bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrolyte Conditions in Li-Ion Batteries in Presence of a Thermal Gradient
Authors: Guillamon Moreira Joaquin I. , Love Corey T. , Carter Rachel E. , Yang Xue , Verma Amit
Published: December 2020

Safety is one of the big concerns to tackle for large-scale application of Li-ion batteries. With higher amounts of energy stored per unit volume and higher current densities flowing through the device, energy dissipation in the form of heat is becoming one of the main issues for proper battery operation. If temperature increases, secondary chemical reactions may be initiated. These reactions release more heat and undesired products, triggering an auto-catalytic feedback process to occur, which is commonly classified into thermal-runaway mechanisms. This can potentially lead to a complete degradation of the battery, and possible explosion or combustion of the battery components.

Several researchers have worked on developing models to predict thermal behavior under abuse conditions with potential thermal runaway outcomes on Li-ion batteries. Hatchard et al. (2001) proposed a model that emulates the SEI decomposition and regeneration reactions on a standard 18650 cylindrical cell. Lopez et al. (2015) extended the previous work and also included the reactions of cathode decomposition and electrolyte decomposition with potential combustion. Although macroscopic level energy balance helps to predict potential thermal behavior in a battery of multiple layers, the study of all the different transport mechanisms that happen inside a single layer battery is essential for a better understanding of the process taking place when temperature begins to rise. With the aim of improving heat dissipation inside a battery, the electrolyte is a key component to consider as it can potentially handle heat flux easier through convention within the solution. This work investigates spatially dependent electrolyte conditions in the presence of a thermal gradient in order to produce a thermal runaway model. The objective of the study is to model transport mechanisms that might lead to thermal degradation of the battery. Li- ions, electrons, momentum, and thermal flux are the main components of the analysis. Numerical simulation techniques are used for this purpose. A thorough comprehension of the transport processes taking place inside the battery contributes to avoiding damage induced due to thermal abuse conditions.
Controlling the Nucleation Morphology of Lithium Using ALD-Grown TiO2
Authors: Oyakhire Solomon , Huang William , Cui Yi , Bent Stacey F.
Published: December 2020

Lithium (Li) metal batteries are desirable as rechargeable storage devices due to their high energy density; however, their practical implementation is hindered by the difficulty in controlling the Li metal plating microstructure. Artificial solid-electrolyte interphases (SEIs) have shown the potential to curtail the electrochemical instabilities of lithium, and atomic layer deposition (ALD) is commonly employed for the synthesis of thin-film artificial SEIs such as Al2O3 and alucone. However, these films quickly become delaminated as a result of their innate resistance to the cyclic shuttling of Li ions, resulting in marginal improvements in cell performance.

Herein, we detail the use of ALD-grown TiO2 as a nucleation layer, rather than as an artificial SEI. We show that by depositing TiO2 directly on the Cu current collector, we can control the deposition morphology of Li in the widely studied ether-based electrolyte - 1M LiTFSi in an equal volume mixture of 1,3 dioxolane and 1,2 dimethoxyethane, with 1 weight percent of lithium nitrate as an additive. By optimizing the thickness of TiO2, we reveal that lithium nucleates into large deposits atop the TiO2 film under significantly reduced overpotential, resulting in a reduction in contact surface area with the electrolyte and an increase in cell performance. We report substantial improvements in cycling efficiency with an average Coulombic efficiency of 96% after 150 cycles at a current density of 1 mA cm-2 in Li/Cu cells. In comparison to the pristine cells, voltage profiles for the champion TiO2-modified cell display negligible loss in charge capacity in the mid and late-stage electrochemical cycles, indicating an improvement in the reversibility of lithium stripping and plating. Using X-ray photoelectron spectroscopy (XPS) and energy dispersive X-ray spectroscopy (EDS), we establish that lithium plates atop TiO2, rather than beneath it, suggesting that the presence of TiO2 supports the enhanced reversibility of Li stripping and plating. Also, we utilize coulometry and transmission electron microscopy (TEM) measurements to establish the effects of the TiO2 film. All performance and characterization data will be presented and discussed.
(Charles W. Tobias Young Investigator Award Address) Understanding Reactivity at Electrode-Electrolyte Interfaces in Li-O2 and Li-ion Batteries
Authors: McCloskey Bryan D. , Diederichsen Kyle M.
Published: December 2020

When expanding the limits of voltage stability, capacity retention, and rate capability in batteries, parasitic processes at electrode-electrolyte interfaces-- such as electrolyte degradation, oxide surface densification, and Li metal plating on graphite electrodes-- play a critical role in defining battery performance. Our laboratory’s objective is to combine quantitative analytical techniques with spectroscopy to understand, and ultimately suppress, these process’s role in observed system lifetime, capacity, and efficiency. This presentation will provide a perspective on our understanding of interfacial reactivity in two systems: the positive electrode in the nonaqueous metal-O2 batteries, and interfaces in Li-ion batteries operating at either high voltage or high rates. First, the impact of electrolyte composition on product formation mechanisms in metal-O2 batteries will be discussed, as will strategies to suppress reactive oxygen-induced degradation. Second, drawing a comparison to Li-O2 batteries, the influence of anionic oxygen redox in interfacial degradation processes will be discussed in emerging high-capacity cathode materials, such as cation disordered rocksalt oxide and oxyfluoride materials and Ni-rich NMC layered oxide materials. Finally, to highlight the versatility of gas evolution-based quantitative techniques developed to study oxygen activity in metal-O2 and Li-ion oxide cathodes, the accurate detection of Li plating onset during fast charging of graphite electrodes will be shown by monitoring hydrogen evolution upon exposure of nominally delithiated graphite electrodes to acid.
Tailoring Electrolyte Solvation for Practical Li Metal Batteries Cycled at Ultra-Low Temperature
Authors: Holoubek John , Liu Haodong , Wu Zhaohui , Xing Xing , Yu Sicen , Yin Yijie , Zhou Hongyao , Pascal Tod , Chen Zheng , Liu Ping
Published: December 2020

Lithium metal batteries (LMBs) hold the key to pushing cell level energy densities beyond 300 Wh kg-1, and remain one of the most promising technologies for the future of electronic devices operating at ultra-low temperatures (< -30 oC). However, current battery technologies generally experience significant reduction in performance at such temperatures, and are commonly paired with external warming devices in order to circumvent this issue. However, this solution is suboptimal due to the inherent inactive volume, mass, and power requirements of such warming devices. It follows that batteries capable of both charging and discharging at these temperature extremes are highly desirable due to their inherent reduction in external warming requirements. However, charging in ultra-low temperature LMBs has been under studied to this point, and thus little is known about the growth dynamics of Li metal under such conditions. Herein, we present evidence that proper design of the local solvation structure of the electrolyte is crucial for achieving high Li metal coulombic efficiency (CE) at ultra-low temperature, using two model systems which were investigated via molecular dynamics (MD) and quantum chemistry simulations. Specifically, the contact-ion pair (CIP) structure dominated 1 M lithium bis(fluorosulfonyl)imide (LiFSI) / diethyl ether (DEE) electrolyte was found to produce remarkable CEs of 99.0% and 98.4 % at -40 oC and -60 oC, respectively, which was in stark contrast to the commonly used 1 M LiFSI 1,3-dioxolane,/1,2-dimethoxyethane (DOL/DME) electrolyte, who’s solvent-separated ion pair (SSIP) structure was found to result in rampant soft shorting of the cells due to dendritic plating. These divergent outcomes were explained via a desolvation mechanism, in which the strong Li+/solvent binding of the SSIP structure promoted tip driven growth whereas the weak Li+/solvent interactions in the CIP electrolyte promoted homogenous deposition. These insights were applied to Li metal full cells, where a high-loading 3.5 mAh cm-2 sulfurized polyacrylonitrile (SPAN) cathode was paired with a one-fold excess Li metal anode, yielding unprecedented capacities of 519 mAh g-1 and 474 mAh g-1 when charged and discharged at -40 oC and -60 oC, respectively. We also put this system in historical context via cell-level energy density calculations, which reveal that our work stands alone, supplying projected energy densities of 218, 143, and 126 Wh kg-1 when charged and discharged at 23, -40, and -60 oC, respectively. This work provides crucial design criteria for the design of ultra-low temperature LMB electrolytes, in addition to providing a defining step for the performance of low-temperature batteries regardless of electrode chemistry.

Figure 1
New Highly Microbial-Induced Corrosion-Resistant Ni-P-Based Coating with Superior Mechanical Properties.
Authors: Fayyad Eman M , Pathath Abdul Rasheed , Abdullah Aboubakr M. , Hassan Mohammad K , Hamdy Fatma , Sharaf Mohammed A , Mahmoud Khaled A. , Mohamed Adel , Jarjoura George , Farhat Zoheir
Published: December 2020

Microbiologically Influenced Corrosion (MIC) has been recognized as a widespread problem in the oil and gas industries because it causes substantial economic losses. Sulfate reducing bacteria (SRB) is one of the essential microorganisms families that have always been linked to MIC mechanisms causing localized corrosion problems. Since the bacterial adhesion on the metal surfaces is a prerequisite condition for the biofilm formation, controlling, and prevention of the colonization/proliferation of the microbial biofilms is of the critical impact regarding the MIC prevention and ensuring the public safety. Titanium-nickel shape memory alloy (TiNi SMA) nanoparticles have several marvelous features, ranging from the physical and chemical properties to the biological performance. Our electroless-plated NiP-TiNi nanocomposite coating (NiP-TiNi NCC) is used to determine the suitability of using it as an inhibition system for SRB on carbon steel (CS). The influence of anaerobic bacteria SRB on the corrosion behavior of API X80 CS, NiP, and NiP-TiNi coatings in simulated seawater was studied by electrochemical impedance spectroscopy (EIS) after different periods of incubation time (7, 10, 14, 21, 28 days). The corrosion products and biofilm formation of the incubated specimens’ surfaces after 7, 10, and 28 days of incubation are checked using the scanning electron microscope (SEM) and X-ray photoelectron spectroscopy. EIS results revealed that the antimicrobial performance of the NiP-TiNi NCC is more efficient compared to the TiNi-free coating that has an inhibition efficiency of 87.5 % after 28 days of incubation time with SRB. Furthermore, SEM, EDS and XPS results confirm that negligible corrosion occurrs for the coated surfaces. Also, The mechanical properties of this coating was proved be superior compared to the Carabon steel and the NiP-based coatings.
Toward Fast Charge of Lithium-Ion Batteries through Advanced Electrolyte
Authors: An Kihun , Song Seung-Wan
Published: December 2020

As the lithium-ion battery (LIB) market for electric vehicles and grid-based energy storage systems is rapidly growing, the upcoming urgent challenge is to charge faster the LIB than ever. Thus, battery chemistry and reaction kinetics are being evolved toward the development of quickly charged LIBs in minutes scale, not in hours scale. In the LIB electrolyte perspective, commercial carbonate-based liquid electrolyte has multiple limitations in attaining high rate performance, due to the limited ionic conductivity and viscosity, sluggish de-solvation kinetics on graphite anode, low thermal stability, etc. To overcome those limitations, extensive research on new electrolyte systems (e.g., highly concentrated salt, aqueous system, etc.) have been reported. Herein, we present the improved rate capability and cycling performance of nickel-rich layered oxide-based lithium cell with our newly designed electrolytes. We are going to discuss electrode-electrolyte interface chemistry and its correlation to performance in this meeting.

Acknowledgements

This research was supported by the National Research Foundation grant funded by the Ministry of Science and ICT (No. 2019R1A2C1084024) and Creative Human Resource Development Consortium for Fusion Technology of Functional Chemical/Bio Materials of BK Plus program by Ministry of Education of Korea.
Polysilsesquioxane Hybrid Polymer Electrolytes for Lithium Ion Batteries
Authors: Lee Albert S , Lee Jin Hong , Baek Kyung-Youl , Hwang Seung Sang , Koo Chong Min
Published: December 2020

A novel inorganic–organic hybrid crosslinker was prepared through synthesis of a fully condensed, high molecular weight ladder-like poly(methacryloxypropyl)silsesquioxane (LPMASQ) in one pot with a facile, base-catalysed system. The fully condensed LPMASQ revealed good thermal (∼380 °C) and electrochemical stability (∼5.0 V) due to the absence of uncondensed silanol groups. LPMASQ also revealed good solubility in various organic solvents and fully gelated 1 M LiPF6 in ethyl carbonate–diethyl carbonate (EC–DEC, 3/7, v/v) electrolyte solution through fast thermal and photocuring even at a very low concentration of 2 wt%. These observations were attributed to the polymeric nature of LPMASQ containing over one hundred methacryl moieties on the rigid double-stranded siloxane backbone. To the best of our knowledge, formation of a gel polymer electrolyte with 2 wt% gelator is the smallest gelation concentration that has ever been reported. This leads to high ionic conductivity (∼6.0 mS cm−1), excellent Coulombic efficiency and battery cell performance, comparable with those of the neat liquid electrolyte. The small crosslinker content, thermal and electrochemical stability, fast thermal and photocuring and facile processing of the LPMASQ based GPEs, as well as excellent Li battery cell performances strongly hold great promise for future industrial battery applications.
On the Origin of Reactive Oxygen Species in Lithium-Excess Layered Oxide Cathode Materials
Authors: Kaufman Lori , McCloskey Bryan D.
Published: December 2020

Lithium-excess layered oxide cathode materials (Li(1+x)TM(1-x)O2) for lithium-ion batteries achieve high specific capacities (~250 mAh/g) via redox participation of oxygen anions as well as the transition metals in the oxide cathode. While oxygen is initially present as O2- in the cathode, oxidized oxygen species such as peroxo-like oxygen (O2
2-) and oxygen gas (O2) are detected on charge. Possible sources of these oxygen species include both the lattice and cathode surface contaminants such as Li2CO3 and LiOH. In this work, differential electrochemical mass spectrometry (DEMS) is used to study the mechanisms by which these oxygen species form and react within the battery. DEMS results show that organic fragments containing diatomic oxygen are present on the cathode surface during the first charge starting around 4.2 V vs. Li/Li+. Since no O2 moieties exist in the carbonate electrolyte, these fragments must be a result of reactive oxygen attack on the electrolyte. In order to further understand the origin of these fragments, controlled amounts of 18O-enriched Li2CO3 are deposited on the cathode surface via reaction with CO2 gas before cycling. These results offer insight into the influence of surface contaminants and oxygen activity on interfacial reactivity in lithium-excess cathode materials.
Acoustic Characterization of Structural Reversibility in Lithium Metal Anodes
Authors: Chang Wesley , Steingart Daniel A.
Published: December 2020

A commercially relevant lithium metal battery is still hindered by issues such as rapid consumption of the electrolyte and an unstable interface. Relative success in stabilizing the solid-electrolyte-interphase and achieving higher Coulombic efficiencies has been found using organoborate electrolyte salts, highly fluorinated solvents, external pressure and surface modification strategies. However, initially dense close-packed plating does not necessarily exhibit structural or mechanical reversibility. Operando acoustic analysis is a reliable technique for interrogating physical changes within a closed-form battery. Specifically, the effective stiffness can be accurately measured to probe changes in the intrinsic material properties of plate metal. Stiffness, in addition to stress and strain, is an important metric in mechanical characterization of phase change or plate metal electrodes. Here, we describe recent efforts to diagnose common failure mechanisms using acoustics and extension of the technique to dynamically probe structural changes in plate metal anodes.

Figure 1
Combined Multi-Physics and Machine Learning Approach to Forecast SEI Decomposition in LIBs
Authors: De Angelis Paolo , Yurkiv Vitaliy , Asinari Pietro , Mashayek Farzad
Published: December 2020

Over the last two decades, the tremendous efforts of researchers brought the Li-ion battery (LIB), based upon the intercalated graphite electrode, to its advanced level enabling their wide-spread application. Unfortunately, high demand led to many safety problems especially associated with thermal runaway. A very common reason of LIBs’ thermal runaway is the exothermic decomposition of solid electrolyte interface (SEI) leading to a battery’s rapid self-heating and in extreme scenarios to explosion. It is very challenging to suppress, control or sometimes even observe the thermal runaway due to the SEI formation/decomposition in realistic operation conditions. However, the evolution of thermal and electric parameters during LIBs operation may indicate the occurrence of thermal runaway, which will allow its early forecasting and corresponding suppression.

In order to predict the thermal runaway in LIBs, we use machine learning (ML) techniques, in particular, convolutional neural network (CNN) and deep neural network (DNN) to identify temperature pattern change leading to the thermal runaway. The ML methods are trained based upon the images obtained from the multi-physics calculations using Comsol software package. The pouch type LIB consisting of five distinct layers, i.e., two current collectors, negative and positive electrodes and electrolyte, is considered. The electrochemical model is based on a 1D continuum description of reaction and transport along electrodes, electrolyte and current collectors, plus an additional dimension in the electrode particle (P2D).1 The SEI formation/decomposition is modeled using the parasitic current approach.2,3 We investigate three regimes of thermal runaway occurrence, i.e., a single heat source, two heat sources and multiple sources. Correspondingly, different CNN and DNN architectures have been built and trained based upon the images from multi-physics calculations. The prediction of the trained network has been tested using simulated and literature available data.

References

[1] Newman, J.; Tiedemann, W. Potential and Current Distribution in Electrochemical Cells. J. Electrochem. Soc.
1993, 140 (7), 1–5.

[2] Wang, K.; Xing, L.; Zhi, H.; Cai, Y.; Yan, Z.; Cai, D.; Zhou, H.; Li, W. High Stability Graphite/Electrolyte Interface Created by a Novel Electrolyte Additive: A Theoretical and Experimental Study. Electrochimica Acta
2018, 262, 226–232. https://doi.org/10.1016/j.electacta.2018.01.018.

[3] Safari, M.; Morcrette, M.; Teyssot, A.; Delacourt, C. Multimodal Physics-Based Aging Model for Life Prediction of Li-Ion Batteries. Journal of the Electrochemical Society
2009, 156 (3), 145–153. https://doi.org/10.1149/1.3043429.
Transport Properties of Water in Salt Electrolytes (WiSE)
Authors: Williams Mateo Sebastian , West Alan C. , Steingart Daniel A.
Published: December 2020

The emergence of new electrochemical technologies employing WiSE (Water in Salt Electrolytes) have proven the utility of high species concentrations (> 8 M) in enabling aqueous electrodeposition of metals (Li, Zn) with an improved solvent stability window. However, the transport of active species as well as the solvent become important in the WiSE concentration range and is not currently well understood. In order to understand the dynamic interplay of ionic strength and solvation, a transport model is developed using the concentrated solution theory as described by Newman. Steady state predictions suggest a thin boundary layer where the local concentration can exceed the solubility limit and cause precipitation of a salt film on the electrode surface. This effect has been shown in previous electrodeposition literature and could help explain loss of performance in WiSE battery systems over continuous cycling. In order to characterize the transition from aqueous solution to WiSE solutions, traditional experimental methods to determine physical properties (density, viscosity, and conductivity) as well as a a low frequency Electro-hydro-dynamic (EHD) Impedance technique are employed. The physical characterization can then be used to estimate important transport properties such as the cationic transference number (t+) and effective Schmidt number (Sc = ν/ρD) within the predicted mass transfer limited boundary layer as functions of electrolyte concentration within the WiSE regime (Cbulk > 8M).
Lithium Deposition in Single-Ion Conducting Polymer Electrolytes
Authors: Borzutzki Kristina , Dong Kang , Nair Jijeesh Ravi , Wolff Beatrice , Hausen Florian , Winter Martin , Manke Ingo , Brunklaus Gunther
Published: December 2020

Lithium metal is considered as potential anode material due to its superior energy density compared to conventional graphitic anodes.[1] However, so far its application is restricted due to inhomogeneous Li deposition during cycling, potentially causing contact losses between bulk and deposited Li or short circuit of the cell related to formation of ‘dendritic’ deposits. Theoretical models propose that single-ion conducting electrolytes afford safe and ‘dendrite-free’ cycling of lithium metal batteries (LMBs) due to immobilization of anions and thus, prevention of cell polarization.[2] In this contribution, a blend type quasi-solid single-ion conducting polymer electrolyte (SIPE), a polymer class that has attracted much attention recently, is consulted for analysis of the Li deposition behaviour. Combined scanning electron microscopy (SEM) and X-ray tomography are applied illustrating the occurrence of inhomogeneous, rather dense Li deposits agglomerating and eventually penetrating the polymer membrane independent of the applied current densities. Raman mapping, nano-mechanical (QNM) and electrochemical strain microscopy (ESM) mapping further reveal that membrane constituents and consequently membrane properties such as (mechanical) stiffness and ionic conductivity are non-homogeneously distributed within the membrane related to the phased separated morphology of the blend. This implies that the intrinsic nature of the polymer membrane is responsible for the formation of conduction channels, also governing the homogeneity of Li deposition. Beyond that, it is demonstrated how characteristics of the Li│polymer interface in salt- free SIPEs limit the achievable cell performance, particularly since limited Li+ ion diffusivity through the interfaces substantially impair efficient charge carrier transport within the cell system.

References

[1] P. Albertus, S. Babinec, S. Litzelman, A. Newman, Nat. Energy 3 (2018) 16–21.

[2] J.-N. Chazalviel, Phys. Rev. A 42 (1990) 7355–7367.
Correlating Calcium Electrodeposition with Solvation Structure: X-Ray Absorption Studies on Ethereal-Calcium Complexes in Solution
Authors: Driscoll Darren , Hahn Nathan T , Balasubramanian Mahalingam
Published: December 2020

Ca-ion electrochemical systems have been on the forefront of multivalent energy storage due to their use of earth-abundant redox materials and their high theoretical specific capacities in relation to monovalent-charge carriers. However, significant pitfalls in cation plating and striping arise from electrolyte decomposition and can be related in-part to the coordination environment around Ca2+ with both the negatively charged anion and the organic–aprotic solvent. X-ray absorption fine structure (XAFS) studies of liquid electrolytes have been performed to identify the elemental and geometric coordination around the multivalent cation. Specifically, we can define the local geometry, coordination and electronic structure of Ca–ethereal complexes through the combined analysis of the X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) to provide clear indication of the extent of Ca2+–solvent interaction. Finally, we combined these characterization results with recent progress in Ca2+ electrochemistry and suggest important structural trends for reversible plating/stripping depending on the extent of solvent chelation. The submitted abstract has been created by UChicago Argonne, LLC, Operator of Argonne National Laboratory (“Argonne”). Argonne, a U.S. Department of Energy Office of Science laboratory, is operated under Contract No. DE-AC02-06CH11357. The U.S. Government retains for itself, and others acting on its behalf, a paid-up nonexclusive, irrevocable worldwide license in said article to reproduce, prepare derivative works, distribute copies to the public, and perform publicly and display publicly, by or on behalf of the Government.
Understanding Anode Capacity Fade in Symmetric Cells
Authors: Yan Zilai , Liu Yijia , Hatchard Timothy , Scott Ben , Cao Yidan , Cao Simeng , Obrovac Mark N
Published: December 2020

Symmetric cells have been developed to evaluate electrode degradation directly associated with solid electrolyte interphase (SEI) growth. This limits their applications to some certain anodes, such as graphite and Li4Ti5O12.1 In this work, symmetric cells have been applied to understand the degradation of high energy density anodes, such as Si-alloys, which undergoes multiple degradation mechanisms, including mechanical failure, SEI growth, and excess capacity. The excess capacity is related to the reversible capacity changes, caused by the electrode upper endpoint potential shift.

A Li inventory model is developed to interpret anode capacity fade in symmetric cells. The Li inventory model attempts to establish a mathematical relationship between multiple anode degradation processes and measured experimental data, such as cycling charge/discharge capacity. This model allows for the measurement of coulombic efficiencies of individual components of blended electrodes (e.g. alloy + graphite). Figure 1 illustrates the main reactions and side reactions during symmetric cell discharge at ith cycle. Except the main reactions in working electrodes about lithiation and delithiation, the side reactions, as mentioned above, have been included.

In this work, a Si-alloy, Si80W20,2 was used as an example. One major benefit of symmetric cells is to measure the coulombic efficiency (CE) of electrodes with standard chargers.3 After deconvolution, the total irreversible capacity (IC) per cycle due to surface reactions on Si80W20 can be obtained from graphite and Si-alloy/graphite blended electrodes. The temperature effects on IC can also be obtained, as summarized in Figure 2.

Reference

J. C. Burns et al., J. Electrochem. Soc., 158, A1417–A1422 (2011).

Y. Liu, B. Scott, and M. N. Obrovac, J. Electrochem. Soc. , 166, A1170–A1175 (2019) 10.1149/2.0851906jes.

Z. Yan and M. N. Obrovac, J. Electrochem. Soc., 164, A2977–A2986 (2017).

Figure 1 (a) An example of potential curves of electrode A, electrode B, and the symmetric cell during symmetric cell discharge. Illustrations of main and side reactions occurred at electrode A and electrode B during symmetric cell discharge at i
th cycle are illustrated in (b) and (c), respectively. The capacity for each reaction during a single symmetric cell discharge/charge process are labelled in the following brackets. Li-Eld, Eld, and Elyt stand for lithiated electrode, delithiated electrode, and electrolyte, respectively.

Figure 2 A summary of the average IC of graphite (MAG-E, 20 μm average size, Hitachi) and on Si80W20 per cycle normalized with respect to reversible capacity at different temperatures, as derived from symmetric cells with graphite and alloy/graphite blended electrodes.

Figure 1
Interface between Sodium Metal and Nasicon Solid-State Electrolyte
Authors: Oh Jin An Sam , Zeng Kaiyang , Lu Li
Published: December 2020

Metal solid-state battery is deem as the future energy storage system due to its high energy density and safety. Sodium-metal solid-state battery has the cost advantage over lithium-based system due to its availability in the earth’s crust. Beside achieving high ionic conductivity, an intimate and robust electrode/electrolyte is vital to the battery performance. In this study, the surface composition of NASICON electrolyte compatibility with sodium metal is studied. It is realised that the presence of functional groups on the surface has led to high interfacial impedance between the sodium and electrolyte. Such functional groups can be removed by a simple thermal treatment in air. Consequently, the area specific interfacial resistance reduced to 11 Ω cm-1 compared to 1716 Ω cm-1.
Large-Area Graphene Transfer through Synthesis of an Interfacial Release Layer between Epitaxial Cu(Ni)(111) and Al2O3(0001) Template
Authors: Tsai Hung-Chieh , Marien Brecht , De Gendt Stefan , Brems Steven
Published: December 2020

As the pioneer two-dimensional material with outstanding properties, graphene is still lacking a CMOS compatible handling process, both for growth and transfer. This restriction slows down the application of large-scale-high-quality monolayer graphene (MLG). The synthesis of wafer-scale single-crystal MLG has matured utilizing a single-crystal Cu(111) deposit epitaxially on c-plane sapphire as a growth template[1,2]. However, the non-straightforward intercalation base transfer process [3] becomes a bottleneck. Hence, an interfacial release layer between Cu and sapphire could provide an alternative route for the graphene transfer process.

Here, we report on the synthesis of large-area multilayer graphene at the interface of epitaxial Cu(Ni)(111)/ Al2O3(0001) using atmospheric pressure chemical vapor deposition (CVD). The interfacial carbon layer (ICL) was synthesized by introducing CH4 and H2 gases in the CVD chamber at 1050°C, and characterized by micro-Raman spectroscopy, XRD, and AFM. Carbon layers with thickness up to 80nm were observed at the interface between 500nm thick Cu and Al2O3.

The effects of the partial pressure of gases - PH2 and PCH4 – and template substrate on the growth dynamics were investigated systematically by optical microscopy and image analysis. The growth rate and deposition area of ICL are positively correlated with PCH4. In the Cu85Ni15(111) system, ICL coverage is significantly lower compared to Cu(111). This is attributed to the faster growth rate of a top surface MLG, which blocks the access of carbon into the interface of Cu(Ni)/Al2O3. A higher PH2 slows down the MLG growth, leading to a denser ICL deposition in both substrates.

The growth mechanism of this ICL is also proposed as the result of two competing effects: 1. The high PCH4 environment drives the decomposed carbon species to the interface from the top surface by diffusion through the bulk of the catalytic metal. 2. The blockage of carbon access to the bulk of metal once the top layer MLG is closed.

After process optimization, the ICL could be synthesized simultaneously with top layer high-quality CVD MLG. In the future, this process could provide opportunities to enable CMOS compatible large-scale-high-quality MLG transfer.

K. Verguts et al., ECS J. Solid State Sci. Technol., 5, Q3060–Q3066 (2016).

M. Huang et al., ACS Nano, 12, 6117–6127 (2018).

K. Verguts et al., ACS Appl.
Mater. Interfaces, 9, 37484–37492 (2017).
(Invited) Electrostriction Driven Preferential Solvation Processes for Divalent Cations in Non-Aqueous Electrolytes
Authors: Murugesan Vijay , Chen Ying , Han Kee Sung , Mueller Karl T
Published: December 2020

The strong electric field from divalent cations (i.e. Mg2+, Zn2+ and Ca2+) can influence conformal structural evolution of organic solvent molecules and subsequently influence emergent properties of battery electrolyte solutions. This electrostriction process typically depends on the charge and size of the ion and on certain properties of the solvent such as molecular flexibility and permittivity. In this work, we focused on the effect of cationic size and structural flexibility of organic solvent molecules commonly used in multivalent batteries. In particular, we analyzed electrostriction driven preferential interactions that lead to contact-ion pair (CIP) and solvent separated ion pair (SSIP) formation in cyclic ether solvents such as tetrahydrofuran (THF) and 2-methyl-tetrahydrofuran (2-MeTHF) and linear structured ether solvents such as glymes (G1 and G2). The concentration and temperature dependent preferential interactions of these electrolyte systems were analyzed using multinuclear (1H,19F, 17O, 25Mg, 43Ca, and 67Zn) NMR spectroscopy and PFG-NMR diffusion measurement combined with classical MD and DFT based computational modeling. Our results show that the solvent-cation interaction is more favorable in the linear glyme-based electrolytes than in the cyclic THF-based electrolytes. In particular, the glyme-based solvents (G1 and G2) drive preferential dissociation of cation-anion pairs, resulting in a higher concentration of SSIPs in these multivalent electrolyte solutions. The correlation between such preferential solvation phenomena and emergent properties including conductivity and chemical stability will be discussed.

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(Invited) X-Ray Absorption Spectroscopy: Investigations of the Interfacial Chemistry of Batteries at APS Beamline 9-BM
Authors: Wu Tianpin
Published: December 2020

As a beamline dedicated to the X-ray Absorption Spectroscopy, 9-BM is capable to cover very wide energy range (2145.5 eV P-K edge to 24350 eV Pd-K edge). In recent years more efforts have been devoted to the fields of catalysis and energy storage, focusing on catalysis for efficient conversion of energy resources into usable forms, and storage of such energy in efficient and safe capacitors. To understand and predict how catalysts and/or energy storage materials function, it’s very important to characterize the materials under actual reaction conditions (in-situ or operando). 9-BM has leveraged the advanced capabilities for in-situ catalysis and electrochemistry, as well as the ability to collect high quality spectroscopy data at a rapid rate (Quick EXAFS). Scientists using 9-BM are able to gain unique insight to how chemical processes affect and are affected by the materials under investigation. In this talk, the capabilities will be displayed with a few examples of the science enabled by them.
(Invited) Electrolyte and Interphase Factors in Zn-Based Battery Chemistries
Authors: Xu Kang
Published: December 2020

As the oldest anode material, Zn has been working in batteries for more than 200 years since Alessandro Volta piled up Cu and Zn plates separated by saline water to produce electric current. Compared with the ultimate anode material Li, Zn-based battery chemistries promise low cost, rich abundance as well as higher volumetric energy density. However, such promises have been significantly discounted due to the notorious reversibility of Zn metal in almost all electrolytes, be it aqueous or non-aqueous. In this talk, we will explore the bulk electrolyte and interphasial factors that dictate the Zn metal reversibility, and demonstrate a few successful examples where such factors are well tailored to enable high energy density Zn batteries with high cycling stability.
Can We Consider SiC Nanoparticles Inert When We Add Them to Electrodeposition Systems?
Authors: Pinate Santiago , Leisner Peter , Zanella Caterina
Published: December 2020

One of the biggest challenges that the electrodeposition of nanocomposites faces is obtaining reproducible results and controlled end products. Albeit, nominally equal particles and similar bath composition often are reported contradictory results in the codeposition rate when nanocomposites are electroplated.

In this study, the chemical response of as-produced SiC nanoparticles (50 and 60 nm size) from different suppliers was examined by ζ-potential measurements and pH titration. The latter revealed a buffering effect at acidic pH with different intensity for each powder, while the ζ-potential values also varied between suppliers. These results highlighted how the particles’ surface state could be the source of contradictory values in their codeposition rate, where SiC50 reported ≈ 0.8% vol. content, whereas SiC60 ≈ 4.5% vol.

The main objective of this work was to tackle the scattering of powder beahviour by a surface treatment (ST) of the powder based on nitric acid, which to the best of the authors’ knowledge has not been proposed before in this context of electroplating nanocomposites. The ST was successful in bringing the particles independently of their size, batch or production route to a common status and behaviour, thus a controlled electrocodeposition. The buffering effect observed by titration reported a similar intensity decrease, and the ζ-potential measurements showed comparable negative values for each powder. Moreover, the ST significantly altered the codeposition rate allowing a similar codeposition for both powders, thus resulting in also a similar microhardness and microstructure.
Paired Electrochemical Hydrogenation and Oxidation of Biomass-Derived Furanic Compounds to Value-Added Monomers in the Single Electrolyzer
Authors: Liu Hengzhou , Lee Ting-Han , Cochran Eric W , Li Wenzhen
Published: December 2020

Organic electrosynthesis is emerging as a cost-effective and environmental-friendly chemical production strategy by utilizing renewable electricity. Paired electrolysis cogenerates valuable chemicals at both electrodes can optimize the energy efficiency and economic feasibility. We report pairing hydrogenation and oxidation of 5-(hydroxymethyl)furfural (HMF) or furfural to desired chemicals at a single electrolysis cell. Electrocatalytic hydrogenation of HMF to 2,5-bis(hydroxymethyl)furan (BHMF) and furfural to furfural alcohol (FA) with high selectivity of >90% can be operated at near-neutral pH on Ag-based and Pb-based catalysts, respectively. In addition, oxidizing HMF to 2,5-furandicarboxylic acid (FDCA) and furfural to furoic acid can both be realized at TEMPO mediated process by using carbon-based catalysts or at Ni-based catalyst in an alkaline medium. Taken together, HMF or furfural can be performed in a single electrolysis cell with a minimized cell voltage only around 1.6 V. Products selectivity and faradaic efficiency are highly related to the reaction conditions, including potential or current density, architectures of the reactor, type of catalysts. By optimizing the single flow reactor, a three-electrode system, two-electrode membrane assembly architecture, and pH-symmetric and pH-asymmetric structure can be designed to reduce the capital expense, minimize required energy, and simplify processing steps. Finally, a complete electrons economy can be achieved by pairing two electrochemical reactions, and the overall charge efficiency can attain over 170% without any crossover issue detected. As a result, the continuous cogeneration of high value-added BHMF or FA and FDCA or furoic acid can be performed in a single electrolyzer.
Eco-Friendly Synthesis of Nanoporous Magnesium By Air-Free Electrolytic Dealloying of Magnesium-Lithium Alloy with Recovery of Sacrificial Lithium
Authors: Fu Jintao , Detsi Eric
Published: December 2020

In recent years, air- and water-sensitive nanostructured materials with minimal surface oxide coverage have received increased attention for their potential role in various applications, such as catalysts for combustion fuels, active ingredients in solid-propellant rockets, and reactants for onboard and on-demand hydrogen generation to feed fuel cells. However, the fabrication of this class of materials has been hindered by their inherently high chemical reactivity. Magnesium, with its standard reduction potential of -2.37 V vs. SHE, is highly water-reactive in its nanostructured form, thus the synthesis of nanostructured magnesium with minimal surface oxide coverage poses a challenge. In this talk, I will introduce a novel eco-friendly air-free selective electrolytic leaching route to fabricate three-dimensional (3D) bicontinuous nanoporous magnesium (NP-Mg) with minimal surface oxide coverage. The starting material consists of a Mg-Li parent alloy, with lithium as the sacrificial component. During selective electrolytic leaching in an anhydrous lithium-conducting organic electrolyte solvent, the sacrificial lithium is stripped from the Mg-Li parent alloy used as the working electrode and plated on a pure lithium foil used as the counter electrode. This process enables sacrificial element recovery, making it eco-friendly. The dealloyed NP-Mg exhibits a characteristic ligament and pore size in the range of 20-30 nm, and its morphology was thoroughly investigated using electron microscopy, inductively coupled plasma (ICP) spectroscopy, small-angle X-ray scattering (SAXS), and X-ray diffraction, as will be shown during my talk. NP-Mg with such ultra-small feature size could be attractive for several applications including hydrogen storage in the form of magnesium hydride, and on-demand hydrogen generation by hydrolysis with pure water.
Solid State Ion Conductors to Enable Low Temperature Molten Sodium Batteries
Authors: Spoerke Erik D. , Peretti Amanda , Gross Martha , Percival Stephen , Small Leo J. , Hill Ryan , Cheng Yang-Tse
Published: December 2020

Molten sodium batteries show clear promise for safe, long-lifetime grid-scale energy storage, and there is growing expectation that they may be able to impact a host of energy storage areas, ranging from vehicle electrification to industrial applications. Key to the successful development and implementation of these technologies, though, are 1) reducing the traditionally high operating temperature of these batteries and 2) identifying robust, zero-crossover solid state separators that will perform effectively at these reduced temperatures. Traditional molten sodium batteries, such as sodium-sulfur and sodium-nickel chloride (ZEBRA), operate near 300°C, where ceramic separators, such as β”-Al2O3 have high ionic conductivity, but these high temperature systems can be cost-prohibitive in large scale applications. Here, we discuss a significant deviation from these chemistries and materials in a sodium-iodide (NaI) battery that utilizes a molten sodium anode and a sodium iodide-based molten salt catholyte, operating at drastically reduced temperatures near 100°C. NaSICONs (Na Super Ion CONductors) show promise as effective ceramic separators in lab-scale demonstrations of this battery chemistry, but challenges to cost, widespread availability of the material, electrochemical compatibility, and mechanical stability of the ceramic have motivated the search for new sodium ion conducting separator materials and designs. We will describe not only critical synthetic considerations, but also important benefits and shortcomings of NaSICON separators for use in this specific battery chemistry. Importantly, we will describe recent efforts build on the promise of NaSICON materials, exploring new composite materials and hybrid structures that meet strenuous demands of ionic conductivity, chemical compatibility, and mechanical robustness for separators in low temperature sodium batteries. Innovative designs that take advantage of controlled particle morphology and organization in polymer-ceramic composites, for example, promise improved mechanical durability and effective ionic conductance in low cost, highly processable systems. Understanding the critical relationships between material composition, microstructure, and electrochemical performance of these emerging materials will be central to the successful development of a new generation of solid-state ion conductors and the realization of effective low temperature molten sodium batteries.

Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.
(Invited) Oxide-Based All-Solid-State Batteries Prepared By Aerosol Deposition
Authors: Iriyama Yasutoshi , Sakakura Miyuki , Motoyama Munekazu , Yamamoto Takayuki
Published: December 2020

Oxide-based all-solid-state batteries (OX-SSBs) have been expected as next generation rechargeable batteries. Although various kinds of high Li+ conductive solid electrolytes have been prepared such as Li7La3Zr2O12 (LLZ), NASICON-structured Li1.3Al0.3Ti2(PO4)3 (LATP), LiTaPO4 etc, there are serious problems to develop low-resistive positive electrode/high Li+ conductive solid electrolyte interface. Because these high Li+ conductive solid electrolytes are crystallized at 800-1000 ℃, high temperature sintering is common way to combine them with conventional crystalline insertion electrode materials (LiCoO2 (LCO), LiNi1/3Co1/3Mn1/3O2 (NCM111) etc). However, both electrodes and solid electrolytes are composed of different elements with different concentrations, such high temperature sintering process frequently provide mutual diffusion region around the interface in addition to structural degradation and then seriously impede the interfacial resistance. Thus, one strategy to prevent those side reactions will be to apply low temperature sintering or densification process.

We have focused on aerosol deposition, AD, a room temperature ceramic coating process. AD can realize quick speed and wide area ceramic coating and has been estimated as a cost-effective process technology for oxide-based energy conversion devices. AD make it possible to prepare electrode-solid electrolyte composite electrodes at room temperature and LiCoO2 film electrode on LiPON film. In addition, AD enables us to investigate the effects of annealing temperature on the interfacial resistances and then limiting temperature for sintering.

In this presentation, our recent works on Ox-SSBs using the AD will be introduced 1) 4V- and 5V-class bulk-type Ox-SSBs, 2) effects of annealing temperature on interfacial resistivity, an example of LCO-LATP system to determine limiting temperature for sintering.