bluuebunny/crossref_metadata_2025 huggingface dataset:
XPS Analysis of the Oxide Films Formed on Non-Charged and Hydrogen-Charged 316L SS in Deaerated High Temperature Water
Authors: Cui Tongming , Ma Jiarong , Zhang Kun , Jia Yibo , Ning Fei , Lu Zhanpeng
Published: February 2020

Austenitic stainless steel components have been used in pressurized water reactors (PWRs) coolants. These austenitic stainless steels may absorb hydrogen from either the dissociation of dissolved hydrogen in PWR primary water or the corrosion processes at the steel surfaces during the immersion in PWR primary water. It is necessary to investigate the effect of hydrogen in alloys on the oxidation and resultant environmental degradation processes in high temperature water environments. In the present study, the oxide films formed in deaerated PWR primary water at 300℃on a cold worked 316L (316LCW) stainless steel with or without prior hydrogen-charging were characterized. Hydrogen-charging of 316LCW was performed by cathodic charging in sulfuric acid solution containing thiourea at room temperature. Prior to the immersion tests, the Immersion tests were performed in a 2-L Ti-autoclave with solution deaerated by purging N2 gas before heating to test temperature.

The oxide films formed on 316LCW and hydrogen-charged 316L CW (316LCW-H) specimens after exposure to deaerated PWR primary water at 300 oC for168 h were observed. The XPS depth profiles of the oxide films formed on 316LCW and 316LCW-H specimens after exposed to simulated PWR primary water are compared. The thickness of the oxide film was estimated from the half height of oxygen concentration and the sputtering rate (0.1 nm/s), for determining the thickness of the oxide film that was about 180 nm on 316LCW and about 250 nm on 316LCW-H. The oxide films formed on both 316LCW and 316LCW-H were enriched in Fe and Ni in the outer layer, and enriched in Cr in the inner part of the oxide film. The Cr content in the inner oxide layer formed on 316LCW-H specimen was lower than that on 316LCW specimen.

Figure 1
Small Molecule Adsorption on Colloidal Alumina and Zirconia Abrasives Used in Chemical-Mechanical Planarization (CMP) Slurries
Authors: Martinez Keri A. , Stewart Michael R. , Campbell Dean J, , Remsen Edward E.
Published: February 2020

Small molecule adsorption on CMP slurry abrasive particles has been investigated previously for silica (1) and ceria (2, 3) abrasives using fluorescence correlation spectroscopy (FCS) and attenuated total reflectance – Fourier transform infrared spectroscopy (ATR-FTIR). The need for further characterization of such adsorptive interactions is dictated by the increasing use of abrasive particles in CMP slurries with minimized hydrodynamic diameters (≤ 10 nm) as a means to reduce surface defects created during CMP processes. Incorporation of ever-smaller abrasive particles in CMP slurries will, however, promote the adsorption of chemical additives on a slurry’s abrasive particles due to the increase in the total abrasive particle surface area.

In the present study, FCS and ATR-FTIR are employed in the analysis of small molecule adsorption on colloidal alumina and zirconia abrasive particles. This work is motivated by the widespread commercial use of alumina-based slurries in CMP processes for planarization of deposited copper films on dielectric layers and the proposed use (4) of zirconia abrasives in CMP slurries for metal film removal on dielectric metal oxide materials. The reported FCS studies use fluorescent dyes as probes for adsorption sites on alumina and zirconia colloids dispersed in aqueous solution. Described ATR-FTIR analyses summarize the characterization of molecular interactions driving glycine and picolinic acid adsorption on porous thin films of colloidal alumina and zirconia, respectively. The potential for employing these methods in studies modelling the adsorption of CMP slurry additives on a metal film deposited on a silicon wafer surface is also discussed.

References:

Jacobson, L.M.; Turner, D.K.; Wayman, A.; Rawat, A.; Carver, C.T..; Moinpour, M.; Remsen, E.E. Characterization of Particle Size and Surface Adsorption for SiO2 Abrasives Used in Chemical Mechanical Planarization via Fluorescence Correlation Spectroscopy. ECS J. Solid State Sci. Tech.
2015,
4, P5053-P5057.

Schorr, D.K.; Smith, M.A.; Rawat, A.K.; Carver, C.T.; Mansour, M.; Remsen, E.E.Fluorescence Correlation Spectroscopic Studies of Particle Properties for Colloidal Ceria Abrasives Used in Chemical-Mechanical Planarization. ECS Trans.
2016,
72, 43-51.

Marsh, J.L.; Wayman, A.E.; Smiddy, N.M.; Campbell, D.J.; Parker, J.C.; Bosma, W.B.; Remsen, E.E.Infrared Spectroscopic Analysis of the Adsorption of Pyridine Carboxylic Acids on Colloidal Ceria.Langmuir
2017, 33
, 13224-13233.

“CMP Composition Containing Zirconia Particles and Method of Use”; Lin, Wiechang; Parker, John; Remsen, Elizabeth; PCT Int. Appl. 2012; US 8,778,212 B2; July 15, 2014.
(Invited) Electrodeposition of Ferromagnetic Materials for Advanced Interconnect and MEMS
Authors: Moffat Thomas P. , Ritzert Nicole L. , Wang Rongyue , Lee Chang Hwa , Kim Soo-Kil , Braun Trevor , Josell Daniel
Published: February 2020

Two relatively new processes for the electrodeposition of iron group metals and alloys, namely, self-terminated deposition and superconformal deposition will be detailed with an eye towards application in the seeding and filling of nanoscale patterned features. Self-terminated deposition derives from the interaction between metal deposition at the onset of water reduction where formation of a monolayer hydroxide blocks further metal deposition. Judicious choice of processing parameters enables the self-limiting deposition of conformal nanometer thick films of iron groups metal and alloy. The utility of microelectrodes and SECM to reveal new insights into the interaction between parasitic reactions and the metal deposition process will be detailed. Discussion will then pivot to the use of additives to obtain superconformal deposition of iron group metals in recessed surface features. A brief survey of feature filling results for Ni, NiFe, Co and CoFe and associated electrochemical measurements will be presented along with a discussion of important physical phenomena associated with filling.
(Invited) Bottom-up Electrodeposition
Authors: Braun Trevor , Josell Daniel , Moffat Thomas P.
Published: February 2020

Superconformal electrodeposition that enables the fabrication of high aspect ratio Cu interconnects is not unique to copper (or for that matter even to electrodeposition). I will detail two known mechanisms underlying such processes: Curvature Enhanced Accelerator Coverage (CEAC) and S-shaped Negative Differential Resistance (S-NDR). I will describe how voltammetric measurements on planar substrates can quantify kinetics for models based on both mechanisms, enabling accurate, a-priori prediction of filling from a given electrolyte in features of various size and aspect ratio. I will summarize the chemistries and associated mechanisms for superconformal Ag, Au, Co, and Ni deposition for fabrication of defect-free nanometer scale damascene to millimeter scale through silicon via interconnects, including model predictions. I will finish by detailing truly bottom-up Au filling of high aspect trenches.
Impact of Manufacturing Tolerance on Lithium Ion Electrode and Cell Physical Properties
Authors: Yourey William
Published: February 2020

In both laboratory and commercial scale manufacturing of lithium ion cells, variability is introduced in numerous stages of the production process. The acceptable tolerances on these produced parts can have a large impact on the final product’s reliability, repeatability, and functionality. In this study, the range of electrode porosity, electrode internal void volume, cell capacity, and capacity ratio that result from electrode coating and calendering tolerance are investigated and offered as one possible explanation for cell-to-cell and lot-to-lot performance variation. Based on an electrode coating tolerance of ± 0.4 mg/cm2 and calender tolerance of ± 3.0 μm the resulting range of physical properties is investigated. For a target positive electrode porosity of 30%, the resulting porosity can range from 19.6-38.6%. To account for this variation during the manufacturing process, as much as 41% excess or as little as 59% of the target electrolyte quantity should be added to cells to match the positive electrode void volume. Similar results are observed for a negative electrode of 40% target porosity, where a range from 30.8% to 48.0% porosity is possible. For the negative electrode as little as 72% up to 28% excess electrolyte should be added to fill the internal void space. Although the results are specific to each electrode composition, density, chemistry, and loading the presented process highlight possible variability of produced parts. These results are further magnified as cell designs moves toward higher power applications with thinner electrode coatings.
Supercapacitor Prognosis for POWER Electronic Applications
Authors: EL Mejdoubi Asmae , Sabor Jalal , Chaoui Hicham , Gualous Hamid
Published: February 2020

The lifetime of an energy storage component is the time required to fail. The failure is defined as the lack of ability of a component to fulfill it's specified function. One of its characteristics will be out of the specification. For example the capacitance will be below its specified limit value, or the series resistance will be above its specified value, the component will be leaking, or will be opened.

This paper is about supercapacitor aging and prognosis. At the first, supercapacitor aging according to the temperature and to the voltage is performed. Experimental tests are realized at constant temperature when the supercapacitors are polarized at the maximum voltage. To quantify the supercapacitor aging, the equivalent series resistance and the equivalent capacitance are measured. To lead to the determination of the supercapacitor lifetime, Arrhenius law, that describes the effect of temperature on the velocity of a chemical reaction, is considered.

The second part of this paper presents prognosis model for supercapacitors considering the aging conditions. The proposed model uses the particle filter (PF) to predict the posterior values of the aging indicators, i.e., capacitance and resistance. In order to validate the proposed method, experiments have been carried out under different aging conditions. The PF prognosis results are compared to the experimental ones using the different aging conditions in order to validate the proposed model performance.

Figure 1
Electrochemical Oxidation of Lignin Using a Novel Lead-Free Electrocatalyst
Authors: Ghahremani Raziyeh , Staser John A.
Published: February 2020

To diminish reliance on the oil industry as a supplier of aromatic compounds, developing an economically viable lignin conversion process is crucial. The cost of depolymerization process should be low to be competitive on the fuel market [1]. Electrochemical oxidation of lignin offers several advantages over catalytic or enzymatic processes such as having control over the reaction by controlling the potential or current, environmental friendliness of electron reagents for electrochemical reaction, feasibility of the process at relatively low temperature and pressure, and simultaneous production of H2 [2]. Lead dioxide is one of the common active and inexpensive catalysts for electrochemical oxidation of lignin, however, environmental regulations have aimed to eliminate using lead due to its toxicity. Therefore, the aim of this research study was to develop an efficient, stable and non-toxic electrocatalyst with a high catalytic activity toward lignin oxidation, and minimal deactivation over time. A flow electrochemical reactor was used to oxidize lignin at the anode side with simultaneous hydrogen generation at the cathode side. A comprehensive protocol was also used to quantify oxidation product concentrations via internal standard method using GC-MS.

References

[1] G. Chatel, R.D. Rogers, Review: Oxidation of Lignin Using Ionic Liquids—An Innovative Strategy To Produce Renewable Chemicals, ACS Sustain. Chem. Eng. 2 (2014) 322–339.

[2] R. Ghahremani, J.A. Staser, Electrochemical oxidation of lignin for the production of value-added chemicals on Ni-Co bimetallic electrocatalysts, Holzforschung. 72 (2018) 951–960.
Long-Range Origins of Electrodeposition Instability in Solid Electrolytes
Authors: Mistry Aashutosh N , Mukherjee Partha P.
Published: February 2020

Transport in solid electrolytes is rather poorly understood as compared to their liquid counterparts, especially in the context of metal anodes in lithium batteries. In liquid electrolytes, at high currents local ionic concentration drops to zero and demarcates the onset of irregular electrodeposition. However, electrodeposition in solid electrolytes is more complicated given the simultaneous presence of mechanical effects. In this work, we present the mechanisms of solid electrolyte transport and why irregular growth is still possible in considerably stiff electrolytes. Based on these considerations, we present the fundamental origins of electrodeposition instability in solid electrolytes including a definition of a critical current density descriptor.
(Invited) Electrochemical Fundamentals of Employing Li Metal Anode in the Next-Generation Battery Technologies
Authors: Xiao Jie
Published: February 2020

To significantly boost the cell-level energy of next-generation battery technologies, one of the most effective approaches is to replace graphite with Li metal which is ultralight but energy concentrated. However, the thermodynamic instability of Li metal leads to many well-known problems that prevent its implementation in realistic batteries. Although many approaches have been proposed to rescue Li metal anodes, most of the work are performed in small-scale coin cells and tested in conditions drastically different from the reality. A full knowledge of Li metal activities at the cell level is lacking but critical for the success of rechargeable Li metal batteries. This talk will discuss the electrochemical fundamentals underlying the formation of Li dendrites which is then correlated to the different Li metal failure mechanisms: cell short or electrolyte/Li depletion. A prototypic Li metal pouch cell with 350 Wh/kg energy has been demonstrated which shows more than 150 stable cycling. A series of fundamentally new insights will be discussed to inspire scientific innovations to take the real challenges of developing future battery technologies.
Surface Modification of Graphite Anode Material By Coating WO3-X for Fast Chargeable Lithium Ion Battery
Authors: Kim Soohwan , Chung Dong Jae , Youn Donghan , Kim Hansu
Published: February 2020

Fast charging capability of lithium ion battery (LIB) is one of the most important requirements for popularization of electric vehicle (EV). However, currently used graphite anode materials cannot fully meet the requirements on the fast charge capability for EV applications. In this work, with an aiming to improve the electrochemical kinetics of graphite anode upon charging process, the surface modified graphite with tungsten oxide (WO3-x) was investigated as an anode material for LIB. The resulting anode material shows the improved electrochemical performance at high rates without severe capacity fading. At a rate of 1800 mA g-1 (5 C-rate), 5 wt% WO3-x coated graphite anode material exhibited 94 % of capacity obtained at a rate of 72 mA g-1 (0.2 C-rate). These results showed that surface modification by coating WO3-x on graphite anode material would be an effective way to advance the fast charging ability of graphite anode materials for LIB for EV. In this presentation, microstructure and electrochemical properties of WO3-x coated graphite material will be discussed in more detail.
Evaluation of High-Rate Pulsed Vs. Continuous Charging in Lithium-Ion Batteries
Authors: Mansour Azzam N. , Ko Jonathan K. , Waller Gordon H.
Published: February 2020

Many current and future Navy systems require high power lithium-ion batteries (LIB), with recent applications including directed energy weapons and the electromagnetic railgun pushing these requirements to new extremes. LIB with extremely high discharge rate are commercially available, however, high rate charging (or “fast charging”) is significantly more difficult to achieve due to complications occurring at the electrode-electrolyte interfaces as each electrode nears the edge of electrolyte stability. These problems are further exacerbated due to increased Ohmic heating with increasing current density, and can lead to potentially dangerous cell failure events. In this study, pulsed current charging was compared with continuous current charging during extended cycling of commercially available LIB with graphite anode and lithium iron phosphate cathode. Pulsed current charging has been shown in the literature to improve the efficiency and reduce the capacity loss penalties associated with continuous current charging. Charging limits at and above the manufacturers recommended operating limits were implemented. Degradation of cells was evaluated by monitoring cell temperature and impedance and accompanied by cell disassembly to analyze electrode degradation from the macro to the nanoscale using visual inspection, scanning electron microscopy (SEM), X-ray diffraction(XRD), and X-ray photoelectron spectroscopy (XPS). Preliminary results show that in addition to the expected temperature rise associated with high current operation, fast charged cells lose capacity at a faster rate than cells charged at lower rates. Furthermore, signs of an increased solid electrolyte interface (SEI) layer thickness and lithium plating were also observed from cell disassembly.
Electrochemical Properties of Petroleum Coke As Active Material of Negative Electrode in Lithium Batteries
Authors: Kuzmina Elena , Chudova Nadezhda , Prosochkina Tatyana , Karaseva Elena , Kolosnitsyn Vladimir
Published: February 2020

The possibility of usage of petroleum coke as active materials of negative electrodes in lithium batteries was studied in presented work.

Studies show that crude petroleum coke has high specific resistance (1.4·107 Ohm·cm), that is in 7 times greater than the resistance of graphite (0.5-1.0 Ohm·cm), used as the active material of negative electrodes in lithium-ion batteries. Thermal treatment of crude petroleum coke at 800 °C in the atmosphere of air or nitrogen during 5 hours decreases the specific resistance to 1.3 and 1.5 Ohm·cm, correspondingly, and increases their specific surface area from <0.1 m2/g to 5.3 m2/g (nitrogen) and 0.7 m2/g (air). Specific surface area was estimated by sorption of dyes (methyl orange).

Crude petroleum coke is not electrochemical active and can not be DC cycled (Figure). Heat treatment of petroleum coke, both in the atmosphere of air and in the atmosphere of nitrogen, leads to the appearance of electrochemical activity and the ability to reversibly intercalate lithium ions. At DC cycling of electrodes based on heat-treated petroleum coke in the range of voltage of 0 - 1.0 V vs Li/Li+ the reversible capacity is 300-350 mA·h/g.

The shapes of charge and discharge curves (Figure) of semi-cells with electrodes based on petroleum coke are similar to the charge-discharge curves of semi-cells with electrodes based on structurally disordered carbons.

This work was performed as part of the Government Order to Ufa Institute of Chemistry of the Russian Academy of Sciences by the Ministry of Science and Higher Education of the Russian Federation (Theme No. AAAA-A17-117011910031-7).

Figure 1
Generation and Evolution of Materials in the Anode Solid Electrolyte Interphase (SEI) of Lithium Ion Batteries
Authors: Lucht Brett
Published: February 2020

A solid electrolyte interphase is generated on the anode of lithium ion batteries during the first few charging cycles. The presence and stability of the solid electrolyte interphase (SEI) is critical to the performance of the battery. Despite thorough investigation of the SEI for over 20 years, the mechanism of formation and function are still relatively poorly understood. We have investigated the structure of the initial SEI on graphite and silicon electrodes along with changes which occur to the SEI upon additional cycling via a combination of ex-situ surface analysis techniques. The investigation of SEI provides significant insight into the structure and properties of the anode SEI.

The one electron reducing agent, lithium napthalenide has been used to independently prepare the reduction products which constitute the SEI. The initial reduction product of ethylene carbonate is lithium ethylene dicarbonate (LEDC). However, the thermal decomposition of LEDC and related lithium alkyl carbonates in the presence of LiPF6 generates a intricate mixture of compounds which greatly complicates the structure of the SEI. The reduction products and their subsequent thermal decomposition products have been thoroughly investigated via a combination of NMR, XPS, IR-ATR, TGA, and GC-MS. Mechanisms for the generation of the complicated mixture of products will be discussed.

Thermal behavior of the SEI on a silicon electrode for Lithium ion batteries has been investigated by TGA. In order to provide a better understanding of the thermal decomposition of the SEI on silicon, the thermal decomposition behavior of independently synthesized lithium ethylene dicarbonate (LEDC) was investigated as a model SEI. The model SEI (LEDC) has three stages of thermal decomposition. Over the temperature range of 50~300oC, LEDC decomposes to evolve CO2 and C2H4 gasses leaving lithium propanoate (CH3CH2CO2Li) and Li2CO3 as solid residues. The lithium propanoate decomposes over the temperature range of 300~600oC to evolve pentanone leaving Li2CO3 as a residual solid. Finally, the Li2CO3 decomposes over 600oC to evolve CO2 leaving Li2O as a residual solid. A very similar thermal decomposition process is observed for the SEI generated on cycled silicon electrodes. However, two additional thermal decomposition reactions were observed characteristic of LixPOyFz at 300oC and the polyimide binder at 550oC. TGA measurements of Si electrodes after various numbers of cycles suggest that the LEDC on Si electrodes thermally decomposes during cycling to form lithium propanoate and Li2CO3, resulting in increased complexity of the SEI.
Electrolyte Development and Its Application for Fast Charging of Li-Ion Batteries
Authors: Du Zhijia , Wu Xianyang , Wood David L. , Zhao Kejie , Belharouak Ilias
Published: February 2020

Energy density, cost and safety are, more than ever, the most significant barriers to overcome in order to increase the wide acceptance of Li-ion batteries (LIBs) in electric vehicles (EVs).1 The U.S. Department of Energy (DOE) has set ultimate goals for battery electric vehicles (BEVs), which include reducing the production cost of the battery pack to $150/kWh, increasing the electrical range of the battery to 300 miles, and decreasing the charging time to 15 minutes or less.2 Increasing electrode thickness, and hence increasing active material loading, is an effective way to achieve these energy density and cost targets.3 The caveat, however, is that thicker electrodes fail during fast charging.

One of the solutions for enabling extreme fast charging while retaining most of the battery energy can be achieved through the significant enhancement of the Li-ion mass-transport in electrolytes such that enough Li ions are available for intercalation in graphite. The mass transport of Li-ions can be evaluated by two macroscopic characteristic values: 1) the Li ions ionic conductivity that is related to the total flux of charge carriers, 2) the Li ion transference number that is related to the fraction of the total current that is carried by Li ions. An electrolyte with both higher Li ions conductivity and transference numbers is ideal for higher Li ions transport, and hence would be a step toward realizing cells with higher charging rates.

The fast charging performance of high-energy density (NMC811/graphite) Li-ion cells iss studied when different lithium salts were used in the electrolyte. The new electrolyte shows both higher ionic conductivity and Li-ion transference number compared to LiPF6 electrolyte. During a 12-minute fast charging step, cells with LiPF6 electrolyte reached the cut-off voltage in 4.2 minutes, which is much earlier compared to 7.4 minutes for the new electrolyte. The new electrolyte showed 13% capacity improvement in the first cycle of the 12-minute charge. The capacity retention was also significantly higher at 87.7% after 500 cycles with less lithium plating observed.

(1) Needell, Z. A.; et al. Potential for Widespread Electrification of Personal Vehicle Travel in the United States. Nat. Energy
2016, 1 (9).

(2) Howell, D.; et al. Enabling Fast Charging: Enabling Fast Charging: A Technology Gap Assessment. 2017, No. October.

(3) Du, Z.; et al. Understanding Limiting Factors in Thick Electrode Performance as Applied to High Energy Density Li-Ion Batteries. J. Appl. Electrochem.
2017, 47 (3), 405–415.

Figure 1
Coconut Sprout-Derived Graphitized Carbon Based Sodium Ion Capacitors
Authors: Surendran Vishnu , Suviresh Arya Raveendran , Vineesh Thazhe Veettil , Babu Binson , Shaijumon Manikoth M
Published: February 2020

Electrochemical Energy storage systems such as rechargeable batteries and supercapacitors play vital role in many applications like portable electronics, electric vehicles, smart electric grids etc. There is always a trade off between the performances of the two devices, with batteries offering high energy density, and supercapacitors exhibiting high power density. Hybrid ion capacitor (HIC), a new concept of energy storage device, wherein the best properties of a battery and a supercapacitor are combined, is attracting lot of interest in recent times.1 Typically, a battery-type electrode is chosen as an anode, while a double layer capacitive electrode forms the cathode in a non-aqueous electrolyte, thus offering intermediate energy and power density compared to batteries and supercapacitors.2
,
3 Recently, sodium based hybrid ion capacitors have been explored due to the large abundance and low cost of sodium.4
,5 Herein, we report the fabrication of an efficient hybrid sodium ion capacitor, in which the cathode, anode and separator are derived from a single precursor, coconut sprout (CS). Graphene like carbon derived from CS, employed as intercalating anode, exhibits a specific capacity of 181 mAh g-
1, while the high surface area (BET surface area of 2000 m2g-1) activated carbon (obtained by KOH activation of CS) cathode delivers a capacity of 90 mAh g-
1
vs. Na/Na+. Full cell hybrid ion capacitor fabricated combining the two electrodes with optimized mass loading, using CS-derived separator, delivers an energy density of 88.12 Wh kg-1 at a power density 273.26 W kg-1, when cycled in a potential window of 1.5 -4.0 V. The fabricated device retains 65% of its initial capacity after 5000 cycles, when cycled at a high current density of 1A g-1. Most interestingly, the spongy sprout separator showed excellent chemical and mechanical stability even after 10000 cycles of charge and discharge. Several factors including the use of low cost single precursor, facile synthesis route, minimal environmental impact, makes our approach promising towards designing eco-friendly and green electrochemical storage systems.

References

(1) Amatucci, G. G.; Badway, F.; Du Pasquier, A.; Zheng, T. An Asymmetric Hybrid Nonaqueous Energy Storage Cell. J. Electrochem. Soc.
2001, 148 (8), A930.

(2) Ding, J.; Wang, H.; Li, Z.; Cui, K.; Karpuzov, D.; Tan, X.; Kohandehghan, A.; Mitlin, D. Peanut Shell Hybrid Sodium Ion Capacitor with Extreme Energy-Power Rivals Lithium Ion Capacitors. Energy Environ. Sci.
2015, 8 (3), 941–955.

(3) Sivakkumar, S. R.; Pandolfo, A. G. Evaluation of Lithium-Ion Capacitors Assembled with Pre-Lithiated Graphite Anode and Activated Carbon Cathode. Electrochim. Acta
2012, 65, 280–287.

(4) Ding, J.; Hu, W.; Paek, E.; Mitlin, D. Review of Hybrid Ion Capacitors : From Aqueous to Lithium to Sodium. Chem. Rev.
2018, 118, 6457–6498.

(5) B. Babu and M. M. Shaijumon, J. Power Sources 353, 85-94 (2017)
Structural and Electrochemical Characterization of Thin Film Li2MoO3 Cathodes
Authors: Self Ethan Craig , Zhang Yiman , Kercher Andrew , Phillip Nathan Dale , Delnick Frank M. , Nanda Jagjit
Published: February 2020

Development of low-cost cathodes with high energy density and long cycle life is critical to enable advanced Li-ion batteries for transportation applications. When charged beyond 4.3 V vs. Li/Li+, most lithium-transition metal oxides (e.g., LiMO2, M = Ni, Mn, Co) undergo irreversible structural changes with concomitant oxygen gas evolution, resulting in irreversible capacity loss and voltage fade during cycling. One strategy to improve cathode stability at high states of charge is to design composite structures containing LiMO2 as the primary Li storage site and Li2MoO3 as a structural stabilizing unit (i.e., cathodes with the formula xLi2MoO3•(1-x)LiMO2). In this regard, Li2MoO3 possesses several attractive properties including a stable oxygen framework (up to 4.8 V vs. Li/Li+) and the ability to reversibly cycle 1 Li per formula unit.

To aid the development of Mo-based composite cathodes, the phenomena occurring at the cathode/electrolyte interface (e.g., Li transport, electrolyte decomposition, charge transfer, etc.) during battery cycling must be well-understood. However, interpreting in-situ and ex-situ data collected with traditional slurry cast electrodes is oftentimes complicated by the presence of conductive carbon and polymer binder which may participate in side reactions with the electrolyte and/or produce signals that overlap with the desired signal from the active material. To resolve this issue, radio frequency (RF) sputtered thin film cathodes composed entirely of active material represent a model system to study the electrode/electrolyte interface. In addition to eliminating unwanted signal arising from inactive components, sputtered thin films have a planar surface which greatly simplifies interpretation of AC impedance spectroscopy data.

The present work describes the preparation and characterization of Li2MoO3 thin film cathodes shown in Figure 1a. When cycled in a conventional liquid carbonate electrolyte (Figures 1b and 1c), the cathodes exhibited an initial reversible capacity of 166 mAh/g which rapidly faded to 99 mAh/g after 20 cycles. In comparison, all-solid-state Li2MoO3/Lipon/Li thin film batteries showed excellent stability with negligible capacity fade during cycling. As will be discussed, these differences are related to the nature of the cathode/electrolyte interface. This presentation will provide additional findings from X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), vibrational spectroscopy, and AC impedance spectroscopy. Overall, these results provide important insights on the fundamental interfacial phenomena that govern cathode performance.

Acknowledgements

This research has been supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Vehicle Technologies, of the U.S. Department of Energy (DOE) through the Advanced Battery Materials Research (BMR) Program.

Figure 1
CoP3@Ppy Microcubes As Anode for Lithium-Ion Batteries with Improved Cycling and Rate Performance
Authors: Liu Qing
Published: February 2020

Porous CoP3@PPy microcubes are synthesized from the cubic Co3[Co(CN)6]2precursors followed by PPy coating. When used as anode material for lithium ion batteries, a large specific capacity of 1310 mAh g−1 can be obtained for CoP3@PPy composite at 100 mA g−1, and retains 650 mAh g−1 after 220 cycles at 500 mA g−1. Even at high current density of 4000 mA g−1, the CoP3@PPy composite still maintains a reversible capacity as high as 800 mAh g−1. When matched with LiFePO4 for full battery, a high capacity of 540 mAh g−1 can be obtained at 100 mA g−1 after 100 cycles. The improved lithium storage performance of CoP3@PPy is ascribed to the unique porous structure of CoP3 microcubes and the homogeneous PPy buffer/conducting layers, which can alleviate the giant volume changes and facilitate fast charge transfer during the lithiation/delithiation process.
Rechargeable Aluminum/Natural Graphite Battery Based on Deep Eutectic Solvents
Authors: Ng Kok Long , Malik Monu , Azimi Gisele
Published: February 2020

Batteries based on aluminum have received significant attention over the past decade as the next generation of energy storage devices due to their desirable properties, such as high volumetric and gravimetric capacities, low cost, high natural abundance and the ease of handling in the metallic state. Al-ion batteries that utilize aluminum chloride/alkyl-imidazolium salts ionic liquid as the electrolyte, in a combination with graphitic cathodes, have demonstrated the viability of an energy storage device with well-defined discharge voltage plateaus, considerable specific capacity and high Coulombic efficiency over a few thousand cycles. However, the usage of the expensive alkyl-imidazolium salts greatly limits the commercialization of Al-ion batteries, particularly in large-scale energy storage applications. To address this challenge, an Al/Natural Graphite battery using an economically and environmentally sustainable electrolyte made from AlCl3-urea deep eutectic solvent (DES) was developed. The battery demonstrated discharge voltage plateaus in the range of 2.0–1.8 V and 1.6–1.4 V (vs. Al/Al3+) and a specific discharge capacity of ~45 mA h g−1 over 2000 cycles with a high Coulombic efficiency of 95 ± 1 % at a high current density of 600 mA g−1. Several ex-situ characterization techniques such as X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), and Scanning Electron Microscopy combined with Energy Dispersive X-ray Spectroscopy (SEM-EDS) were utilized to study the intercalation/deintercalation behaviors of the AlCl4
− anions during charging/discharging. The results based on the affordable AlCl3-urea (DES) harbor a potential towards developing large-scale energy storage systems.
Development of Selenium Substituted Lithium Titanium Sulfide Materials (Li2TiSexS3-x) As Positive Electrodes for Li-Ion Batteries
Authors: Celasun Yagmur , Colin Jean François , Peralta David , Martinet Sebastien
Published: February 2020

Rock salt materials are experiencing a comeback and being reconsidered as promising positive materials for lithium ion batteries due to recent advancements. This reappraisal has been accelerated by the latest studies1 which have shown that the overlithiated compositions could provide much higher capacities (> 250 mAh/g) than the stoichiometric compositions. As the material becomes richer in lithium, the probability for Li+ ions finding an available space in the lattice increases due to the percolating network that is formed through the lithium diffusion channels2. Thus, greater material capacities can be achieved.

Lithium titanium sulfide (Li2TiS3), which has been reported by Sakuda et al., demonstrated excellent capacity owing to the multi electron redox reactions3. By utilizing both sulfur and titanium redox, more than two lithium ions were reversibly intercalated through the structure and the capacity reached 425 mAh/g upon cycling between 3 V and 1.5 V vs Li+/Li. Although Li2TiS3 possesses such a large reversible capacity, its cycling stability is rather poor. Therefore, new approaches are necessary to enhance its cyclability. Partial substitution mechanisms are promising solutions in this issue.

Here, we propose Se-substituted lithium titanium sulfide materials (Li2TiSexS3-x), which have recently been patented. By applying our patented synthesis process, Se substituted materials showed better cycling stability. For comparison, we will provide a comprehensive study of pure and substituted materials through fine characterization tools (XRD, SEM, EDX, ex situ and in situ XRD) in order to examine electrochemical and structural properties as well as the capacity degradation mechanism.

References:

[1] N. Yabuuchi, Proc. Natl. Acad. Sci., 112 (25), 7650–7655 (2015)

[2] J. Lee, Science, 343 (6170), 519-521 (2014)

[3] A. Sakuda, Sci. Rep, 4 (1), 4883 (2015)

Figure 1
Solvent-Free Mechano-Fusion Assisted Carbon Coatings for High Capacity Cathode - a Practically Feasible Approach
Authors: Selvamani Vadivel , Phattharasupakun Nutthaphon , Wutthiprom Juthaporn , Sawangphruk Montree
Published: February 2020

Spinel LiMn2O4 (LMO) has emerged attractive as well as a potential alternative candidate to toxic LiCoO2 for high energy applications because of its relative abundance, low cost and environmentally benign. Although LMO has several advantages, it suffers from immense polarization, severe capacity decay and Mn dissolution resulting in Jahn-teller distortion with 6.5 % increased unit cell volume. Various strategies have already been proposed to alleviate these detrimental issues such as heteroatom doping, surface blocking coatings, and functional electrolyte additives. However, the surface coating is one of the promising techniques to improve the kinetics and long-term cycling performance over others. Herein, a simple and cost effective Mechano-thermal fusion was proposed because of its practical feasibility. The strong centrifugal force followed by a high shear and compression force fuse the guest molecule (super P) over the host (LMO), which ensures the uniform innate coating as like core-shell structure. Further, the fused carbon coating not only helps to reduce the polarization by improved conductivity but also acts as a barrier layer to control the Mn dissolution. The core-shell material delivered a specific capacity of 125 mAh g-1 at the initial and decreased to 103 mAh g-1 after 1000 cycles with 82 % of capacity retention at 0.75 C. Similarly, the above material exhibits excellent rate capability behaviour. The improved kinetics of the core-shell material has further been confirmed by heterogenous rate calculation and found to be 3.9 to 4.1. Further, the core-shell material exhibits stable cycling performance while couple to MCMB anode (full-cell) with above 70 % retention for the studied 1000 cycles.
"Dead" Lithium: Interface Evolution and Characterization
Authors: Tewari Deepti , Perumaram Rangarajan Sobana , Mukherjee Partha P.
Published: February 2020

During stripping of lithium metal anode, some fraction of lithium becomes detached from the lithium anode. This remnant lithium is electrochemically inactive and is called “dead” lithium. This leads to irreversible loss of capacity and lowers the Coulombic efficiency of the battery. The presence of dead lithium also affects the transport of lithium ions in the electrolyte which can potentially alter the conditions for plating during subsequent cycling.

The aim of this work is to identify the dominant mechanisms responsible for the formation of dead lithium as well as quantify the amount of dead lithium. Mesoscale modeling along with experimental corroboration to probe the evolution of the interface between lithium anode and liquid electrolyte during discharging will be presented. The effect of ionic diffusion in electrolyte, surface diffusion of lithium and electrochemical reaction rate kinetics are considered.

Figure 1
Microstructure Simulation and Virtual Material Design of Electrospun Gas Diffusion Layers for Polymer Electrolyte Membrane Fuel Cells
Authors: Balakrishnan Manojkumar , Fahy Kieran F. , Schulz Volker P , Bazylak Aimy
Published: February 2020

Polymer electrolyte membrane fuel cells (PEM-FC) are promising electrochemical devices for the production of electrical power without local emissions of CO2. In the PEM-FC, hydrogen and oxygen electrochemically react to produce water and heat. The generated liquid water is necessary for protonic conductivity in the electrolyte membrane, but excess liquid water hinders reactant gas diffusion from the gas flow channels to the reaction sites. Therefore, effective water management is vital for achieving high power density with PEM-FCs. In this context, a well-designed gas diffusion layer (GDL) must simultaneously facilitate the transport of reactants, excess liquid water, electrons, and heat.

Here, we present a characterization of electrospun gas diffusion layers (eGDL) as a new material used in PEM-FCs [1]. Compared to conventional GDL materials such as carbon paper (e.g. Toray-H-60) with fiber diameters in the range of 7 to 10 micrometers [2], the fiber diameters of the eGDL materials are in the range of 150 to 600 nanometers only.

While the improved performance of the PEM-FC with eGDLs has been shown in experiments [1], we describe the eGDL properties based on its micro-structure. The basis of this characterisation is the virtual material design as in [3,4]. Based on 2D microscopic images of the eGDL, its 3D structure is reconstructed as stochastically overlapping straight fibers with appropriate orientation. Given the bulk geometric properties of the fibers, we calculate single and multiphase properties by solving the appropriate partial differential equations. Examples of these parameters are the thermal and electrical conductivity, the diffusivity, and the capillary pressure-saturation curves.

Finally, the determined parameters are used as inputs to a 1D PEM-FC model and the modeling results are compared to experimental data.

REFERENCES

[1] Chevalier, S.; Lavielle, N.; Hatton, B. D.; Bazylak, A. (2017). Novel electrospun gas diffusion layers for polymer electrolyte membrane fuel cells: Part I. Fabrication, morphological characterization, and in situ performance, Journal of Power Sources, Vol. 352, 272–280. doi:10.1016/j.jpowsour.2017.03.098

[2] Mathias, M.; Roth, J.; Fleming, J.; Lehnert, W.L. (2003). Handbook of Fuel Cells: Fundamentals, Technology, and Applications. John Wiley & Sons, Hoboken, NJ.

[3] Schulz, V. P.; Becker, J.; Wiegmann, A.; Mukherjee, P. P.; Wang, C.-Y. (2007). Modeling of Two-Phase Behavior in the Gas Diffusion Medium of PEFCs via Full Morphology Approach, Journal of The Electrochemical Society, Vol. 154, No. 4, B419. doi:10.1149/1.2472547

[4] Wargo, E. A.; Schulz, V. P.; Çeçen, A.; Kalidindi, S. R.; Kumbur, E. C. (2013). Resolving macro- and micro-porous layer interaction in polymer electrolyte fuel cells using focused ion beam and X-ray computed tomography, Electrochimica Acta, Vol. 87, 201–212. doi:10.1016/j.electacta.2012.09.008

Figure 1
Correlative Multiscale Tomography on Inert Supported Solid Oxide Fuel Cells
Authors: Wankmüller Florian , Russner Niklas , Weber André , Meffert Matthias , Schmieg Johannes , Störmer Heike , Lupetin Piero , Gerthsen Dagmar , Ivers-Tiffée Ellen
Published: February 2020

The solid oxide fuel cell (SOFC) offers a great potential for stationary energy conversion applications because of its high combined heat and power efficiency. It is of great interest to understand performance relevant aspects of both material selection and manufacturing optimization. A design, which is made by co-sintering of inert substrate and functional layers, offers great possibilities for further methodological development. Findings can be transferred to different cell concepts. To understand and link fabrication parameters to the cell performance and identify aging mechanisms, sophisticated investigation of the 3D microstructure is necessary.

This contribution will demonstrate how advanced correlative multiscale tomography can be used to identify microstructural parameters ranging from millimeter to nanometer scale. We combine optical microscopy (OM), X-ray computed tomography (μ-CT), focused ion beam – scanning electron microscopy (FIB-SEM) tomography and energy dispersive X-ray spectroscopy - scanning transmission electron microscopy (EDXS-STEM). The resulting microstructure data can be used to visualize performance critical cell areas such as inhomogeneities and secondary phases. In addition, pore and tortuosity distributions obtained from data of different length scales allow modeling of gas diffusion losses of all cell layers. This exemplifies how correlative tomography helps to understand specific contributions to overall cell performance.

Figure 1
Die Level Model for Electroplated Copper Pillars
Authors: Graham Gabe , Chua Lee Peng , Buckalew Bryan , Ponnnuswamy Thomas , Mayer Steve
Published: February 2020

In wafer level packaging, within die Co-Planarity (CoP) of Cu Pillar (CuP) heights has always been critical for ensuring good electrical connections and low stresses in the final package. The recent market trend towards advanced packages imposes even more stringent CoP demands, thus warrants fundamental understanding of CoP drivers as well as innovations in plating technology.

The relatively large scale of CuP structures leads to sensitivities to mass transport during plating, especially for dies with multiple feature sizes and/or depths. Therefore a useful model for of CuP structures must include mass transport considerations. These models are typically computationally intensive and would not be feasible to solve at a die level.

In this work we develop a model which includes mass transport, but treats features as 1D elements. This approach enables solutions at a die level which may include many thousands of features. This model is validated by comparison to on-wafer data for two different die types.
Prediction of Electrochemical Characteristics for Yttrium Doped Barium Zirconate Based Solid Oxide Fuel and Electrolyzer Cells Using a Multiscale Framework
Authors: Priya Pikee , Zhang Chi , Aluru Narayana R.
Published: February 2020

Yttrium doped Barium Zirconate (BZY) is one of the best-known proton-conducting solid oxides and understanding its behavior is the key to designing better proton conducting electrolytes for Solid Oxide Fuel/Electrolyzer Cells (SOFC/SOEC). Functioning of an SOFC/SOEC involves a complex interplay of factors like temperature, chemistry, microstructure, etc., at different length and time scales which necessitates the use of multiscale computational techniques. A multiscale framework involving Density Functional Theory at atomic, Transition State Theory at meso and Electrochemical Theory at continuum scales has, therefore, been developed that could accurately predict Current-Voltage Characteristics for direct current and Impedance Spectra for alternating current in BZY based SOFC/SOECs. The effect of operating conditions on charge carriers and, hence, the performance of the cell has been analyzed. Temperature and the environment (reducing/oxidizing) have a significant effect on proton conductivity of the electrolyte. The activation energy for oxidizing atmosphere is found to be lower facilitating use at lower temperatures in these environments. Using Neural Networks as a surrogate model, a multi-dimensional uncertainty quantification and sensitivity analysis has also been performed to point out the important parameters determining the performance of the SOFC/SOEC. Hydration energy, proton diffusivity, and permittivity are found to influence the efficiency of the cell significantly. These parameters serve to delineate design guidelines for the development of new chemistries and compositions of proton conducting solid oxides through a Random Forest model, correlating material property descriptors for these parameters to the proton conductivity of various proton conducting solid oxides studied in the literature.