bluuebunny/crossref_metadata_2025 huggingface dataset:
Heterogeneity in Li-S Batteries Resolved through Operando Synchrotron Diffraction Studies
Authors: Wang Yulong , Barnes Pete L. , Chen Shuru , Zhang Hongxing , Olds Daniel , Efaw Corey M. , Cai Mei , Li Bin , Dai Fang , Dufek Eric J. , Khalifah Peter G.
Published: August 2024

Lithium-Sulfur (Li-S) batteries are promising candidates for electric vehicle applications due to their very high theoretical specific capacity (1670 mAh/g) and the tremendous availability and low cost of elemental sulfur. However, their practical capacity is substantially smaller (~1000 mAh/g) and their cycling performance is hindered by numerous technical challenges caused by issues on both cathode and anode sides of the system. While Li-S cells with extended cycling lifetimes can be built, they are typically only effective when using excess electrolytes and applied pressure, limiting their utility for practical applications. To gain deeper insights into the origin of missing capacity and the capacity fade of Li-S cells, we conducted operando studies on Li-S pouch cell batteries using synchrotron powder diffraction techniques. This approach enabled us to sensitively track the various crystalline phases involved in the cycling of Li-S batteries and to resolve a variety of inhomogeneities within cells that may affect their performance and lifetime.
Fabricating Solid-State Electrolyte Li-Ion Cells through Composite Ionogel Electrodes
Authors: Schorr Noah B. , Bhandarkar Austin , McBrayer Josey D, , Talin Albert Alec
Published: August 2024

Fabricating high loading electrodes is essential to realizing Li-ion cells with solid-state electrolytes (SSE) that have relevant energy densities. However, making sure lithium can reach the active materials is complicated if the ions are isolated in the electrolyte phase. Low loading electrodes can prevent this issue by having all active material in contact with the SSE, but this tactic makes scalability and relevance to commercialization an issue. To this end we devised a strategy to create electrodes with sufficient Li+ conductance and 10 mg/cm2 loading to ensure cells without liquid electrolyte are capable of achieving high capacity utilization at room temperature. This was done through creating an ionogel-derived SSE and using the same ionogel based precursors to fabricate composite electrodes. By tuning the ratio of ion conducting polymer, carbon, and active material composite lithium titanate electrodes were cycled with an ionogel SSE in a half cell configuration that achieve theoretical capacity at C/5 and stable cycling at ~6 mA/cm2. Full solid state coin cells were also constructed with a composite lithium iron phosphate cathode, SSE, and composite lithium titanate anode. These cells were able to cycle at 1C rate at room temperature. We believe this version of cells is a scalable approach to solid state batteries.

SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525
Numerical Modeling of 3D Printed Structures for Lithium Metal Batteries
Authors: Cross Nicholas R. , Feng Longsheng , Zhu Cheng , Wood Marissa , Bucci Giovanna
Published: August 2024

The development of lithium metal batteries to enable their use in commercial applications can have a significant impact on the fight against climate change due to the increase in energy density compared to state of art Li-ion batteries. However, technical challenges related to limited cyclability and non-uniformity of Li electroplating need to be addressed. This requires understanding the interplay between nucleation density, solid-electrolyte-interphase (SEI) formation, transport limitations, and unstable growth. 3D printed electrodes are of interest for electrochemical devices for their ability to tailor the electrode shape and structure to minimize system losses through enhanced ion transport and increased surface area for electrochemical reactions. 3D printed structures are constrained by the resolution of the printing method which can limit the feature size of the printed architecture. Numerical modeling of these structures can elucidate the interactions of competing physical phenomena, demonstrate tradeoffs, and estimate critical length scales and design principles that make 3D printed structures outperform traditional planar electrodes. Additionally, simulations can be used to identify failure points, complement experimental results, and deepen the understanding of fundamental questions hindering Li-metal deployment. In this presentation, we will show our recent work using continuum modeling to guide the design and evaluation of 3D printed electrodes for lithium metal batteries.

This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 and was supported by the LLNL-LDRD program under project numbers 22-ERD-043 and 23-SI-002.
Current Collector Primers with Improved Physical and Electrochemical Properties
Authors: Gallagher Devin J , DiMeglio John L , Kannan Balaji , Valdisera Kevin
Published: August 2024

Lithium-ion batteries are the dominant technology for powering the growing markets of electric vehicles, consumer electronics, and grid storage. However, to meet the increasing demands for higher energy density, faster charging, lower cost, and longer cycle life, continued research of new materials and designs are required. One of the key components that affects the performance and durability of lithium-ion batteries is the current collector, which provides a conductive substrate for active materials. The interfacial conductivity, adhesion, and corrosion resistance of these foils is largely dictated by their native oxide surface layer. To improve any of these features, specialized primers may be applied prior to electrode manufacturing, presenting a unique electrode/active material interface. For instance, carbon-coatings may be applied to aluminum to improve the conductivity and adhesion of lithium iron phosphate (LFP) formulations. These carbon coatings are limited in their cost, thickness, and performance, particularly in next generation cell designs and application methods. PPG is exploring novel current collector coating technologies addressing the physical, electrochemical, and stability requirements of these chemistries and manufacturing process. In this presentation, we will elaborate on coatings development and the effect that novel primer layers have on mechanical properties and single-layer pouch cell cycle life.
Enhanced Electrochemical Performance of Disordered Rocksalt Cathode in a Localized High Concentration Electrolyte
Authors: Ahmed Ridwan , Koirala Krishna Prasad , Lee Gi-Hyeok , Li Tianyu , Clement Raphaele J , Yang Wanli , Wang Chongmin , Xu Wu
Published: August 2024

Lithium (Li) transition metal oxides with layered structure, commonly employed as cathodes in Li-ion batteries, exhibit limited capacity, and employ less abundant and costly materials, raising sustainability concerns amid surging battery demand. Addressing this, lithium rich cation disordered rock salt cathode (DRX) materials have garnered substantial attention as they offer high capacity and cost benefits. Manganese (Mn) based DRXs, in particular, show promise due to the utilization of earth abundant materials and good thermal stability of Mn. However, these cathodes often face challenges when cycled in state-of-the-art carbonate-based electrolytes. These include severe side reactions between the cathode and the electrolyte, transition metal dissolution and structural instability of the cathode particles all of which result in fast capacity fading. In this work, an advanced localized high concentration electrolyte (LHCE) is developed to mitigate these problems and enable stable cycling of Li1.2Mn0.6Ti0.2O2 (LMTO). The developed LHCE exhibits high voltage stability, forming an ultrathin and stable electrode/electrolyte interphase. Consequently, Li||LMTO half cells with the developed LHCE demonstrate increased capacity, enhanced cycling stability and superior rate capabilities compared to the cells with the conventional electrolyte. For instance, the Li||LMTO cells cycled in LHCE show higher initial capacity of 205.2 mAh/g, and a capacity retention of 72.5 % in contrast to an initial capacity of 187.7 mAh/g and a capacity retention of 19.9 % observed in Li||LMTO cells with the conventional electrolyte after 200 cycles at a current density of 20 mA/g. This work paves the way for the development of practical DRX cathode- based high-energy Li batteries.
Electrochemical Performance of Lithium-Ion Cells with Lithium- and Manganese- Rich Oxide Cathodes
Authors: Badami Pavan , Wang Bingning , Liao Chen , Trask Stephen E. , Abraham Daniel P.
Published: August 2024

State-of the-art (SOA) lithium-ion batteries (LIBs) being developed for transportation applications contain a transition metal (TM) oxide cathode and a graphite anode; both serve as host-matrices to house lithium ions during battery operation. The cathodes typically contains Li1+xNiaCobAlcO2 (NCA) or Li1+xNiaMnbCocO2 (NMC) oxides: both oxide chemistries contain Co, which is known to preserve the layered structure during lithium extraction/insertion reactions. However, the possibility of a global Co shortage and soaring costs has galvanized the LIB community to explore sustainable cathode chemistries, while maintaining cell performance (energy/power densities), safety and cycle/calendar life. In this context the U.S. Department of Energy (DOE) initiated the Earth-Abundant Cathode Active Material (EaCAM) Program for the development of sustainable cathode chemistries, based on earth-abundant elements.

Materials of particular interest to the EaCAM program are the x Li2MnO3 ● (1-x) LiMnaNibZcO2 composites; here Z refers to various elements that could be included in the oxide structure. These lithium- and manganese- rich materials are considered attractive candidates because of their high specific capacities, zero cobalt content, and lower costs compared to the SOA oxides. We have been examining the electrochemical behavior of cells with these oxides, with a particular focus on the 0.3 Li2MnO3 ● 0.7 LiMn0.5Ni0.5O2 (LMR) compound.

During this presentation, we will show results from battery cells, containing LMR cathodes and either graphite or lithium-titanate anodes. In particular, the use of a microprobe reference electrode to monitor the cathode and anode potentials will be discussed. The effect of activation on cell performance and the performance loss characteristics during cycling will be highlighted. We will show how cell impedance is affected by voltage hysteresis and the voltage fade that results from cycling. Our ultimate goal is to identify constituents and mechanisms responsible for the cell performance loss and develop solutions to mitigate this degradation.

Acknowledgement: This document has been created by UChicago Argonne, LLC, Operator of Argonne National Laboratory (“Argonne”). Argonne, a U.S. Department of Energy Office of Science laboratory, is operated under Contract No. DE-AC02-06CH11357.
Role of Halogen Elements in Conductivity and Electrochemical Stability of Sulfide Based Solid Electrolytes
Authors: Raj Hari , Pralong Valerie
Published: August 2024

All-solid-state batteries (ASSBs) are a promising candidate for future energy storage technology with better safety and higher energy density [1]. Safety of solid state batteries come from solid electrolytes used instead of organic liquid electrolytes in conventional Li-ion batteries. The various types of solid electrolytes have already been reported for SSBs which can be divided into oxides, sulfides, halides and polymers based on their properties, advantages and disadvantages [2]. Among them, sulfide based solid electrolytes have advantages over other due to high conductivity and ductile nature of sulfides [3]. The discovery of Li10GeP2S12 solid electrolyte called LGPS structured sulfide electrolyte have shown great potential to replace liquid electrolyte as ionic conductivity of LGPS was found 1.2×10-2 S cm-1 at room temperature comparable to the conductivity of organic liquid electrolyte [4]. However, Li10GeP2S12 electrolyte suffers with poor cyclability in solid state batteries due to reduction of Ge+4 ions to Ge0, and instable against lithium metal anode [5, 6].

The solid electrolytes (SEs) with high conductivity and better stability against lithium metal are most important requirements for successful commercialization of solid state battery (SSB) technology. Therefore, in the search for new SEs with above mentioned qualities, halogen elements (Cl, Br, I) are explored in Li-P-S-O system to prepare Li10GeP2S12 (LGPS) structured SEs. In all prepared SEs, LPSOBr and LPSOI compositions show highest conductivities of 0.55 mS cm-1 and 0.67 mS cm-1 at 25 °C. The phase identification of newly synthesized solid electrolytes is done by X-ray diffractometer technique along with Rietveld refinement analysis. The conductivity of prepared solid electrolytes is determined by electrochemical impedance spectroscopy. These similar compounds also show superior stability against lithium metal in symmetric cells (Li/Ses/SE) as well as in full SSB cells (NCA/SEs/graphite) tested with LiNi0.8Co0.15Al0.05O2 cathode and graphite anode. These compounds also show 5 times higher stability in ambient environment conditions as compared to non-doped LPSO compound.

References:

Nikodimos et al. Adv. Energy Mater. 2022, 2202854

Scrosati et al., Power Sources 195, 2010, 2419.

Zhang et al., Energy Storage Mater. 10, 2018, 139-159.

Jiang et al., ACS Appl Mater Interfaces 12, 2020, 54662-70.

Kamaya et al., Mater., 10, 2011, 682–686.

Neveu et al., Power Sources 467, 2020, 228250.
Ionblox’s SiOx-Based, High-Energy, High-Power Li-Ion Battery for Performance Electric Vehicles and Electric Aviation
Authors: Hays Kevin A , Elangovan Ayyappan , Lopez Herman A. , Sinkula Michael , Kumar Sujeet
Published: August 2024

Demands on land-based, high-performance electric vehicles (EVs) and electric aviation, by means of electric conventional takeoff and landing aircraft (eCTOLs) and electric vertical takeoff and landing aircraft (eVTOLs) demand more on a secondary cell chemistry than ever before. There are many secondary cells on the market that offer energy density, power density, fast-charge capability, or cycle life, but few, if any other manufacturing-ready cells, offer a combination of all four. IONBLOX has solved this by pairing it’s patented, Pre-lithiated SiOx anode with a high nickel, NMC cathode to produce cells exceeding 330 wh/kg. Herein we describe the performance of our 32 Ah cell, featuring high-energy density, high-power density, extreme fast charge capability, and good cycle life, within a package that is already in production.

In particular, challenges for the eVTOL market will be addressed, which require peak power demand on the cell at low state-of-charge, without reducing the energy density. Methods for characterizing cells for such high-power applications will be further explored. DCIR pulse characterization and more customized testing like usable energy testing, which is important for identifying the applicable energy density for high-power use cases, will be demonstrated. Additionally, extreme fast charge capability is described on our large format cells with 5 min charge to >60% total cell capacity, over 1000 cycles. This shows such a cell is up to the expectations of a consumer familiar with the timing of a standard gasoline pump. Contribution from the information presented herein demonstrates the state of Si-based anode chemistry and can serve as useful guidelines to the academic community as future technologies are pursued for similar applications

Figure 1
Continuum-Level Modeling of Li-Ion Battery SEI by Upscaling Atomistically Informed Reaction Mechanisms
Authors: Weddle Peter J , Spotte-Smith Evan Walter Clark , Verma Ankit , Patel Hetal , Fink Kae E. , Tremolet de Villers Bertrand J. , Schulze Maxwell C. , Blau Samuel M , Smith Kandler , Persson Kristin A. , Colclasure Andrew M.
Published: August 2024

Understanding and controlling solid-electrolyte interphase (SEI) formation to stabilize cell performance is a significant challenge for next-generation Li-ion battery technologies. In recent years, computational modeling has become an essential tool in providing fundamental insights into SEI properties and dynamics. However, neither atomistic nor continuum-level approaches alone can capture the complexities of SEI chemistry across all relevant length and time scales. In this work, a continuum-level model is developed that is informed by reaction mechanisms obtained from first-principle calculations. The atomistically informed continuum-level model is used to understand electrolyte degradation, including the decomposition of ethylene carbonate (EC), ethyl methyl carbonate (EMC), and fluoroethylene carbonate (FEC). The model presented here is the most chemically complex continuum-level SEI model in the literature to date. The SEI model is calibrated against experimental irreversible leakage currents and shows qualitative agreement with expected SEI growth trends. The model framework is expected to accelerate fundamental understanding of SEI formation, facilitate mechanism development feedback, and dynamically interact with experimental insights.

Figure 1
(Invited) Graphene Oxide As an Additive for Ni-Fe Electrodeposition
Authors: Bahrololoomi Arash , Podlaha Elizabeth J
Published: August 2024

In contrast to graphene, graphene oxide (GO) is readily disperse in aqueous electrolytes and can be reduced along with nickel and iron metal ions. While others had incorporated graphene in Ni-Fe deposits, no previous studies have addressed the role of GO particles on metal deposition. Ni-Fe is characterized by the anomalous codeposition behavior where there is a tendency of more Fe to be deposited than Ni even though there is an excess of Ni ions in the electrolyte. This behavior has been modeled assuming adsorbed intermediates. Here, the influence of GO on the deposit composition, structure and anomalous codeposition effect is investigated. The deposits were galvanostatically electrodeposited from a boric acid-sulfamate electrolyte at pH 2 containing commercial graphene oxide platelets. Two different cell configurations were examined:1) a rotating cylinder electrode (RCE) and 2) a copper mesh. The rotating cylinder as a working electrode was used in order to investigate mass transport. The copper mesh working electrode was placed in close contact to a flat bottom pH probe in order to examine the local pH change. The addition of GO to the electrolyte had an effect on the deposit composition and the local pH change (Fig 1). The deposit composition had either more Ni or remained the same compared to an electrolyte without GO on the RCE electrode at electrode rotation rates of 372 and 1000 rpm (Fig 1 (a) and (b)). The larger Ni content in the deposit was due to an enhanced Ni partial current density in the presence of GO. The local pH during the deposition on the mesh electrode with vigorous electrolyte stirring increased the local pH (Fig 1(c)). The composition behavior is similar to the results from the RCEs, with higher Ni content in the presence of GO. The local pH increase when GO was present is considered a factor that drives the enhanced Ni content, that may be a consequence of changes in adsorbed hydrogen. GO was not incorporated into the deposit; however, it had a dramatic effect on the morphology. There was less micro-cracks when GO was present in the electrolyte suggesting less adsorbed hydrogen. Thus, GO influenced the adsorbed intermediates making the electrodeposition less anomalous and having less cracks.

Acknowledgement: This work was supported in part by the AESF Foundation.

Figure 1. The influence of GO in the electrolyte during Ni-Fe electrodeposition (a) composition on a RCE, rotating rate (a) 372, (b)1000 rpm and (c) local pH measurements on a mesh electrode under vigorous stirring, 30 mA/cm2.

Figure 1
Preparation of Soft Magnetic Composite Using Cold Sintering Technique
Authors: Paradis Linsea , Altaf Noor Ul-Huda , Gray Jennifer , Waryoba Daudi , Rajagopalan Ramakrishnan
Published: August 2024

Soft magnetic composites are powder metal products under development as an alternative to 2D laminates in electric motor applications. The 3D design of SMCs offers greater energy efficiency but poses a challenge to maintain adequate strength properties required for application. Soft magnetic composites are fabricated through compaction and heat treatment of iron particles coated with insulated coating to form a dense compact. The soft magnetic properties of the compact are affected by the properties of the iron powder, density of compact as well as the efficacy of forming uniform thin insulating coating at the particle boundary. Additionally, the strength of the compact is also affected by the nature of the insulating boundary at the particle interfaces. We report a low temperature process that involves cold sintering phenomenon to densify and strengthen soft magnetic composites. Iron powders have been modified using a co-precipitation method that forms a hydrated copper/iron oxalate coating on individual iron particles. Warm compaction of the modified iron powders at 100°C resulted in a highly dense soft magnetic composite which demonstrated ~ 3x improvement in strength. The compacts can be further heat treated in air at higher temperatures to form high strength oxide coating iron based soft magnetic composites. Results of the AC and DC magnetic measurements of fabricated cold sintered toroid compacts made as a function of heat treatment temperature reveal that DC permeability increased with heat treatment temperature. Analysis of AC core loss data showed that hysteresis power losses dominated the performance at lower heat treatment temperatures (< 300°C) beyond which dynamic core losses significantly increased.
Initial Value and Initial Current Discrepancy in Simulating Lithium-Ion Battery Packs - Resolution from Dr. Ralph White’s Analytical Approach
Authors: Telmasre Tushar , Mishra Lubhani , Thiagarajan Raghav Sai , Subramaniam Akshay , Ramadesigan Venkatasailanathan , Garrick Taylor R. , Subramanian Venkat R.
Published: August 2024

Battery models are useful tools that provide insight into electrochemical processes within an electrochemical device those can typically not be measured, either due to a lack of experimental methods or due to the transient nature of the phenomena in question. Irrespective of the complexity of the models involved, a general view is that a good model, once established for a single cell in terms of complexity of the physics, choice of simulation algorithm, value for the parameters, and mechanisms for fade, can be easily extended for pack simulations.1–3 This type of extension is critical to the virtual engineering efforts currently underway at OEMs which rely on accurate and representative battery models. In this work, pitfalls during scaling up approximate and detailed physics-based models developed for single-cell to pack-level simulations are highlighted using representative examples. Interesting mathematical nuances were found depending on the numerical simulation approach used. A discrepancy at initial times (t = 0) during the pack-level simulations was highlighted and resolved using the Laplace transform approach to get an analytical solution for the simplest model. A few thoughts on numerical challenges and the index of differential-algebraic equations (DAEs)4,5 while using the strong form and the weak form formulation of DAEs are also provided in the paper.6

References:

M. Dubarry, N. Vuillaume, and B. Y. Liaw, J. Power Sources, 186, 500–507 (2009).

T. Tranter et al., J. Open Source Softw., 7, 4051 (2022).

J. M. Reniers and D. A. Howey, Appl. Energy, 336, 120774 (2023) https://doi.org/10.1016/j.apenergy.2023.120774.

E. Hairer and G. Wanner, Solving Ordinary Differential Equations II, 2nd ed., p. 15–37, Springer Berlin, Heidelberg, Berlin, (1996).

L. Petzold, SIAM J. Sci. Stat. Comput., 3, 367–384 (1982).

T. K. Telmasre et al., J. Electrochem. Soc., 170, 103512 (2023).

Figure 1
Streamlining Electrode Optimization for Sustainable Organic Electrohydrogenation
Authors: Wickert Leon , Kraenbring Mena-Alexander , Hansen Meinert , Sanden Sebastian , Pellumbi Kevinjeorjios , Wolf Jonas , Siegmund Daniel , Özcan Fatih , Apfel Ulf-Peter , Segets Doris
Published: August 2024

Electrochemical hydrogenations are becoming increasingly important in today’s world, representing a gateway reaction for the sustainable production of base and fine chemicals. However, finding optimal reaction conditions for such systems can be challenging due to a vast variety of adjusting screws that influence the overall performance of the reactor. Especially the tailored electrode fabrication is one of the most complex, but also most important parts of scalable electrochemical cells. Combining catalyst and binder materials, and optimizing their subsequent deposition are critical steps in the electrode fabrication process and have a significant impact on the final electrode performance. For the deposition of the catalyst, a suitable coating technique, catalyst substrate and catalyst loading must be found to provide an optimal hydrogenation environment. However, the complex interplay of all these process variables of the electrode fabrication can make an optimal electrode design very challenging. We herein present a coherent workflow that allows for a fast and accurate optimization of electrodes for the electrochemical hydrogenation, with well-adjustable experimental effort. The approach covers the selection of catalyst-binder combinations, layer deposition methods, electrode substrates and catalyst loadings. To determine the influence and interplay of these fabrication parameters, the performance of the electrodes was tested in the hydrogenation of phenylacetylene to styrene as a model reaction with a selection of earth-abundant metal sulfides of the pentlandite class. For this, we employed an in-house built zero-gap electrolyser that can operate at industrially relevant current densities and low cell voltages. Special focus is laid on the evaluation of the electrochemical performance and post-mortem analyses of the catalytic layers to detect changes in catalyst structure after electrolysis. Our findings show that rapid optimization of tailored electrodes is possible with reasonable experimental effort and that understanding the interplay of the electrode fabrication variables will ease the way towards establishing industrial electrochemical hydrogenations.

Figure 1
Electrodeposition of Nanotwinned Cu Foils with Different Microstructures
Authors: Chen Bo Yan , Chen Chih
Published: August 2024

In recent years, electric vehicles have been considered one of the most forward-looking industries in the world. In 2023, electric vehicles have occupied 16% of the light vehicle sales market. The expansion of the electric vehicle market is expected due to the goal of 2050 net zero emissions. This has led to increased performance requirements for automotive lithium batteries (LIBs). In general, copper foil is an important material for LIB anode current collector. Since The volumetric expansion during the charge-discharge cycles of LIBs introduces significant stress, the resulting large stress may damage the copper foil at the anode, causing the battery to eventually fail. Therefore, the mechanical properties of the copper foil need to be enhanced. In this study, different organic additives are added during electrodeposition to increase the mechanical strength of the nanotwinned copper (NT-Cu) foil while still maintaining good electrical conductivity. With organic additive B, the ultimate tensile strength (UTS) can be increase to 750 MPa, yield strength (YS) to 550 MPa, with an increase of 66% and 74 % compared to the Cu foils fabricated by additive A, and the international annealed copper standard (IACS) remains at 83.7%. Facilitated by focused ion beam (FIB), in the case of organic additive A, its microstructure is columnar nanotwin copper, and for additive B, its microstructure is a mixture of columnar nanotwin copper and fine grains. The difference of the microstructure contributes to the additional strength. Furthermore, linear sweep voltammetry (LSV) analysis is used to illustrate the relationship between type of additives, tensile strength, and reduction potential.

Figure 1
(Invited) Electroflow: Sustainable Electrochemical Lithium Chemical Production
Authors: McShane Eric J. , Gardner Evan J.
Published: August 2024

The demand for lithium has soared in recent years as the adoption of electric vehicles has grown rapidly, and lithium supply will need to grow another ~5x from current day to meet projected demand for lithium in 2030. To keep pace with this exponentially growing demand, novel methods of lithium sourcing are needed. Direct lithium extraction (DLE) from saltwater brines holds promise to unlock the lithium resources needed to power the electric vehicle revolution.

Lithium is traditionally sourced via two methods. Open pit hard rock mining is the method which many are familiar with. In this method, rocks are excavated, roasted with sulfuric acid, and the eluent is processed to produce a pure lithium product. This is well known to be environmentally destructive, and it produces larges amounts of waste products. The second method employed to produce lithium chemicals is brine evaporation ponds. In this method, brine is pumped to a surface pond, often multiple acres across, and solar evaporation concentrates the lithium in the brine to the point that it can undergo further processing. This method is extremely land and water intensive, and local residents adjacent to such ponds are increasingly worried about the effects of such methods on local water tables.

Electroflow employs a DLE process to convert brine directly into pure, battery grade lithium chemicals via a sustainable electrochemical process. Our electrochemical cell design enables extraction from dilute lithium brine resources with as low as 10 ppm Li, which unlocks huge swaths of new lithium resources across the globe, and specifically in North America. We use lithium-selective electrode materials as the basis for lithium separation from brine solutions, and this allows a new paradigm of DLE processes that have not yet been thoroughly studied. This talk will describe the operation of our technology and explore the impact that it could have at scale.
(Invited) Challenges and Successes of an Industrial Start-up to Global Electrolyzer Company
Authors: Capuano Christopher B. , Ayers Katherine E. , Dalton Luke T. , Anderson Everett , Carmo Marcelo
Published: August 2024

Hydrogen generation via electrolysis has gained much attention internationally as not only a sustainable source of fuel for the transportation, but as a carrier of energy to capture stranded renewable energy due to the carbon-free chemical cycle and response characteristics of the technology. The barrier to entry preventing this technology from being widely adopted is the overall cost associated with both the upfront capital expense as well as the operating cost incurred over the product life. The majority of this cost is driven by 1) low electrical efficiencies due to the high ohmic resistance of thicker membranes required by electrolysis systems to electrochemically compress generated hydrogen for storage and the overpotential associated with the water splitting oxygen evolution reaction (OER) catalysts typically used, 2) high cost of system and cell stack materials, which need to be durable for up to 100,000hrs at potentials approaching 2V in both reducing and oxidizing environments, and 3) the lack of a robust supply chain for high volume manufacturing to further drive down cost through economies of scale.

Nel Hydrogen has worked to commercialize this technology, originally developed for aerospace and miliary applications where cost and efficiency were not the drivers. Since the founding of Proton Energy Systems in 1996 and to the present as Nel Hydrogen we have worked to address these problem areas in an attempt to develop products that can serve cost sensitive markets, such as energy capture and storage. During this talk, I will look back on the challenges we faced as an industrial start-up dealing with uninterested suppliers, creating relationships, and establishing partnerships, all while developing our first 28cm2 products to the point today, where we are producing and siting multi-MW systems.
On-Site Electrochemical Oxygen Reduction to Hydroxide and Hydrogen Peroxide for Sulfuryl Fluoride Solution Hydrolysis
Authors: Badr Hussein O. , Napier Cade , Jaramillo Thomas F. , Mitch William
Published: August 2024

Sulfuryl fluoride (SO2F2) has been largely used as a postharvest fumigant replacing methyl bromide (widely recognized among ozone-depleting substances). Sulfuryl fluoride, however, is a potent greenhouse gas with a Global Warming Potential (GWP) of ~ 5000 for a 100-year time zone far higher than that of carbon dioxide and methane. Ongoing pilot work showed that SO2F2 fumes vented from fumigation chambers can be captured and hydrolyzed by hydroxide (OH-) and hydrogen peroxide (H2O2) solution at pH ~12 in a scrubber with a complete conversion into SO4
2- and F- as waste salts. The purchase, shipment, storage, and handling of concentrated stocks of H2O2 and NaOH for use in SO2F2 hydrolysis involve cost and safety concerns. Herein, we present an on-site, facile, and cost-effective pathway for the electrochemical production of OH- and H2O2 in large enough concentrations to fully degrade ~ 95% of SO2F2 captured. In that, we employed a commercial carbon catalyst that produced 250 mM H2O2 at pH 12.6 within 4 h with a Faradaic efficiency of 98.8% for O2 reduction to H2O2. We also propose a facile approach via surface oxidation of abundant carbon materials to significantly enhance both activity and selectivity for OH- and H2O2 production under electrochemical oxygen reduction reaction. These findings provide new insights in the on-site production of industrial chemicals by means of clean, facile, and environmentally friendly electrochemical pathway. Moreover, the capability of recycling the hazardous SO2F2 fumes and using the SO4
2- and F- waste products as free sources of electrolyte can’t be overemphasized.
Enhancing the Performance of Electrochemical RAM (ECRAM) through Modeling Guided Device Engineering
Authors: Tessler Nir , Jeon Seonuk , Woo Jiyong
Published: August 2024

Traditionally, the only ions allowed or welcomed by the microelectronic industry are those that act as fixed dopants. The issue of mobile ions became welcome primarily due to the memristor technology however, thin film transistor technologies benefit from them too. The electrochemical (transistor) random access memory (ECRAM) is emerging as a promising building block for multi-level neuromorphic computing. Using FAB-compatible materials we construct the ECRAM using CuOx as the gate and ions source (Cu+). The morphology of the HfOx gate insulator layer is tuned to render it ion transporting such that it can act as a uniform electrolyte layer. Lastly, the channel material is WOx with tungsten metal as the source/drain contact.

While there are several reports of ECRAM devices, the operation mechanisms are not fully known/understood thus withholding progress of this field. Using the Sentaurus device simulator by Synopsis, including the hydrogen diffusion module, we simulate the mixed ionic electronic operation of the device. We have recently reported that by fitting the simulation to the device performance, we could identify the potentiation mechanism (i.e., insulator charging) and the occurrence of copper plating that takes place under high Cu+ ion flux (as in fast charging of Li batteries).[1]

In the first part of the talk, we will expand on the chemical-physics details of the ECRAM device mentioned above. Next, we will present a new device architecture where we remove the WOx layer and study the ionic-electronic conduction of a modified HfOx layer. By fine-tuning the stoichiometry of the HfOx layer, it assumes both roles of ionic electrolyte and electronic conducting channel. Following detailed modelling of the measured properties, we introduce AlO2 as an ionic barrier layer at the WOx/HfOx interface to enhance the ionic retention of the HfOx layer. Using the above three device architectures in conjunction with the mixed ionic-electronic device simulation we reveal the role of the two memory mechanisms: a) Electric field-activated ion transport and b) Structure-induced trapping by ion-barrier layers.

Reference

[1] Nir Tessler, Nayeon Kim, Heebum Kang, Jiyong Woo; Switching mechanisms of CMOS-compatible ECRAM transistors—Electrolyte charging and ion plating. J. Appl. Phys. 21 August 2023; 134 (7): 074501. https://doi.org/10.1063/5.0154153

Figure 1
(Invited) Material Engineering for the GAA and Post-GAA Transistors and Interconnects
Authors: Moroz Victor , Smidstrup Soren , Choi Munkang , Gull Ronald , Aboud Shela
Published: August 2024

Feature scaling in advanced CMOS technology has been slowing down starting at 10 nm node and is expected to stop completely in the next few years. Nevertheless, transistor density scaling is continuing at a Moore’s law pace, driven by DTCO and 3D IC.

Transistor dimensions and minimum metal pitch are expected to be massaged down only by 10% to 20% during the next decade. However, both the transistor and the interconnect will continue to evolve and improve both in performance and in variability.

Currently, the industry is transitioning from FinFET technology to GAA (Gate All-Around) technology. The next transition, from GAA to the NMOS and PMOS GAA transistors stacked on top of each other (often referred to as CFET (Complementary Field Effect Transistor)) is expected in 8 to 10 years from now.

The main methodology for GAA and CFET transistor engineering comes down to bandstructure engineering, where material composition, shape and thickness of different layers, and mechanical stress are engineered to tailor a bandstructure of the channel that maximizes on-state driving strength and minimizes off-state leakage and variability. The key methodology for bandstructure engineering is ab-initio analysis of transistor components and then transfer of the obtained bandstructure to transistor scale analysis to characterize its behavior.

For the interconnect engineering, the tight metal pitches and increasingly tall and narrow vias dictate transition from copper to alternative metals, with a preference for the metals that can be etched and selectively grown. The key methodology for interconnect engineering is ab-initio analysis of electron scattering at the interfaces and grain boundaries. The scattering is then converted into interconnect resistance that defines speed and power consumption of the advanced CMOS circuits.

This work introduces the concepts of transistor band structure engineering and interconnect scattering engineering and provides illustrations of these methodologies applied to GAA and post-GAA technologies.
(Invited) Bioinspired Molecular Electrets: “Misbehavior” of Dipoles, Solvation, and Interfaces
Authors: Vullev Valentine I. , O`Mari Jaime O. , Goddard William A , Yang Moon Young
Published: August 2024

Charge transfer (CT) and charge transport are of fundamental importance for sustaining life on Earth and for making our modern ways of living possible (Phys. Chem. Chem. Phys.
2020, 22, 21583-21629). Concurrently, the ubiquitous nature of electric dipoles warrants deep understanding of how they affect CT. Possessing order electric dipoles, electrets are the electrostatic analogues of magnets, and they present outstanding paradigms for exploring dipole effects on CT (Can. J. Chem.
2018, 96, 843-858). Polypeptide α-helices are some of the best-known molecular electrets. These natural structures, however, do not efficiently mediate CT at distances exceeding 2 nm, which limits their utility. Therefore, we undertake the task for developing bioinspired molecular electrets based on synthetic amino acids that provide sites for charge-hopping and allow CT beyond the 2-nm limit. Even a single electret amino-acid residue can rectify CT (Angew. Chem. Int. Ed.
2018, 57, 12365-12369; J. Am. Chem. Soc.
2014, 136, 12966-12973). The molecular macrodipoles and the CT properties of these bioinspired molecular electrets strongly depend on their structure and conformational flexibility. Sinergy between molecular-dynamics (MD) simulations and quantum-mechanical (QM) calculations provides insights into the structural properties of these macromolecules. The structures of the molecular electrets do not fluctuate much. Nevertheless, the macrodipoles of these conjugates show picosecond fluctuations with amplitudes amounting to a factor of two or three from the average values. The structural variations of the electret oligomers cannot account for the dipole fluctuations. The analysis, however, reveals that the solvent dynamics, inducing fast-oscillating Onsager reaction fields in the solvated cavities, is principally responsible for the huge dipole fluctuations. The impact of this discovery extends way beyond the realm of electrets and our explorations show that solvent-induced picosecond dipole fluctuations are a norm, rather than an exception, for solvated species and interfaces. Averaging these dipole fluctuations over 10-ps or 20-ps intervals drastically decreases their amplitudes. It indicates that they would have a minimum effect on nanosecond and sub-nanosecond CT. Nevertheless, these dipole fluctuations may have decisive effects on picosecond and sub-picosecond processes, such as ultrafast CT. These revelations about the dipole dynamics present unexplored paradigms for condensed-phase interfaces and electronic materials.
(Invited) Probing the Influence of the Dielectric Environment on Charge Carrier Dynamics in Semiconducting Polymers
Authors: Ferguson Andrew J , Gish Melissa , Kopcha William , Mohapatra Aiswarya Abhisek , Carr Joshua , Rumbles Garry , Reid Obadiah , Greenaway Ann L
Published: August 2024

Pi-conjugated semiconducting polymers have garnered attention for a variety of electronic and optoelectronic applications, such as field-effect transistors, thermoelectric generators, and photovoltaic devices. In these systems, the charge carrier dynamics are primarily governed by the properties of the polaron and the polymer microstructure. More recently, there has been growing interest in the suitability of these polymer for electrochemical transistors and (photo)electrochemical applications, where the understanding is further complicated by the presence of ions and solvent molecules, as well as the dynamic transport of these species into the semiconducting polymer. Here, we will employ steady-state and transient spectroscopic techniques to probe the influence of charge carrier doping, as well as the extrinsic and local dielectric environments, on charge carrier generation, transport, and recombination in prototypical semiconducting polymer(s). Incorporation of electrochemical techniques enables in-situ spectroscopic measurements that mimic operando conditions. Our observations will provide a better understanding of the factors that control the carrier dynamics in these compositionally complex systems and will have implications for their viability and optimization for (photo)electrochemical applications.
(Invited) Influence of Y6 Aggregation on Energetics and Charge Generation in High Performance OPV Blends
Authors: Asbury John B.
Published: August 2024

We investigated the origin of the high ratio of open circuit voltage to charge transfer state energy (eVOC/ECT) of OPV polymer blends consisting of the electron donating polymer PM6 and the non-fullerene electron acceptor Y6. PM6-Y6 and related donor-acceptor OPV blends exhibit remarkable optoelectronic properties and record power conversion efficiencies in part because of their unusually high eVOC/ECT ratios, which is believed to be related to the small energetic offset of the HOMO levels of PM6 and Y6. In this study, we varied the amount of Y6 in PM6 blends as a means to control the aggregation of Y6 molecules. We examined the corresponding influence that Y6 aggregation has on the energetic offsets and the charge generation efficiency of the materials by probing the appearance of polaron absorption signals in the mid-infrared using time-resolved infrared spectroscopy. Furthermore, we examined the optical absorption and emission spectra of the PM6-Y6 blends over the range of compositions to correlate the efficiency of charge generation with the signatures of Y6 aggregation in the optical spectra. We observed an abrupt transition around 30 mass% Y6 content at which polarons were efficiently generated by charge separation from PM6 to Y6. Comparison to composition dependent GIWAXS studies of PM6-Y6 blends revealed the formation of Y6 aggregates around the same 30 mass% threshold. These observations demonstrate that aggregation of Y6 molecules is required for charge separation to occur from PM6 to Y6 as measured through the mid-infrared absorption of polarons in the TRIR spectra. Although charges were efficiently generated in blends with only 30 mass% Y6 content, OPV device studies revealed that 50-60 mass% Y6 was needed to reach optimized short-circuit current and OPV device efficiency because these measurements convolve charge generation with charge transport. These findings clarify the optoelectronic properties of the novel class of Y6 acceptors and emphasize the importance of molecular aggregation for tuning the energetics of high performance systems that minimize energy offsets for maximum OPV power conversion efficiencies.
(Invited) Organic Source-Gated Transistors for High-Gain Sensor Signal Conditioning
Authors: Sporea Radu Alexandru
Published: August 2024

A set of important developments have been recently demonstrated in contact-controlled thin-film transistors [1-3] realized with organic semiconductors.

Targeted at obtaining superior power efficiency, layout utilization and signal integrity, these advances largely focus on the electrical and geometrical optimization of the source area. Field-relief structures embedded into the source contact produce high intrinsic gain in both n-type and p-type inkjet-printed organic source-gated transistors (SGTs) [4-5], toward achieving the potential of such devices in high gain unipolar amplifiers [6]. Thermal effects are reduced via contact barrier – semiconductor interplay [7] and robust optical sensing of blue light is demonstrated [8]. Finally, utilizing the source barrier, as opposed the W/L geometry of the transistor to dictate drain current magnitude leads to compact and practical CMOS inverters when p-type DNTT-based organic SGTs are paired with n-type IGZO SGTs [9].

By judicious and application-driven design (Figure 1) [10], the source-gated transistor and its evolution, the multimodal transistor [11], are showing significant potential in signal conditioning and sensing applications.

[1] J. M. Shannon et al., IEEE Trans. Electron Devices, 60, 2444–2449 (2013).

[2] A. Valletta et al., J. Appl. Phys. 114 064501 (2013).

[3] J. Zhang, et al., PNAS
116, 4843 (2019).

[4] Y. Hemmi, et al., Nanomaterials, 12, 4441 (2022).

[5] Y. Hemmi, et al., Adv. Electron. Mater., 9, 2201263 (2023).

[6] E. Bestelink, et al., IEEE Sens. J., 20 (24), 14903 (2020).

[7] E. Bestelink, et al., Adv. Electron. Mater., 9, 2201163 (2023).

[8] E. Bestelink, et al., Adv. Opt. Mater., 2301931 (2023).

[9] E. Bestelink, et al., J. Mater. Chem. C, 11, 11688 (2023).

[10] E. Bestelink, et al., Adv. Electron. Mater., 8, 2101101 (2021).

[11] E. Bestelink, et al., Adv. Itell. Sys.,
3, 2000199 (2021).

Figure 1