bluuebunny/crossref_metadata_2025 huggingface dataset:
Developing Routes for 3D Printed Carbon Aerogel Electrodes
Authors: Worsley Marcus Andre
Published: December 2024

Aerogels are porous solids used in a number of electrochemical applications including catalysis, batteries, and supercapacitors due to their high internal surface, composition, and small pore/particle size. Carbon electrodes (e.g. nanotubes, graphene, etc.) are particularly attractive due to their low electrical resistance. The efficient transport of charged species within energy storage devices, in particular, is critical to realizing both high power and energy densities, especially when operating under extreme conditions (e.g. ultralow temperatures, high charge/discharge rates, etc.). A number of resistances can contribute to sluggish ion/electron transport in a cell such as charge transfer at interfaces, electrolyte resistance, electrode resistance, and diffusive transport within porous electrodes. Several strategies have been pursued to address these transport limitations. Electrode materials discovery and development is a popular strategy as the charge storage mechanism and electrode resistance play a key role in kinetics of the device. Within electrode materials development, engineering of the electrode pore architecture is an extremely effective strategy to decrease the diffusive transport lengths and electrode resistances. This pore engineering can be achieved through synthetic chemistry for small pores (e.g. <10 um) and via additive manufacturing for larger pores (> 10 um). Here we show how electrode materials development can be used to overcome sluggish transport in aerogel-inspired electrodes. Particular focus will be given to the use of synthetic means to tune to the properties of electrode material (e.g. surface area, pore size, mechanical properties) and 3D printing to define the larger pore structure to improve the ultimate performance of the device. We explore a number of additive manufacturing techniques (e.g. direct ink write, projection microstereolithography, etc.) to print a variety of simple and complex structures to determine the optimal electrode architecture. The impact of these different methods on both aerogel properties and device function will be discussed.

This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
Enhancing the Li-Ion Storage Capacity of Nitrogen-Doped Bilayer Graphdiyne in Li-Ion Battery: A First-Principles Study
Authors: Kuo Liang-Yin , Wu Yi-Zhan , Le Minh Tam , Nguyet Pham Thi Nhu
Published: December 2024

Carbon-based materials are among the most important anode materials for Li-ion batteries (LIB). To improve the electrochemical performance of LIBs for large-scale manufacturing, advanced carbon allotropes are currently intensively evaluated. In this work, we applied density functional theory to investigate the atomistic and electronic structures as well as the maximum Li storage capacity of graphdiyne. The atomistic structures of monolayer graphdiyne (MGDY), bilayer AB(𝛽1)-stacking graphdiyne (AB(𝛽1)BGDY), and nitrogen-doped AB(𝛽1)BGDY (N-AB(𝛽1)BGDY) at different lithiation states were investigated. A detailed analysis of interlayer distance, Li adsorption energy, and voltage profile of MGDY, AB(𝛽1)BGDY, and N-AB(𝛽1)BGDY shows that the increased interlayer distance improves the theoretical capacity and open circuit voltage. Furthermore, our findings indicate that a small amount of N doping enhances the Li-ion storage for N-AB(𝛽1)BGDY. The superior capacity suggests the potential of N-doped bilayer AB(𝛽1) as a high-capacity anode material for LIBs. Thus, our study helps to discover novel anode materials for advancing LIB technology.
(Invited) Parallelized Fabrication and Functionalization of Graphene Field-Effect Biosensors
Authors: Bouilly Delphine
Published: December 2024

Graphene field-effect transistors (GFETs) are increasingly recognized for their potential as biosensors, due to their unique electrical and surface properties [1]. However, the difficulty to achieve high throughput and control in the fabrication and functionalization of GFETs remains a significant limitation, hindering the scalability and widespread adoption of these devices. In this presentation, we will discuss our recent work using parallelization and automation to develop innovative processes for the fabrication, functionalization and measurement of GFETs. First, we will introduce an automated method for the simultaneous transfer of arrays of graphene ribbons onto patterned wafers [2]. We developed a simple apparatus based on transfer columns and pumps to achieve the precise positioning and orientation of macroscopic graphene ribbons. Our method significantly reduces the time and materials consumption compared to traditional and large-scale transfer approaches, while maintaining an excellent quality of graphene. We will demonstrate the unique advantages of this approach to assemble arrays of multilayered devices. Second, we will present our approach using an electrolyte gating potential to dynamically modulate the functionalization of GFET arrays [3]. We will demonstrate the capacity of this approach to rapidly trigger, modulate and stop the reaction of graphene with aryldiazonium salts. Using a multiplexed electrical probing system interfaced with a flow cell, we will show that the unbiased execution of this chemistry results in heterogeneous and low yields of reaction on GFET arrays, whereas our technique results in a tunable and homogenous degree of functionalization across all devices. Finally, we will discuss how these approaches not only improve efficiency and control but also open new possibilities for the large-scale production of GFET arrays, and their interest for biosensing applications.

[1] A. Béraud et al., Analyst 146, 403-428 (2021)

[2] A. Bencherif et al., ChemRxiv. doi.org/10.26434/chemrxiv-2023-3ck5c (2023)

[3] C. M. Bazán et al., Nano Letters 22, 2635–2642 (2022)
Carbon Nanotube Optical Sensors for Drug Discovery
Authors: Heller Daniel A. , Jena Prakrit , Kim Mijin , Horoszko Christopher , Ruiz Stephen , Gwynne Declan , Chen Chen
Published: December 2024

The identification of therapeutic vulnerabilities in cancers and other diseases has been substantially aided by tools that advance the monitoring of cellular processes and analytes. We have developed optical sensors using carbon nanotubes to detect intracellular analytes, including a reporter for lipids that specifically accumulate in the lysosome. Using this reporter, we found that certain cancer cell lines exhibit lysosomal lipid dysfunction and accumulation. We screened a library of lipid-modulating experimental therapeutics using the lipid reporter, finding that the inhibition of some classes of phospholipase enzymes can abrogate the accumulation of lipids in the lysosomes. Follow-up studies found that certain phospholipase enzymes have a protective role in regulating redox stress, and if inhibited can induce cell death in cancer cell lines and in vivo. Our work demonstrated that a carbon nanotube reporter that provides a new type of intracellular measurement can enable target and discovery efforts for the treatment of cancer.
MoOX–Graphene Nanocomposite Electrode As a High-Performance Bifunctional Electrocatalyst for All Vanadium Redox Flow Battery
Authors: Bayeh Anteneh Wodaje , Kabtamu Daniel Manaye manaye , Ou Ying Yi , Wang Chen-Hao
Published: December 2024

As one of the most promising electrochemical energy storage systems, vanadium redox flow batteries (VRFBs) have received increasing attention owing to their attractive features for large-scale storage applications. However, their high production cost and relatively low energy efficiency still limit their feasibility. One of the critical components of VRFBs that can significantly influence the effectiveness and final cost is the electrode. Therefore, the development of an ideal electrocatalyst with low cost, high electrical conductivity, large active surface area, good chemical stability, and excellent electrochemical reaction activity toward the VO2+/VO2
+ and V2+/V3+ redox reactions is essential for the design of VRFBs. Extensive research has been carried out on electrode modification routes for VRFBs to improve the energy density and overall performance for large-scale applications. In the present work, we reported the successful preparation of low-cost MoOX–reduced graphene oxide nanocomposite (MoOX–rGO) acts as the electrode material for all-vanadium redox flow battery (VRFB). MoOX–rGO composite exhibits excellent electrocatalytic redox reversibility for V3+/V2+ and VO2
+/VO2+ and higher anodic and cathodic peak currents than those of other individual MoOX and rGO samples. The voltage efficiency of the VRFB using the optimized MoOX–rGO nanocomposite electrode at 80 mA cm−2 is 82.14%, which is 4.23% and 13.56% higher than the VRFBs using the rGO-coated graphite felt electrode and the graphite felt electrode, respectively. It still shows the voltage efficiencies of 73.83% and 68.50% at 120 mA cm−2 and 140 mA cm−2, respectively, but other samples have no effective discharge. This improvement is attributed to the uniform distribution of MoOX nanoparticles on the rGO surface, avoiding the restacking of the rGO sheets and suppressing nanoparticle aggregation, which might increase the effective surface area and improve mass transport at the electrode-electrolyte interface. Furthermore, oxygen vacancies on MoOX, the high electrical conductivity of rGO, and the high content of oxygen functional groups act as active sites for the vanadium ion redox reaction.

References

W. Bayeh, G-Y. Lin, Y-C. Chang, D.M. Kabtamu, G-C. Chen, H-Y. Chen, K-C. Wang, Y-M. Wang, T-C. Chiang, H-C. Huang and C-H. Wang, ACS Sustain. Chem. Eng., (2020).

Zhou, Y. Shen, J. Xi, X. Qiu and L. Chen, ACS Appl. Mater. Interfaces, 8, 15369- 15378 (2016).

M. Kabtamu, J-Y. Chen, Y-C. Chang and C-H. Wang, J. Power Sources, 341, 270-279 (2017).

Amini, J. Gostick and M.D. Pritzker, Adv. Funct. Mater., 30, 1910564 (2020).

M. Kabtamu, J-Y. Chen, Y-C. Chang and C-H. Wang, J. Mater. Chem. A, 4, 11472-11480 (2016).
Low-Dimensional Snse – Ti3C2 Mxene Composite As Binder-Free Anode for Energy Storage Applications
Authors: Arunasalam Kavin , Santos Jesus Medina , Liang Meiying , Zhang Teng , Gogotsi Yury , Nicolosi Valeria
Published: December 2024

Two-dimensional (2D) materials exhibit unique structural and electronic properties such as reduced thickness, high conductivity, packing density and tuneable band gap.[1] These properties present compelling opportunities for their applications in sustainable battery technologies.[1] Sodium-ion batteries (SIBs) are attracting great interest as an alternative to lithium-ion batteries due to their material abundance, lower cost, and environmental sustainability. However, the quest for a high-performance anode for SIBs remains challenging owing to the severe volume expansion caused by the intercalation of the large Na-ion.

Tin (II) selenide (SnSe), a layered 2D material, demonstrates very high theoretical capacity as an anode for sodium and lithium-ion batteries. Nevertheless, its instability primarily, attributed to the substantial pulverization of active materials during cycling, poses a challenge.[2] To address this, we investigated a novel 2D composite material comprising SnSe nanoparticles and MXene (Ti3C2Tx) nanosheets (Figure 1) to be used as an anode in batteries. Due to the exceptional conductivity and viscosity of MXene [3], it can act as a conductive binder in this composite eliminating the need for traditional non-conductive binders like PVDF and CMC. This reduces the dead volume in the electrode and enhances its specific capacity. Additionally, the MXene layers with terminating fluorine functionals promote the growth of stable solid-electrolyte interfaces (SEI) improving the overall Coulombic efficiency of the battery.[4] Further optimization studies were done with VC and FEC electrolyte additives. Characterization techniques, including XPS, SEM, EDX, XRD, and AFM were performed on the composite nanomaterial to study its morphology, as well as compositional and structural changes upon processing. The electrode material showed a high initial discharge capacity of 700 mAh/g and 98% Coulombic efficiency for 100 cycles in lithium-ion batteries. This shows promise in overcoming the instability issues of SnSe, thereby improving the performance and longevity of SIBs for sustainable energy storage solutions.

References

[1] Jie Wang, et al., Nature Communications, 2021, Vol. 12

[2] Wei Wang, et al., Small, 2017, Vol.13

[3] Mohamed Alhabeb, et al., Chemistry of Materials, 2017 Vol. 29

Figure 1: SEM images of the cross-section of the SnSe-MXene composite slurry cast electrodes. a) shows the thickness of the slurry-casted electrode to be 11.6 microns and b) shows the SnSe nanoparticles between the MXene nanosheets.

Figure 1
(Invited) Novel Electrode Materials for Sodium-ion Batteries
Authors: Paranthaman Mariappan Parans , Pethe Saurabh , Sun Xiao-Guang
Published: December 2024

The main goal of this research is to develop low-cost electrode materials for sodium-ion batteries (SIBs). Lack of low-cost commercial hard carbon anodes for SIBs has greatly hindered its application. High value hard carbon electrode materials have been recovered from end-of-life tires. High capacity with stable over several cycles has been achieved. Presodiation approach has been applied to reduce the first cycle loss. This study provides a pathway for inexpensive, environmentally benign, and value-added waste tire-derived carbon products towards sodium-ion batteries.

Acknowledgements

This research was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division.
(Invited) Assessment of Extreme High-Power Demand for Evtol Li-Ion Batteries
Authors: Belharouak Ilias , Dixit Marm , Bisht Anuj , Kweon Chol-Bum , Amin Ruhul , Abouimrane Ali
Published: December 2024

Designing battery systems for electric vertical take-off and landing (eVTOL) platforms is challenging because they require high-power demands during crucial flight maneuvers. The eVTOL application needs exceptionally high discharge rates from the on-board lithium-ion batteries (LiBs) during several phases of its mission. However, LiBs have not been explored enough under high-power discharge scenarios, such as that of an eVTOL, because the current application spectrum in electric vehicles (EVs) and electronic devices does not require such high power.

In a recent study, we simulated the initial take-off step of electric vertical takeoff and landing (eVTOL) vehicles powered by a lithium-ion battery subjected to an intense 15C discharge pulse at the beginning of the discharge cycle followed by a subsequent low-rate discharge. we conducted extensive electrochemical testing to assess the long-term stability of a lithium-ion battery under these high-strain conditions. The main finding is that despite the performance recovery observed at low rates, the re-application of high rates leads to drastic cell failure.

These results highlight the eVTOL battery longevity challenge and emphasize the need for tailored battery chemistry designs for eVTOL applications to address both anode plating and cathode instability.
High-Temperature Corrosion Characteristics of Copper for Deep Geological Disposal of Spent Nuclear Fuel
Authors: Kim Seunghyun , Park Gitae , Kim Gidong , Song Sang-Woo
Published: December 2024

In this study, we evaluated the high-temperature corrosion characteristics of copper(Cu), which is considered a candidate material for disposal containers in deep geological repositories for spent nuclear fuel, through electrochemical methods. Deep geological repositories serve to isolate spent nuclear fuel from humans and the environment, employing a multi-barrier concept consisting of engineered and natural barriers. Among these, engineered barriers consist of canisters, bentonite buffer materials, and others. Various countries are progressing with conceptual designs, with Cu, known for its corrosion resistance, being considered a key material for canister. While Cu is predicted to experience minimal corrosion in groundwater environments where deep geological repositories are typically situated, recent studies suggest that exposure to temperatures exceeding 100oC may lead to some corrosion. In previous studies by the authors, Cu corrosion evaluations were conducted in environments with various compositions at temperatures ranging from 60 to 70oC. The results confirmed that corrosion of copper could occur in the presence of corrosive species such as Cl-. Expanding upon these findings, the current study aims to assess various base metal and weld of Cu under high-temperature and high-pressure conditions using electrochemical methods.
Corrosion Failure Analysis of Peak Load Boiler Using Landfill Gas
Authors: Lee Soo Yeol , Song Min Ji , Lee Keun Hyung , Kang Taeuk
Published: December 2024

A peak load boiler using landfill gas as a fuel is one of the heat production facilities of a district heating system. It undergoes frequent start-and-stop operations for flexible heat supply. Landfill gas is refining gas produced from local landfills through a series of processes. Methane and carbon dioxide are the main elements, and volatile organic compounds (VOCs), hydrogen sulfide and halides are the minor elements. In this study, the causative factors of corrosion damage in the peak load boiler using landfill gas were identified, and a lifetime of selected materials under the corrosive environment was evaluated. The higher the concentration of acid ions and water vapor, the higher the dew point temperature is formed. It is concluded that the high hydrogen sulfide component in the landfill gas and the humidity in the facility resulted in an increase in the dew point formation temperature, from which the corrosion damage led to a leakage of boiler tube.
(Invited) Proton Insertion into Wadsley-Roth and Related Phases
Authors: Yamada Atsuo , Park Sunghyun , Nishimura Shinichi , Okubo Masashi
Published: December 2024

Proton (H+) serves as an energy carrier in various electrochemical systems. Because of its ubiquity and unique characteristics, solid-state proton conduction and faradaic proton storage emerge as pivotal for high-capacity, fast-charging electrochemical systems. In our consideration, proton host should require (i) short O-O distance that facilitates proton diffusion via O-H bond rotation and hopping from donor to acceptor O atoms , and (ii) structural flexibility that accommodates large polarization of densely distributed O-H bonds. With this regards, edge-sharing MO6 is preferable for (i), while corner-sharing octahedron is suitable for (ii). Additionally, near d0 configuration in transition metals will further provide tolerance to lattice distortion related to (ii). Considering these criteria, we have investigated several hitherto-unexplored Mo-, W-, Nb-, or V- containing Wadsley-Roth and Bronze related phases constitute of mixture of corner- and edge- sharing octahedral network. To expand the candidate materials, water-in-salt, hydrate-melt, molecular crowding, and protic ionic liquid electrolytes with minimal water activity, were applied to ensure wide potential window while suppressing chemical dissolution of electrode materials. Details on the unique electrochemical properties and their applications to several energy storage/conversion systems will be demonstrated and discussed as time permits.
(Invited) A Flexible and Sustainable Gel Electrolyte Toward Safe Zn-MnO2 Alkaline Rechargeable Batteries
Authors: Khan Usman Ali , Ganduri Teja , Madan Deepa
Published: December 2024

Zn-MnO2 alkaline batteries form inactive compounds during charging and discharging that hinder their ability to be utilized in rechargeable settings. Design and development of functional gel polymer electrolyte (GPE) to replace traditional electrolyte have become an effective way to inhibit irreversible compound formations and Zn dendrite growth, avoid leakage issues and metallic packaging. However, many challenges such as reliable and reproducible ionic conductivity and ion transference number of free-standing electrolyte films at lower thickness (250 µm), and interfacial contact resistance between electrolyte and electrode layer still exist. Our assumption is producing reliable and consistent ionic conductivity and ion transference number of electrolytes at lower thickness (250 µm) will help in providing the faster redox reaction kinetics at electrolyte-electrode interface. Moreover, by reducing the interfacial contact resistance between electrolyte and electrode interface will help in reducing the charge transfer resistance and zincate ion movements and results in improving the reversible life cycle of batteries. Additionally, by improving the mechanical strength and flexibility of free-standing GPE layer will be helpful to suppress the dendrite formation. Our assumption is well-arranged continuous porous structure of GPE will result in easy movement of ions and well absorption and retention of alkaline or acidic salt solution. It will also provide mechanical strength to the overall gel films at lower thickness to reduce dendrite formation. To fabricate well-arranged continuous porous GPE structure, we propose to use freeze casting method.

Here, we propose to use naturally occurring sustainable chitosan, with different additives like PVA, PAAK to form GPE using freeze casting method. The different thickness electrolytes were soaked into alkaline solution e.g. Hydroxide (KOH) and fluorinate compounds and compared on their Ionic Conductivity, Ionic Conductance, Ion Transference Number, PH, and Swelling Ratio. To reduce the interfacial contact resistance between electrolyte and electrode, free standing electrolyte layer will be dipped into Chitosan solution and then put in contact with electrodes. We will also perform SEM to observe the arrangement of polymer chain using freeze casting method. These electrolytes were then used in the fabrication of Zn-MnO2 batteries and measure their performance using cyclic voltammetry and galvanostatic charge-discharge.
Advancement of High Temperature Electrochemistry for Decarbonization Applications at Idaho National Laboratory
Authors: Ding Dong
Published: December 2024

Decarbonization is vital for addressing climate change, protecting public health, enhancing energy security, fostering economic prosperity, and advancing sustainable development. High temperature electrochemistry is playing an increasingly important role in decarbonization as we reduce energy use and address uncertain supply chains driven by industrial electrification and cheap heat resources. As one of DOE’s premier multi-program energy research laboratories, Idaho National Laboratory’s (INL) mission is to ensure the nation’s energy security with safe, competitive and sustainable energy systems and unique national and homeland security capabilities. INL’s initiative, integrated energy systems (IES) provides carbon-free nuclear and renewable energy for downstream use in manufacturing and transportation. The manufacturing component of IES focuses on integrating clean, carbon-free electrons with waste/renewable heat and includes both manufacturing of electrochemical devices and implementing them in energy-efficient processes. In this talk, we will provide representative examples for the pillar of energy to molecules and materials (E2M2) by developing, validating and demonstrating the high temperature electrochemical technologies towards chemical/fuel/hydrogen production as well as CO2 capture and utilization. INL research portfolio represents an outstanding example that links basic research to applied technology for DOE national laboratory complex and uniquely provide technology deployment models through synergistic collaboration among national labs, universities and industry.
Electrochemical CO2 Capture By Intermediate-Temperature Hybrid Electrolyte Electrochemical Assembly
Authors: Bian Wenjuan
Published: December 2024

Electrochemical capture of CO2 from the power plants is an efficient way to mitigate greenhouse gas emissions. In this work, we proposed an innovative hybrid electrolyte membrane electrochemical assembly to couple the electrochemical and thermal processes for high-efficiency CO2 capture at intermediate temperatures (500-600 oC). A novel electro-catalyst with high electron conductivity and CO2 absorption capability at intermediate temperature is developed. Our investigation on the electro-catalyst working mechanism under applied voltage/current including the roles of the oxygen vacancy and dopants on the CO2 absorption and desorption process will be presented. Additionally, the reaction of molten carbonate with the electro-catalyst is studied by in-situ characterization to understand the carbonate ions transportation route. This work aims to provide comprehensive insights into the electrochemical CO2 capture at intermediate temperature.
Electron Irradiation of Self-Healing and Internal Ooxidation of Self-Healing Ceramics
Authors: Nanko Makoto , Nguyen Nguyen Thi , Khlaisongkhram Phanuwat , Kuo Yen-Ling , Xu Alan , Thorogood Gordon , Do Thi-Mai-Dung , Suematsu Hisayuki
Published: December 2024

Influence of electron irradiation on self-healing and internal oxidation was studied in the present work. Usage of self-healing ceramics are very useful to improve anti-accident performance of nuclear power plants. However self-healing performance of their structural ceramics may be affected with any irradiations of several radioactive rays such as electrons, neutrons and gamma-ray. Two self-healing ceramics, alumina ceramics dispersed with nickel particles (Ni/Al2O3) and yttrium silicate ceramics dispersed with silicon carbide particles (SiC/YSiO) were selected as the samples to study the influence of electron irradiation. Their self-healing ceramics were densified with pulsed electric current sintering technique. The samples were irradiated with accelerating electrons with 2MeV at different radiation dose from 1 to 1000 kGy at room temperature. Vickers indentations were introduced into the irradiated samples to make surface cracks. Then Ni/Al2O3 samples were heated at 1100°C for 6 h in air. SiC/YSiO samples were done at 1100°C for 6 h and 1300°C for 1 h in air. Self-healing of surface cracks was evaluated with the fraction of disappearance of surface crack length against the initial crack length. Depth of the internal oxidation was measured from the cross-sectional images of scanning electron microscopy. With respect to Ni/Al2O3 ceramics, electron irradiation did not affect disappearance of surface cracks and depth of internal oxidation with the heat treatment in air. On the other hand, self-healing and internal oxidation on SiC/YSiO ceramics were enhanced with electron irradiation in the present study. Point defects in YSiO are most likely increased by electron irradiation and causes increases in inward diffusion of oxygen ions for internal oxidation and outward diffusion of yttrium ions for self-healing. On the other hand, point defects in Al2O3 are inert against the electron irradiation in the present experimental conditions.
High Temperature Corrosion Induced By Calcium-Based Deposits
Authors: Ravi Vilupanur A , Kloesel Michael , Dilig Regina , Ochoa Diego , Maldonado Steven , Jimenez Ezequiel , Reyes Ronald
Published: December 2024

Corrosion of gas turbine components at high temperatures under salt deposits is a critical issue that adversely affects their performance and longevity. The consequences of the reactions between the salt deposits and the alloy substrate can result in enhanced solute depletion, and removal/ destruction of the external protective scale. In this presentation, the focus will be on the effect of chromium content, and process variables such as temperature, time, and atmosphere, on the deposit-induced corrosion of nickel-based alloys. These materials were exposed to thin calcium-containing films. The effects of chloride salt additions were also studied. Key results will be presented and discussed.
(Invited) Processing and Characterization of Solid-State Batteries
Authors: Dixit Marm
Published: December 2024

We present a comprehensive investigation into the impact of isostatic pressure (ISP) processing on multi-layer pouch cells and the redox-sensitive mapping of Li | LAGP solid electrolyte interfaces with advanced X-ray characterization techniques. For processing study, we investigate baseline electrodes made using conventional manufacturing methods with those subjected to isostatic pressing under various conditions. Extensive characterization evaluates the disparities between baseline cells and those treated with isostatic pressing. Electrochemical performance of the isostatically pressed cathodes is assessed via impedance spectroscopy and galvanostatic charge-discharge tests, revealing notable improvements in porosity, adhesion, and rate performance compared to baseline cathodes. Microstructural changes induced by ISP in lithium-ion battery cathodes are elucidated, underscoring the technology's potential for enhancing battery manufacturing. On the characterization front, the redox-sensitive mapping technique reveals no degradation of the solid electrolyte upon passive contact with Li metal, but after electrochemical cycling, isolated locations of reduced Ge phases are identified, potentially leading to large-scale degradation of solid electrolytes. Understanding the onset mechanism of electrolyte degradation offers pathways for designing mitigation strategies.
Application of Scanning Probe Microscopy Towards Clarifying the Mechanism of Localized Corrosion
Authors: Takara Yuya , Ozawa Takahiro
Published: December 2024

Aluminum alloys are applied to transportation equipment due to their lightweight and excellent mechanical properties, making a significant contribution to reducing CO2 emissions. In the material structure, intermetallic compounds, such as μm-order or nm-order precipitates, are formed by unavidable impurities or components added for the purpose of improving mechanical properties. On the other hand, these precipitates cause localized corrosion around themselves, which lead to the formation of large pits. Localized corrosion is well known to be caused through a mechanism where potential difference generated between the compounds and the matrix drives the formation of local battery, and intensive electrochemical reactions occur with the noble region becoming cathode and the less noble region becoming anode. However, localized corrosion behavior varies depending on potential difference changes caused by the material structure or the environment. Therefore, it is important to understand the localized corrosion mechanism in detail from the viewpoint of potential difference and environment to improve alloy's corrosion resistance.

One of the useful tools for clarifying the localized corrosion mechanism is Scanning Probe Microscopy (SPM). SPM enables us to measure not only the shape of the material surface but also its physical values in various environment such as vacuum, atmosphere and liquid. For example, Kelvin probe Force Microscopy (KFM) is a technique that measures the contact potential difference between the probe and the sample surface, allowing us to measure the distribution of the potential difference on the sample surface. Open-Loop Electric Potential Microscopy (OL-EPM) is also capable of measuring the nanoscale distribution of ion concentrations in liquids and can visualize the anodic and cathodic regions during corrosion reactions, because the potential in the liquids is dependent on the cation/anion concentration occurring at the reaction interface. Thus, SPM can be used to obtain information on the potential difference of material structure and the electrochemical reaction field in a small area, which cannot be obtained by macroscopic electrochemical tests such as polarization tests.

In this study, we use these SPM techniques to clarify the localized corrosion mechanism of aluminum alloys based on their material structure.
Enhancing Pitting Corrosion Resistance of AA7075 through Surface Alkalization By Mg2Si and Conversion Coating
Authors: Ebina Ko , Nishimoto Masashi , Muto Izumi
Published: December 2024

AA7075 is a high-strength aluminum alloy. Although AA7075 has excellent mechanical properties, this alloy is known for its high susceptibility to pitting corrosion. In our previous study, protective films which improve its pitting corrosion resistance were produced by alkalization of the alloy surface through cathodic polarization.1 Therefore, Mg2Si was added to AA7075 to promote surface alkalization, and conversion treatment of the specimens was attempted.

AA7075 containing Mg2Si particles was fabricated. The surface of specimens was observed using an optical microscope and a field emission scanning electron microscope (FE-SEM) equipped with energy dispersive X-ray spectroscopy system (EDS). As conversion treatments, the specimens were immersed in Ce-containing solution. To evaluate the pitting corrosion resistance, dip-and-dry test was conducted.

By the conversion treatment, coatings were formed on the surface of AA7075 containing Mg2Si particles. During dip-and-dry, initiation of pitting corrosion was inhibited by conversion coatings. The increase in pH on the specimen surface is thought to contribute to formation of the coatings.

References:

K. Ebina, M. Nishimoto, I. Muto, and Y. Sugawara, Corros.
Sci., 220, 111299 (2023).
Initiation of Localized Corrosion of Die-Cast ADC12 Aluminum Alloy
Authors: Takeuchi Kaito , Nishimoto Masashi , Muto Izumi
Published: December 2024

Die-cast ADC12 (Al-3Cu-10Si) aluminum alloy is used for automobiles. Localized corrosion on ADC12 causes failure and accidents. To clarify initiation site of corrosion is the first step for the improvement of corrosion resistance.

As-die-cast ADC12 was used as specimen. The microstructure of ADC12 was consisted of α-Al, Al-Si eutectic phases and Intermetallic particles (IMPs). The size of IMPs was around 1 μm.

OCP measurement was conducted for various time with various electrode areas in 0.1 M NaCl. To clarify initiation site, in-situ observation was carried out during OCP measurement. Bubble generation was observed during immersion. After immersion, Al was dissolved. Bubble generation sites were analyzed to identify initiation site of corrosion.
Enhancement of LiCoO2 Electrode Reaction by Considerable Amounts of Powdery Alpha-LiAlO2
Authors: Arachi Yoshinori , Sanzen Arisa , Nakamura Tatsuya
Published: December 2024

Considerable amounts of powdery LiAlO2 (LAO) with a layered NaCl-type crystal structure increased a specific capacity of LiCoO2 (LCO) and decreased a polarization resistance. Though LAlO is an electronic insulator, both impedance measurements and low-temperature charge-discharge testing showed that LCO electrode reaction was activated by including the LAO powder with well-crystalized.

Alpha-LAO was prepared via sol-gel method. Rietveld refinement showed that the crystal structure was the same as that of conventional LCO. The LCO electrodes including several tens of mass percent of LAO were obtained by mixing the LAO and LCO powders with vibrational milling at room temperature. The obtained electrodes were characterized by electrochemical testings. LiCoO2 powder (C-5H, Nippon Chemical Industrial Co. Ltd.) was used. The average particle size is around 6 to 7 μm. The working electrode was composed of LCO composite, acetylene black and binder. Li metal was used as a negative electrode and the electrolyte was 1 M LiPF6 in ethylene carbonate (EC):dimethyl carbonate (DMC) (3:7 v/v%). The charge-discharge testing were conducted galvanostatically at various current densities over the voltage range from 2.0 to 4.2 V at 25 °C.

The XRD patterns of samples showed an overlapping of those of LCO and LAO, but no solid solutions were formed. The charge-discharge curves for various investigated LCO composites kept those of bare-LCO, but the specific capacity increased. STEM-EELS of fully-charged LCO composite indicated that the electronic states of LAO (Li K-and Al L-edges) were the same as those of as-prepared. In addition, DFT calculation suggests that it is unable to remove Li ions from LAO up to 4.2 V and LAO may undergo an oxidation reaction at voltages of 5 V or higher. Therefore, the LAO does not participate in the increased capacity, but LAO makes the LCO electrode reaction active kinetically. Accordingly, it enhances a rate-performance of LCO electrode as well as shown in Figure 1.

The LCO-LAO composite electrode potentially could reduce the usage of rare metal cobalt and lead a cost cut as well while improving the battery performance. We will present and discuss an unique effect of powdery LiAlO2 on the LiCoO2 electrode reaction in details.

Figure 1
Rationally Designed Cyclic Sulfonamide-Based Electrolyte for Improved Electrochemical Performance for Rechargeable Li Batteries
Authors: Prasad Thapaliya Bishnu , Dai Sheng
Published: December 2024

Electrolyte instability poses a significant challenge in stabilizing the interfacial chemistry of rechargeable batteries. The engineering of electrolyte architecture has emerged as a promising strategy to enhance electrode compatibility and interfacial stability. In this study, we present the synthesis of a rationally designed cyclic sulfonamide electrolyte tailored to improve the electrochemical performance of Anodeless Li metal batteries and Li-S batteries. This electrolyte is meticulously crafted to optimize crucial electrochemical properties, including Li ion transport, stability, and interface compatibility. Through systematic investigation, we illustrate that the incorporation of cyclic sulfonamide moieties leads to enhanced electrolyte stability, thereby mitigating detrimental side reactions and improving the cycling performance of Li metal batteries. Notably, the use of cyclic sulfonamide electrolyte prevents corrosion of the aluminum current collector caused by TFSI anion, which is commonly associated with the use of LiTFSI salt in commercial batteries, thus facilitating safe battery recycling. Additionally, the cyclic sulfonamide-based electrolyte effectively inhibits the polysulfide shuttle in Li-S batteries, achieving a remarkable coulombic efficiency exceeding 99.5% in the absence of LiNO3 additive. Furthermore, these engineered electrolytes demonstrate exceptional compatibility with Li metal anodes, promoting uniform Li deposition and suppressing dendrite formation, thereby enhancing battery safety and longevity. Our findings underscore the importance of rational electrolyte design in driving the advancement of Anodeless Li metal and Li-S batteries, offering a promising avenue for the realization of high-energy-density and durable energy storage solutions across diverse applications.
Composite Porous Structure Formation By Metal-Assisted Etching of p-Type Silicon
Authors: Yae Shinji , Azuma Kyohei , Nishinaka Rin , Hashiguchi Tatsuki , Nakayama Takuma , Matsumoto Ayumu
Published: December 2024

Metal-assisted etching of silicon can produce porous silicon and silicon nanowires by simply immersing metal-modified silicon in a hydrofluoric acid solution without electrical bias [1]. Such etching proceeds by a local galvanic cell mechanism consisting of local anodic dissolution of silicon and local cathodic reduction of an oxidizing agent, such as oxygen [2, 3] or hydrogen peroxide [1, 4-7], on catalytic metal. The structure of porous silicon is widely controlled from nanometer to sub-millimeter scale in pore size and from straight to an ant-nest like in pore morphology by changing etching conditions [1-3]. We fabricate various porous structures on silicon wafers and apply them to antireflection of solar cells and autocatalytic electroless formation of metal nanorods and metal films on silicon surfaces. Recently, we have reported that general corrosion occurs on the top surface of the silicon substrate around the metal particles and composite porous structure consisting of the straight macropores and mesoporous layer is formed even under the dark condition [4-8]. In this study, the composite structure formation on p-Si substrates is investigated by microscopy, electrochemical measurements and device simulation.

Acknowledgements

The present work was partly supported by JSPS KAKENHI (20KK0122, 22K04779, 23K04791).

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[8] A. Matsumoto, R. Nishinaka, Y. Shimada, K. Furukawa, K. Azuma, and S. Yae, J. Electrochem. Soc., 170, 052505 (2023).
Atomic Layer Deposition on Anodic TiO2 Nanotubes for Electrochemical Applications
Authors: Macak Jan M. , Zazpe Raul , Sopha Hanna , Rodriguez Pereira Jhonatan , Bawab Bilal
Published: December 2024

One-dimensional nanomaterials – materials with one dimension outside the nanoscale, further noted as 1D NMs – represent a class of very important nanomaterials with continuously increasing importance. Due to their intrinsic features, unique properties and diversity of functionalities, they count among the most widely studied materials nowadays. While considerable research efforts have been spent to synthesize various 1D NMs (e.g. nanopores, nanotubes or nanofibers), limited efforts have been devoted to surface modification and property tailoring of these materials.

However, it is their surface that comes into direct contact with various media (air, gases, liquids, solids) and influences the reactivity, stability and biocompatibility of these materials. The surface and aspect ratio (defined as their diameter to length ratio) influence the performance of these materials in various applications. Considering these facts, it is more relevant to tailor the surface of these materials and to be able to influence their properties and reactivity at the nanoscale, rather than to deal with tailoring their own bulk material composition.

The focus of this presentation is on the modification of anodic TiO2 nanotubes by coatings achieved by Atomic Layer Deposition (ALD). From all available techniques, ALD is the only capable of really uniform and homogenous coating of these 1D nanomaterials, in particular those of very high-aspect ratio.

Experimental details and some very recent application examples in electrocatalysis, photocatalysis, sensors, batteries, etc. [1-10] and structural characterizations of these modified materials will be discussed.

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(Invited) Mild Anodization of Aluminum: From Fundamentals to Industrial Applications
Authors: Asoh Hidetaka
Published: December 2024

Considering the recent energy crisis and global environmental pollution, the weight reduction of vehicles through the modification of several parts (e.g., engines and wheels) is emerging as an important research area. One strategy for achieving this is the use of aluminum. Aluminum, a lightweight material with excellent recyclability, is widely used in various industrial fields. There are various surface treatment methods for aluminum, depending on the purpose of use in each operating environment. Corrosion resistance and hardness of native oxides are not enough under some environment.

To improve the surface properties of aluminum, anodic oxidation of aluminum (so-called anodizing or anodization), is generally applied. The surface treatment has a history of nearly 100 years. In Japan, anodization using oxalic acid was first patented in 1923. A porous-type oxide film formed on aluminum by anodization, or a product covered with the porous alumina film, is industrially called alumite in Japan. The structure of a porous-type oxide film (alumite) determines the various surface properties of aluminum. For instance, to increase the hardness of anodic films on aluminum, the anodization is industrially carried out at low temperature to avoid chemical dissolution of the formed oxide film during anodization.

Here, I present an overview of the progress of anodization in common acidic electrolytes (e.g., sulfuric acid, oxalic acid, or phosphoric acid) containing alcohol as an additive [1-6]. Anodization was mainly conducted using various alcohols with different physical properties under mild anodization conditions with a constant current of 100 A·m−2 at 20 °C. The effects of alcohol addition in electrolytes on the anodization behavior of aluminum, the coating ratio, the porosity, the maximum attainable film thickness, and the hardness of anodic films will be discussed in terms of both basic research and commercial applications.

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H. Asoh, T. Sano, J. Electrochem. Soc., 168, 103506 (2021).

H. Asoh, H. Kadokura, R. Murohashi, M. Matsumoto, J. Electrochem. Soc., 169, 073510 (2022).

T. Sano, Y. Wakabayashi, H. Asoh, Surf. Coat. Technol., 459, 129399 (2023).

H. Asoh, S. Ota, K. Hagiwara, J. Electrochem. Soc., 171, 033502 (2024).
Formation of Porous Anodic Aluminum Oxide with a Thick Barrier Layer and High Porosity By Anodizing Aluminum in Sodium Metaborate Solutions
Authors: Iwai Mana , Kikuchi Tatsuya , Kitano Sho , Fushimi Koji , Habazaki Hiroki
Published: December 2024

Porous-type anodic aluminum oxide (AAO) can be fabricated by anodizing an aluminum substrate in suitable aqueous electrolyte solutions. The morphological properties of the AAO, including the interpore distance, pore size, and thickness, are controlled by various operating parameters, such as the applied voltage, temperature, and anodizing time. However, their structural controllability is limited because the fabrication process is based on the typical anodizing method in acidic solutions. The authors previously found that AAO with a novel nanostructure can be fabricated by anodizing using alkaline ammonium carbonate and sodium tetraborate. Therefore, further research on aluminum anodizing using various alkaline solutions opens the possibility of novel AAO fabrication. Herein, we report the fabrication of a new AAO film, which is different from the typical nanostructure formed in acidic solutions, by anodizing in alkaline sodium metaborate (NaBO2).

Electropolished aluminum specimens were anodized at a constant voltage of 0.1-200 V in a 0.3 M sodium metaborate electrolyte solution (pH = 11.9) at 278 K. The surface and cross-section of the anodized specimens were examined by field-emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), and Cs-corrected scanning transmission electron microscopy (STEM). The elemental depth profile of the specimens was analyzed by radiofrequency glow discharge optical emission spectroscopy (rf-GDOES).

An AAO film consisting of an outer porous layer and an inner hemispherical cap barrier layer, similar to typical AAO films formed in acidic solutions, was formed at lower voltages below 50 V. In contrast, an AAO film with a flat barrier layer, deviating from the typical Keller-Hunter-Robinson model, was obtained at voltages above 100 V. The porosities of the porous layer obtained above 20 V were almost constant (0.16-0.19). However, there was a significant increase in the porosity at lower voltages (0.93 at 0.1 V). The AAO formed in sodium metaborate was composed of amorphous, anion-free aluminum oxide.

Figure 1