bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study on Catalyst and Binder Degradation Analysis during Electrode Degradation Using EIS in PEMFC
Authors: Yoo Donggeun , Park Kwonpil 
Published: December 2024

Research is underway to reduce the cost of PEMFCs by decreasing the loading amount of Pt catalyst, which necessitates research on catalyst structures and binders to compensate for the resulting decrease in performance and durability. Recent studies have focused on improving performance using binders such as high oxygen permeation ionomer (HOPI), but research on the durability of such binders is lacking. The primary challenge in studying binder durability lies in the difficulty of binder degradation analysis. Since the binder in the catalyst layer exists in small quantities within the catalyst layer, and degradation is difficult to distinguish from membrane degradation, it is crucial to develop analysis methods to identify binder degradation. Distribution relaxation time (DRT) analysis is a method that utilizes Electrochemical Impedance Spectroscopy (EIS) to analyze resistance in detail by representing it as distribution relaxation time peaks. By using DRT analysis, the resistance in EIS can be subdivided into ORR charge transfer resistance, oxygen transfer resistance, and proton transfer resistance and changes in the ion transfer resistance of the catalyst layer can be analyzed in situ to observe binder degradation. In this study, we aim to analyze the degradation of catalyst and binder ionomer during electrode degradation using EIS in situ. In addition, we compare the electrochemical analysis results and post-analysis results with the EIS analysis results to examine the suitability for EIS analysis.
Electrode degradation was carried out using the DOE catalyst degradation protocol. Characterization during electrode degradation included I-V, EIS, mass activity, CV, LSV, while post-degradation analysis involved AFM, XRD, XRF analysis to analyze electrode catalyst and binder degradation.
As catalyst degradation progressed, the cell's performance decreased, leading to increased charge transfer resistance (CTR), decreased electrochemical surface area (ECSA), and decreased mass activity. Catalyst degradation was observed through changes in ORR charge transfer resistance in DRT analysis, while binder degradation was confirmed through changes in proton transfer resistance in DRT results and Warburg-like response impedance. The results obtained from the postmortem of degraded MEAs matched well with the results obtained from DRT analysis.
Influence of Alkaline-Metals Co-Doping on Luminescence Intensity of Er-Doped Up-Conversion Oxide Phosphors
Authors: Koikawa Tomoki , Brik Mikhail G. , Yamamoto Tomoyuki 
Published: December 2024

Up-conversion (UC) phosphors, which can convert lower energy photons to higher energy ones, have been widely investigated owing to a wide range of applications, including bioimaging to visualize information in living organisms [1], solar cells to improve power conversion efficiency [2], and security inks to prevent counterfeiting [3]. However, in device applications, there are two big problems to overcome, those are 1) UC efficiency and 2) lifetime for long term use. Currently materials containing fluoride are often used for UC phosphors, but several types of oxides with rare-earth ions such as Y2O3:Er, Yb [4] and CaWO4:Er [5] have been reported as efficient UC phosphors with long lifetime. UC phosphors using organic solvents have also been reported to improve emission intensity, but they are difficult to apply to devices and are virtually unusable. To improve UC efficiency, it was reported that UC luminescence intensity can be enhanced by a co-doping of alkaline-metals in CaTiO3:Er [6].
In this study, we have investigated the influence of alkaline-metal co-dopings on UC luminescence intensity of various types of oxides doped with Er ions. All the samples were prepared by a conventional solid state reaction method. The systematic analysis were carried out for the synthesized samples, i.e., the crystal structures and the phase analysis were examined by X-ray diffraction, the elemental analysis by X-ray fluorescence, energy levels and electronic structure analysis by diffuse reflectance with UV-vis spectrometer equipped with integration sphere, surface morphology and grain size observation by scanning electron microscope. In addition to such experimental analysis, first-principles calculations within a density functional theory have also been conducted to interpret the influence of alkaline metal co-dopings on the geometrical and electronic structures.
As an example of our current UC measurements, UC luminescence spectra of CaMoO4:Er with and without alkaline-metal co-dopings are shown in Fig. 1, in which significant enhancement of UC luminescence has been achieved by alkaline-metal co-dopings in CaMoO4:Er.

References

[1] J. W. Chung et al., Appl. Spectrosc. Rev., 51 (2016) 678-705.
[2] A. Gha et al., Sol. Energy Mater. Sol. Cells, 230 (2021) 111234.
[3] H. Jia et al., ACS Material Lett., 4 (2022) 1306-1313.
[4] H. Guo et al., Opt. Mater., 31 (2009) 583-589.
[5] X. Che et al., Opt. Mater., 58 (2016) 449-453.
[6] H. N. Lui et al., Phys. Status Solidi A, 214 (2017) 1600899.
Fig.1 Up-conversion luminescence spectra of CaMoO4:Er excited by 980 nm with Na(blue), K(green), Rb(purple) co-dopings and without (red) ones

Figure 1
Distinctive Electrochemical Surface-Enhanced Raman Spectroscopy and Its Application for DNA-Sensor
Authors: KIM Donghyeon , Kim Nakyung , Kim Jihee , Kang Mijeong 
Published: December 2024

Raman scattering is used in basic research on the physical chemistry of molecules and practical analysis applications for molecular detection. To obtain sufficient intensity of Raman scattering, Surface-enhanced Raman Scattering (SERS) is adopted, in which signals are amplified by the localized surface plasmons of metallic nanomaterials. Electrochemical surface-enhanced Raman spectroscopy (EC-SERS) is employed to further enhance SERS signals. Conventional EC-SERS further enhances signals by simply biasing the SERS substrate and forming a resonance condition in which a charge transfer between the SERS substrate and Raman-active molecules can occur.
We amplified Raman signals using an electrochemical reaction in a different way from conventional EC-SERS. We provided a potential to the SERS substrate in the presence of a plasmonic precursor to generate secondary plasmonic layer and to induce additional chemical enhancement, resulting in the significant amplification of SERS signal. To deepen our understanding of the phenomena occurring in the EC-SERS process, we fabricated a nanoporous Au substrate and systematically varied its characteristics (e.g., pore size, thickness of a porous layer) and observed the dynamic response of the EC-SERS signal. The condition of the SERS substrate that maximizes the EC-SERS signal was explored.
An application experiment was conducted to detect DNA with high sensitivity under these experimental conditions. DNA capture was achieved via a sandwich hybridization procedure: capture DNA was immobilized onto the SERS substrate and bound to a portion of the target DNA, while probe DNA with a tethered Raman-active probe bound to the remaining portion. Raman-active probes were positioned near SERS substrate only in the presence of target DNA. EC-SERS signals were measured by inducing a secondary plasmonic surface through an electrochemical reaction. We confirmed that these EC-SERS could serve as effective DNA-sensor, providing higher detection sensitivity than SERS.
(Invited) Patent Citation Analysis to Guide Research and Innovation
Authors: Taylor Earl Jennings 
Published: December 2024

Patents are widely understood to provide exclusive protection for inventions for a limited time, currently 20 years from filing. The legal protection provided by patents consists of market advantage and/or defensive purposes vis-à-vis competitors [1]. Per United States laws, patents are to have the attributes of property [2]. Consequently, patents are often referred to as intellectual property and their claims may be simply considered as the “metes and bounds” or boundary lines of said property. As such, during the examination (i.e. prosecution) of a patent application, "neighboring" as prior art (published patent applications, patents, technical publications and the like) as well as prior art upon which the pending patent application would “trespass” are identified in office actions from the U.S. Patent & Trademark Office. Prior art which impacts the patentability of a patent application results in the inventor adjusting the boundary lines (i.e. limiting the claims) in order to overcome the rejections. Alternatively, the inventor is forced to abandon the patent application.
Consequently, the examination of patent applications provides a rich landscape of prior art. Additionally, once the subject patent application is published, it becomes prior art and may be cited during the examination of subsequently filed patent applications. These forward citations can provide a guide to research and innovation [3].
The presentation will begin by differentiating research, innovation and invention and then expand on the patent – property analogy as particularly related to prior art citations. The presentation will conclude with a case study of the use of forward patent citations to guide research initiatives and innovation.
[1] E. Jennings Taylor and Maria Inman 2017 Electrochem. Soc. Interface
26 45
[2] E. Jennings Taylor and Maria Inman 2017 Electrochem. Soc. Interface
26 41
[3] E. Jennings Taylor and Maria Inman 2017 Electrochem. Soc. Interface
26 57
(Invited) Innovative Alkaline Electrolyzer for Electrochemical Production of Ammonia from Diverse Waste Nitrogen
Authors: Li Wenzhen , Chen Yifu , Liu Hengzhou , Gu Shuang 
Published: December 2024

NH3 is an essential nutrient for life, but its production through anthropogenic N2-fixing process has caused alarming damages to ecosystems and human health. Excessive NO3
- leakage into water bodies due to overfertilization has led to the formation of "dead zones" in coastal areas. Denitrification generates N2O, which is 300 times more potent than CO2. Restoring the balance between the generation and elimination of Nr is an urgent task for humanity. A promising approach is to convert other forms of Nr to NH3 in an electrochemical reactor, which could reduce the environmental impact of Nr and decrease the NH3 demand from the Haber-Bosch process, while also reducing the use of fossil-derived H2.
In this presentation, we report our innovative membrane-free alkaline electrolyzer (MFAEL), which can transform diverse reactive nitrogen (Nr) into NH3 as the sole N-containing product. By properly choosing the conditions of NH3 collection from MFAEL, continuous production of pure NH3 can be realized without the need for additional separation procedures. A mixture solution of H2O-NaOH-KOH with 40 wt.% of water is typically used as the reaction medium at 80~200 °C to dissolve and digest the nitrogen species including nitrate, nitrite, urea, amino acids, and proteins. Taking advantage of the high alkalinity of the reaction medium, ammonia evolves instantly once it is generated with the assistance of an airflow, which is subsequently collected in an acidic trapping solution as ammonium salts. Our tests with pure nitrogen-containing compounds showed that the MFAEL system is capable of converting both inorganic and organic forms of nitrogen to NH3 with high selectivity. Pure nitrogen-containing compounds [(NH4)2SO4, KNO3, KNO2, urea, and amino acids] with 0.2 mmol of nitrogen are added into the MFAEL, in all cases the amount of evolved ammonia matches the amount of added nitrogen (i.e., ~100% recovery of nitrogen) regardless of its form in the specific chemical, suggesting the high efficiency of the MFAEL in extracting and transforming total nitrogen into ammonia as a single product. An ultrahigh NH3 partial current density of 4.22 ± 0.25 A cm−2 with a faradaic efficiency of 84.5 ± 4.9% can be achieved at 4.5V cell voltage, 85oC. In addition, the MFAEL is highly robust and can handle insoluble wastes, as demonstrated by the ~100% nitrogen recovery (to ammonium sulfate) for a nitrogen-rich algae sample (with 11.5 wt.% of nitrogen content). Techno-economic analysis (TEA) suggests the potential economic feasibility of the nitrogen waste-to-NH3 process by coupling electrodialysis (ED) for Nr concentration and the MFAEL process for Nr conversion, offering an all-sustainable route for upcycling waste nitrogen into the pure N-based fertilizer and chemical products.
(Invited) A Random Forest–Based Artificial Intelligence Model Decoupling Ion Concentrations from Effluent Conductivity in Capacitive Deionization: Implications and Future Directions
Authors: Kim Hoo , Choi Byeongwook , Ullah Zahid , Jeong Nahyeon , Cho Kyung Hwa , Park Sanghun , Baek Sang-Soo , Son Moon 
Published: December 2024

Effluent conductivity is a widely used parameter in evaluating the performance of desalination processes, such as capacitive deionization (CDI) and pseudocapacitive deionization (BDI), due to its simplicity in measurement. However, the conversion of effluent conductivity to ion concentration is often inaccurate, necessitating a more reliable method for real-time monitoring of effluent ion concentrations. To address this issue, a random forest (RF)-based artificial intelligence (AI) model was developed, demonstrating excellent prediction accuracy for both CDI (R2 = 0.86) and BDI (R2 = 0.95) data for effluent conductivity. Furthermore, the model successfully predicted the concentration of individual ions (Na⁺ and Cl⁻) from the conductivity values, with an even higher accuracy than that of the effluent conductivity prediction. The impact of sampling interval on the model's performance was also investigated for both conductivity and ion concentrations. The results showed no significant difference in the model's error value for sampling intervals up to <80 s. These findings highlight the potential of the RF model as a valuable tool for predicting ion concentrations in CDI/BDI processes, which can serve as key indicators in assessing desalination performance.
By providing a more reliable method for predicting ion concentrations, the RF model can contribute to the optimization and automation of CDI and BDI systems, ultimately leading to more efficient and cost-effective desalination technologies. The ability to decouple ion concentrations from effluent conductivity can lead to more accurate monitoring and control of desalination systems, enabling operators to make informed decisions and optimize process performance. Future directions for this research could include the expansion of the RF model to incorporate additional input variables, such as pH, temperature, and flow rate, to further enhance its predictive capabilities, and improving robustness of the model under conditions more closely resembling industrial settings. Such implications and future directions of the research will be discussed in further details in the presentation.
(Invited) Blended Positive Electrode Materials for Li-Ion Batteries: Electrode Dynamics and Operando XRD
Authors: Palacin M. 
Published: December 2024

Transport electrification has resulted in an expansion of the Li-ion battery application from Wh to kWh storage. This has brought up additional requirements to improve performance (e.g. power, cycle life) enhance of sustainability and decrease of cost. Blending different active materials at the same cell electrode, an empirical approach commonly used for primary cells, has been readily applied to commercial EV Li-ion batteries mostly on the positive side. The global aim is to promote positive synergetic effects between the different electrode components, which have unfortunately received limited attention at the fundamental research level.
Materials with fast reaction kinetics, such as LiMn2O4 (LMO) can sustain significantly higher effective rates than the nominal rate applied to the electrode. This has motivated the widespread commercial use of NMC:LMO blends as LiNixMnyCozO2 (x+y+z=1, NMC) despite having slow kinetics, exhibits high capacity (especially for large amounts of Ni) and the addition of LMO lowers overall costs while enhancing power performance. Olivine LiMPO4 (M=Fe, Mn) based blends have a lower presence in commercial cells to date but they have also deserved attention at the laboratory scale as they can as well exhibit fast kinetics and are based on low cost abundant transition metals.
Results will be presented related to different blends, consisting of combinations of LMO, NMC, LiFePO4 (LFP) and LiFe0.35Mn0.65PO4 (LFMP). Electrochemical experiments coupled to time-resolved synchrotron operando X-ray diffraction experiments enable to capture charge transfer events between blend components which are dependent on both voltage profile and kinetics of individual blend components. The results demonstrate the significant impact of the voltage profiles of individual materials on the current distribution, with the effective C-rate of each component varying throughout the state of charge (SoC).
Finally, systematic operando synchrotron X-ray diffraction and absorption experiments will be presented for NMC and LFP with diverse experimental conditions (cell type, radiation energy etc.) to illustrate the existence of beam-induced effects which may bias interpretation of results. These range from total reaction inhibition to partial hindrance and negligible deviations from the expected mechanism, and have been consistently observed across various experimental conditions, photon energies, photon fluxes and exposure times. The total radiation dose per cycle seems to be a useful predictor of the magnitude of beam-induced electrochemical delay and could serve as a guideline to define reliable measurement protocols.
Multivalent Cation Additives for Building Dendrite-Free and Stable Electrode-Electrolyte Interface on Lithium-Metal Anodes
Authors: Li Hongyi , Ichitsubo Tetsu 
Published: December 2024

Li-metal anodes are ideal anode materials for Li-based batteries owing to high theoretical capacity and low redox potential. However, the practical application of Li-metal anodes face challenges, such as uneven deposition morphology and progressive electrolyte decomposition during repeated Li deposition and dissolution. To improve the reversibility, high-concentration electrolytes (HCEs), such as 4 M Li[FSI] in DME,[1] have been reported to effectively flatten the deposition morphology and improve the Coulombic efficiency. Nevertheless, HCEs have several limitations, including poor oxidation stability, high viscosity, and high production costs.[2] Therefore, technologies for creating the HCEs’ features in lower concentration ranges are expected to be developed.
In this presentation, we introduce an effective approach to utilize multivalent cations (e.g. Ca2+, Ba2+) as electrolyte additives to construct dual-cation electrolytes (DCEs) for Li-metal anodes. Because multivalent cations have much stronger coordination with anions and solvent molecules than Li+, it is usually difficult to reduce multivalent cations to metal state in organic electrolytes. When multivalent cations are mixed with Li+ in electrolytes, the Coulomb interaction among different cations would modify the solvation structure. Anions are promoted to directly coordinate with cations increasing the ratio of the contact-ion pairs (CIPs) to diminish the free energy of the electrolyte system.[3] This phenomenon creates the solvation environment similar to HCEs, which contributes to maintaining a dendritic-free deposition morphology. Furthermore, as a unique feature of DCEs, multivalent cations are prone to be involved in the formation of solid-electrolyte interphase (SEI) in addition to Li+. The chemical bonds between multivalent cations and the other SEI compositions (e.g., F, O, S, C and N) can enhance the structural stability and functionality of SEI, as an effective controlling factor for the reaction behavior of Li-metal anodes.[4]
[1] J. Qian, J-G. Zhang et al, Nat. Commun.
6, 6362 (2015)
[2] Y. Yamada, A. Yamada et al, Nat. Energy
4, 269 (2019)
[3] H. Li, T. Ichitsubo et al, Cell Rep. Phys. Sci.
3, 100907 (2022)
[4] H. Li, T. Ichitsubo et al, submitted.
Simulation of the Solid Electrolyte Interphase Layer in Lithium Metal Batteries – a Systematic Study
Authors: Morey Madison , Lobel Maya , Ryan Emily 
Published: December 2024

Instability of the anode-electrolyte interface and uncontrolled lithium (Li) dendrite growth pose serious safety concerns hindering the commercialization of high energy density Li metal batteries (LMBs). In particular, the Solid Electrolyte Interphase (SEI) layer is a key factor causing instability at the interface. The SEI layer is formed due to side reactions between Li, electrons, and electrolyte. When stable, this layer acts as a passivation layer that allows for transport of Li ions (Li+) to the anode while keeping the electrolyte and anode separated reducing the side reactions along the anode surface. However, following the initial growth of the SEI layer, the diffusion and reaction kinetics initiate dendrite growth, leading to the rupture of the SEI layer and exposure of fresh metallic Li. The high reactivity of Li metal results in continuous and rapid growth due to high reaction rates and fast kinetics. Finally, the SEI layer will reform over the exposed Li leading to excess electrolyte consumption causing permanent capacity loss and reduced coulombic efficiency.
We present a systematic computational study of the various methods that are used to simulate the impact of the SEI layer, with varying level of complexity. Methods that were studied include varying reaction rates based on thinning and fracture of the SEI layer, a fixed SEI layer that possesses effective transport properties based on the porosity and tortuosity of the compact layer, the consideration of surface energy, and a competing current system that accounts for the ions consumed due to the parasitic SEI formation reaction.
Cycling Performance Research on Disordered Rock Salt Cathode Material in Lithium Ion Batteries
Authors: Fu Yanbao , Battaglia Vincent 
Published: December 2024

A worldwide effort is presently underway to develop electric vehicles (EVs) or hybrid electric vehicles (HEVs) to reduce fossil fuel consumption in the transportation area. Lithium-ion batteries are the first choice to be used in EVs and HEVs due to their high energy and power density in the existing commercial battery eco-system. With the ever growing EV market, lithium ion battery manufacturers and researchers are facing many challenges, one of which, is how to cut down the metals in the cathode which are rare, expensive, and unbenign to the environment. Over past few years, cobalt-free is a popular topic in the cathode materials research and development effort. Under this topic, disordered rock salt (DRX) cathode materials, that were invented in recent years, have been attracting interest due to their potential high capacity and high energy-density compared with current commercial cathode materials. In the DRX materials, a disordered arrangement of cation species is established, which imparts the DRX materials with its unique lithium transport properties and small volume changes during charge–discharge cycling [1]. Disordered arrangement of cation species also leads to the sloping voltage profile which makes the capacity of the DRX materials dependent on the cut-off voltage. In this research the effect of cut-off voltage on the electrochemical performance of Li1.2Mn0.6Ti0.2O1.8F0.2 DRX was investigated along with the long-term cycling performance.
Figure 1. The cycling performance of Li1.2Mn0.6Ti0.2O1.8F0.2/Li half cells with different test protocols.
Reference
[1] R. J. Clement, Z. Lun and G. Ceder. Cation-disordered rocksalt transition metal oxides
and oxyfluorides for high energy lithium-ion cathodes, Energy Environ. Sci., 2020,13, 345-373.

Figure 1