bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydrogen Contaminant Detectors for Ensuring Hydrogen Fuel Quality
Authors: Mukundan Rangachary , Romero Christopher J , Rockward Tommy , Brosha Eric L.
Published: August 2024

The California Energy Commission tracks Hydrogen Refueling Station (HRSs) installations within California and states that there are 66 light duty retail stations open within the State with another 34 in the planning stages.1 The hydrogen dispensed in these stations is expected to meet SAE J2719 standards for the maximum allowable concentration of various impurities.2 Currently HRSs have their fuel analyzed periodically to verify that they meet fuel specifications. However, this implies that any anomaly in the purification system resulting in contaminated hydrogen can result in significant damage to fuel cell vehicles before being detected. Therefore, the development of hydrogen contaminant detectors that can continuously monitor the hydrogen for impurities like Carbon monoxide (CO) and hydrogen Sulfide (H2S) is of great interest. LANL has developed a hydrogen contaminant detector based on a hydrogen pumping cell that is sensitive to < 200 ppb CO and < 4 ppb H2S.3,4 In this talk we will present details of the working mechanism of this hydrogen contaminant detector and present results from the field testing of the detector at a HRS.

Acknowledgements

This research is supported by the U.S. Department of Energy Fuel Cell Technologies Office, through the Safety, Codes & Standards (SCS) sub-program (Project Manager: Laura Hill).

REFERENCES:

https://www.energy.ca.gov/data-reports/energy-almanac/zero-emission-vehicle-and-infrastructure-statistics/hydrogen-refueling.

San Marchi, E. S. Hecht, I. W. Ekoto, K. M. Groth, C. LaFleur, B. P. Somerday, R. Mukundan, T. Rockward, T; J. Keller, C. W. James, Int. J. Hydrogen Energy, 42(11), 7263-7274 (2017)

Brosha, T. Rockward, C. J. Romero, M. S. Wilson, C. Kreller and R. Mukundan, U.S Patent # 10,490,833 (2019).

R. Mukundan, E. L. Brosha, C. J. Romero, D. Poppe, T. Rockward, “Development of an electrochemical hydrogen contaminant detector”, Journal of The Electrochemical Society, 167(14), 147507 (2020)
Development and Field Testing of Multi-Electrode Mixed Potential Electrochemical Sensors for Natural Gas-Hydrogen Mixture Emissions Monitoring
Authors: Halley Sleight , Ramaiyan Kannan , Smith James , Ian Robert , Agi Kamil , Garzon Fernando H. , Tsui Lok-kun
Published: August 2024

Transportation of hydrogen is one of the greatest hurdles to overcome in the development of a clean hydrogen economy [1]. A cost-effective solution to transportation of hydrogen is to mix it with natural gas (NG) and utilize current pipeline infrastructure for transportation [2]. However, hydrogen embrittlement, the higher diffusivity of H2, and the uncertain state of much of existing infrastructure makes leaks of H2 an environmental and safety concern. Current NG leak detection technologies largely use optical sensors such as IR spectrometers that are incapable of detecting H2 gas [3]. Mixed potential electrochemical sensors (MPES) are low-cost, robust devices capable of detecting a wide variety of gases [4], with the sensitivity and selectivity necessary for point source monitoring of natural gas leaks [5].

Multi-electrode MPES devices using Indium Tin Oxide, Au, and La0.87Sr0.13CrO3 and Pt electrodes have previously successfully quantified CH4 in natural gas at the 10-40 ppm level [5]. In this work, we demonstrated that the Au vs. Pt electrode has a low limit of detection of < 3 ppm for H2 in an air atmosphere. We also performed field testing of H2 emissions at CSU’s Methane Emissions Technology Evaluation Center (METEC) in both underground and above-ground emissions of H2 and H2 + natural gas mixes (Figure 1) with successful detection of H2 at the ppm level. Finally, we evaluate the stability of the selectivity and sensitivity during prolonged exposure to H2 and CH4.

This work was supported by US Department of Energy Award DE-FE0031864.

References:

[1] R. Scita, P. P. Raimondi, and M. Noussan, Fondazione Eni Enrico Mattei (FEEM), 2020. Accessed: Dec. 01, 2023. Available: https://www.jstor.org/stable/resrep26335.5

[2] F. Öney, T. N. Veziro, and Z. Dülger, Int. J. Hydrog. Energy, vol. 19, no. 10, pp. 813–822, Oct. 1994, doi: 10.1016/0360-3199(94)90198-8.

[3] T. Aldhafeeri, M.-K. Tran, R. Vrolyk, M. Pope, and M. Fowler, Inventions, vol. 5, no. 3, Art. no. 3, Sep. 2020, doi: 10.3390/inventions5030028.

[4] F. H. Garzon, R. Mukundan, and E. L. Brosha, Solid State Ion., vol. 136–137, pp. 633–638, Nov. 2000, doi: 10.1016/S0167-2738(00)00348-9.

[5] S. Halley, K. Ramaiyan, F. Garzon, and L. Tsui. Sens. Actuators B Chem., vol. 392, p. 134031, Oct. 2023, doi: 10.1016/j.snb.2023.134031.

Figure 1. (a) Field test configuration of an above-ground emission with sampling lines drawing gas to IoT powered sensors. (b) Concentration measurements for H2 and CH4 captured on a Mixed Potential Sensor and an Aeris Mid-IR analyzer.

Figure 1
(Digital Presentation) Temperature-Induced Conversion of 2D Vanadium-Doped MoSe2 Nanosheets to 1D V2MoO8 Rods: Enhanced Performance in Electrochemical Antibiotic Detection in Biological and Environmental Samples
Authors: Ramaraj Sukanya , Raj Karthik , Breslin Carmel B
Published: August 2024

A new strategies were developed to prepare 1D-V2MoO8 (VMO) rods from 2D V-doped MoSe2 nanosheets (VMoSe2) with good control over morphology and crystallinity by a facile hydrothermal and calcination process. The morphological changes from 2D to 1D rods were controlled by changing the calcination temperature from 300 to 600 °C. The elimination of Se and the incorporation of O into the V-Mo structure were evaluated by TGA, p-XRD, Raman, FE-SEM, EDAX, FE-TEM, and XPS analyses. These results prove that the optimization of the physical parameters leads to changes in the crystal phase and textural properties of the prepared material. The VMoSe2 and its calcined products were investigated as electrochemical sensors for the detection of the antibacterial drug nitrofurantoin (NFT). At a calcination temperature of 500 oC, the modified SPCE proved to be an excellent electrochemical sensor for the detection of NFT in neutral media. Under the optimized conditions, VMO-500 oC/SPCE exhibits low LOD (0.015 µM), wide linear ranges (0.1-31, 47-1802 µM), good sensitivity, and selectivity. The proposed sensor was successfully used for the analysis of NFT in real samples with good recovery results. Moreover, the reduction potential of NFT agreed well with the theoretical analysis using quantum chemical calculations, with the B3LYP with 6-31G(d,p) basis set predicting an E
0 value of -0.45 V. The interaction between the electrode surface and NFT via the LUMO diagram and the electrostatic potential surface is also discussed.
Double Perovskites: Promising Positive Electrode Materials for Potassium Ion Batteries
Authors: Chen Xin , Payne Julia Louise
Published: August 2024

The popularity of electric vehicles over the last decade has led to a boom in lithium-ion battery production. Large amounts of lithium resources have been consumed resulting in a lithium shortage.[1] To overcome the challenge of excessive consumption of lithium resources, alternative battery technologies to Li-ion batteries must be considered. Potassium-ion batteries (KIBs) have been proposed as an alternative battery technology to Li-ion batteries and are at the early stage of development.

This study focuses on investigating the viability of employing the novel double-perovskites as positive electrodes for KIBs. Double perovskites have some structural similarities to the well-developed KIB positive electrode materials, Prussian White or Prussian Blue Analogues. The 3D open framework is favorable for supporting the insertion/deinsertion of K-ions and K-ion diffusion. In this research, new double-perovskites have been successfully synthesized using the solid-state methods, under both inert and reducing atmospheres. The utilization of choice of transition elements on the B-site in the perovskite structure is beneficial for increasing energy density, enhancing electronic conductivity, and improving the structure stability of the material. Preliminary characterization, including powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS), were conducted to verify the phase purity, crystal structure, and atomic ratio of different elements in the synthesized material.

At the same time, electrochemistry tests were conducted by cycling the perovskite in half-cells, revealing an irreversible capacity decay in the first cycle. To further investigate structural changes of the perovskite during cycling, operando X-ray absorption spectroscopy (XAS) was employed. This method enabled the study of the oxidation states of the transition metals in the perovskites, providing advanced insights into the redox reactions occurring within cells with positive electrodes.

Obtaining a detailed understanding of the structure of these perovskites is crucial. Thus, powder neutron diffraction (PND) and variable temperature neutron diffraction (VT-PND) have been gathered to study the structural evolution, site occupancy and octahedral tilting with upon heating in both inert and reducing atmospheres.

Reference:

[1] AP News, https://apnews.com/article/china-ev-lithium-united-states-battery-87eb9382a0181bb7ee64e835efe7b170, (accessed December 2023).
Shedding Light on Lithium-Sulfur Battery Dynamics: Real-Time Insights through in-Situ UV-Vis Spectroscopy on Modified Lab Equipment
Authors: Gomes Luisa Larissa Arnaldo , Sanctis Victor , Dai Huidong , Mukerjee Sanjeev
Published: August 2024

In current post-lithium-ion research, the focus is directed toward Lithium-Sulfur (Li-S) batteries, motivated by their outstandingly high energy density (2640 Wh/kg) and the widespread availability of sulfur in the Earth's crust. Moreover, in-situ UV-Vis spectroscopy has proven to be instrumental, allowing for the real-time observation of alterations in the chemical composition of various battery components during operational cycles [1,2].

Our current study delves into the influence of solvent selection, particularly donor and acceptor numbers, in formulating gel polymer electrolytes for Lithium-Sulfur batteries. Leveraging in-situ UV-Vis spectroscopy, our research provides real-time insights into dynamic interactions within the gel during battery operation, shedding light on evolving electrochemical processes. Systematically analyzing the impact of solvent properties on gel characteristics reveals a meaningful relationship, underscoring the importance of tailored solvent selection for optimizing gel performance. Moreover, this technique tracks polysulfide behavior, offering a comprehensive understanding of the gel's role in mitigating polysulfide shuttling. Notably, our study introduces a novel dimension by employing a custom-built in-situ UV-Vis cell featuring 3D-printed components, enhancing the versatility and applicability of these spectroscopic techniques in probing intricate interactions within gel polymer electrolytes. Moreover, by combining the UV-Vis results with Nuclear Magnetic Resonance and FTIR, we aim to advance fundamental knowledge and provide a pathway for optimizing battery performance and mitigating degradation mechanisms.

References

1- Patel, Manu UM, Rezan Demir‐Cakan, Mathieu Morcrette, Jean‐Marie Tarascon, Miran Gaberscek, and Robert Dominko. "Li‐S Battery Analyzed by UV/Vis in Operando Mode." ChemSusChem 6, no. 7 (2013): 1177-1181.

2- He, Qi, Anna TS Freiberg, Manu UM Patel, Simon Qian, and Hubert A. Gasteiger. "Operando identification of liquid intermediates in lithium–sulfur batteries via transmission UV–vis spectroscopy." Journal of The Electrochemical Society 167, no. 8 (2020): 080508.
Exploring the Impact of Oxygen Doping in Li2FeS2 Cathode Materials for Li-Ion Batteries
Authors: Hailemariam Adane , Hidaru Zeru Syum , Mamo Tadios Tesfaye , Qorbani Mohammad , Wu Heng-Liang , Chen Li-Chyong , Chen Kuei-Hsien
Published: August 2024

Over the past few decades, rechargeable lithium-ion batteries have become popular for a variety of applications, such as electric vehicles, smart grids, and portable energy devices. However, due to their limited capacity, stability, and lifespan, they are not suitable for advanced transportation applications. To overcome these challenges, researchers have investigated the use of low-cost, high-energy-density, and safe positive electrode materials for secondary lithium batteries, including lithium iron sulfide. In this particular study, our focus is to investigate the effect of highly electronegative anion doping on the properties of lithium iron sulfide cathode through the solid-state method. Our approach involves using both in-situ and ex-situ observations to establish a correlation between the Redox behavior and structural properties of the prepared cathode materials. We have designed and characterized the material using various techniques, such as X-ray absorption spectroscopy (XAS) and synchrotron-based X-ray diffraction (XRD). Scanning electron microscope (SEM) measurement was conducted to study the morphology of the cathode material. Transmission electron microscopy (TEM) was employed to further study the microstructure of the cathode material at an atomic level. We analyzed the electron density distribution of the modified cathode material using XANES measurement and studied the structural properties through synchrotron-based XRD. Our study has revealed that oxygen-doping helps to improve material stability. As a result, the modified cathode (with optimal oxygen doping) exhibited a 50% capacity enhancement compared to pristine after 100 cycles. We also observed a shift to a higher voltage oxidation plateau of the oxygen-doped cathode material which is due to the influence of anion substitution on the electrochemistry and charge storage mechanisms. In summary, our detailed characterization and experimental results demonstrate the potential of oxygen-doped Li2FeS2 as a promising cathode material for advanced lithium-ion battery applications. The study's detailed characterization and experimental results will be presented, along with future perspectives.
Quantifying Mixed Redox and Parasitic Processes in Li-Rich Disordered Rocksalt Li-Ion Battery Cathodes
Authors: Rastinejad Justin , Rinkel Bernardine Lucia Deborah , McCloskey Bryan D.
Published: August 2024

Li-ion battery demand is expected to increase dramatically as the transportation and power generation sectors become electrified. To address the expense and scarcity of cobalt and nickel used in current layered cathodes, alternative transition metals must be explored. Disordered rocksalt (DRX) cathodes can be fully comprised of affordable, earth-abundant metals such as manganese and titanium and have shown high practical capacity but currently suffer from poor capacity retention and voltage fade [1]. Many researchers have attributed this to O redox, and the subsequent formation of deleterious reactive oxygen species, which can occur in DRX cathodes at states-of-charge as low as 40% [2,3]. Recently, researchers have increased the Mn content in DRX cathodes, with the intent of increasing Mn redox and suppressing O redox [4]. Furthermore, these Mn-rich DRX cathodes undergo a beneficial phase transformation upon electrochemical cycling, increasing capacity and almost eliminating voltage fade [4]. Yet, the redox contributions of Mn and O in these Mn-rich cathodes, especially after this phase transformation, are not understood.

Here we decouple capacity contributions from Mn-redox, O-redox, and parasitic processes (e.g. electrolyte decomposition) for Mn-rich DRX using a combination of operando gas measurements and inductively coupled plasma – optimal emission spectrometry (ICP-OES). Mn-rich DRX cathodes were cycled to various states of charge in coin cells and the resulting Mn and O oxidation state were determined via titration mass spectrometry (TiMS) using oxalic acid and triflic acid, respectively. To account for lattice O2 loss, differential electrochemical mass spectrometry (DEMS) was used on select cells. To account for Mn dissolution during cycling, ICP-OES was used to quantify the amount of Mn remaining in the cathode as a function of cycle number. The results of this study provide insight into the various redox processes and interfacial degradation that occurs in DRX cathodes, thereby informing future design to improve high-voltage stability of these promising materials.

[1]: Raphaële J. Clément et al 2020 Energy Environ. Sci. 2 345

[2]: Tzu-Yang Huang et al 2023 Adv. Energy Mater. 13 2300241

[3]: Roland Jung et al 2017 J. Electrochem. Soc. 164 A1361

[4]: Zijian Cai et al 2023 Nat. Energy 1
Accurate Battery Life Prediction Using Early-Cycle Features
Authors: Sugiarto Lawnardo , Lu Yi-Chun
Published: August 2024

Data-driven machine learning (ML) applications on battery prognosis are thriving with compatible accuracy owing to advancements in computing and data storage technologies. Unfortunately, several experimental obstacles including sparse operating conditions and time cost affect the data quality which restricts the ML model generalizability and applicability given the nonlinear degradation pattern for lithium-ion batteries (LIBs). From a broader perspective, multiple electrochemical attributes have not been investigated thoroughly and therefore, we proposed to build an early-cycle lifetime prediction model by exploring the capability of features extracted from the battery’s extrinsic properties (ex: temperature, dis/-charge time) using cycling data taken from only up to the first 10 cycles. A simple linear model is employed and validated on datasets amounting about 200 cells in total with various environmental temperature settings, cycling protocols, and lithium-based cathode chemistries such as lithium - iron phosphate (LFP), nickel cobalt aluminium oxide (LNCA), and nickel manganese cobalt oxide (LNMC) with mean absolute percentage error (MAPE) cycle life prediction less than 17.3%. Integrating the short-listed explored features together with state-of-the-art features on a fast-charging dataset of 124 LFP cells, the model achieved a satisfying 11.8% overall MAPE using data from the first 10 cycles. This work provides an impactful insight into simple feature engineering on early-cycle prediction applications. Details on the methodology, data-standard challenges, and wider applications will be discussed to explore further derivation of potent early-cycle features.
Efficient Zn-Ion Pouch Cell Assembling Based on Aramid Nanofiber Hydrogel
Authors: Wang Peng , Andrei Petru
Published: August 2024

With the fast advancement of portable and wearable electronics, it is urgent to develop safe, stable and flexible power supply devices. Safe and environmentally friendly aqueous zinc-ion batteries (AZIBs) have a low-cost and are perfect candidates for energy storage device in such applications [1-4]. Giving the general challenges, such as the formation of the dendrites on the Zn anodes and hydrogen evolution and side reactions, extensive and wide research has focused on building stable AZIBs with high performance, but less attention was paid to making Zn ion pouch cells which are flexible and with high capacity In this presentation, we developed an efficient method to assemble Zn-ion pouch cells based on the process of formation of the aramid nanofiber hydrogel. The method involves the dipping precursor solution, solvent exchanging, and in-situ electrodeposition of MnO2. The assembled Zn-ion pouch cells exhibit excellent mechanical performance, flexibility and electrochemical performance, which are ideal for portable and wearable electronics. Based on this method, we successfully assembled 3-layer (cathode/anode/cathode, A/C/A) and 5 layer (A/C/A/C/A) pouch cells with over 100 times higher capacity compared with coin cell. In addition, the pouch cell with aramid nanofiber hydrogel and in-situ electrodeposited MnO2 cathode on carbon nanotube mat demonstrates superior cycling stability [5,6]. More details about our assembling method for flexible and stable pouch cells for AZIBs and experimental measurements related to the cycling and stability characteristics, will be presented at the meeting.

[1] Yu, Peng, et al. "Flexible Zn‐ion batteries: recent progresses and challenges." Small 15.7 (2019): 1804760.

[2] Li, Yingbo, et al. "Recent advances in flexible zinc‐based rechargeable batteries." Advanced Energy Materials 9.1 (2019): 1802605.

[3] Li, Chunyang, et al. "High-rate and high-voltage aqueous rechargeable zinc ammonium hybrid battery from selective cation intercalation cathode." ACS Applied Energy Materials 2.10 (2019): 6984-6989.

[4] Yu, Feng, et al. "Aqueous alkaline–acid hybrid electrolyte for zinc-bromine battery with 3V voltage window." Energy Storage Materials 19 (2019): 56-61.

[5] Wang, Peng, and Petru Andrei. "High Performance Separator and Hydrogel Based on Aramid Fibers for Zn Ion Batteries." Electrochemical Society Meeting Abstracts 242. No. 4. The Electrochemical Society, Inc., 2022.

[6] Xu, Lizhi, et al. "Water‐rich biomimetic composites with abiotic self‐organizing nanofiber network." Advanced Materials 30.1 (2018): 1703343.
Extreme Cycling Longevity in Additive Free T-Nb2O5 over a Quarter Million Lithiation Cycles
Authors: Wechsler Sean Cade , Gregg Alexander , Stefik Morgan
Published: August 2024

Rapid energy storage via intercalation requires quick ionic diffusion and often results in pseudocapacitive behavior. The long-term cycling stability of such energy storage materials remains understudied despite the relevance to their lifetime cost and market feasibility. Orthorhombic niobium oxide (T-Nb2O5)is a rapid ion intercalation material with a theoretical lithiation capacity of 201.7 mAh g-1 (Li2Nb2O5) and good cycling stability due to the minimal unit cell strain during (de)intercalation. Prior reports of T-Nb2O5 cycling between 1.3-3.1 V vs. Li/Li+ noted a 50% loss in capacity after 10k cycles, stemming from a convolved effect of amorphization, dissolution, and/or delamination. Here, cyclic voltammetry is used to identify the role of the voltage window, state of charge (SOC), and potentiostatic holds on the cycling stability of mesoporous T-Nb2O5 thin films. Films cycled at high-rate between 1.2-3.0 V vs. Li/Li+ without voltage holds (kinetically limited SOC of Li1.1Nb2O5) exhibited extreme cycling stability with 90.8% ± 2.1% capacity retention after a quarter million cycles without detectable morphological/crystallographic changes.1 In contrast, inclusion of 60 s voltage holds (SOC of Li2.18Nb2O5) led to rapid capacity loss with only a 61.6% retention after 10k cycles and corresponding x-ray diffraction evidence of amorphization. Cycling with other limited voltage windows identified that most crystallographic degradation occurred at higher extents of lithiation (<1.4 V vs Li/Li+). These results reveal remarkable stability, up to 25x higher than what has been previously observed, over limited conditions and suggest that T-Nb2O5 amorphization is associated with high extents of lithiation.

[1] Wechsler, S. C.; Gregg, A.; Stefik, M. Highly Reversible Lithiation of Additive Free T-Nb2O5 for a Quarter of a Million Cycles. Adv. Funct. Mater.
2023, ASAP. 10.1002/adfm.202312839.
Combatting Antibiotic-Resistant Pathogens: Disrupting Pseudomonas Aeruginosa Biofilm Viscoelasticity Using Carbon Dot Nanoparticles
Authors: Faleke Hammed , Sawant Vikram , Christopher Gordon , Pappas Dimitri
Published: August 2024

Bacterial infection is a global burden, killing one in every eight people worldwide, primarily due to antibiotic resistance. Pseudomonas aeruginosa is one of the top five bacteria responsible for around 7.7 million fatalities caused by bacterial infections. P. aeruginosa secretes biofilm, a biological substance with viscoelastic characteristics to avoid antimicrobial treatments particularly, in chronic and serious wound infections. In the bid to create topical treatments, we investigated the mechano-active potentials of cellulase-based carbon dots as a therapeutic agent against P. aeruginosa biofilm where we envisage the retaining of the cellulase hydrolytic activity in the cellulase-based carbon dots. Cellulase is a glycoside hydrolase that has already been shown to be effective in causing biofilm dispersal as well as reduction in biofilm stiffness and elasticity.

The cellulase carbon dots were synthesized using the microwave while citric acid carbon dots (CA-CDs) were hydrothermally synthesized to serve as non-protein-based carbon dots and then characterized for surface properties, size, elemental compositions, and fluorescence profile. P. aeruginosa biofilms were grown in a microfluidic environment for 24 hours and then treated with these carbon dots at a range of concentrations. Using microrheology, it was seen that biofilms treated with cellulase-based carbon dots were more viscous and less stiff compared to those treated with citric acid-based carbon dots. This appears to be because the cellulase carbon dots impact PSL within the biofilm based on microrheology studies examining bacteria strains with specific EPS components removed. This is consistent with the impact of molecular cellulase on biofilms. In general, initial studies suggest that the cellulase-based carbon dots have the potential to act as an excellent multi-antibiofilm therapeutic in the future.
Reversible Nickel Electrodeposition Electrolytes for Dynamic Window Applications
Authors: Patra Rituparna , Madu Desmond , Barile Christopher J.
Published: August 2024

Amid the energy crisis, reducing energy consumption has become a growing field of energy research. When analyzing energy usage, buildings are responsible for 30% of global energy consumption.1 One of the ways to reduce this enormous energy consumption in buildings is to reduce the amount of heating, cooling, and air conditioning needed to provide comfortable work and living spaces. In this regard, dynamic windows are an innovative approach to increasing building energy efficiency as they electronically switch between light and dark states.2 By controlling the transparency of the window, dynamic windows help control the temperature of a space and, therefore, save on average 10% of energy consumption in buildings.3 Reversible metal electrodeposition (RME) provides a method of constructing dynamic windows that possess color neutrality, high switching speed between dark and light states, low cost, and durability over thousands of cycles.4 In recent years, zinc has emerged as a standout metal for application in dynamic windows.2,5 However, the interactions of the deposited zinc film with the surrounding water in the aqueous electrolytes can slowly deteriorate device performance.6 To ameliorate the situation, we are developing dynamic windows with nonaqueous nickel electrolytes, which have many of the advantageous properties of typical RME dynamic windows, but are more robust than analogous zinc systems.

References:

Energy sector CO2 emissions include emissions from energy combustion and industrial processes.

Islam, M. ., Barile C, Dynamic Windows Using Reversible Zinc Electrodeposition in Neutral Electrolytes with High Opacity and Excellent Resting Stability, Adv. Energy Mater. 2021, 11, 2100417.

Lee, M. Yazdanian, S. Selkowitz, The Energy-Savings Potential of Electrochromic Windows in the US Commercial Buildings Sector, Lawrence Berkeley National Laboratory 2004, LBNL-54966.

Tao, D. Liu, J. Yu, and H. Cheng, Reversible Metal Electrodeposition Devices: An Emerging Approach to Effective Light Modulation and Thermal Management, Adv. Opt. Mater., 2021, 2001847.

Desmond C. Madu et al., Water-in-Salt Electrolytes for Reversible Zinc Electrodeposition for Dynamic Windows, J. Electrochem. Soc., 2023, 170 112502.

Madu D. C., Lilo M. V., Thompson A. A., Pan H., McGehee M. D., Barile C. J, Investigating Formate, Sulfate, and Halide Anions in Reversible Zinc Electrodeposition Dynamic Windows., ACS Appl. Mater. Interfaces, 2022, 14, 47810.
(
General Student Poster Award Winner, 2nd Place)
Template-Assisted Fabrication of Transparent SERS Sensor with Uniform Au-Ag Nanoparticle Electrodeposition
Authors: Tu Zhengke , Saito Mikiko , Kunimoto Masahiro , Yanagisawa Masahiro , Homma Takayuki
Published: August 2024

Surface-enhanced Raman spectroscopy (SERS) is a very powerful tool for analyzing molecular interactions and provides unique spectral fingerprint information about chemical bondings.[1] SERS enhances weak Raman scattering signals through surface-localized plasmon resonance (LSPR) of the plasmonic metal nanoparticles. Arbitrarily distribution of plasmonic metal nanoparticles can result in a non-uniform SERS enhancement effect (EF) and low reproducibility, which hinders the practical application of this ultra-sensitive analysis technology.[2] The development of a cost-effective, highly reliable, and highly reproducible SERS sensor with precisely controlled nanoparticle size and distribution is still a challenge.[3] Electron beam lithography (EBL) is commonly used to achieve well-controlled nanoscale patterns, which can be used as a top-down SERS sensor fabrication technique.[2] However, the time-consuming and extremely costly method makes the SERS sensor not easily accessible.

In this research, we propose a template-assisted fabrication process by electrodepositing nanoparticles into nanoarrays on a transparent ITO surface. This method precisely controls the surface morphology and provides high reproducibility without relying on EBL techniques. For the fabrication process, first, a layer of sol-gel SiO2 solution was spin-coated onto the ITO surface, and an array of nano-pillars was used to imprint the nanopattern to the sol-gel solution layer, to realize the nano-ordered uniformly distributed nanoarrays. (Fig.1) For the plasmonic material, Au-Ag alloy was deposited into the nanoarray due to its high durability and high SERS EF.[4] The use of a pulse current deposition, additives, and self-assembled monolayer (SAM) was also discussed from the perspective of altering the surface property of the ITO surface, to achieve dense and smooth filling of deposits in the nanoarray. The SERS sensor fabricated was tested with Janus Green B (JGB) and demonstrated a good SERS EF and good signal uniformity. We believe this sensor is widely applicable for different systems, further optimization and application of this sensor can bring us one step closer to the quantitative analysis by SERS. The fabricated sensor should be especially useful in electrochemical reaction analysis and biomolecular sensing.

[1] Fleishmann et al., Phys. Lett., 26, 163(1974)

[2] Lee et al., Chemical Society reviews., 48, 731(2019)

[3] Shi et al., 66, 6525(2018)

[4] B. Liu et al., 55
, 117104(2016)

Figure 1
Electroless Plating of Nanoporous Substrates for Thin Film-Solid Oxide Fuel Cells
Authors: Hopkins Emma , Ryu Sangbong , Minh Nguyen Q. , Liu Ping
Published: August 2024

Thin-film solid oxide fuel cells (TF-SOFCs) are an attractive renewable energy source due to their high efficiency, increased power output and ability to be efficiently stacked for power generation at a small or large-scale. [N. Q. Minh, J Am Ceram Soc. 1993; 76(3):563-588.] Nanoporous Al2O3, also known as anodized aluminum oxide (AAO) is an appropriate substrate for TF-SOFCs due to its high temperature stability, chemically inert nature, and porosity that allows gas flow to the anode. The aligned, nano-sized pores allow for both conformal sputtering on the surface and efficient fuel delivery to the anode, making it particularly suited for thin film deposition. Electroless nickel plating is used to achieve a fully conductive, nanoporous substrate which catalyzes the hydrogen oxidation reaction and improves current collection efficiency in TF-SOFCs. A minimum plating temperature of 60°C is needed to grow nanoscale Ni deposits into a conductive film without compromising the porosity of the surface. Effective stirring methods are used to deliver the plating solution throughout the high-aspect ratio pores of the AAO substrate and create thru-plane conductivity. To achieve conformal plating, the number of pre-treatment steps was optimized to prevent overplating and create a homogenous Ni deposit. Finally, with the creation of a conformally coated, conductive porous substrate, we can improve the efficiency and power output of TF-SOFC performance with commercially relevant active areas (larger than 1 cm2).
Numerical Study of Liquid Water Formation and Transport in Porous Media
Authors: Najafianashrafi Zabihollah , Chuang Po-Ya Abel
Published: August 2024

Fundamental understanding of liquid water formation and transport in fuel cells is of great importance for achieving high durability, reliability, and maximizing cell performance. For low temperature fuel cells, water may exist as vapor or liquid phase and is involved in various electrochemical reactions and transport mechanisms. The condensation process occurs when local water vapor pressure exceeds the saturation pressure. In this work, we first investigate the permeation of liquid water in the gas diffusion layer (GDL). To this aim, a two-dimensional isothermal model considering reconstructed GDL microstructure in conjunction with VOF model is implemented. The effects of mixed wettability of materials, operating temperature, and Polytetrafluoroethylene (PTFE) loadings on liquid water transport in the porous media are investigated numerically. The liquid water breakthrough and the capillary fingering regime are captured and compared. The results show that liquid water saturation in the GDL increases with decreasing PTFE loadings. Moreover, the results demonstrated that the local microstructure in the GDL has a strong effect and can dominate the overall water distribution. To further study water condensation, the isothermal model is expanded to non-isothermal for including physics of phase change heat transfer and species transport. In addition, anisotropic thermal conductivity is incorporated to study its effect on temperature distribution and liquid water distribution. The results show that initially the liquid water is formed as micro droplets and then these micro droplets are combined to form large droplets. Moreover, the impacts of water generation rate, temperature gradient, operating pressure, and contact angle on condensation have been investigated. The findings of this work are expected to provide insights into designing more reliable GDL in fuel cells.

Figure 1
Effect of Membrane Thickness and Operating Conditions on PEMFC Limiting Current Analysis
Authors: Sarker Mrittunjoy , Mora Joy Marie , Mojica Felipe , Chuang Po-Ya
Published: August 2024

Hydrogen powered proton exchange membrane fuel cells (PEMFC) have great potentials to replace the traditional internal combustion engines due to its inherent advantages of zero greenhouse gas emissions, better fuel efficiency, quick startup, silent operation, less required maintenance, etc. In a PEMFC, oxygen transport is a critical performance limiting factor because of the sluggish oxygen reduction reaction kinetics. Limiting current method is a well-established in-situ diagnostic tool to measure the oxygen transport resistance in a PEMFC. To obtain accurate oxygen transport resistances, a few key assumptions need to be made including: (1) the effect of temperature gradient in the diffusion media is negligible, (2) no convective flow in the porous media, (3) oxygen is diluted in a gas mixture of nitrogen and water vapor, (4) the total oxygen transport resistance combines gas diffusion layer, microporous layer, and catalyst layer, (5) the effect of membrane thickness has negligible effect, and (6) the anode side does not affect the measurement results due to fast hydrogen oxidation reaction. In this study, we perform a systematic study of the effect of membrane thickness and operating conditions on obtaining robust and reliable limiting current measurement. Standard Nafion membranes of three different thicknesses (25, 50, and 85 µm) are tested with Toray 060 and Freudenberg H23C8 diffusion media. In addition, we further study the interaction between membrane thickness and asymmetric pressure and relative humidity and their effects on limiting current results. Our results show that membrane thickness and relative humidity are critical factors in obtaining reliable oxygen transport resistance due to their effect on overall water balance in the cell. Lastly, the experimental data are compared with the simulation results to establish fundamental understanding. Detailed experimental and analytical results will be presented at the conference.
Effects of Fuel Cell Operating Conditions on Electrochemical Pressure Impedance Spectroscopy (EPIS) Diagnostics
Authors: Schneider-Coppolino Merissa , Zhang Qingxin , Niroumand Amir , Homayouni Hooman , Gates Byron D.
Published: August 2024

Fuel cells are versatile, low-emission alternative energy sources, but their optimization and failure analyses are complex due to their black-box nature. Conventional in-situ diagnostic techniques such as electrochemical impedance spectroscopy (EIS), are widely used to deconvolute transient processes within operating fuel cells. EIS is invaluable to understanding some of these processes, but other processes within the cell, such as mass transport and individual water fluxes, get overshadowed and are hard to detect.

In an effort to provide information that is currently unattainable with conventional fuel cell diagnostic techniques, this project focuses on the further development of electrochemical pressure impedance spectroscopy (EPIS). EPIS is based on a pressure alternating frequency response analysis (pFRA). This diagnostic method is similar to EIS, except that it implements mechanical perturbations in the form of gas pressure oscillations, rather than voltage or current oscillations, to achieve an electrochemical response. Since EIS is based on electrical perturbations, the results are primarily based on the transport of electrons and provides electron-based performance metrics, including charge transfer, adsorption, diffusion, and double-layer behaviors. Conversely, the mechanical perturbations in EPIS enable the investigation of non-electron-based mechanisms, such as flow and gas transport resistances.

This project builds from the work of Zang et al., who developed an experimental setup for EPIS and showed that pressure perturbations affect local reaction rates and transport phenomena within the cell, providing a sinusoidal voltage response.1 This study focused on systematically analyzing the effects of varying fuel cell operating conditions to better understand the benefits and limitations of EPIS as a diagnostic technique. The EPIS response and subsequent flow resistances and gas transport resistances were monitored to understand the effects of variations in the cathode inlet relative humidity, the cell inlet temperatures, and the oxygen stoichiometry (stoic). The goal is to improve the metrics by which fuel cells are measured by providing new methods to assist in the real-time probing of processes and failure mechanisms within operating cells.

1 Zhang, Q., Homayouni, H., Gates, B. D., Eikerling, M. H., & Niroumand, A. M. (2022). Electrochemical Pressure Impedance Spectroscopy for Polymer Electrolyte Fuel Cells via Back-Pressure Control. Journal of The Electrochemical Society, 169(4), 044510.
Utilizing Advanced Bipolar Membranes in Next Generation Electrodialysis Systems
Authors: Vulpin Olivia T. , Boettcher Shannon W.
Published: August 2024

Bipolar membranes (BPMs) have experienced a renaissance, owing to their proposed use in membrane electrode assembly (MEA) systems. MEA systems encompass technologies such as fuel cells and electrolyzers, where the BPM allows for fine pH control at the electrodes and helps to prevent ion-crossover that may lead to lower system efficiencies and fouling of the system. The exploration of MEA systems has significantly expanded our fundamental understanding of BPM functionality and limits, setting the stage for future advancements in BPM applications.

Beyond MEA systems, BPMs have been seen in a wide array of technologies such as CO2 sequestration systems, electrodialysis, brine remediation, organic acid/base production, and more. These applications all present unique stressor to the BPM that prevent the direct translation of advanced, MEA optimized BPM to these non-MEA systems. Initial investigations into transferring advanced BPM to non-MEA applications have found issues with membrane delamination at scale and a need for system specific catalyst optimization. However, the fundamentals learned from MEA systems translate well and can be used to inform advancements of BPM in these non-MEA systems. Here we present initial findings and proposed solutions for durability issues when optimizing advanced BPM for application in BPM electrodialysis.
ZnIn2S4-Catalyzed Anodic Direct Electrochemical Oxidative Cleavage of C-O Bonds in Alpha-O-4 Linkage in an Aqueous Environment
Authors: Zhu Qi , Lam Jason Chun-Ho
Published: August 2024

Electrochemical selective oxidative cleavage of biomass-derived lignin feedstocks, such as C-O bond, into high-value oxygenated fine chemicals and pharmaceutical products offers an emerging route for biomass valorization. Here, we developed an efficient anodic valorization of α-O-4 lignin model compound benzyl phenyl ether (BPE) to the desirable monoaromatics products via the C-O bond direct cleavage at ZnIn2S4 anode under +1.6-2VAg/AgCl supply. A series of carbon-supported ZnIn2S4 electrodes with different hexagonal and rhombohedral phase distributions were carefully controlled and exhibited over 99% BPE conversion with specific C-O bond selectivity. We then studied substrate competition to compare the electrocatalytic performance of different ZnIn2S4 crystal phases. The experimental results were supported by density functional theory calculations. The substrate scope study revealed the suitability of the R-ZIS induced electrocatalytic system for a variety of substituted lignin α-O-4/β-O-4 model dimers. Overall, this work provides an efficient electrode and approach for enabling atom-efficient electro-refinery of diverse lignin-derived oxygenated chemicals.
Ion Transfer Kinetics at the Tungsten Oxide Interface
Authors: Barnard Nadia F. , D'Antona Nicholas R , Kempler Paul A. , Boettcher Shannon W.
Published: August 2024

Investigating the kinetics of interfacial ion transfer is imperative for the enhancement of electrochemical energy storage technologies, such as cation batteries. Consequently, we study the enigmatic proton transfer mechanisms that occur at solid-liquid interfaces to evaluate parameters that may modulate the optimization of battery efficiency. Utilizing electrochemical techniques, our objective is to deconvolute the mechanistic and rate-limiting factors associated with proton insertion from an acidic aqueous electrolyte into a thin film of tungsten trioxide (WO3). While WO3 has been investigated as a battery anode, the kinetics of cation insertion remain inadequately explored despite their effects on system efficiency. Through the Potentiostatic Intermittent Titration Technique (PITT), a developed application of chronoamperometry, along with Butler-Volmer equation fitting, our research endeavors to define the exchange current density and activation energy pertinent to cation insertion. The broader implications of exploring interfacial ion transfer phenomena manifest in advancing the fundamental understanding of energy storage processes.
Effect of Temperature on Faradaic Efficiency and SEI Formation in Lithium Mediated Nitrogen Reduction
Authors: O'Rafferty Alden , Benedek Peter , Niemann Valerie Anne , Lee Sang-Won , Nielander Adam C. , Jaramillo Thomas F.
Published: August 2024

Lithium-mediated nitrogen reduction (Li-N2R) can be distributed and powered by renewable energy, making it a sustainable ammonia production alternative to the Haber Bosch process. While Haber Bosch is responsible for 1.3% of CO2 emissions yearly and requires centralized facilities with high temperatures and pressures, Li-N2R works at near-ambient conditions and therefore allows for decentralized production.1 First, lithium (Li+) ions electroplate as lithium metal on the working electrode. Second, the deposited lithium reacts with N2 gas to form lithium nitride (Li3N). Lastly, Li3N reacts with a proton source to form ammonia (NH3) (Figure Right).

During Li-N2R, the NH3 selectivity is controlled through the mass transport of N2, Li+, and protons to the working electrode electrode (WE). The transport of these species is limited by the solid electrolyte interface (SEI), a passivation layer formed on top of the WE.2 The thickness and ratio of organic and inorganic species in the SEI change at different cycling temperatures, thus affecting the rates of transport between charge and uncharged species traveling to and from the electrode. Here, we study the impacts of temperature on FE and SEI composition in 1M LiBF4 in both diglyme (DG) and tetrahydrofuran (THF) with a 1v% ethanol (EtOH) proton source (Figure Left). Using ion chromatography (IC), nuclear magnetic resonance (NMR), and inductively coupled plasma mass spectrometry (ICP-MS) on the SEI dissolved in D2O, we quantify the SEI species formed at different cycling temperatures. Our correlation of temperature and SEI compositions to FE provide opportunities to engineer the SEI for improved Li-N2R FE and stability.

1J. W. Erisman et al., Nat. Geosci 2008. 1, 636–639

2K. Steinberg et al., Nat. Energy 2022, 8 (2), 138

Figure 1
Carbon-Monoxide Assisted Synthesis of Cobalt-Nickel Phosphides for Hydrogen Evolution Reaction
Authors: York Sarah Meixin , Chen Jingyi
Published: August 2024

Alkaline water electrolysis is a method for production of hydrogen as an alternative source for renewable energy. This method can be completely free of greenhouse gas emissions if it is paired with another alternative energy source, such as solar energy or wind power, to provide the necessary electricity to drive the reaction. Water electrolysis requires catalysts to make that necessary amount of electricity low enough for competitive hydrogen production in the current market. Vast numbers of studies have been performed in an attempt to fill this need for cost-effective catalysts for water electrolysis. This work focuses on the development of synthesis methods for cobalt-nickel phosphide catalysts for the hydrogen evolution reaction (HER) for water electrolysis in alkaline media. The methods for preparation of the catalysts are explored for cobalt, nickel, and cobalt-nickel alloy phosphides in the presence of carbon monoxide as a shape-controlling capping agent. Depending on the condition of carbon monoxide addition, the reaction results in high vs. low-aspect ratio nanorods or nanospheres for mono- or bimetallic cobalt-nickel phosphide nanostructures. These phosphides are then subjected to evaluation for HER via cyclic voltammetry and linear sweep voltammetry to study the effects of morphology on their HER activity. Materials characterization such as XRD, TEM, and ICP-MS are performed before the HER electrochemical evaluation for better understanding of the structure-activity relationship. The catalytic activities of these phosphides are also compared to the noble metal benchmark HER catalyst Pt/C in the same environment at their equal mass loadings. The best-performing phosphide is further tested for HER at increased mass loadings to study the effects of catalyst loadings on the mass transport and thus the activity. Further TEM characterization is performed on the most active catalyst after HER to evaluate morphological stability. It is found that in order to achieve an overpotential at the current density of 100 mA/cm2 comparable to Pt/C for 50 μg/cm2, the necessary loading for the phosphide is 250 µg/cm2.