solid-electrolyte interphase layer formation at the SSE/Li metal interface. The side reactions could be primarily responsible for the high resistance at the interface between SSE and Li metal anode, but the underlying mechanisms still remain unclear. To better understand the structure and property changes of the sulfide SSE due to the reaction with Li metal, we took β-Li3PS4 (LPS) as a model system and systematically analyzed the structural, electronic, transport, and mechanical properties of lithiated LPS with varying Li contents using first-principles methods. Moreover, we examined the compositional and structural evolution at the LPS/Li metal interface using ab initio molecular dynamics (AIMD) simulations. Our results unequivocally show that Li incorporation leads to decomposition of PS4
3- to Li2S and Li3P when fully lithiated. With lithiation, Li-ion conductivity is predicted to remain in the same order of magnitude despite the significant structural and compositional changes. Both the band gap and density of the lithiated LPS becomes smaller than those of the unlithiated LPS. More importantly, we found the formation of voids at the LPS/Li metal interface. In this talk, based on our results we will discuss the mechanisms responsible for the high interfacial impedance as often observed in previous experimental studies.
Fabrication and Performance of Li-S/Se Solid State Cathodes with Holey Graphene As a Conductive Scaffold and Binder
Authors: Walker Brandon , Yamakov Vesselin , Su Ji , Dornbusch Donald , Viggiano Rocco P. , Wu James , Sun Sam-Shajing , Connell John , Lin Yi
Published: July 2022

Electric aircraft demonstrate potential as the future of aviation, offering zero emissions, lower noise, and potentially lower operational costs than aircraft powered by internal combustion engines. Currently, state-of-the-art lithium (Li) ion batteries used to enable today’s electrical vehicles lack the specific energy (< 250 Wh/kg) required to make electric flight (ideally requiring >400 Wh/kg) an economically beneficial endeavor. Additionally, Li ion batteries introduce serious safety concerns due to the highly flammable organic liquid electrolytes contained within the cell. Li-sulfur/selenium (Li-S/Se) cell chemistries possess high theoretical energy densities (2600 and 1160 Wh/kg, respectively) and therefore are a promising option to power electric aircraft. Rings of S doped with Se as the active cathode material result in a cell electrochemistry that can provide a balanced energy and power output during their reaction with Li. To improve safety, the S/Se cathode can be implemented with a solid-state electrolyte (SSE) to ensure the batteries would not be flammable. However, there are tremendous challenges in optimizing the interface between SSEs and the active material in the cathode composite to achieve desirable performance. In this presentation, we report our findings on the cathode fabrication and performance for solid-state Li-S/Se battery cells. We demonstrate that holey graphene (hG), a structural derivative of graphene, can serve as a scaffold host and binder to facilitate the close contact between the active material and SSEs. In addition, hG has unique properties such as through plane holes and dry compressibility that can aid in the fabrication and electrochemical performance of these high energy density solid-state batteries.
(Invited) Lanthanide-Based Nanoparticles Via Rapid Microwave-Assisted Synthesis and Their Application from Biomedicine to Printing
Authors: Hemmer Eva
Published: July 2022

Based on their outstanding optical properties, lanthanide-based compounds have been suggested for a wide range of applications including the fields of biomedicine, optoelectronics, and solar energy conversion. For instance, the capability of lanthanide-based materials to emit visible and near-infrared (NIR) light under NIR excitation is highly sought after when aiming for biomedical applications. This is as NIR light penetrates deeper into biological tissue and is less phototoxic than UV light commonly used for optical bioprobes. Our favorite nanomaterials are lanthanide-based fluorides (MLnF4, M = alkali metal, Ln = lanthanides and Yttrium), and our research addresses challenges in their synthesis as well as the establishment of structure-property relationships. The growing attention toward such optically active materials has prompted the development of novel synthesis methods for a more reliable and efficient access to these systems. In this regard, microwave-assisted approaches provide unique advantages over traditional solvothermal methods reliant on convectional heating: namely, significantly shorter reaction durations, more rigid reaction conditions, and thus a higher degree of reproducibility. The developed approach allows to control the material’s crystalline phase and doping of various Ln3+ ions into core/shell architectures. Additional surface modification with biopolymers renders the nanomaterials dispersible in various solvents and allows for their assembly into multipurpose micro-carriers. The resultant emission color-tunable upconverting nanoparticles are promising candidates for versatile applications, ranging from multiplexed imaging and light-induced therapy to inks for printing of micropatterns for optoelectronic devices.
(Invited) Photoluminescence Monitored Digital Photocorrosion of GaAs/AlGaAs Nanoheterostructures
Authors: Dubowski Jan J , Vermette Jonathan , St-Onge René
Published: July 2022

Conventional etching techniques do not have the ability to achieve precision of monolayer etching of crystalline solid materials. In recent years, atomic layer etching (ALE) has emerged as a method addressing this challenge based on the application of self-limiting sequential reactions. Nevertheless, monitoring of the ALE process, important for real time information about the location of the etching front, is not trivial and could be an expensive task. We have investigated the innovative process of digital photocorrosion (DIP) of GaAs/AlGaAs nanoheterostructures, which is based on photoexcitation driven decomposition of these materials.1 The process is carried out in a flow cell filled with etchants designed for selective removal of the photocorrosion products. For instance, water dilutes relatively easily As and most of the Ga oxides, but dilution of Ga2O3 or Al oxides and hydroxides requires dedicated etchants. Under optimized conditions, DIP allows etching of (001) GaAs/AlGaAs nanoheterostructures with average rates approaching 1 Å/cycle. The process could be monitored in situ by measuring, e.g., open circuit potential2 or photoluminescence3 effect. The sensitivity of these effects to the surface states of a semiconductor allows for convenient marking of the location of a GaAs/AlGaAs interface when crossed by the etching front.

In this presentation, I will discuss mechanisms of DIP of GaAs/AlGaAs nanoheterostructures and the conditions for formation of stoichiometric surfaces. Examples of the DIP process applied for formation of an unusual density alkanethiol self-assembled monolayers and operation of optical devices for detecting electrically charged molecules immobilized in the vicinity of a semiconductor-electrolyte interface will also be discussed. Finally, I will also address the potential of this economically attractive invention for the research of other semiconductor materials.

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1. S. Aithal, N. Liu and J. J. Dubowski, Journal of Physics D: Applied Physics 50 (3), 035106 (2017).

2. S. Aithal and J. J. Dubowski, Appl Phys Lett 112 (15), 153102 (2018).

3. M. R. Aziziyan, H. Sharma and J. J. Dubowski, Acs Appl Mater Inter 11 (19), 17968-17978 (2019).
A Thermal Tanks-in-Series Model for Capacity Fade Studies in Lithium-Ion Batteries
Authors: Thiagarajan Raghav Sai , Kolluri Suryanarayana , Uppaluri Maitri , Preger Yuliya , Subramanian Venkat R.
Published: July 2022

Lithium ion batteries are widely adopted due to their high energy density, low self-discharge rate and fast charging capabilities1. However, during their operation, capacity fade occurs as a result of various parasitic reactions causing loss of cyclable lithium ions. A dominant and widely studied fade mechanism is the formation of the Solid Electrolyte Interphase (SEI) layer caused by the reduction of electrolyte at the anode-electrolyte boundary. Temperature plays a crucial role on the electrochemical performance of individual cells, affecting the diffusivities of ions, kinetics of reactions and rate of degradation of the battery. Thermal battery models allow us to study the thermal behavior of cells and are often used for cell configuration optimization and thermal management system design2.

In literature, thermal models are incorporated with empirical and physics-based models to capture battery dynamics influenced by temperature. Empirical thermal models are simple and fast to solve but are applicable only for specific operating conditions and cannot capture electrochemical subtleties. Conversely, physics-based models use equations that incorporate transport phenomena and electrochemical reactions occurring in the cell. Common physics-based models are the Single Particle Model (SPM) and the Psuedo-2D (P2D) model. The P2D model is robust but computationally expensive3 and the SPM model does not capture electrolyte transport which has a non-linear temperature dependence.

The Thermal Tank-In-Series4,5 model is a systematically volume-averaged form of the P2D model with energy balance equations for the current collectors, cathode, separator and anode. This reduces the number of equations in the model and improves computational speed while maintaining accuracy. This model can be ideal to predict capacity fade during fast charging.

Extending on our previous work, we now couple the Thermal Tanks-in-Series model with the growth of the SEI layer for a single-cell sandwich. This model will facilitate understanding of diffusive, kinetic and temperature effects on the growth of the SEI layer and cell capacity fade.

References

M. Pathak, S. Kolluri, and V. R. Subramanian, J. Electrochem. Soc., 164, A973–A986 (2017).

H. Liu, Z. Wei, W. He, and J. Zhao, Energy Convers. Manag., 150, 304–330 (2017).

V. Ramadesigan et al., J. Electrochem. Soc., 159, R31–R45 (2012).

A. Subramaniam, S. Kolluri, S. Santhanagopalan, and V. R. Subramanian, J. Electrochem. Soc., 167, 113506 (2020).

A. Subramaniam et al., J. Electrochem. Soc., 167, 013534 (2020).
Parametrization of a Doyle-Fuller-Newman (DFN) Model for a Commercial 37Ah Li-Ion Battery and Validation with Incremental Capacity Analysis
Authors: Haber Marc , Genies Sylvie , Azaïs Philippe , Martin Alexis , Chandesris Marion , Raccurt Olivier
Published: July 2022

Physico-chemical modeling is considered as a very interesting way of simulating the behavior of a Li-ion battery cell by linking its internal state to its performance and aging. However, an accurate parametrization of such models is necessary for a truly representative outcome. In the case of commercial batteries, the parametrization procedure is hardly ever entirely undergone, leaving room for parameters tweaking and inaccurate simulation results. In the framework of this work, over 70% of the parameters were measured for a Samsung SDI 37Ah Li-ion prismatic battery (NMC111/Graphite) for PHEV (Plug-in Hybrid Electric Vehicle) applications. A Doyle-Fuller-Newman (DFN) Pseudo 2D model is chosen based on the work of Dufour et al.1. The major electrochemical characterization technics and measurement results for every component in the cell will be presented. The cells were opened in the ante-mortem procedure2, materials were identified, geometrical parameters were measured and samples were taken for coin-cell experiments. A small portion of the electrolyte was recovered and studied to conclude that it was made of EC-DMC-EMC at 1:1:2 portions. A similar solution was synthetized in order to conduct ionic conductivity measurements at temperatures ranging from -30 to 60°C. Samples from the separator were taken for both effective ionic conductivity and porosity measurements. The tortuosity of the electrodes was calculated via an EIS (Electrochemical Impedance Spectroscopy) with a blocking-electrodes configuration, and finally the diffusion factor in the active particles was estimated via GITT (Galvanostatic Intermittent Titration Technique) experiments. A very slow current regime was used to lithiate and de-lithiate the active materials in a half-cell experiment for electrode balancing purposes. The model was compiled using COMSOL Multiphysics 5.5, and results were compared to validation experiments conducted on the full-setup prismatic cell. The charge curve was validated under different current and power regimes at 25°C, and the Incremental Capacity (IC) curve showed a reasonable accuracy. With this in hand, the following step would be to couple this performance model to an aging model and to compare the evolution of the IC peaks with the experimental aging.

References:

N. Dufour, M. Chandesris, S. Geniès, M. Cugnet, and Y. Bultel, Electrochimica Acta, 272, 97–107 (2018) http://www.sciencedirect.com/science/article/pii/S0013468618307229.

T. Waldmann et al., Journal of The Electrochemical Society, 163, A2149–A2164 (2016) https://doi.org/10.1149/2.1211609jes.

Figure 1
(Digital Presentation) Effects of Solvents and Additives in Non-Conventional Liquid Electrolytes for Lithium-Ion Batteries
Authors: Jia Hao , Kim Ju-Myung , Gao Peiyuan , Xu Wu
Published: July 2022

Lithium (Li)-ion batteries (LIBs) have now been the major power sources in consumer electronic devices and electric vehicles. To further enhance the battery performances, more efforts are required to address significant challenges in improving cycle life, rate capability, energy density, working temperature range and safety of state-of-the-art LIBs. The conventional LiPF6/carbonate electrolytes have been found unable to meet all the requirements for advanced LIBs with high-capacity cathodes and anodes although proper additives can improve the battery performances in certain aspects. For instance, the presence of acidic species like HF in LiPF6 electrolytes and specifically at elevated temperatures is still detrimental to the layered oxide cathodes and the electrode/electrolyte interphases, and the issue of electrochemical oxidation stability of conventional electrolytes at voltages over 4.3 V needs to be addressed for the high-voltage cathodes and batteries. In response to the challenges facing to the conventional LiPF6/carbonate electrolytes in LIBs, especially the long-term cycling stability, non-conventional electrolytes based on functional localized high-concentration electrolytes (LHCEs) have been developed for LIBs in recent years. Due to the unique solvation structures of LHCEs, LHCEs lead to formation of thin, compact and uniform electrode/electrolyte interphases, thus greatly improve LIB performances. In this work, we comparatively studied the effects of solvating solvents and additives in LHCEs on the solvation structures and properties of LHCEs as well as the battery performance of LIBs with nickel-rich cathode and graphite anode. More details will be reported during the presentation.
(Invited) Designing Interphase in Rechargeable Lithium Metal Batteries Via Liquid Electrolyte Additives
Authors: Guo Juchen
Published: July 2022

The goal of reaching specific energy at 500 Wh kg-1 resurrects Li metal anode in recent years due to its high capacity (3860 mAh g-1) and low reductive potential (-3.04 V vs. standard hydrogen electrode). However, the reductive decomposition and chemical instability of the liquid electrolytes against Li metal result to unstable solid-electrolyte interphase (SEI) formation and porous Li deposition with low coulombic efficiency and severe volume expansion. Therefore, one strategy to enhance the cycle life of Li metal anode is to design robust SEI to improve the interfacial stability. Herein, we demonstrate two liquid electrolyte additives that can form and regulate desirable SEI on the Li metal anode. Acrylonitrile (AN) can be electrochemically polymerized as an additive to form a Li-ion conductive SEI during Li deposition. Electrochemical analyses, scanning electron microscopy, and X-ray photoelectron spectroscopy confirm the formation of the polymeric SEI, which induces uniform and dense Li deposition and reduced decomposition of the Li-ion electrolyte. Phosphorous pentoxide (P2O5) is also studied as an additive in the typical 1M LiPF6 electrolyte in carbonate solvents for Li metal batteries. P2O5 can effectively scavenges the active impurities in the carbonate electrolytes and form phosphorous-rich stable SEI. Significantly improved battery performance due to these two additives is demonstrated in 0.4 Ah pouch cells composed of LiNi0.6Mn0.2Co0.2O2 (NMC622) cathode (3 mAh cm-2) and Li anode (50 mm thick) with a lean electrolyte/capacity ratio of 3 g/Ah.
(Digital Presentation) Pulsed-Waveform Electrodeposition of Fe-W Brazing Interlayers for Fusion Applications
Authors: Garich Holly , Lee Katherine , Snyder Stephen , Skinn Brian
Published: July 2022

Numerous government and commercial entities are currently engaged in research toward net-energy-positive nuclear fusion electricity generation technology, which if successfully developed would revolutionize the energy economy and have a significant beneficial impact on carbon emissions and anthropogenic climate change. One fusion subsystem with significant remaining engineering challenges comprises the multitude of divertor modules installed on the plasma-facing surface of modern nuclear fusion reactors. These divertors must absorb/conduct steady-state heat fluxes on the order of 10–20 MW/m2 in an extremely harsh environment, including high-energy neutron bombardment. One common material choice for the plasma-facing portion of these components is tungsten, which provides a high melting point, high sputtering resistance, low tritium retention, and other benefits. As the thermal conductivity of tungsten is somewhat low, however, these tungsten components are often paired with a heat sink made from a more thermally-conductive material, such as copper-chromium-zirconium alloy, CuCrZr. While these materials can be joined by a number of methods, such as diffusion bonding and brazing, the dramatic mismatch in coefficient of thermal expansion (CTE; ~4 μm/m/K and ~17 μm/m/K for tungsten and CuCrZr, respectively) has a significant detrimental effect on the joint strength under these high-temperature, high-heat flux conditions. Development of a means for mitigating this CTE mismatch is imperative for the use of these materials to be feasible in a practical fusion device.

This talk will present results to date on development of an electrodeposited functionally-graded iron-tungsten (Fe-W) interlayer system for mitigation of the CTE mismatch between tungsten and CuCrZr in brazed joints. In theory, an interlayer with a CTE functionally graded between “tungsten-like” and “copper-like” values should significantly mitigate the thermally-induced stresses at the tungsten/CuCrZr joint. A key objective of the work is to demonstrate sufficient control over the local interlayer composition, residual stress, and other properties by adjusting primarily the pulse/pulse-reverse electrical waveform parameters, so as to allow interlayer preparation from a single electrodeposition bath. Results from electrodeposition trials and mechanical testing of brazed joints under ambient conditions as an initial screen for interlayer performance will be discussed, in anticipation of high-heat flux testing of joint performance under fusion-relevant conditions, where the ultimate goal is demonstration of increased tungsten/CuCrZr joint lifetime under thermal load via inclusion of graded interlayers, as compared to similar joints without interlayers.

Figure Caption

(Left) Tungsten substrate with electrodeposited Fe/W interlayer. (Right) Brazed tungsten/CuCrZr sample with Fe/W interlayer.

Figure 1
Electrohydrodynamic Redox 3D Printing: Confined Electroplating of Alloys for Additive Manufacturing at the Submicron Scale
Authors: Nydegger Mirco , Porenta Nikolaus , Menétrey Maxence , Hammadi Souzan , Reiser Alain , Spolenak Ralph
Published: July 2022

Combining the unprecedented design freedom in microscale additive manufacturing (AM) with the ability to control the chemical nature of each printed voxel could unlock unique possibilities for tailoring mechanical, chemical, electrical, optical and magnetic properties of metal microstructures. A variety of techniques for micro- and nanoscale AM has been proposed for the fabrication of device-grade metals and alloys [1]. Electrochemical approaches to small-scale AM generally lead to superior microstructures (in terms of porosity and contamination) compared with techniques that transfer pre-synthesized materials [2]. The deposition of alloys with controlled composition, however, remains a challenge with electrochemical small scale AM techniques.

In this talk, we will present our work on additive manufacturing of alloyed structures using electrohydrodynamic redox (EHD-RP) 3D printing [3]. EHD-RP is based on the deposition of solvent droplets containing metal ions onto a conductive substrate, where the solvent evaporates and the ions are reduced. In general, this technique allows the direct deposition of polycrystalline 3D metal structures with a resolution of approx. 250 nm and a feature size down to 100 nm. We will present our work in expanding the materials range of EHD-RP from the limited range reported previously to a wide range of metals and subsequently discuss in detail the direct deposition of alloys. As it will be shown, the approach of spatially confining electrodeposition enables the fabrication of multi-metal and alloyed structures with a chemical voxel size <400 nm, hence making a step towards chemically architected materials. We will show how we can control the composition of the deposited material and the challenges involved in its characterization.

In summary, we present a novel approach to the bottom-up manufacturing of locally alloyed microstructures, adding an additional parameter in the design of novel nano- and microstructured inorganic materials.

[1] L. Hirt, A. Reiser, R. Spolenak & T. Zambelli. Additive Manufacturing of Metal Structures at the Micrometer Scale. Adv. Mater., 29(17), 2017.

[2] A. Reiser, R. Spolenak et al. Metals by Micro-scale Additive Manufacturing: Comparison of Microstructure and Mechanical Properties. Adv. Funct. Mater., 30, 1910491, 2020

[3] A. Reiser, M. Lindén, P. Rohner, A. Marchand, H. Galinski, A. S. Sologubenko, J. M. Wheeler, R. Zenobi, D. Poulikakos & R. Spolenak. Multi-metal electrohydrodynamic redox 3D printing at the submicron scale. Nat. Comm., 10(1):1-8, 2019.

Figure 1
(Digital Presentation) Electrochemical Deposition of Sn-Cu Alloys for Applications in 3D Stacking in Microelectronics Industry
Authors: Radisic Aleksandar , Inoue Fumihiro , El-Mekki Zaid , Struyf Herbert , Hou Lin , Derakhshandeh Jaber , Beyne Eric , Hsia Chih-Hao , Chang Iris , Kuttner Elisabeth , Fluegel Alexander , Arnold Marco
Published: July 2022

The use of eutectic Sn-Cu alloys in packaging applications in microelectronics industry is not something entirely new. However, this alloy was mostly used in large features and fabricated using metal powders and metallurgical deposition techniques. The diameter of an individual grain of the eutectic Sn-Cu powder is typically similar in size to the diameter of pillars or bumps currently used in 3D stacking, and if we were to check its usefulness as a solder on this scale, an alternative manufacturing technique had to be used.

We have electrochemically deposited Sn-Cu alloys having up to 10 wt.% Cu and explored its possible benefits when used as a solder in combination with different Under bump metallization (UBM) materials. Sn-Cu alloys were deposited on blanket and patterned coupons, and promising experiments then transferred to a wafer-scale, i.e. Sn-Cu alloys were deposited on 300 mm wafers in an industrial-type plating tool. A typical sample/wafer had a Cu seed with a diffusion barrier (e.g. TiW) underneath and patterned features defined with a photoresist mask. Characteristic dimensions of the patterned features were on the order of mm and cm (lines), (diameter)D50µm × (height)H60 µm (pillars), and D8µm × H15 µm (bumps). Cu, Ni, or Co were used as UBM layers.

Chemical composition of deposited alloys has been examined by using X-ray fluorescence (XRF), Micro X-ray fluorescence (Micro-XRF), Inductively coupled plasma mass spectrometry (ICP-MS), and Electron probe microanalysis (EPMA). Surface morphology and the shape of deposited features have been examined using Scanning electron microscopy (SEM) and Laser scanning microscopy (LSM), while thermodynamic properties have been studied using Differential scanning calorimetry (DSC). Within-wafer (WIW) and within-die (WID) height uniformity of the pillars has been analyzed using Falcon 630 Plus tool (Camtek Ltd), capable of capturing heights of all the structures on the wafer simultaneously. The kinetics of Intermetallic compound (IMC) formation have been studied in the number of selected samples by combining ex-situ Focused ion beam (FIB) and in-situ measurements of resistance change of the features during anneal/thermal ageing [1].

We will discuss possible benefits and drawbacks for use of electrochemically deposited Sn-Cu alloy solders in combination with different UBM layers based on these results.

References:

[1] Lin Hou, Jaber Derakhshandeh, Eric Beyne, and Ingrid De Wolf, “A Novel Resistance Measurement Methodology for in-situ UBM/Solder Interfacial Reaction Monitoring”, DOI 10.1109/TCPMT.2019.2950448, IEEE Transactions on Components, Packaging and Manufacturing Technology.

Figure 1
(Digital Presentation) Modifying LiNiO2 with W Via a Single Step Synthesis Route
Authors: Goonetilleke Damian , Mazilkin Andrey , Weber Daniel , Ma Yuan , Fauth Francois , Janek Jürgen , Brezesinski Torsten , Bianchini Matteo
Published: July 2022

LiNiO2 has been long considered as a promising cathode material owing to its high practical energy density. However, structural and surface instabilities, coupled with complexities in the LiNiO2 synthesis, have thus far prevented its commercialisation. To address issues with the material’s stability during synthesis and cycling, the use of an ammonium tungstate flux is demonstrated here to modify both the LiNiO2 crystal structure and primary particle morphology without introducing additional steps into the synthesis. The successful preparation of LiNiO2 modified with an industrially relevant amount of W (< 5 mol %) was confirmed using a combination of electron microscopy and synchrotron-based X-ray diffraction (XRD). Refinement of structural models against the data suggests tungsten dopant ions occupy the Ni site and concurrently induce migration of Ni2+ to the Li sites. Moreover, W enrichment at grain boundaries has been observed under some of the synthesis conditions. Variable temperature XRD was used to highlight the improved stability of the W-doped materials during the calcination at high temperatures. Electrochemical characterisation shows that W-doped LiNiO2 offers improved cycle life at the expense of little specific capacity. The structural consequences of tungsten doping on the behaviour of the material during electrochemical cycling was also investigated using operando XRD, showing reduced mechanical stress upon cycling. In conclusion, we will show that LiNiO2 modified by W with a simple route and no additional processing steps exhibits structural stability at high temperatures, offering a path towards the reliable synthesis of LiNiO2 with controlled morphology, improved chemomechanics and longer cycling life.