bluuebunny/crossref_metadata_2025 huggingface dataset:
(Invited) Materials Manufacturing and Process Scale up for Energy Storage
Authors: Li Jianlin , Zhang Yuepeng , Shin Youngho , Kahvecioglu Ozgenur
Published: August 2024

The demand for energy storage devices is ever increasing with their applications to electrical vehicles and grid storage. To keep up the ever-growing battery manufacturing capacity, it is critical to develop novel processes that can produce materials and electrodes at scale at low cost and with high throughput and low environmental impact. This presentation will discuss multiple processes in material and electrode manufacturing from batch to continuous or roll-to-roll operation. Benefits and challenges of each process will be discussed.
(Invited) Advanced Electrode Fabrication for Enhanced Battery Performance
Authors: He Meinan , Dai Fang , Cai Mei
Published: August 2024

In recent years, the highly emerging EV market evokes intensive search for more advanced batteries with higher energy density to increase the driving range and further reduce the cost. Compared to consumer electronics, automotive industry generally has critical requirements for specific characteristics of EV battery cells. Among many critical requirements on specific characteristics of EV batteries, cost and energy density are always interconnected as the main factors being considered in new battery cell designs. For advanced EV battery development, aside from scientific discovery, it’s very important to understand how cell designs, material properties, and the scaling up process play an important role in the final cost, energy density, and commercial feasibility of the batteries. When researching any new materials, In this talk, we will discuss what OEM is looking for and how to further unleash the power of battery chemistry and cell design as well as the manufacturing scaling up to expedite the advanced battery technologies for vehicle application.
(Invited) Advanced Electrode Processing for Next Generation Batteries
Authors: Kaskel Stefan , Schumm Benjamin , Althues Holger , Hippauf Felix
Published: August 2024

The development of environmentally friendly processing techniques is a key requisite for future sustainable battery development. The so-called DRYtraec® process is a solvent-free process developed as a viable approach to replace slurry-based binders by fibrous polymers and produce laminated electrodes with a low carbon footprint. It has been demonstrated to work for both, liquid and solid electrolyte batteries. NMC cathodes can be produced in a wide range of loading. For lithium sulfur batteries carbon/sulfur composites can be processed without sulfur loss. In particular in the field of solid state batteries it shows significant advantages. All-solid-state lithium-ion batteries are promising candidates to overcome safety and energy limitations of established lithium-ion batteries (LIBs). Excellent results have been reported for sulfide based electrolytes on a small scale. More and more companies announce their first pilot production lines. Therefore, scalable concepts for material and component development are of crucial need. We evaluate this process for the fabrication of thin argyrodite separator films and compare it with slurry-based separators in ASSBs. To test new cell concepts and components under relevant conditions, it is important to manufacture prototype cells with thin separator layers and flexible housing. Therefore, we prepared slurry-free pouch cells based on Ni-rich NMC cathodes and PVD-synthesized Si anodes.

The presentation highlights recent developments of the DRYtraec® process and its application to ASSBs, LiS and LIBs.
Development of Efficient Ink Dispersion Process for Solid-State Electrolyte and Electrode Manufacturing
Authors: Miller Samuel David , Lee Jungkuk , Xu Shaomao , Chen Mengyuan , Wang Chuanlong , Zhang Yubin , Zhang Yuepeng
Published: August 2024

All-solid-state lithium batteries (ASSBs) have several advantages over lithium-ion batteries (LIBs) such as higher safety thresholds associated with solid electrolytes (SEs) and the possibility of using lithium metal or silicon anodes to achieve comparatively higher energy and power density. The SE can also prevent chemical interactions with dissolved active materials, and thus solve the issue of long-term instability of LIBs. However, there are also challenges associated with ASSBs manufacturing, such as local stress and contact-loss between SE and active materials in cathodes due to active material “breath”, poor contact and high ionic resistance at the SE-cathode interface, difficulty in fabricating thin SEs, and the absence of scalable and cost-effective manufacturing processes (J. Janek and W.G. Zeier, Nature Energy 8 (2023): 230-240). A key to tackling these issues begins with ink formulation for electrolyte and cathode coating, including ink compositions and rheological properties.

In this study, we report the influence of ink preparation methods and conditions on the solid-state electrolyte and cathode coating qualities, where lithium lanthanum zirconium oxide (LLZO) and lithium nickel manganese cobalt oxide (NMC) are used as model systems. Various mixing methods, such as acoustic wave mixing, high-speed off-axis mixing, and thin film mixing, are compared. Their influence on ink viscosity and particle dispersion, coating thickness and microstructure uniformity, and electrolyte and electrode electrochemical properties will be discussed.
Rotary Electrodeposition of High-Strength Nanotwinned Copper Foils
Authors: Kang Ping Lee , Chen Chih
Published: August 2024

Due to the 2050 Net Zero Emissions becoming a major goal worldwide, electric vehicles have emerged as the future mainstream products. Among them, copper foils play a crucial role as the anode current collector in lithium-ion batteries (LIBs). Enhancing the strength and decreasing the thickness of copper foil are both important factors improving the lifespan of LIBs. The thickness of Cu foils can be reduced by rolling copper sheets, but it is challenging to achieve the required thinness below 10 micron for electronic applications. Direct current electroplating not only effectively increases the deposition rate but also reduces costs for thin Cu foils. In this study, we utilized a rotary direct current Cu-Ni co-electroplating method to enhance the mechanical strength of nanotwinned copper. The ultimate tensile strength (UTS) of nanotwinned copper-nickel alloy reached over 847.3 MPa (an increase of approximately 12.6 % compared to the maximum UTS of nanotwinned copper, which was 752.8 MPa) while maintaining excellent electrical conductivity similar to nanotwinned copper. Through potentiostat analysis, it was discovered that nickel ions inhibit copper growth, causing the reduction potential of copper to shift negatively, resulting in a decreased deposition rate and increased twin density. The nickel content, measured by ICP-MS, was found to be 0.467 ppm, suggesting that nickel acts as an impurity that refines grain size in copper foils. Therefore, this method not only significantly improves the strength of copper foils but also maintains low electrical resistance and low-cost characteristics. It provides a new material option for the anode current collector of the next-generation LIBs.

Figure 1
Compression Testing of Individual Battery Electrode Particles
Authors: Barthold-Robinson Jarid , Gabler William , Macey Christopher
Published: August 2024

The friability of powder materials used to fabricate battery electrodes is an important parameter in determining battery lifetime. Particulate electrode materials are subject to significant stresses during cell fabrication. While in use, battery cyclic charging and discharging induces mechanical stresses in the electrode materials which can significantly impact long-term stability.

Our presentation will describe a novel micro-compression instrument and technique for determining the compression strength of individual particles as small as 1 micron in diameter. Brief examples of the technique used to characterize and compare the hardness of battery anode materials will be discussed. Further in-depth references will also be provided.
(Invited) Scaling-up High Energy Density Solid-State Batteries
Authors: Meng Shirley
Published: August 2024

Recent years have seen monumental and exciting developments in the research and development of all-solid-state batteries (ASSBs). Despite its promises, they still face a multitude of technical hurdles before commercialization can be achieved. In this talk, I will provide a perspective on a wide range of scalability challenges and considerations for ASSBs, including solid electrolyte synthesis, dry electrode and separator processing, cell assembly, and stack pressure considerations at the module level.
Ontology Creation and Database Implementation for Lab-Scale Solid-State Battery Cells
Authors: Albertus Paul , Larson Karl , Schulman Omri , Kattouf Basila , Damatov Delina , Anderson Assaf Y
Published: August 2024

New developments and publications on alkali metal solid-state batteries are being published at a high rate, with the total number of publications now in the thousands, but the search and analysis of the data in these publications is still largely done using key words and through careful reading of the article and the supporting information. The challenges of efficiently searching and extracting data from thousands of publications in a field are also present in other fields, such as perovskite solar cells, for which a large (>15,000) set of cell data has been entered into a database that continues to be updated.1 A database for alkali metal (e.g., based on Na+ and Li+ conduction) solid-state cells that could be easily searched and that facilitated advanced forms of data analysis could accelerate research progress, and is consistent with efforts such as definition of the “Principles of the Battery Data Genome” and the BIG-MAP project.2 In this talk, we describe our approach to creating an ontology and database for lab-scale solid-state cells, along with results to date. Key areas for the ontology include component material identities, material properties, component properties (e.g., active material loading, mass fractions, thicknesses), processing conditions for materials and the cell itself (e.g., ball milling time, sintering time), and both performance (e.g., rate capability) and degradation (e.g., cycle life). Results based on several hundred solid state cells in our database are presented in terms of histogram plots, violin plots, correlation plots, and other representations. We also describe our efforts to integrate our ontology and tool with broader efforts in the field, and to make it broadly useful to battery researchers.

1. Nature Energy, volume 7, pages 107–115 (2022) and https://www.perovskitedatabase.com/

2. Joule 6, 2253–2271, October 19, 2022 and https://www.big-map.eu/dissemination/battinfo
In Situ Sodium Plating and Stripping at the Aluminum/Nasicon Interface
Authors: Tseng Flora , Lee Kiwoong , Sakamoto Jeff
Published: August 2024

Solid-state sodium metal batteries have emerged as compelling alternatives to lithium-ion batteries due to their abundance, geopolitical stability, and cost. However, the development of solid-state sodium metal batteries faces challenges such as achieving high ionic conductivity in solid electrolytes, ensuring stable interfaces between the solid electrolyte and sodium metal anode, as well as the complexity of manufacturing due to the air reactivity of sodium metal. To overcome these challenges, the anode-free manufacturing process to fabricate is a promising approach to enable the commercialization of sodium metal batteries.

In this work Na3.4Zr2Si2.4P0.6O12 (NaSICON) was synthesized and densified to >99 % relative density with a total ionic conductivity of 5 mS cm-1 using a solution assisted solid-state reaction process followed by rapid induction hot-pressing, respectively. Using the hot-pressed NaSICON in an anode-free cell design, we demonstrate the feasibility and ease of using commercially available aluminum foil with a sputtered metal layer as the current collector (CC). We show stable sodium plating of several microns at the NaSICON | CC interface with a current density of 0.5 mA cm-2 at room temperature. In addition, this study demonstrates good reversibility after several cycles of plating and stripping.

This study not only explores the electrochemical behavior of in situ sodium plating contributing to the advancement of cost-effective energy storage solutions, but also offers valuable insights into practical manufacturing processes for solid-state sodium metal batteries.
Scalable Synthesis and Electrochemical Study of Ceramic-Polymer Nanocomposite Solid Electrolytes for Solid-State Battery Manufacturing
Authors: Zhang Yuepeng , Tepavcevic Sanja , Lee Jungkuk , Counihan Michael , Go Wooseok , Barai Pallab , Tucker Mike C , Doeff Marca M. , Srinivasan Venkat
Published: August 2024

Solid-state lithium batteries (SSBs) have the potential to achieve high energy and power densities due to the use of solid electrolytes (SEs) that are compatible with lithium metal or silicon-based anodes. However, fabrication of SEs with good ionic conductivity, mechanical strength, electrochemical stability, and interfacial contact with solid electrodes have been challenging. One promising approach is to combine ceramic lithium conductors that is expected to show a relatively high room-temperature Li-ion conductivity and a soft polymer matrix that facilitates mechanical integrity at the electrode-electrolyte interface during charge-discharge cycling. In this study, we report a scalable synthesis of Al0.25Li6.25La3Zr2O12 (LLZO) nanofibers and polyethylene oxide (PEO) composite SEs using roll-to-roll manufacturing. Our LLZO fibers showed 0.3 mS/cm conductivity at room temperature and the LLZO-PEO composites showed three times higher critical current density than a single PEO polymer electrolyte. Microstructural and electrochemical properties of the composite electrolytes will be discussed.
Multiphysics Simulation of Battery Electrode Drying
Authors: Monismith Scott , Roberts Scott A. , Liu Wanjiao , Horner Jeffrey Scott
Published: August 2024

Scaling Li-ion battery production to meet the demands of increasingly electrified grids and transportation systems will require higher throughput at all levels of the battery cell production process. One of the more energy intensive battery manufacturing steps is the necessary drying of solvents which persist in the electrodes after the initial slurry coating of their current collectors. It is critical to both optimize this drying process to minimize the time and resources required, as well as to understand the effect that the drying has on the electrode microstructure. As it is both expensive and time-intensive to iteratively test different temperatures on multiple initial electrode microstructures, it is necessary to have reliable, high-fidelity simulations which can model the evaporation process. Furthermore, it is easier to control microstructural features such as porosity, and particle size in a simulated environment, Indeed, by simulating evaporation, the design-of-experiments space can be minimized, and process conditions can be established to accelerate the production of high quality, lower cost electrodes.

To that end, we develop a multiphysics model of solvent evaporation using Sandia’s in-house finite element software. By coupling the solvent equations of motion to species conservation equations for the carbon binder material and energy flux driven by evaporative cooling, we demonstrate good agreement between simulation and simple evaporation experiments. This model tackles several difficult aspects of evaporation, namely the evolution of free surfaces and gas-liquid phase-changes. We additionally extend our model to account for mesoscale features (i.e. particle size, porosity, binder distribution) and determine how different temperature profiles and microstructures affect the heating requirements for the electrode. These extensions present a key advantage over conventional 1D models, as these features can have a significant effect on the evaporation process and the final distribution of conductive additive and binder. We leverage this advantage to examine how several design parameters such as porosity, particle size distribution, and heating rate affect the resulting electrode structure and binder distribution. These results demonstrate a pathway to optimizing the electrode drying process and promise to inform the development of improved multiphysics models in the future.

SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525.
The Heterogeneity of Turn-over Number in Electrocatalysis
Authors: Orozco Miguel , Gott Joseph , Sepunaru Lior
Published: August 2024

Chemical catalysts dominate the multi-billion global revenue of the chemical industry because they accelerate the time it takes a particular reaction to reach equilibrium without altering the equilibrium constant. Electrocatalysis can provide significant benefits compared to other methods, as it has minimal purification and separation costs, is operational at low temperatures and pressures, replaces hazardous and toxic chemical sources with electric current, and can be integrated with renewable energy sources. From a techno-economical point of view, some considerations are critical during a catalyst design: cost, activity, and durability. One useful metric to quantify catalyst durability is turn-over number (TON), which represents the maximum yield of products attainable from a catalytic center. Mathematically speaking, the TON is defined as: TON = ∫0
∞ TOF(t) dt, where TOF is the turn-over frequency, which is the rate of turn-overs (N) per active site. Currently, without any exception, the TON is given as a fixed number describing the total amount of substrate converted until the catalysts fully degrade. Our approach studies electrocatalytic deactivation processes at the single catalyst level using a technique entitled single-entity electrochemistry for freely diffusing catalysts. The hydrogen evolution reaction (HER) is investigated with platinum nanoparticles as the model catalyst because it deactivates at the nanoscale when the catalytic activity decreases over time. At specific applied potentials, the current measured when a single platinum nanoparticle impacts the electrode creates a transient spike and decay back to the baseline current. TON is quantified by fitting the current decay response and integrating above the fit to find the charge transferred to catalyze the reaction. Our results show that electrocatalyst degradation and TON have a distribution, where some catalysts are more stable than others, and depends on the applied potential and size of the nanoparticles. In order to study how the surface facets of platinum affect the TON, SECCM was coupled with scanning electron microscopy (SEM) to compare the deactivation of a polycrystalline platinum surface in the macro scale with immobilized platinum nanoparticles on a glassy carbon surface. Combining local structural, electrochemical activity, and durability will bridge our fundamental understanding of macro and nanoscale catalyst deactivation processes to assist in the bottom-up approach of material development and design of large-scale industrial electrocatalysts.
Modeling Stochastic Kinetics of Cathodic Cu Surface Corrosion and Ionic Interaction in Nanoscopic Water Pools
Authors: Ranka Karnamohit , Kang Richard , Prakash Prabhat , Kwon Soonho , Houle Frances , Head-Gordon Martin , Goddard William A
Published: August 2024

Cathodic Cu corrosion has been reported to occur in both the presence and absence of carbon dioxide in aqueous electrolytes and while the mechanism is not understood well it implies carbide-, hydride- and hydroxide-formation mediated pathways. Corrosion leads to roughening, which creates local pockets of electrolyte that are somewhat disconnected from the bulk. In this talk, we describe a combination of theoretical studies to identify reaction pathways, and kinetics modeling of them to obtain a working description of corrosion in water. Corrosion at metal surfaces is both influenced by and influences the formation of nanoscopic aqueous pools by trapping electrolyte solution in microscopic pockets. Such electrolyte nano-pools exhibit non-bulk behavior, and the lifetime of locally trapped ions can be significantly different than in the bulk. This can potentially have an effect on the chemistry in the local microenvironment. Stochastic reaction-diffusion models can be used to model kinetics of electrochemical processes at length and time scales relevant to laboratory experiments, allowing a direct comparison of transient observable quantities to time-resolved experimental data. Atomistic simulations employ methods of electronic structure theory (such as density functional theory (DFT)) and molecular dynamics (both classical and ab initio) to describe a detailed picture of the (electro-)chemistry at microscopic time and length scales. Scaling up these methods to macroscopic levels is not trivial but required for direct comparison to experiment. By using Gibbs free energies obtained from atomistic simulations it is possible to calculate rate constants for individual elementary steps in reaction schemes describing kinetics of relevant processes. We use Kinetiscope to implement stochastic kinetics models of two reaction schemes describing: 1. cathodic Cu surface corrosion through formation of copper hydroxides, through which we aim to describe essential steps in the cathodic corrosion mechanism of metal surfaces; 2. interactions between bicarbonate and hydronium ions, both present in the bicarbonate salt buffers used routinely in electrochemical reduction at copper surfaces, in a nanoscopic water droplet to understand time-dependent changes in the local concentrations of electrolytes trapped at or near metal surfaces.

Figure 1
(Invited) A Study of the SEI Layer Cross-Talk in Si/C Composite Li-Ion Anodes
Authors: Ihsan-Ul-Haq Muhammad , Larson Jonathan M. , Cha Hyungyeon , Dopilka Andrew , Kostecki Robert
Published: August 2024

Composite electrodes, especially silicon/carbon (Si/C) anodes, present significant opportunities for advancing the energy density of lithium-ion batteries (LIBs). However, challenges emerge, particularly in performance metrics when a high weight percentage of Si beyond 8-10 wt.% is employed 1. A nuanced understanding of the solid electrolyte interphase (SEI) in Si/C composites is imperative to overcome these limitations and enhance energy density. Conventional techniques such as ex-situ X-ray photoelectron spectroscopy and cryogenic electron microscopy face inherent drawbacks, including exposure to ultrahigh vacuum and the need for solvent washing, potentially altering the SEI layer 2. In contrast, nano-FTIR, utilizing Fourier transform infrared near-field spectroscopy, overcomes these challenges, enabling non-destructive probing of the SEI layer's chemistry and structure at room temperature within an inert atmosphere 3–5.

In this study, we engineer custom-patterned electrodes featuring amorphous Si on atomically flat highly ordered pyrolytic graphite (HOPG) to emulate model composite electrodes. Leveraging nano-FTIR spectroscopy, near-field nanoscale white-light imaging, and atomic force microscopy measurements, our investigation reveals that the SEI on HOPG is enriched in organic lithium ethylene decarbonate (LiEDC), while the SEI on lithiated silicon unveils the presence of inorganic Li2CO3. Notably, we unveil a unique "mixed" SEI layer zone at the Si/HOPG interface, comprising a mixture of dominant SEI species from the surfaces of both the lithiated Si and the HOPG. The coexistence of these species suggests the formation of an SEI layer with presumably unique physicochemical properties, forming along Si-C interfaces in Si/C composite electrodes. These findings provide a comprehensive approach to studying model composite electrodes and offer valuable insights into optimizing the surface passivation of Si/C composite electrodes for high-performance LIBs.

Acknowledgments

This research was supported by the US Department of Energy (DOE)’s Vehicle Technologies Office under the Silicon Consortium Project directed by Brian Cunningham and managed by Anthony Burrell.

References

V. G. Khomenko and V. Z. Barsukov, Electrochim Acta, 52, 2829–2840 (2007).

J. Wu, M. Ihsan-Ul-Haq, Y. Chen, and J. K. Kim, Nano Energy, 89, 106489 (2021).

X. He, J. M. Larson, H. A. Bechtel, and R. Kostecki, Nat Commun, 13, 1398 (2022).

I. Yoon, J. M. Larson, and R. Kostecki, ACS Nano, 17, 6943–6954 (2023).

A. Dopilka, Y. Gu, J. M. Larson, V. Zorba, and R. Kostecki, ACS Appl Mater Interfaces, 15, 6755–6767 (2023).
Elucidating the Interactions between Different Transition Metal Cations and Ti3C2Tx MXene through Intercalation Method for Electrochemical Applications
Authors: Wee Shianlin , Gomez Vazquez Dario , Lian Xiliang , Tayal Akhil , Salanne Mathieu , Lukatskaya Maria R.
Published: August 2024

MXenes, are a family of two-dimensional (2D) transition metal carbides, nitrides and/ or carbonitrides.[1] The intercalation of different metal cations and organic molecules into MXene for tuning MXenes’ electronic and electrochemical properties have been widely reported.[2]
[3]
[4] However, transition metals (TMs) which have distinct electrochemical behaviors[5]
[6] have not been explored in the literature of MXenes’ intercalation. Therefore, we herein compared the intercalation effects of different TM cations on Ti3C2Tx, for offering a general insight on the influences of multi-valent, redox-active TMs on MXenes. In particular, the changes on the physiochemical and electrochemical properties of MXenes were investigated using different in-situ and ex-situ methods, for a better understanding on the interfacial interactions of TM cations and MXenes in the confined environment of MXenes’ multilayer structures. This work serves as a foundation for the fine-tuning of MXenes’ properties by utilizing a variety of TM cations intercalation for different electrochemical systems.

[1] B. Anasori, M. R. Lukatskaya, Y. Gogotsi, Nature Reviews Materials
2017, 2, 16098.

[2] M. R. Lukatskaya, O. Mashtalir, E. Ren Chang, Y. Dall’Agnese, P. Rozier, L. Taberna Pierre, M. Naguib, P. Simon, M.W. Barsoum, Y. Gogotsi, Science
2013, 341, 1502-1505.

[3] J. Li, H. Wang, X. Xiao, Energy & Environmental Materials
2020, 3, 306-322

[4] M. Ghidiu, S. Kota, J. Halim, A. W. Sherwood, N. Nedfors, J. Rosen, V. N. Mochalin, M. W. Barsoum, Chemistry of Materials
2017, 29, 1099-1106.

[5] D. Göhl, H. Rueß, M. Pander, A. R. Zeradjanin, K. J. J. Mayrhofer, J. M. Schneider, A. Erbe, M. Ledendecker, Journal of The Electrochemical Society
2020, 167, 021501.

[6] M. Esmaeilirad, A. Baskin, A. Kondori, A. Sanz-Matias, J. Qian, B. Song, M. Tamadoni Saray, K. Kucuk, A. R. Belmonte, P. N. M. Delgado, J. Park, R. Azari, C. U. Segre, R. Shahbazian-Yassar, D. Prendergast, M. Asadi, Nature Communications
2021, 12, 5067.
Understanding Reaction Kinetics of Iron Oxide (α- Fe2O3) Reduction with Single Entity Measurements
Authors: Shekhar Raj , Boettcher Shannon W. , Kempler Paul A.
Published: August 2024

Emitting minimal amount of CO2 during the production of steel is one of the major challenges that can be overcome by producing iron using electrowinning method. The reaction of interest is at the cathode where the direct reduction of Iron oxide (α-Fe2O3) to iron takes place. In this study, we are investigating the electrochemical conversion of hematite (α-Fe2O3) Nanoparticles to iron in an extremely alkaline medium (50 wt% NaOH) using Single Entity Electrochemistry (SEE).

Single Entity Electrochemistry is the study of single atom, molecule or particle colliding with the surface of the electrode usually by diffusion or migration. For these experiments, we are developing alkaline stable carbon-fiber (C)/Nickel (Ni) ultra-microelectrode (UME), prepared using multiple pathways such as plasma-focused ion beam.

A spike in current transient during chronoamperometry (CA) experiments is observed when a hematite particle collides stochastically with the UME and gets reduced in the process. Each spike is the reduction event of one hematite nanoparticle to iron. Individual reduction events, that last 0.2-0.3 s and resulting in 0.1-0.2 nC of charge being passed were observed at Ni and C microelectrodes, this shows good agreement with the average particle radius of 100 nm. The shape of the current transient was distinct from previously reported transients for metal deposition at cathode1-3. However, A. Allanore, et.al. model was used to support a mechanism for the direct oxide reduction process at nanoscale particles4.

The results presented here illustrate the reaction kinetics and the mode of reduction propagation in a single nano-sized hematite particle in alkaline conditions. The kinetics of hematite reduction in alkaline medium is considerably slow as observed from the slope of current spikes in SEE experiments. Furthermore, considering Allanore’s model, the reduction propagation occurs from the outer surface to the inner core.

(1) Luo, L.; White, H. S. Electrogeneration of single nanobubbles at sub-50-nm-radius platinum nanodisk electrodes. Langmuir
2013, 29 (35), 11169-11175.

(2) Xiao, X.; Fan, F.-R. F.; Zhou, J.; Bard, A. J. Current transients in single nanoparticle collision events. Journal of the American Chemical Society
2008, 130 (49), 16669-16677.

(3) Bard, A. J.; Zhou, H.; Kwon, S. J. Electrochemistry of single nanoparticles via electrocatalytic amplification. Israel Journal of Chemistry
2010, 50 (3), 267-276.

(4) Allanore, A.; Lavelaine, H.; Valentin, G.; Birat, J.; Delcroix, P.; Lapicque, F. Observation and modeling of the reduction of hematite particles to metal in alkaline solution by electrolysis. Electrochimica Acta
2010, 55 (12), 4007-4013.
Synthesis of Highly Oriented Nanocrystal Thin-Films and Their Applications to Electrochemical Devices
Authors: Jun Beom Hwang , Oh Myoung Hwan , Lee Sanghan
Published: August 2024

The precisely defined particle assembly at the nanoscale with simultaneously scalable patterning at the microscale is indispensable for enabling functionality and improving the performance of devices. While synthetic advances in the past decades now allow precise control of their size, shape, and composition, they must be processed from dispersion into functional films for many applications, which presents additional challenges. In this work, we introduce the self-assembly of inorganic nanoubes (Co3O4 NCs) and we also describe the fabrication of centimeter-scale NC superlattice thin-films on silicone substrate with anisotropic NC building blocks, thin-film patterning, and the supercrystal formation of superlattice structures. As a result, the Raman spectra of Co3O4 NC thin-films clearly exhibits the distinct feature of vibration modes of Co3O4 and synchrotron-based X-ray diffraction techniques showed the Co3O4 NCs order into [100] aligned arrays. Also, the uniformly prepared Co3O4 NC building blocks and thin-films were examined by field-emission scanning electron microscopy analysis and it shows well-defined nanostructures with ~13nm-side of NCs and ~3nm space between self-assembled NCs. To investigate the distinct feature of functional films, we prepared various type of device structures (memory, electrode, gas sensor) and examined the performances. In case of memristor, the device exhibits excellent bipolar resistance switching characteristics with better reliability and stability over various polycrystalline metal oxide nanostructures. Utilizing our approach enables the creation of miniaturized devices, followed by the transfer of NC thin-films onto TEM grids. Subsequent in-situ TEM analysis offers the potential to observe unique phenomena at the nano-scale, unveiling phase transitions in nanocrystalline materials or electrochemical reaction mechanisms previously unexplored by researchers.
(Invited) Dissolution of Organic Overlayers Modified Platinum Single Crystal Interfaces in Acidic Medium
Authors: Qiu Yunsheng , Briega Valentin , Yang Juntao , Hilpert Felix , Mayrhofer Karl J. J. , Brummel Olaf , Libuda Jörg , Cherevko Serhiy
Published: August 2024

Electrocatalysts design has been an important researching discipline in the filed of electrochemical energy conversion and storage, among which, surface (organic) modification has becoming an efficient, selective, and flexible approach in electrocatalysis study and applications. In the focus of direct modulation on electrocatalysis interfaces, the functionalization of metallic catalysts with organic ligands (i. e. functional organic molecule, ionomers, ionic liquids) has demonstrated its capacity on improving catalytic activity and selectivity in electrochemical reactions such as ORR, CO2RR, as well as oxidation processes. However the electrocatalysts stability behavior and surface degradation dynamics of such modified systems are still not sufficiently studied.

To fully decipher the potentials of surface/interface modification in electrocatalysis, we focus our studies on the dissolution behavior of functional organics (i. e. melamine, immidazolium ionic liquids) modified model Pt (hkl) single crystal facets, in acidic medium. In regard of the excellent system sensitivity of our inductively coupled plasma mass spectrometer (ICP-MS, detection limit down to 0.1-1 ng/L), we employed a customized scanning flow cell (SFC) coupled on-line monitoring system to probe the potential-resolved surface metal dissolution dynamics. With designed electrochemical system configuration, we acquired results demonstrating the delicate stability behavior changes over transient and accumulative dissolution study on (modified) Pt facets. In combination of other state-of-art operando spectroscopy methods (electrochemical infrared reflection absorption spectroscopy, electrochemical scanning tunneling microscopy, Raman spectroscopy, etc.), we further comprehended the surface oxidation process, surface blockage/modification mechanisms on electrocatalysis interface. Our research conferred a model stability study approach on surface modification of electrodes and electrocatalysts, providing important insights into the dynamic interfacial interaction between functional modifier and electrocatalysts.
Programmable Assembly of Semiconductor Mesostructures Via Inorganic Phototropism
Authors: Carim Azhar I , Lewis Nathan S
Published: August 2024

Plants exhibit a phototropic response and direct the addition of new biomass to optimize collection of solar insolation. Analogous inorganic phototropism growth enables the programmable assembly of complex 3D nanoarchitectures with instruction by an incoherent, unstructured, mW cm-2 intensity light beam. Inorganic phototropism has been demonstrated via the light-mediated electrochemical assembly of semiconductor deposits from solution-phase precursor ions. No structured light field (no photomask), no lithographic processes and no templating agents (ligands, surfactants, etc.) are utilized. Nevertheless, ordered nanoscale features are conformally assembled over full macroscale (cm2) areas with feature heights on the order of several um with growth times < 5 min. In-plane anisotropy is a function of the input polarization. Isotropic morphologies consisting of ordered arrays of nanoscale holes were generated using unpolarized illumination whereas linearly polarized light resulted in anisotropic lamellar structures with in-plane orientations set by the polarization direction. The structure pitch was dependent on the spectral distribution of the input light with shorter wavelengths effecting higher feature densities. The out-of-plane growth direction is related to the propagation direction of the input light. Time-varying optical inputs enable programming of 3D intricacy by evolving the in-plane structure along the out-of-plane dimension, e.g. an abrupt reduction in the input wavelength results in a concomitant increase in the interfacial density resulting in tuning fork structures. Additional morphological control has also been effected by using multiple simultaneous illumination inputs. Modeling of the growth using a combination of full-wave electromagnetic simulations of light absorption and scattering coupled with Monte Carlo simulations of mass addition successfully reproduced the experimentally observed morphologies and indicated that assembly was directed by evolution of the growth front to maximize anisotropic light collection. The assembly was observed to be a highly emergent phenomenon involving optical communication between neighboring features including cooperative scattering and synergistic absorption.
(Invited) Enhancing Stability for Elevated Temperature CO2 Electrolysis: Insights from Catalyst Development and Impact of Carbon Protection
Authors: Rossen Alana , Daems Nick , Choukroun Daniel , Breugelmans Tom
Published: August 2024

While most lab-scale CO2 reduction experiments are conducted at ambient temperatures (20-25°C), maintaining such low temperatures at an industrial scale will become challenging due to joule heating. In our study, we pushed the boundaries further than the already existing systems, opting for a higher temperature of 85°C for CO2 reduction. This deliberate choice was made to accentuate the deviations from ambient conditions and explore their effects on CO2 electrolyzers.

Our current emphasis at elevated temperatures focuses on catalyst development, specifically addressing stability issues induced by the increased temperature. Nevertheless, it was soon discovered that several modifications were required to the system, both in terms of cell materials and operational conditions (e.g. gaskets, pressure arrangements, GDE type, etc.) to allow stable operation at 85°C for extended duration and especially to avoid flooding. Prior research provided valuable insights into the multifaceted impacts of elevated temperatures on the electrochemical reduction of CO2, and proof they go beyond catalyst kinetics. With this in mind, we have synthesized a series of bismuth-related nano catalysts, including oxidized, metallic and carbon containing nanoparticles, and have quantitatively evaluated their activity, selectivity towards formate, and stability at 85°C. Preliminary observations suggest that catalysts without carbon exhibit high initial selectivity, but demonstrate diminished stability over a 24-hour timeframe compared to catalysts with a protective carbon layer. Specifically, we observed an initially high faradaic efficiency toward formate of 85% for commercial bismuth oxide nanoparticles, in contrast to 75% for bismuth nanoparticles with carbon. However, over a 24-hour timeframe, the carbon-free catalyst showed a 20% decrease in FE, while for the carbon-containing catalyst this drop was halved in the same timeframe.

By evaluating the role of carbon additives (e.g. their oxidation state, pore size, surface area, hydrophobicity, etc.) our results yield valuable insights into the impact of carbon additives on stability and overall performance, especially at elevated temperature. These findings uncovered critical aspects for catalyst design, providing essential knowledge for future larger-scale applications. Moreover, we shed light on the required advancements and remaining challenges for elevated temperature CO2 reduction electrolysis, which we believe will become the predominant mode of operation for CO2 electrolysis in the future.

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Computational Analysis of Ion Clustering Statistics in Liquid Battery Electrolytes
Authors: Wang Jingyang , Xie Yujun , Kim Sang Cheol , Cohen Orion , Ophus Colin , Ercius Peter , Zheng Haimei , Cui Yi , Persson Kristin A.
Published: August 2024

The transport properties of liquid battery electrolytes critically depend on molecular-level solvation structures of ions. In contrast to the dilute regime where the majority of counterions are sufficiently separated spatially, in global or localized high-concentrated electrolytes (HCEs) counterions tend to form superstructures such as contact-ion pairs (CIPs) or aggregates (AGGs). The presence and relative population of such superstructures can drastically change the ionic transport behavior in liquid electrolytes. We have developed a computer program [1] that can efficiently perform analysis of ion clustering statistics from molecular dynamics simulations, complementary to experimental measurements. We have successfully applied our method to various systems, including (1) a prototypical concentrated liquid electrolyte (Li:EC:DEC) [2], and (2) a series of newly developed high-entropy liquid electrolytes [3]. In both cases, we find consistent agreements between our prediction and experimentally measured nanostructures and solvation strengths. We envision that our method would be widely applicable to generic structurally disordered systems.

[1] Cohen et al., Journal of Open Source Software 8, 84 (2023)

[2] Xie and Wang et al., Science Advances 9, eadc9721 (2023)

[3] Kim and Wang et al. Nature Energy 8, 814–826 (2023)
(Invited) Smartphone-Based Nanosensors for Environmental, Food Safety, and Health Monitoring
Authors: Du Dan (Annie)
Published: August 2024

Abstract: Biosensors are a modern engineering marvel with widespread applications across diverse areas, including healthcare, environmental monitoring, microbiology, and food safety and security. The integration of nanotechnology with biosensor technology has led to novel sensing mechanisms, significantly enhancing performance and sensing capabilities beyond the constraints of traditional methods. In our laboratory, several nanotechnology-enabled biosensors have been developed to overcome the limitations of current bioanalytical methods, particularly in terms of sensitivity, throughput, ease-of-use, and miniaturization. We have synthesized various innovative nanomaterials, such as protein cages, single-atom nanozymes, and mesoporous bimetal nanoparticles. These materials have been crucial in the fabrication of 3D printed nano-immunosensors, which are effective in detecting pesticides, food pathogens, and exposure biomarkers.

My research specifically focuses on the development of nanotechnology-enhanced biosensors that leverage these novel nanomaterials. This endeavor aims to revolutionize biosensor fabrication, with a particular emphasis on creating new, handheld devices. These devices are designed for rapid, on-site detection of molecules, offering immense potential for point-of-care diagnostics. The integration of these biosensors with smartphone technology has further opened avenues for real-time data analysis and sharing, making them invaluable tools for environmental, food safety, and health monitoring. This talk will delve into the specifics of these developments, highlighting the innovative approaches and potential impacts of smartphone-based nanosensors in various sectors.
(Sensor Division Student Research Award) Ultra-Sensitive Photothermal Spectroscopy for Attogram-Level Detection
Authors: Zhao Yaoli , Chakraborty Patatri , Passian Ali , Thundat Thomas
Published: August 2024

Molecular-level spectroscopy is crucial for sensing and imaging applications, yet detecting and quantifying minuscule quantities of chemicals remains a challenge, especially when they surface-adsorb in low numbers. Here, we introduce a photothermal spectroscopic technique that enables high selectivity sensing of adsorbates with an attogram detection limit. Our approach utilizes the Seebeck effect in a microfabricated nanoscale thermocouple junction, incorporated into the apex of a microcantilever. We observe minimal thermal mass exhibited by the sensor which maintains exceptional thermal insulation. The temperature variation driving the thermoelectric junction arises from the non-radiative decay of molecular adsorbates' vibrational states on the tip. We demonstrate the detection of photothermal spectra of physisorbed trinitrotoluene (TNT) and dimethyl methylphosphonate (DMMP) molecules, as well as representative polymers, with an estimated mass of 10-18 g.

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Next-Generation Electrochemical Biosensing Based on Ternary Nanocomposites of nMoS2@Rgo@MWCNT for Label-Free Cancer Biomarker Detection in Undiluted Human Serum
Authors: Yadav Amit Kumar , Solanki Partima
Published: August 2024

Sperm protein-17 (Sp17) is a cancer-testicular antigen that is expressed in various types of cancers and has been proposed as a potential biomarker for cancer. However, the detection of Sp17 in human serum is challenging due to its low concentration and the lack of specific and sensitive methods. Hence, there is an urgent need to develop fast, accurate, reliable, and cost-effective disposable biosensors for Sp17 detection. Herein, we report sensing of Sp17 with a disposable carbon cloth-based electrode (CC) modified with a ternary nanocomposite comprising molybdenum disulphide (MoS2), reduced graphene oxide (rGO), and multi-walled carbon nanotube (MWCNT). The nanocomposite was synthesized by a facile hydrothermal method and was well-characterized in terms of structural, morphological, and chemical attributes using X-ray diffraction, transmission electron microscopy, scanning electron microscopy, Raman spectroscopy spectral techniques, and electrochemical studies to prove the robust formation of the electroactive ternary nanocomposite and its suitability for Sp17 detection. The nanocomposite exhibited excellent electrocatalytic activity, biocompatibility, and stability. We immobilized a Sp17-specific antibody on the surface of the nanocomposite-modified electrode and used it as a biosensor for Sp17 detection. The biosensor showed a linear response range from 0.01 to 11 ng mL-1 and a limit of detection (LOD) and limit of quantification (LOQ) of 0.23 ng mL-1 and 0.79 ng mL-1, respectively having sensitivity of 9.97 mA ng mL-1 cm-2. The biosensor was successfully applied to detect Sp17 in human serum samples and showed good accuracy, reproducibility, and selectivity, making it helpful for use in translational medicine research and clinical applications. The biosensor also demonstrated a high correlation with a commercial enzyme-linked immunosorbent assay (ELISA) kit. Our results suggest that the proposed biosensor is a promising tool for Sp17 detection in human serum and could be useful for the diagnosis and prognosis of ovarian cancer and other Sp17-related cancers.

Keywords: Carbon cloth; Biosensor; Electrochemistry; Sperm protein 17; Cancer biomarker; Nanocomposite
Highly Efficient Dopamine Sensing with Carbon Nanotube Encapsulated Metal Chalcogenide Nanostructure
Authors: Singh Harish , Nath Manashi
Published: August 2024

Carbon nanotube encapsulated nickel selenide composite nanostructures were used as a non-enzymatic electrochemical sensor for dopamine detection. These composite nanostructures were synthesized through a simple, one-step, and environmentally friendly chemical vapor deposition method, wherein the CNTs were formed in situ from pyrolysis of carbon-rich metallo-organic precursor. The composition and morphology of these NiSe2 filled hybrid nanostructures were confirmed by powder X-ray diffraction, Raman, XPS, and HRTEM images. Electrochemical tests demonstrated that the as-synthesized nanostructures exhibited outstanding electrocatalytic performance toward dopamine oxidation, with a high sensitivity of 19.62 μA μM−1 cm−2, low detection limit, broad linear range of (5 nM – 640 μM), and high selectivity. The synergistic effects of enhanced electrochemical activity of nickel selenide along with enhanced conductivity of carbon nanotubes leads to the high efficiency for these nanostructured composites. The high sensitivity and selectivity of this nano-structured composite could be exploited to develop simple, selective, and sensitive electrochemical sensor to detect and quantify dopamine in human tear samples with high reliability. This nanotube encapsulated sensor hence paves the way for new discoveries in the development of novel dopamine sensors with low cost and high stability than can be used for non-invasive dopamine detection in peripheral fluids.