bluuebunny/crossref_metadata_2025 huggingface dataset:
(Digital Presentation) Novel Layered Materials with Rapid Ion Transport for Capacitive Deionization
Authors: Wang Yang , Deng Dingfei , Pan Qianfeng
Published: November 2022

Capacitive deionization is a very promising method for future water desalination. However, desalination capacity and rate limit its wide application. In our study, layered carbon materials and layered double hydroxides with rapid ion transport were investigated to overcome the rate issue. A layered activated carbon was synthesized by carbonizing and activating chestnut inner shell and the biochar showed lamellar structure and high specific surface area (>1000 m2 g-1). The one obtained at 500 ℃ (CS500) exhibited the highest specific surface area (1943.2 m2 g-1) and more oxygen-containing functional groups. Correspondingly, CS500 achieved a significant average salt adsorption rate of 5.7 mg g-1 min-1, with a high salt adsorption capacity of 17.7 mg g-1 NaCl (0.5 g L-1). CS500 also maintained high cycle stability (87.0%, 1.2 V) within 50 adsorption/desorption cycles. Besides, CoAl-layered metal oxide nanosheet intercalated by sodium dodecyl sulfate (SDS) with enhanced interlayer spacing (1.33 nm) was synthesized and used as anode (CoAl-LMO-SDS). The enlarged interlayer spacing and heat treatment provided an enhanced ion diffusion channel, improved the utilization of the interlayer electroactive sites and offered additional active oxidation reaction sites to facilitate the electro-sorption rate. CoAl-LMO-SDS achieved a high salt adsorption capacity (31.78 mg g-1), average salt adsorption rate (3.75 mg g-1 min-1) at 1.2 V in 500 mg L-1 NaCl solution, and excellent long-term cycling stability (92.9%) after 40 CDI cycles, proving the strong electronic interaction between SDS and the host layer. The desalination performance significantly show that layered materials can be promising candidates for rapid desalination and large-scale application.
(Invited) Electrooxidation Pathway and Kinetics for Aminomethyl Phosphonic Acid (AMPA) Degradation in Diluted Water Matrices
Authors: Zhao Jiaxiang , Yang Zilan , Alderman Brandon , Zou Shiqiang
Published: November 2022

The U.S. agriculture and related industries consume 280 million pounds of glyphosate each year. Most applied glyphosate is released into the aquatic environment and biochemically transformed into Aminomethyl Phosphonic Acid (AMPA). The generated AMPA can trigger eutrophication, bioaccumulation in food webs, potential cell damage, and embryonic mortality in living organisms. To effectively control AMPA, biological retention systems (e.g., wetlands) have been utilized to degrade AMPA. However, bioretention systems are characterized by slow degradation kinetics, a large footprint, and low resilience toward shock loads. This study proposes an alternative electrooxidation system as an abiotic, chemical-free approach to transforming organic AMPA into easy-to-separate inorganic phosphate. Our system selected a boron-doped diamond as the anode due to its wide electrochemical window and high electrochemical stability. We comprehensively explored AMPA degradation pathway, kinetics, and system energy requirement in diluted water matrices. Initial 24-h batch tests revealed more than 83% of 0.01-mM AMPA were electrooxidized by hydroxyl radicals under a chronoamperometry mode. The highest oxidation rate could reach 12 mmol AMPA m-2 h-1 in the first 6 hours. The oxidation end products are determined to be CO2, NH4
+, and PO4
3-, indicating complete mineralization of organic C, N, and P within AMPA molecules. We further evaluated three electrooxidation operating modes, including chronoamperometry (CA), chronopotentiometry (CP), and applied voltage (AV). All three operating modes exhibited >80% AMPA oxidation in 24 hours. Eventually, we selected the AV mode for a subsequent long-term test due to its higher compatibility with on-site applications. During this 30-day operation, our flow-through electrooxidation system was operated under a hydraulic retention time of 3-12 hours and was able to degrade a maximum AMPA loading of 12 mmol AMPA m-2 h-1. Our promising results confirm the capability of our electrochemical retention system to degrade AMPA in diluted water matrices and warrant future efforts to probe parasitic reactions for reduced system energy input.
Dynamic Multi-Dimensional Numerical Transport Study of Lithium-Ion Battery Active Material Microstructures for Automotive Applications
Authors: Lopata Joseph Steven , Garrick Taylor R. , Zeng Yangbing , Shimpalee Sirivatch
Published: November 2022

Conventional porous electrode battery modeling for a variety of applications makes assumptions to reduce the complexity of the simulation where tradeoffs between computational complexity and electrode detail can be realized without significantly impacting the accuracy of the results. The most common porous electrode battery model is the pseudo-two-dimensional (P2D) model as popularized by Newman and colleagues. These porous electrode battery models typically focus on simulating gradients in two dimensions; the primary dimension through the thickness of the battery cell electrodes and separators, and the secondary dimension in the radial direction of spherical active material particles. The particles are distributed throughout what is assumed to be a homogeneous porous electrode domain. Typically, uniformity in particle size, porosity, and tortuosity is assumed.

In this work, the development of a three-dimensional microstructure (3DMS) lithium-ion battery model will be presented. With the increase in computational resources available in academia and industry, simulation of the microstructure in 3D is possible. Active material domains of both the anode and cathode can be generated stochastically to create microstructures representing the electrodes, with voids surrounding the particle representing the electrolyte. A comparison between the P2D and 3DMS models with sensitivity analysis focused on items that can be probed with microstructure simulations will be discussed and similarities and/or differences in charge/discharge characteristics, overpotentials, and concentration profiles will be presented. The findings from this work will provide a path to simulate at the microstructure level, drive electrode design, and translate the effects of heterogeneity into a homogenous porous electrode model.
(Digital Presentation) Cr-Doped FeC2O4 Micro-Rods Directly Grown on Stainless Steel for Electrochemical Nitrate Reduction in Circum-Neutral pH with Enhanced Selectivity to N2
Authors: Rahman Evandi , Cho Kangwoo , Hong Seok Won
Published: November 2022

Here, we synthesized micro-rods of iron oxalate (FeC2O4) decorated by chromium (Cr3
+) on the stainless steel AISI 420 as a cathode for nitrate (NO3
-) electrochemical reduction in the absence of Cl- ions. Through the investigation, Cr-doped FeC2O4 cathode successfully reduced 74.27% of NO3
--N and produce 22.25% of N2 during galvanostatic electrolysis in 8 mM (112 mg L-1 of NO3
--N) of sodium nitrate (NaNO3) and 50 mM of sodium sulfate (Na2SO4) aqueous solution. Possible mechanism of direct N2 generation at the cathode surface was derived by considering that Fe2+ as the main active site for NO3
- ions and C2O4
2- as the proton diffusion channel. Meanwhile, Cr3+provides unique electrical property as the electron extractor. Repetitive NO3
- ([NO3
-]0 = 8 mM, pH~7) electroreduction process and a re-generation method in sodium borohydrate (0.01 M NaBH4) were proposed to verify feasibility of Cr-doped FeC2O4in electrochemical water/wastewater treatment application.
(Invited) Iron/Iron Redox Flow Battery Optimisation Studies
Authors: Noack Jens , Wernado Mike , Ortner Jens , Pinkwart Karsten
Published: November 2022

Due to the steadily increasing growth of renewable energies, the importance of stationary energy storage systems is growing significantly. A potentially very cheap alternative to lithium-ion and vanadium redox flow batteries are iron/iron redox flow batteries. Iron is an extremely inexpensive active material, thus enabling cheap energy storage solutions and perhaps batteries with very low investment costs while maintaining low toxicity and aggressiveness due to the moderate pH and relatively low potential of the positive electrode. An iron(II) salt solution serves as the initial solution and is oxidized to iron(III) at the positive electrode and reduced to elemental iron at the negative electrode during the charging process.

One of the biggest problems is the formation of hydrogen at the iron electrode during the charging process at low pH values and the precipitation of iron(II) hydroxides from slightly acidic pH values [[i]]. When operating this type of battery, the negative electrode must be kept within a narrow pH window where no precipitation occurs and as little hydrogen as possible is evolved, which in turn significantly reduces battery life and efficiency.

As part of a feasibility, different iron/iron redox flow batteries were constructed and their electrochemical properties were investigated. One of the most important components of the battery was the recombination cell, which allows hydrogen evolution to be reversed, thus significantly increasing the number of cycles. Different substrates for iron deposition were investigated, different membranes as well as different charging and discharging parameters of the battery. With the recombination cell, it was possible to complete up to one hundred cycles with long cycle times of 1 h charging time, and to calculate and compare efficiencies and other performance values. A kynol fabric achieved the best performance and all membranes investigated showed potential applications. An optimized battery achieved up to 70% energy efficiency at 12.5 mA/cm² and max. 47 mW/cm² power density at 75 mA/cm².

[i] [1]L. W. Hruska, J. Electrochem. Soc. 1981, 128, 18.

Figure 1
(Invited) Plasma-Based Thin Film Technology in Fabrication of Nano- to Giga-Sized Electronics
Authors: Kuo Yue
Published: November 2022

This talk is presented to honor Professor Noel Buckley who has made many important contributions in compound semiconductors, copper thin film deposition, batteries, and other topics critical to the manufacture of modern optoelectronics. He is also a good friend, colleague, and collaborator for 3 decades.

Plasma technology has been broadly used in the mass production of modern electronics varying from nano-sized devices in ICs to giga-dimension flat panel displays. It is especially critical to the preparation of thin films with well-controlled properties, geometry, and reliability. In this talk, the speaker shall discuss the recent development of plasma thin film deposition, etching, and reaction in his laboratory for the manufacture of electronic and optoelectronic products.

Room-temperature plasma-based copper etch processes for sub 0.5 μm geometry patterns ICs and large-area direct-view TFT LCDs

Sputter deposited sub 1 nm EOT high-k gate dielectrics, nanocrystals embedded high-k dielectric nonvolatile memories, and solid-state incandescent light emitting devices (SSI-LEDs)

Plasma oxidation of copper as a self-aligned passivation film
(Invited) Fluorination and No-Carrier-Added Radio-Fluorination of Organic Molecules Using Cation Pool Technique
Authors: Balandeh Mehrdad , Sadeghi Saman
Published: November 2022

Positron emission tomography (PET) is a molecular imaging method is being employed in preclinical and clinical studies such as oncology or diagnosis of certain diffuse brain diseases. The growth of PET as a powerful method in biomedical research, needs development of more efficient methods for developing the positron-emitting radiotracers. The fluorine radioactive isotope (18F) has a short half-life of 110 min, making it as an ideal PET radiotracer. 18F labeling of electron rich moieties such as aromatic molecules is highly desirable due to their high biostability.

In 1990 Yoshida and co-workers developed the cation pool method which stabilized carbamate cationic intermediates generated during a two electron oxidation followed by deprotonation that takes place in the anodic compartment of a two compartment cell under low temperatures.1 The method allows for rapid reactions with nucleophiles that may be unstable during electrolysis and can be added to the reaction mixture at the end of electrolysis to form the final product.

Here, we report on the extension of the cation pool method for the application of electrochemical fluorination and radio-fluorination of methyl (phenylthio)acetate. Electrochemical fluorination and no-carrier-added radio-fluorination were successfully achieved using the cation pool method. The cation pool method has tremendous potential for radiofluorination experiments. The excess concentration of cations may provide an efficient reaction mechanism for late-stage fluorination under low fluoride concentrations encountered in radiochemistry. Furthermore, radiochemical yield, which is reduced by decay of the radioisotope, can benefit from a rapid late-stage fluorination reaction. The cation pool can be prepared prior to cyclotron production of 18F isotope, thereby, providing a rapid late-stage fluorination reaction, maximizing radiochemical yield by minimizing decay through a rapid reaction of the previously prepared cations with 18F-fluoride.

Synthesis parameters such as temperature, supporting electrolyte concentration and type, and precursor concentration were studied and optimized. Optimum reaction yield was obtained at -20 °C. The products were characterized using gas chromatography–mass spectrometry (GC-MS), nuclear magnetic resonance (NMR), radio-thin-layer chromatography (radio-TLC) and high-performance liquid chromatography (HPLC).

References

Yoshida, J. et al. Direct Oxidative Carbon−Carbon Bond Formation Using the “Cation Pool” Method. 1. Generation of Iminium Cation Pools and Their Reaction with Carbon Nucleophiles. J. Am. Chem. Soc.
121, 9546–9549 (1999).
Vapor Phase Infiltration of Conjugated Polymers Using TiCl4 and VOCl3 and Their Resulting Optical and Electrical Properties
Authors: Zhang Li , Gregory Shawn , Malinowski Kristina , Savaresse Astrid , Losego Mark D
Published: November 2022

Chemical doping alters the electrical and optical properties of conductive, conjugated polymers. Although liquid-phase doping is effective, the solvents can deleteriously alter a polymer’s microstructure and are often environmentally-hazardous. In this work, we investigate the use of vapor phase infiltration (VPI) to dope conjugated polymers using both TiCl4 and VOCl3 as vapor-phase dopants. VPI results in not only oxidative doping of the polymer via adducts with the metal halide precursor but also acid doping via byproduct generation upon metal halide reaction with water vapor. The resulting electrical properties of the new hybrid materials are characterized with both in situ and ex situ electrical measurements to determine how exposure time to the VPI precursor affects doping. Initially electrical conductivity increases with metal halide exposure time due to increasing the number of charge carriers. However, upon oxidation of the metal halide precursor, conductivity begins to decrease due to the formation of metal oxide clusters that presumably scatter charge carriers. The effects on optical properties is found to differ significantly between VOCl3 and TiCl4 dopants. VOCl3 leads to a greater absorbance in the visible spectrum. To understand the structural changes that lead to these variations in optical behavior, UV-Vis spectroscopy and x-ray photoelectron spectroscopy are undertaken. In particular, we observed that the polaron peak initially increases but eventually saturates while the oxide peak seemingly continues to increase with metal halide exposure time. These effects are further understood by changes to the inorganic’s chemical environment studied with XPS.
Direct Patterning of ZnO Deposition By Atomic-Layer Additive Manufacturing Using a Safe and Economical Precursor
Authors: Barr Maissa K. S. , Stefanovic Sonja , Gheshlaghi Negar , Zanders David , Devi Anjana , Bachmann Julien
Published: November 2022

AS-ALD has the potential to overcome many of the challenges the semiconductor industry is facing by enabling self-aligned fabrication, instead of lithography’s cost, resit, equipment. Main challenges in AS-ALD are the need for pre-patterned substrates, defects outside of the desired growing area resulting from insufficient selectivity, and limited selection of substrate materials that allow deposition. [1, 2]

To overcome these challenges, we chose for the first time the novelty of direct patterning with an AL-3D printer, also called atomic layer additive manufacturing (ALAM). 3D-printing is a flexible and efficient tool for reducing the cost and time spend for designing and manufacturing. AL-3D in principle functions similar to conventional g-ALD and the special design of nozzle led in producing direct patterning. All the commercially available precursors which have been used in g-ALD are compatible with our invented equipment and not only we can produce the same films conveniently but also this device allows us to use new precursors e.g. Zn(DMP)2 opening a new chemistry window. We have already deposited different materials TiO2, Pt, SiO2, Al2O3 successfully using TTIP, (MeCp)PtMe3, APTES, TMA as precursor. The ZnO process is very well behaved in ALD community as a diethylzinc (ZnEt2) precursor’s very high vapor pressure and its very high reactivity to water. Our attempts at reducing the amount of vapor delivered were successful in part but the results were not sufficiently reproducible, therefore we turned to the use of a new zinc precursor instead.

In this work we focus on the new precursor Zn(DMP)2 instead of ZnEt2 for ZnO deposition. The Zn(DMP)2 has a very low vapor pressure, the ethyl groups are complemented by dimethylamino substituents that stabilize central zinc ion and thereby render the molecule less reactive to water. Our characterization results shows the deposited ZnO films with our new precursor has same structure and composition as with ZnEt2 with a constant growth rate of 1.0 Å per cycle. the crystals are oriented in a roughly isotropic manner.

After testing Zn(DMP)2 in classical ALD we achieved to print homogeneous patterns with well-defined edges and uniform thicknesses among the whole pattern. The rough particulate deposits indicative of uncontrolled CVD-mode deposition obtained with the ZnEt2 + water reaction are completely absent of lines obtained from the Zn(DMP)2 + water reaction. Furthermore, we fabricate a metal oxide transistor MOSFET to demonstrate the practical applications of the device.

Clark; K. Tapily; K.-H. Yu; T. Hakamata; S. Consiglio; D. O´Meara; C. Wajda; J. Smith; G. Leusink; Perspective: New Process Technologies Required for Future Device and Scaling. APL Mater. 2018, 6, 05203

Fang; J. C. Ho, Area-Selective Atomic Layer Deposition: Conformal Coating, Subnanometer Thickness Control, and Smart Positioning. ACS Nano 2015, 9 (9), 8651-8654.
Oxidative Molecular Layer Deposition of Conjugated Amine Polymer Thin Films
Authors: Wyatt Quinton K. , Vaninger Mitchell , Paranamana Nikhila C , Heitmann Thomas , Kaiser Helmut , Young Matthias J.
Published: November 2022

Conjugated amine polymers such as polypyrrole (pPy), and polyaniline (pAni) exhibit high electrochemical capacities, making them appealing as electrode materials for energy storage, electrochemical desalination, and chemical sensing. Nanoscale thin films of these polymers are attractive to provide lower weight, faster charging, and higher sensitivity in these applications. This report describes the first demonstration of molecular layer-by-layer growth of conjugated amine polymers using alternating gas-phase exposures of amine monomers and MoCl5 oxidant in a process termed oxidative molecular layer deposition (oMLD). Pyrrole (Py) and MoCl5 undergo self-limiting surface reactions by oMLD to form conformal pPy thin films, but oMLD using aniline (Ani) and p-phenylenediamine (PDA) monomers yield unexpected azo functionality. This is attributed to a MoCl5-amine surface adduct that directs polymerization near amine groups, producing azo groups for primary amines. oMLD pPy exhibits record 282 mAh/g capacity in aqueous electrolyte, and PDA/MoCl5 oMLD yields azo-polymers of interest as anode materials for alkali-ion batteries. Alternating between Py and PDA monomers during oMLD produces molecularly mixed copolymers with qualitatively different electrochemical responses from the isolated monomer structures. This work lays the foundation for the growth of conformal thin films of conjugated amine polymers with molecular-level control of composition and thickness.
Using Density Functional Theory and Machine Learning to Predict the Binding Energies of Metal-Organics to Organic Functional Groups for Hybrid Material Creation
Authors: Liu Yifan , McGuinness Emily K , Jean Benjamin , Losego Mark D , Ramprasad Rampi
Published: November 2022

Understanding chemical interactions between organic and metal-organic molecules has wide-ranging interest to the vapor deposition community for creating hybrid organic-inorganic materials via techniques such as molecular layer deposition and vapor phase infiltration (VPI). In the case of VPI, a vapor-phase metal-organic precursor is infused into the bulk of a polymer and becomes incorporated at the nanoscale through either chemical interaction with the polymer or the formation of a non-volatile species via the introduction of a co-reactant. VPI has applicability in a number of industrially relevant fields including the creation of novel organic-inorganic hybrid membranes which have shown enhanced stability in organic solvents, while retaining high permeance and selectivity. Motivated by this application, this work uses density functional theory (DFT) to explore chemical interactions occurring during the VPI of polymer of intrinsic microporosity (PIM-1, a polymeric membrane material) with trimethylaluminum (TMA) and its co-reaction with water. These computations revealed that the coordination between the polymer and metal-organic is a critical mechanism for the formation of the hybrid and its resultant solvent stability. To expand understanding of this critical characteristic and accelerate the design of organic-inorganic hybrid materials, a DFT dataset of computed binding energies was generated from suitable and representative atomic-level models of several common polymer functional groups and over 100 metal-organic precursors. From this dataset, a predictive machine learning model for the binding energy of metal-organic molecules to polymers has been developed. This predictive model, along with the chemical guidelines obtained from feature analysis, will aid the selection of potential candidates for novel organic-inorganic hybrid membranes as well as hybrid material creation as a whole.
(Invited) ALD of FeSe2, CoSe2, and NiSe2
Authors: Wang Xinwei
Published: November 2022

The iron-group transition-metal diselenides (MSe2, M = Fe, Co, Ni) have recently gained tremendous interest in many areas. The MSe2 compounds normally form similar pyrite or marcasite crystal structures, and, with a progressive increase in the metal 3d electrons, FeSe2, CoSe2, and NiSe2 exhibit diverse and fascinating optical, magnetic, and electrical properties. In this talk, I will present our latest progress on the atomic layer deposition (ALD) of FeSe2, CoSe2, and NiSe2. These ALD processes employ the corresponding metal amidinates as the metal precursors and diethyldiselenide (DEDSe) as the selenium precursor, together with Ar/H2 plasma for DEDSe activation. All of the ALD processes are able to grow pure, smooth, and crystalline MSe2 (M = Fe, Co, Ni) films, and the MSe2 films can also be uniformly deposited into 10:1 high-aspect-ratio microtrenches with excellent conformality, which thereby shows the great promise for conformal coating on 3D complex topologies in general. In situ ALD mechanism investigation further reveals that the efficient dissociation of DEDSe by plasma is key to the success of these ALD processes.
Using Atomic Layer Deposition (ALD) to Immobilize Molecular Catalysts on Solid Powder Supports
Authors: Ayare Pooja , Gregory Shawn , Yom Typher , Losego Mark D , Vannucci Aaron
Published: November 2022

While homogeneous molecular catalysts are valued for their high reaction specificity, they are not as easily recoverable at industrial scales as heterogeneous catalyst powders that can be rapidly separated from the reaction solution. Here, we will discuss a new approach using atomic layer deposition (ALD) to immobilize molecular catalysts onto heterogeneous powder supports to achieve this combination of selectivity and recoverability. In this presentation, we demonstrate applicability using a non-noble metal (nickel) molecular catalyst to do Suzuki carbon-carbon cross-coupling reactions. Due to extremely short catalyst lifetimes caused by dimerization, this catalyst exhibits limited catalytic reactivity under homogeneous conditions. However, when heterogenized and immobilized, product yields of over 90% can be achieved in aqueous conditions, and the catalytic activity is preserved through over five hundred recovery and wash cycles. Following this work, we will also report on how modification of the ALD surface chemistry and number of ALD cycles affect catalytic performance.
(Digital Presentation) Controllable Preparation of Ultrasmall Pt-Based Intermetallic Nanocrystals Via Atomic Layer Deposition for Hydrogen Fuel Cell
Authors: Liu Hang , Huang Chaojun , Lu Qizi , Liu Xiao , Chen Rong , Shan Bin
Published: November 2022

The cost and endurance anxiety about proton exchange membrane fuel cells (PEMFCs) has prompted the rapid development of platinum-based (Pt-based) oxygen reduction electrocatalysts towards smaller particle sizes, higher durability and alloying. However, well-balanced these advanced trends by a simple approach is difficult in practice, because the existing solutions are problematic in removing the protective organic coating or oxide shell that preventing the high-temperature agglomeration of Pt-based nanocrystals, or broadening the size range of Pt-based nanocrystals which caused by the heterogeneous distribution of heteroatom anchor points on supports. With a self-developed strategy that based on the atomic layer deposition (ALD), we have addressed these problems in two aspects. One is directly loading size and distribution controllable Pt nanocrystals on diverse supports, and another is indirectly depositing easily removed ultra-thin metal oxide coating with dual functions on prefabricated ultrasmall Pt nanocrystals to restrain their sintering effect during high temperature ordering. By controlling the temperature and pulse time of ALD, we successfully synthesized ultrasmall (< 2 nm) Pt nanocrystals on surface inactive TiC nanoparticles and nanowires. These two new electrocatalysts exhibited comparable oxygen reduction activity and durability on par with commercial Pt/C with lower Pt loading. And using this strategy, about 1 nm ZnO coating on Pt nanocrystals was performed to construct uniform PtZn intermetallic nanocrystals with the ultrasmall size of 2.50 ± 0.65 nm and excellent stability for oxygen reduction reaction. The mass activity of PtZn intermetallic nanocrystals reaches to 0.60 A mgPt
-1 at 0.9 V (6 times than commercial Pt/C) and only 13 mV decrease of half-wave potential after 30000 cycles of accelerated durability testing rivaling the most recently reported PtZn catalysts. Ultrasmall sizes and excellent features of our Pt and Pt-based intermetallic nanocrystals are all attributed to the accurate control of ALD and could be a promising method applying to other Pt-based intermetallic nanocrystals.
Fabrication of Block Copolymer Templated Extended Surface Model Electrocatalysts By Atomic Layer Deposition and Physical Vapor Deposition
Authors: Bhattacharya Deepra , Arges Christopher G.
Published: November 2022

Templating platinum group metal (PGM) nanostructures from microphase separated block copolymers (BCPs) allows for electrocatalytic activity to be studied on highly ordered, model surfaces with precisely controlled feature sizes and morphologies, thereby allowing catalyst electroactivity and stability to be probed as a function of nanoscale geometry. In our previous work [1], BCP templated electrocatalysts fabricated via incipient wetness impregnation of PGM precursors were tested for hydrogen oxidation/evolution and water-splitting activity on interdigitated electrodes using liquid and solid polymer electrolytes. This talk presents the fabrication of such electrocatalysts via Atomic Layer Deposition (ALD) and Physical Vapor Deposition (PVD) techniques (e-beam evaporation and sputtering). Self-assembled lamellae of poly-(styrene-block-methylmethacrylate) (PSbPMMA) thin films on Si wafer and glassy carbon substrates were subjected to 5 - 15 ALD cycles with trimethylaluminium (TMA) precursor to induce selective growth of alumina in the PMMA domains via Sequential Infiltration Synthesis. Thereafter, the polymer template was removed via Reactive Ion Etching (RIE) with oxygen plasma. The resultant alumina nanostructures templated from self-assembled PSbPMMA was then used as a substrate either for Platinum ALD with (trimethyl)methylcyclopentadienylplatinum(IV) precursor atop a Titanium Nitride adhesive layer, or for sputtering of Pt atop a Ti adhesive layer to obtain conformal Pt coatings of up to 20 nm in thickness. When e-beam evaporation was used, The PMMA domains were selectively removed by successive wet and dry etch steps, followed by deposition and lift-off. The PGM electrocatalyst nanostructures were characterized via a combination of electron microcopy, X-ray diffraction, and X-ray photoelectron spectroscopy, and the Pt content of the catalysts were determined via microwave leaching and digestion of the electrocatalyst thin film followed by Inductively Coupled Plasma Mass Spectroscopy. The nanostructured electrocatalysts were tested for oxygen reduction (ORR) activity in a conventional rotating disk electrode setup using 0.1 M perchloric acid electrolyte, and the ORR mass activities and active surface area were obtained.

[1] Bhattacharya, D., Arges, C. G., et al., Small,
2021, 17, 2100437
(Invited) ALD-Based Infiltration and Growth of Inorganic Materials in Polymers
Authors: Segal-Peretz Tamar
Published: November 2022

Sequential infiltration synthesis (SIS) has emerged in the past decade as a powerful technique for growth of inorganic materials within polymers through atomic layer deposition (ALD) chemistry. In SIS, ALD precursors diffuse into the polymer and interact with it, leading to inorganic materials growth within the polymer’s free volume. If desired, the polymer can later be removed, yielding polymer-templated inorganic structures. Combining SIS with self-assembled block copolymer (BCP) patterns results in selective growth of inorganic materials within the polar domains of the BCP, making it an attractive method for directed templating of inorganic nanostructures. Thus, SIS opens a pathway for exploiting ALD precision and rich materials library in new 3D morphologies, defined by the polymer.

To build SIS design rules and expand SIS’ possibilities, we probed SIS growth and evolution at the atomic scale and explored the role of reversible polymer-precursor interactions in SIS growth through a plethora of methods: in-situ growth analysis (microgravimetry and FTIR), ex-situ high-resolution electron microscopy and extended X-ray absorption fine structure (EXAFS), and density functional theory (DFT) calculations. This knowledge was then applied in fabrication by design of metal oxide fibers, porous particles, and membranes.

We fabricated Al2O3 and ZnO nanofibers, nanobelts, and core-shell fibers using designed growth profiles within electrospun polymer fibers. By controlling the organometallic precursors’ diffusion time, simultaneous but spatially controlled growth of Al2O3 and ZnO within the fibers was achieved, leading to the formation of metal oxide core-shell fibers. Self-assembled BCP particles were used to template porous metal oxide particles by selective growth of Al2O3 in the major block of the self-assembled structure. The uniform BCP assembly led to uniporous pores in the metal oxide particles. Finally, we utilized SIS and ALD within and onto BCP membranes for exceptional pore size control and pores’ surface engineering, yielding highly selective filtration membranes.
Interactive MD-DFT Model to Predict the Multi-Component Electrolyte Reduction within the Electrical Double Layer
Authors: Wu Qisheng , Qi Yue
Published: November 2022

A typical liquid electrolyte for lithium (Li)-ion and Li-metal batteries is a liquid mixture with salt, solvent, and additives. The reduction products of the electrolytes form the solid-electrolyte interphase (SEI) layer, whose composition, heterogeneity and thickness largely determine the Li plating and stripping processes and thus the cycling performance. It is highly desirable to obtain atomistic insights into the reduction reactions of the electrolytes to help predict and control the formation of the SEI layer. The reduction reactions of the liquid electrolyte occur near the charged electrode surface within the electric double layer (EDL). The electrolyte structures within EDL must change under an electric field, which impacts the electrolyte reduction and SEI formation. This has been rarely considered in previous theoretical investigations of the reduction potentials and reduction products.

In this work, we have developed an interactive model combining molecular dynamics (MD) simulations and density functional theory (DFT) calculations to predict the multi-component electrolyte reduction within the EDL.[1] First, MD simulations, which can deal with thousands of atoms and even more, are used to capture the dynamics and statistics of the EDL structures. Then DFT calculations are used to compute the reduction products and corresponding reduction potentials of the representative clusters in the EDL. Finally, a formulation was proposed to calculate averaged reduction potential based on DFT-calculated reduction potentials of all the possible Li+-coordinated structures and their distribution probabilities obtained through MD analyses.

We have applied this new interactive MD-DFT model to two types of essential multi-component electrolytes, the carbonate-based electrolyte (LiPF6@EC:EMC) and the ether-based electrolyte (LITFSI@DOL:DME). We find in both electrolytes the Li+ ions within the EDL tend to have less coordination with other electrolyte species (salt anion, solvent and additive) compared to those in the bulk electrolyte. For LiPF6@EC:EMC, we reveal that FEC can enter into the EDL region and is favorable to be reduced, which helps form the F-containing SEI component (e.g., LiF). In addition, we have studied the effects of the FEC additive on LiTFSI@DOL:DME at various temperatures. We find that, at -40 °C, the number of F atoms that come near the electrode is largely increased after adding FEC, while no big change is observed at 20 °C. This explains that adding FEC is more effective in forming stable F-containing SEI and in promoting cycling performance at low temperatures.[2] Our simulations have also explained why ether based electrolyte works better than carbonate base electrolyte for Li metal anode.

Reference:

[1] Qisheng Wu,Yue Qi. Manuscript under preparation, 2022.

[2] Akila C. Thenuwara, et al. ACS Energy Lett. 2020, 5, 2411−2420
A Thermal Tanks-in-Series Model for Capacity Fade Validation Studies in Lithium-Ion Batteries
Authors: Thiagarajan Raghav Sai , Subramaniam Akshay , Kolluri Suryanarayana , Uppaluri Maitri , Preger Yuliya , Subramanian Venkat R.
Published: November 2022

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

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

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

Extending on our previous work, we take the Thermal Tanks-in-Series model coupled with SEI layer formation for a single-cell sandwich and apply it to analyze capacity fade under different temperature cycling conditions. Experimental validation of the model will facilitate understanding of diffusive, kinetic and temperature effects on the growth of the SEI layer and cell capacity fade.

References

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

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

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

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

A. Subramaniam et al., J. Electrochem. Soc., 167, 013534 (2020).
Electrolytes for High Nickel Lithium-Ion Batteries
Authors: Liao Chen , Rodrigues Marco-Tulio F , Abraham Daniel P. , Gim Jihyeon , Son Seoung-Bum
Published: November 2022

We have shown different strategies1, 2 in improving capacity retention and reducing impedance rise in modifying additives: in situ electrolyte additives to synthesize the beneficial lithium tetrafluorophosphate components3, 4 or dual-salt electrolytes1 for reducing cathodic impedance.

The cathodes we have tested have a LiNiO2 structure with an ultra-low amount of Co/Mn. An improved structural stability compared to that of LiNiO2 can be achieved while maintaining the high Ni content and high specific capacity. Using an optimal ratio of Ni/Mn/Co of 90/5/5 for a LiNi90Mn5Co5O2 cathodes,5 we here report the reduced reactivity of electrolytes using a combinatorial approach of reducing EC and introducing effective additives, targeting both a more robust SEI formation and a less resistive cathode electrolyte interface.

Multifaceted posttest analytical methods were used to understand the failure mechanism of the baseline cells and how additives/solvents approaches help the performance. For example, the new electrolytes prevent the transesterification reactions on anode surface, form a stable cathode interface, and mitigate structural damage on the cathode surface. Further analysis also investigated the how electrolytes protect the cathode bulk structure.

[1] J. Yang, M.-T. Fonseca Rodrigues, S.-B. Son, J. C. Garcia, K. Liu, J. Gim, H. Iddir, D. P. Abraham, Z. Zhang and C. Liao, ACS Applied Materials & Interfaces, 2021.

[2] J. Yang, I. Shkrob, K. Liu, J. Connell, N. L. Dietz Rago, Z. Zhang and C. Liao, Journal of The Electrochemical Society, 2020, 167, 070533.

[3] J. Yang, I. Shkrob, Q. Liu, N. L. Dietz Rago, Y. Liu, K. Liu, Z. Zhang and C. Liao, Journal of Power Sources, 2019, 438, 227039.

[4] I. A. Shkrob, B. Han, R. Sahore, A. P. Tornheim, L. Zhang, D. P. Abraham, F. Dogan, Z. Zhang and C. Liao, Chemistry of Materials, 2019, 31, 2459-2468.

[5] C. S. Yoon, M. H. Choi, B.-B. Lim, E.-J. Lee and Y.-K. Sun, Journal of The Electrochemical Society, 2015, 162, A2483-A2489.
(Digital Presentation) Lifsi Based Electrolyte Corrosion Study on Al Current Collector and Its Effect on Cu Side
Authors: He Meinan , Cai Mei
Published: November 2022

High energy density Li-ion battery with ultra-stable electrolyte is essential to facilitate the massive application of electric vehicles. Despite being used ubiquitously in Li-ion batteries, lithium hexafluorophosphate (LiPF6) is not stable both chemical and electrochemically, rendering the battery using LiPF6 based electrolyte. While lithium bis(fluorosulfonyl)imide (LiFSI) based electrolyte possesses both higher conductivity and better compatibility with the electrode materials compared to the traditional LiPF6 electrolyte, the high cost and the inability to suppress aluminum corrosion hinder its application in Li-ion batteries. In this work, we developed a bi-salt electrolyte by blending LiPF6 and LiFSI, as well as introducing Lithium difluoroborate (LiDFOB) as the anti-corrosion additive to mitigate the Al corrosion. Although the newly formulated electrolyte shows promising result at coin cell level, the big format pouch cell using the new electrolyte failed after prolonged cycling due to the detachment of the Cu tab. Based on the NMR results, we revealed that Al corrosion was accelerated by the change in the electrolyte formulation during cycling, and the situation was further escalated by the high state of charge (SOC). Most importantly, the Al3+ ions dissolved from the cathode side migrated to the anode side and formed alloy with Li and Cu, triggering the detachment of Cu tab, which was confirmed by SEM, ICP-MS and HRXRD. Owing to the higher current density and temperature on the tab region, it has significantly higher chance to be torn apart. In sum, it is imperative to precisely control both the SOC and the amount of LiFSI added to minimize the corrosion problem.
Development of New Borate-Based Lithium Ionic Liquid for Next Generation Lithium-Ion Battery
Authors: Watanabe Hikari , Tabata Yuya , Han Jihae , Shitanda Isao , Umebayashi Yasuhiro , Itagaki Masayuki
Published: November 2022

Solvate ionic liquids (SILs), which consist of a solvate ion and its counter ion, are expected as the electrolyte for the new generation Lithium-ion batteries [1]. Li-glymes SIL is an equimolar mixture of lithium salts and glyme of an oligoether such as triglyme and tetraglyme (Gn: CH3O-(CH2CH2O)
n
-CH3, n = 3 and 4). Li-glymes SIL shows favorable liquid properties like ordinary aprotic ionic liquids; negligible vapor pressure, practically non-inflammability, ionic conductivity and electrochemical stability, and so on. Watanabe et al. [2] have proposed that the specific Li+ ion hopping conduction occurs in the Li-glymes SIL. In Lithium-ion batteries with Li-glymes SIL, the desolvated Li+ ions are intercalated into graphite electrode, however, the co-intercalation of Li+ ion and glyme into the electrode occurs in the battery using the excess glyme electrolyte solution [3]. This suggests that the solvent activity affects the electrode reaction. In the present study, we prepared lithium ionic liquids with oligoether chains (Figure 1) and measured those physical and electrochemical properties.

Infrared spectroscopic (IR) measurements were carried out to identify the prepared lithium ionic liquids. An intense peak, which cannot be observed in the IR spectra of the raw materials, appears in approximately 1000 cm-1. This peak is attributable to B-O vibration mode, suggesting that the lithium ionic liquids are synthesized. We here define the new lithium ionic liquids as LiB(Gn)4 (n = 3 or 4). The ionic conductivities of LiB(G3)4 and Li(B4)4 are 0.20 and 0.37 mS cm-1, respectively. In addition, Li+ ion transport number is approximately 0.5 for both LiB(G3)4 and Li(B4)4., which is higher than that of electrolyte solution used in a commercial lithium-ion battery. This suggests that Li+ ion hopping conduction may occur via the exchange among glymes which are side chain of anion.

References

[1] C. Austen Angell, Y. Ansari, Z. Zhao, Faraday Discuss., 154, 9-27 (2012).

[2] K. Yoshida, M. Nakamura, Y. Kazue, N. Tachikawa, S. Tsuzuki, S. Seki, K. Dokko, M. Watanabe, J. Am. Chem. Soc., 133, 13121-13129 (2011).

[3] H. Moon, R. Tatara, T. Mandai, K. Ueno, K. Yoshida, N. Tachikawa, T. Yasuda, K. Dokko, M. Watanabe, J. Phys. Chem. C, 118, 20246-20256 (2014).

Figure 1
(Battery Division Technology Award) Understanding Metals' Roles in Layered Structure Oxides for High-Energy Lithium-ion Batteries
Authors: Lu Jun
Published: November 2022

The ever-increasing requirements in the high-energy density of lithium-ion batteries (LIBs) and current bottlenecks in cobalt supply place restrictions on the development of the state-of-the-art cathode materials with fine-tuned chemical composition by substituting the cobalt with nickel and manganese. In the layered structure ternary systems (LiNi1-y-zMnyCozO2, NCM), three transition-metal ions play a distinctive role that determines the physicochemical properties. A comprehensive understanding of the basic contribution of each transition metal is critical for further complete replacing expensive cobalt.[1] Here, we demonstrate cobalt and manganese behaviors by comparing various layered oxides with different chemical compositions to reveal their corresponding contributions.[2] Our results affirmed that cobalt plays an undeniable role in fast degradation, and found that cobalt is more destructive than Ni at high voltages. Even the possible instability induced by manganese (III) Jahn-Teller distortion [3], Mn(IV) substitution in the lattice can effectively alleviate this destructive and enables a high potential functionality. By further regulating the chemical composition with a concentration gradient strategy, Co-enriched surface and Mn-enriched core design in Ni-rich particles determines a robust structure, which can effectively suppress the owing to the low stiffness of the surface and stable structure in the core region. With these fundamental discoveries, we provide a guide for developing the promising Co-free cathodes to meet the increasing demand for high-energy density LIBs.

References

[1] M. Li, J. Lu. Science, 2020, 367, 979-980.

[2] T. Liu, L. Yu, J. Liu, J. Lu, X. Bi, A. Dai, M. Li, M. Li, Z. Hu, L. Ma, D. Luo, J. Zheng, T. Wu, Y. Ren, J. Wen, F. Pan, K. Amine. Nat. Energy, 2021, 6, 277-286.

[3] T. Liu, A. Dai, J. Lu, Y. Yuan, Y. Xiao, L. Yu, M. Li, J. Gim, L. Ma, J. Liu, C. Zhan, L. Li, J. Zheng, Y. Ren, T. Wu, R. S.-Yassar, J. Wen, F. Pan, K. Amine. Nat. Commun., 2019, 10, 4721.

[4] T. Liu, L. Yu, J. Lu, T. Zhou, X. Huang, Z. Cai, A. Dai, J. Gim, Y. Ren, X. Xiao, M. V. Holt, Y. S. Chu, I. Arslan, J. Wen, K. Amine. Nat. Commun., 2021, 12, 6024.