Widespread Commercial Adoption Research Articles

Impact of biopolymer-based Trichoderma harzianum seed coating on disease incidence and yield in oilseed crops

The use of microbe-based biological control for crop pests is recognized as an environmentally safe substitute for conventional chemical pesticides. However, the practical application of microbial inoculants in large-scale agriculture is underexplored, impeding their widespread commercial adoption. This study addresses the scarcity of research on effective delivery methods for microbial inoculants, particularly through seed coating, which has the potential to be a cost- and time-efficient strategy in crop management. In this research, the Trichoderma harzianum strain Th4d, a biological control agent (BCA), was incorporated into specially formulated biopolymeric compositions based on chitosan and cellulose. The efficacy of this seed coating approach was tested against various soil- and seed-borne pathogens in oilseed crops, including soybean, groundnut, and safflower. Results indicate that safflower treated with the biopolymer chitosan-based T. harzianum Th4d 1 % liquid formulation blend exhibited a higher seed yield of 793 kg/ha, seed germination of 84.7 %, and a significant reduction in wilt and root rot by 64.7 %. In groundnut crops, the seed coating led to a seed germination rate of 88.6 %, a 72 % reduction in root rot incidence, and a seed yield of 3040 kg/ha. Similarly, soybean crops treated with the biopolymer chitosan and T. harzianum Th4d displayed 83.4 % seed germination, a 70.9 % reduction in root rot, and a seed yield of 1239 kg/ha. Further on-farm evaluations demonstrated promising results, with the biopolymer chitosan-based T. harzianum Th4d 1 % liquid formulation blend seed treatment showing a high incremental cost-benefit ratio in safflower (1:4.5), soybean (1:2.5), and groundnut crops (1:3.3). This study underscores the potential of microbe-based seed coating as a sustainable and economically viable strategy for pest management in oilseed crops."

Analyzing multicomponent permeation and coupling effects in pervaporation of Acetone-Butanol-Ethanol solutions using Maxwell-Stefan based modeling

The state-of-the-art research in pervaporation lacks a comprehensive understanding of the selective membrane permeation in real and multicomponent mixtures, a factor critical for its widespread commercial adoption. This work elucidates the contribution of various interaction effects, known as coupling phenomena, on the pervaporation of multicomponent Acetone-Butanol-Ethanol (ABE) solutions through a commercial PDMS membrane. Maxwell-Stefan (MS) diffusion formulations, combined with the UNIQUAC thermodynamic model, mostly restricted in literature to binary solutions permeating through a polymer membrane, are extended to multicomponent feed solutions. The thermodynamic correction factor [Γ] and correlation [B]−1 matrices are analyzed to resolve coupling into its thermodynamic and kinetic (diffusive) constituents.A generalized and explicit analytical derivation for calculation of [Γ] by UNIQUAC model is proposed, allowing estimation for any number of permeants. Subsequently, a significant inhibitory coupling of the component fluxes to the driving forces of its accompanying penetrants is revealed. In addition to the non-ideality arising from diagonal elements Γii, the substantial negative off-diagonal elements Γij in the thermodynamic correction matrices anticipate a decline in effective driving forces, butanol fluxes and permeation selectivity as we transition from binary butanol-water to multicomponent ABE mixtures.Following this, a detailed hit-and-trial based strategy is implemented to evaluate the relevance of membrane plasticization, cluster formation and interspecies frictional interactions towards the MS self and cross diffusivities within the [B]−1 matrix. Existing semi-empirical expressions for self-diffusivities in binary alcohol-water systems incorporating plasticization and clustering constants are reformulated and compared for their ability to accurately describe fluxes in binary and ternary ABE solutions. Furthermore, the optimal model fit was found to be insensitive to variation in MS cross-diffusivities. This suggests that the contribution of correlation effects may be neglected altogether, provided the expressions for self-diffusivities are adequately tailored for membrane plasticization and clustering. Notably, while only butanol clustering suffices for binary mixtures, additional aggregates involving butanol-water, water-water, and butanol-acetone/ethanol are suggested to play a crucial role in steering diffusivities in ternary solutions.Consequently, the proposed models exhibit exceptional agreement with experimental data, achieving R2 values of approximately 0.96, 0.95, and 0.98 for butanol flux in binary butanol-water and ternary solutions containing acetone and ethanol, respectively. Besides providing a more cohesive fit to the overall experimental permeation data, the usefulness of this approach lies in significantly simplifying model computations, thus easing the potential modeling of even more complex mixtures.

(Invited) Unlocking Long-Duration Energy Storage with Unitized Reversible Fuel Cells

As the proportion of energy supplied by renewable sources continually rises, the intermittent nature of these sources necessitates efficient energy storage to meet the demand of the grid. Hydrogen is a promising energy carrier for grid-scale storage due to its capacity for months-long storage without energy loss or self-discharge.(1) Reversible fuel cells generate power for the grid in fuel cell (FC) mode during periods when renewable power production is lower than demand, utilizing stored H2 generated by water electrolysis (WE) during periods when renewable power production exceeds demand from the grid. Unitized reversible fuel cells (URFCs) efficiently integrate WE and FC operation in a single electrochemical device, potentially reducing costs and providing higher energy density. In constant gas URFC operational configuration, both the oxygen evolution reaction (OER) for WE and the oxygen reduction reaction (ORR) for FC occur within the same electrode.(2) The contrasting electrode requirements for FC and WE have constrained the round-trip efficiency (RTE) of URFCs, highlighting the crucial need to improve RTE for greater competitiveness and widespread commercial adoption. This presentation will discuss the results from development of novel bifunctional catalysts, electrode architectures, and porous transport layers (PTLs) aimed at enhancing efficiency and durability of URFCs. This talk will present the development of bifunctional catalysts and their supports to boost OER and ORR performance. Additionally, we will present insights into innovative electrode architecture designed for optimal utilization of the catalysts, thereby maximizing efficiency. The development of specialized PTLs featuring amphiphilic wettability and intricately engineered microporous layers will be presented emphasizing their role in increasing the performance and durability of URFCs. Acknowledgement This research is supported by the Laboratory Directed Research and Development (LDRD) program at Los Alamos National Laboratory (LANL) under project 20240061DR, and by the U.S. Department of Energy Hydrogen and Fuel Cell Technologies Office (DOE-HFTO) with support from technology manager Donna Ho. References Hydrogen Council, Hydrogen scaling up: a sustainable pathway for the global energy transition, in (2017).S. Komini Babu et al., Advanced Energy Materials, 13, 2203952 (2023).

Porphyrin-Based Hole-Transporting Materials for Perovskite Solar Cells: Boosting Performance with Smart Synthesis.

Perovskite solar cells (PSCs) are becoming a promising and revolutionary advancement within the photovoltaic field globally. Continuous improvement in efficiency, straightforward processing methods, and use of lightweight and cost-effective materials represent superior features, among other notable aspects. Still, long-term stability and durability are issues to address to facilitate widespread commercial adoption and practical application prospects. Research has focused on overcoming these challenges, and charge transport materials play a critical role in determining charge dynamics, photovoltaic performance, and device stability. Conventional hole-transporting materials (HTMs), spiro-OMeTAD and PTAA, contribute to remarkable power conversion efficiencies owing to high thin-film quality and matched energy alignment. However, they often show a high material cost, low carrier mobility, and poor stability, which greatly limit their practical applications. Now, this review outlines recent advances in synthetic approaches to porphyrin-based HTMs to tune the charge dynamics by optimizing their molecular structures and properties. The main structural features comprise porphyrins of A4-type, trans A2B2-type, and photosynthetic pigment analogues. Strategies include well-established routes to provide the required macrocycles, such as condensation of pyrrole or dipyrromethanes with suitable aldehydes, metalation of the porphyrin inner core, and postfunctionalization of peripheral positions. These functionalizations involve conventional procedures (e.g., halogenation, esterification, transesterification, nucleophilic oxidation, reduction, and nucleophilic substitution) as well as metal-catalyzed ones such as Suzuki-Miyaura, Sonogashira, Buchwald-Hartwig, and Ullmann cross-coupling reactions. As HTMs can also protect the perovskite layer from the external environment, porphyrin structures play a pivotal role in chemical, mechanical, and environmental stability, with their high hydrophobicity ability as the most significant parameter. The impact of porphyrins on the hole hopping of other HTMs while acting as an additive or an interlayer, passivating defects, and improving charge transport is also highlighted to provide real insights into ways to develop efficient and stable porphyrin-based materials for PSCs. This perspective aims to guide the scientific community in the design of new porphyrin molecules to place PSCs as an outperformer in photovoltaic technologies.

High mechanical strength Si anode synthesis with interlayer bonded expanded graphite structure for lithium-ion batteries

Despite advancements in silicon-based anodes for high-capacity lithium-ion batteries, their widespread commercial adoption is still hindered by significant volume expansion during cycling, especially at high active mass loadings crucial for practical use. The root of these challenges lies in the mechanical instability of the material, which subsequently leads to the structural failure of the electrode. Here, we present a novel synthesis of a composite combining expanded graphite and silicon nanoparticles. This composite features a unique interlayer-bonded graphite structure, achieved through the application of a modified spark plasma sintering method. Notably, this innovative structure not only facilitates efficient ion and electron transport but also provides exceptional mechanical strength (Vickers hardness: up to 658 MPa, Young’s modulus: 11.6 GPa). This strength effectively accommodates silicon expansion, resulting in an impressive areal capacity of 2.9 mA h cm−2 (736 mA h g−1) and a steady cycle life (93% after 100 cycles). Such outstanding performance is paired with features appropriate for large-scale industrial production of silicon batteries, such as active mass loading of at least 3.9 mg cm−2, a high-tap density electrode material of 1.68 g cm−3 (secondary clusters: 1.12 g cm−3), and a production yield of up to 1 kg per day.

Recent Advances in Superhydrophobic Materials Development for Maritime Applications.

Underwater superhydrophobic surfaces stand as a promising frontier in materials science, holding immense potential for applications in underwater infrastructure, vehicles, pipelines, robots, and sensors. Despite this potential, widespread commercial adoption of these surfaces faces limitations, primarily rooted in challenges related to material durability and the stability of the air plastron during prolonged submersion. Factors such as pressure, flow, and temperature further complicate the operational viability of underwater superhydrophobic technology. This comprehensive review navigates the evolving landscape of underwater superhydrophobic technology, providing a deep dive into the introduction, advancements, and innovations in design, fabrication, and testing techniques. Recent breakthroughs in nanotechnology, magnetic-responsive coatings, additive manufacturing, and machine learning are highlighted, showcasing the diverse avenues of progress. Notable research endeavors concentrate on enhancing the longevity of plastrons, the fundamental element governing superhydrophobic behavior. The review explores the multifaceted applications of superhydrophobic coatings in the underwater environment, encompassing areas such as drag reduction, anti-biofouling, and corrosion resistance. A critical examination of commercial offerings in the superhydrophobic coating landscape offers a current perspective on available solutions. In conclusion, the review provides valuable insights and forward-looking recommendations to propel the field of underwater superhydrophobicity toward new dimensions of innovation and practical utility.

First principle investigation of nitric oxide reduction reaction for efficient ammonia synthesis over a Fe–Mo dual-atom electrocatalyst

Electrocatalytic conversion of NO-to-NH3 holds immense potential for removing contaminants and producing zero-carbon fuel. To facilitate widespread commercial adoption of this technology, electrocatalysts with exceptional stability, high activity, and selective performance are urgently desired. We developed a novel dual-atom electrocatalyst, Fe–Mo@NG, in which Fe–Mo dimer is anchored to N-doped graphite. Through the first principle calculations, it is discovered that Fe–Mo@NG provided exceptional performance in NO-to-NH3 conversion. The parallel adsorption type was found can maximize the activation of NO. And the most favorable adsorption structure exhibits a limiting potential of −0.26 eV, surpassing that of most conventional electrocatalysts. The remarkable NORR activity of Fe–Mo@NG is traced back the synergistic effect between the dual-atom active site and the electronic interactions between the active site and NO. At high coverages, the interaction between intermediates and free NO molecules may lead to the formation of N2 or N2O. Overall, our research introduces a promising dual-atom electrocatalyst with broad applicability in NO reduction reactions, providing novel insights into the dual-atom catalysts design.

Hypercrosslinked porous and coordination polymer materials for electrolyte membranes in lithium‐metal batteries

AbstractRechargeable lithium‐metal batteries (LMBs) hold great promise for providing high‐energy density. However, their widespread commercial adoption has been inhibited by critical challenges, for example, the capacity fading from irreversible processes at electrolyte/electrode interfaces and safety concerns originating from the inhomogeneous lithium deposition. Polymer electrolytes benefiting from enhanced electrolyte/electrode contact and low interfacial impedance provide a variable solution to address these challenges and enable a high‐energy and flexible battery system. Although promising, inefficient bulky ionic conductivity and poor mechanical stability confront the stable operation of polymer electrolytes in tangible batteries, which highly requires the development of innovative polymer electrolyte chemistries. Among various polymer materials, microporous polymers stand out due to their abundant porosity and customizable micropore structure, positioning them as promising candidates for next‐generation electrolyte membranes. This review, therefore, summarizes recent advances in electrolyte membranes based on two new chemistries, hypercrosslinked polymers (HCPs) and porous coordination polymers (PCPs). Other microporous polymers, such as covalent organic polymers, porous organic cages, and polymers of intrinsic microporosity, are also discussed with an emphasis on their applications in LMBs. Most importantly, by reviewing the design strategies, synthesis protocols, and performance in LMBs, we gain insights into the design principles of high‐performance electrolyte membranes based on HCPs and PCPs and highlight potential future research directions.

Investigating Nano-Sized Dispersity and High Crystallinity of Perfluoro-Sulfonic Acidionomer in Polymer Electrolyte Fuel Cell Electrodes Via Electrospray Deposition

Polymer electrolyte fuel cells (PEFCs) hold great promise for mitigating the worldwide climate crisis by tapping into the potential of producing clean energy from renewable sources. However, widespread commercial adoption of PEFCs requires addressing the challenges associated with PEFC performance and durability, particularly concerning electrode materials and design. The PEFC electrode is a crucial component of PEFC performance, with the ionomer playing a vital role as both an electrode binder and proton conductor. Nano-sized dispersity and high crystallinity of the ionomer are vital properties that are crucial for achieving enhanced performance and durability. However, existing methods for fabricating PEFC electrodes have been unable to attain these desirable ionomer characteristics. In this work, we propose a novel approach to fabricating PEFC electrode architectures with ionomers possessing nano-sized dispersity and high crystallinity using the electrospray deposition (ESD) technique. In the ESD process, a precursor solution is atomized into charged droplets, while evaporating the solvent, and results in the formation of advanced electrode with vertical architecture that exhibits high crystallinity of ionomer, in contrast to much lower crystallinity of those fabricated by conventional decal methods. The ionomer characteristics significantly impact the overall fuel cell performance and durability. Therefore, controlling the residual solvent content during the ESD process is a crucial aspect that is vital for achieving the desired ionomer characteristics. The residual solvent content is tuned by investigating the initial mixed solvent ratio, substrate temperature, and distance between the nozzle to substrate. By fine-tuning the residual solvent content and optimizing the deposition parameters, the ESD technique can overcome the limitations of traditional fabrication methods, resulting in PEFC electrodes that offer enhanced performance, increased durability, and improved energy efficiency. The electrospray deposition (ESD) technique provides precise control over the amount of residual solvent required for deposition, making it a scalable technique. This work shows that the residual solvent content of PEFC electrodes significantly impacts the ionomer crystallinity and the electrode architecture using a well-controlled and optimized electrospray technique, without the use of any additives or special ionomer. In summary, this work demonstrates a novel approach to fabricating PEFC electrode architectures with ionomers possessing nano-sized dispersity and high crystallinity using the electrospray deposition technique. This approach provides precise control over the residual solvent content, allowing for enhanced performance and increased durability of PEFC electrodes due to the high-crystallinity of the ionomer. These findings have important implications for the development of sustainable energy technologies and contribute to the ongoing efforts towards mitigating the worldwide climate crisis.

Flexible operation of Post-combustion CO2 capture process enabled by NARX-MPC using neural network

Post-combustion CO2 capture (PCC) process is expected to serve as the role of a bridge solution during the transition from fossil-based to renewable energy, but extensive energy consumption is a significant hurdle to its widespread commercial adoption. Operating a PCC process economically often requires large operating condition changes in response to power plant load changes and time-varying energy prices. The ‘flexible’ operation requires a controller that aids in such a dynamic operating environment of the PCC process. To balance model complexity with prediction accuracy, we adopt NARX-MPC which employs a neural network-based NARX model as a prediction model for MPC. Under various dynamic operation scenarios, the proposed NARX-MPC is evaluated and compared with a linear MPC (LMPC) controller. Our observations indeed reveal that the NARX-MPC delivers significantly superior closed-loop control performance over the LMPC, especially in scenarios involving large changes in the power plant load or inlet flue gas flow rate and simultaneous changes in the flue gas flow rate and the CO2 capture rate.

UV-Controlled Nitrene Crosslinking in Poly(phenylene oxide) Anion Exchange Membranes

Anion exchange membranes (AEMs) promise significant capital cost saving associated with enabling use of Pt-group-free electrodes and components in alkaline fuel cells and electrolyzer devices. However, AEMs often lack the chemical and mechanical stability required for widespread commercial adoption. Crosslinking has proven to be an effective method to permit increased ion exchange capacity (IEC) while preventing exponential water uptake and retaining both conductivity and mechanical strength. In this work, we leverage molecular dynamics simulations to explore crosslinking methodologies in silico. We present a reproducible and quantitative UV-based nitrene chemistry that utilizes a mobile crosslinker that is straightforward to synthesize and implement. This crosslinking strategy significantly mitigates excess water uptake and improves alkaline stability without sacrificing IEC during the cure process. Additionally, we characterize electrochemically fielded AEMs by small angle X-ray scattering, mechanical strength testing, and other post-mortem analyses. The operational lifetime of crosslinked AEMs prepared in this work is 5 times greater than corresponding untreated AEMs.This work is performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 within the LDRD program 21-ERD-013. LLNL-ABS-848147.

Enhanced, continuous, liquid-liquid extraction and in-situ separation of volatile fatty acids from fermentation broth

In 2018 alone, the US landfilled 35.3 million tons of food waste, about 24% of the total landfilled mass. In addition to the negative impacts landfills have demonstrated on the environment and human health, some states have begun to outlaw or dissuade the disposal of food waste and sewage sludge into landfills altogether. An urgent need has thus been created for the development of digestion processes like anaerobic digestion (AD) and arrested methanogenesis (AM) to convert food waste into valuable chemical products. Unfortunately, the buildup of volatile fatty acids (VFAs) during these processes eventually halts the reaction, and energy efficient methodologies for VFA removal are critical for the operation of fermenters. Additionally, VFAs themselves can serve as valuable chemical precursors, and recently AD processes have been modified to increase VFA production during fermentation. However, even with significant research over the past three decades, the separation of VFAs from the fermenter broth has remained expensive. Moreover, the separation of these VFAs from the fermenter broth may cost up to 50% of the entire process budget, hindering the widespread commercial adoption of AD and AM. In this work, we present a novel liquid–liquid extraction process termed CLEANS (Continuous Liquid-liquid Extraction And iN-situ Separation) as a highly efficient method for continuously separating VFAs from a real fermentation broth solely under gravity. Our optimized process (using an aqueous broth feed pH of 2.5, tri-n-octylamine as an extractant, and a 10:1 ratio of aqueous broth to organic extractant), achieved a VFA distribution constant KD = 44.5 ± 7.9, a single-pass recovery = 81.3 ± 2.5%, and an extraction factor = 8.1 ± 0.3. These KD values are over an order of magnitude higher than what has been previously reported for comparable processes. A high aqueous-to-organic flowrate ratio, enabled for the first time by CLEANS, was found to be particularly crucial for achieving optimal extraction. Our separation process demonstrates excellent reproducibility and potential for scalability. The economic and environmental implications of this work are briefly discussed.

Influence of Sr-Site Deficiency, Ca/Ba/La Doping on the Exsolution of Ni from SrTiO3

Cermet catalysts formed via exsolution of metal nanoparticles from perovskites promise to perform better in electro- and thermochemical applications than those synthesized by conventional wet-chemical approaches. However, a shortage of robust material design principles still stands in the way of widespread commercial adoption of exsolution. Working with Ni-doped SrTiO3 solid solutions, we investigated how the introduction of Sr deficiency as well as Ca, Ba, and La doping on the Sr site changed the size and surface density of exsolved Ni nanoparticles. We carried out exsolution on 11 different compositions under fixed conditions. We elucidated the effect of A-site defect size/valence on nanoparticle density and size as well as the effect of composition on nanoparticle immersion and ceramic microstructure. Based on our experimental results, we developed a model that quantitatively predicted a composition’s exsolution properties using density functional theory calculations. The model and calculations provide insights into the exsolution mechanism and can be used to find new compositions with high exsolution nanoparticle density.

A Survey of Trusted Computing Solutions Using FPGAs

Ensuring the security and privacy of computation and data management in the cloud and edge is an ever-important requirement. There are several working solutions today for trusted computing with general purpose processors, for instance, Intel SGX and ARM TrustZone. However, with the widespread commercial adoption of specialized hardware accelerators in the cloud and at the edge, most importantly FPGAs, two questions emerge: 1) How secure are they against threats? and 2) How could FPGAs be utilized for more efficient trusted computing? In this survey, we investigate these two questions precisely. Even though there have been numerous surveys in the past on the security of FPGAs, we believe it is timely to study the space of related work again, given the large number of data-centric applications aimed at targeting trusted execution environments that have recently appeared. Therefore, in addition to presenting an overview of state of the art, we also highlight some opportunities for FPGAs in the context of providing efficient trusted computation.

High Performance AEM Water Electrolysis with PGM-Free Electrocatalysts

Water electrolysis technologies for hydrogen production are getting much attention due to drastic cost reduction in renewable energy sources, like solar, wind, tidal etc. Traditional alkaline water electrolysis has limitations of low current density operation, slow system response and low hydrogen discharge pressure. Proton exchange membrane (PEM) water electrolysis offers compact design, high current density operation, fast system response and pressurized discharge hydrogen. However, PEM electrolyzers require the use of Platinum Group Metal (PGM) based electrocatalysts, expensive perfluorinated membranes and specialized component materials due to its acidic environment. These are all hurdles to its widespread commercial adoption. A relatively new technology, the anion exchange membrane (AEM) electrolyzer can potentially combine benefits from PEM and traditional alkaline electrolyzers, offering high current density operation, pressurized discharge gas and low cost – by utilizing PGM-free electrocatalysts and inexpensive component materials due to the less corrosive alkaline operating environment.However, modern AEM electrolyzers have continued to use high loadings of PGM catalysts in both the cathode and anode. Given the magnitude and recent volatility in the market price of many PGM-group metal catalysts (e.g. Ru, Ir, etc.), it is now even more important for AEM electrolyzers to be realized with significantly lower PGM content – and eventually approaching the complete elimination of PGMs.In this study, we evaluate the performance of several low-PGM and PGM-free electrocatalysts for the oxygen evolution (OER) and hydrogen evolution (HER) reactions for high performance and durability. Here, PGM-free Lanthanum Strontium Cobalt (LSC), Nickel Ferrite (NiFeOx) and low PGM Lead Ruthenate (PbRuOx) were used at the anode for the OER. For the HER cathode, PGM-free Nickel Molybdenum (NiMo) and low-PGM PtNi electrocatalysts were evaluated for their in-situ activity and durability. It will be shown that LSC and NiFeOx show comparable performance to IrOx, with a typical steady-state operating voltage at 60oC and 1.0 A/cm2 (with 0.3 M KOH fed to the anode only) below 1.80 V. Cells with PGM-free anode catalysts were operated stably for over 100 hours. At the cathode, NiMo showed relatively higher overpotentials compared to Pt black, PtNi or Pt/C for the HER. Because of this, various strategies were adopted to reduce the PGM loading while achieving high performance and durable AEM electrolyzer operation. The achieved experimental results provide important insights for the development of AEM based water electrolyzer systems and represent an active step towards its commercial viability.

Determining Substrate Oxygen Transport Resistance at Limiting Current Using Pore Network Modelling

The polymer electrolyte membrane (PEM) fuel is a promising technology to supplant traditional, greenhouse gas emitting energy conversion devices. However, widespread commercial adoption of the PEM fuel cell is hindered by the high cost of the precious metals required for its catalyst (1). The amount of catalyst required in a PEM fuel cell can be reduced if the reactant (oxygen) is delivered more efficiently to the catalyst. Therefore, previous studies have sought to characterize the mechanisms affecting oxygen transport in PEM fuel cells (2)(3)(4)(5). In past studies, the oxygen transport resistance of a PEM fuel cell was measured at limiting current, and this value was further decomposed into contributions from individual PEM fuel components using empirical modelling. By resolving each PEM fuel cell component’s contribution to oxygen transport resistance, an informed approach can be undertaken to design next generation components with enhanced oxygen transport capabilities.In this study, we employed pore network modelling to quantify the oxygen transport resistance arising from the presence of liquid water within the substrate region of the gas diffusion layer (GDL). First, we captured the operando liquid water distribution within a PEM fuel cell operating at limiting current using synchrotron X-ray radiography. Next, we used a combination of invasion percolation and an in-house water invasion inlet selection algorithm to partially saturate the representative pore network of the substrate and to reproduce the mean water saturation. Finally, we obtained substrate oxygen transport resistance values by performing transport simulations on the partially saturated pore network and compare our findings with the experimental observations. References X. X. Wang, M. T. Swihart, and G. Wu, Nature catalysis, 2, 7 (2019).D. R. Baker, D. A. Caulk, K. C. Neyerlin, and M. W. Murphy, J. Electrochem. Soc., 156, B991 (2009).T. Reshtenko, J. St-Pierre, J. Electrochem. Soc., 161, F1089 (2014)D. Muirhead, R. Banerjee, M. G. George, N. Ge, P. Shrestha, H. Liu, J. Lee, A. Bazylak, Electrochimica Acta, 274 (2018).N. Ge, P. Shrestha, M. Balakrishnan, D. Ouellette, A. K. C. Wong, H. Liu, C. H. Lee, J. K. Lee, A. Bazylak, Electrochimica acta, 328 (2019).

How to promote the widespread commercial adoption of photovoltaic microgrids under investment uncertainty? A real options analysis in China

Microgrids can integrate the production and consumption process of renewable energy and realize the sustainable development of power systems. However, it remains difficult to promote the widespread commercial adoption of photovoltaic microgrids due to high costs. This study develops a real options model for it to assess peak-valley electricity prices and electricity price subsidies under the uncertainties in the initial investment dynamic. The adjustment mechanism is also established in the real options model to analyze the tendency of incentive policies changing with uncertainty. The results demonstrate that the optimal electricity price subsidies of 31 provinces in China range from 0.30 RMB/kWh to 1.05 RMB/kWh, and the optimal rates of peak-valley price range from 3.09 to 6.32. On this basis, we conduct a sensitivity analysis of optimal electricity price subsidy and peak-valley price rate and find that the threshold goes down significantly as the cost goes down. However, rapid cost variations and fluctuations make developers hesitate to invest, which will seriously hinder the widespread commercial adoption of PV microgrids. This study extends the understanding of participants' strategies in a dynamic framework by analyzing the impacts of uncertainty on investment decisions. We suggest developers pay attention to the changes in the market and reduce investment risks by signing option contracts. A stable investment market corresponds to smaller peak-valley price rates and less electricity price subsidies. The policy-maker should provide flexible and efficient incentives depending on the application scenario. It is also suggested that in areas lacking solar resources, the government should not only speed up the establishment of peak-valley electricity prices but also provide long-term subsidies.

62‐2: Ultra‐flat, Low‐density, and High‐refractive‐index Glass Wafers for Augmented Reality: Weight Reduction as Key Enabler for Consumer Devices

Planar high‐refractive‐index glass wafers are the backbone of leading Augmented and Mixed Reality devices. They route the virtual image to the user's eye, while helping to keep the form factor small. While the glass characteristics directly affect fundamental design parameters such as field of view, the optical system of the wafer with its interfaces as a whole determines the image quality. Here we report on latest achievements both on the glass and on the wafer level that allow for significant weight reduction without sacrificing optical performance. Based on a state‐of‐the‐ art two layer device with a refractive index of 1.9, an overall weight reduction >20% is feasible. This creates a basis to drive AR devices from niche applications toward more widespread commercial adoption.

Charge Carrier Molecular Sieve (CCMS) Membranes with Anti-aging Effect for Long-Life Vanadium Redox Flow Batteries

Vanadium crossover hinders widespread commercial adoption of vanadium redox flow batteries (VRFBs). Superglassy polymers have the potential to offer high selectivity needed to control the crossover but as yet do not possess the requisite proton conductivity and stability. Here, we explore nanocomposite separators that can improve this selectivity. We report a dual-function charge carrier molecular sieve (CCMS) membrane, consisting of a high free volume microporous glassy polymer, poly[1-(trimethylsilyl)-1-propyne] (PTMSP)/sulfonated PAF (PAF-1-SO3H), that effectively hinders the migration of hydrated vanadium ions. Furthermore, ideally placed PAF-1-SO3H pores not only proved excellent for developing proton conductive channels but also suppressed physical aging within the separator. Experiments then linked this to an increased battery cycle life. As a consequence of achieving higher and more stable VRFB performance compared to benchmarked Nafion (Coulombic efficiencies of 97 vs 87% and capacity retention values of 85 vs 58% at a current density of 60 mA cm–2, respectively), our integrated design heralds a class of stable separators for hydrogen-based energy technologies.

Fundamental Limitations for Solid Polymer Electrolytes in Secondary Batteries

Homogeneous solid polymer electrolytes have been extensively explored as potential replacements for liquid electrolytes in various secondary battery chemistries; however, poor ionic conductivity at room temperature has prevented their widespread commercial adoption for all-solid-state batteries. An upper bound relationship dictates a tradeoff between permeability and selectivity in polymer membranes. Here, the extension of this relationship to solid polymer electrolyte systems for lithium and sodium batteries has illuminated a fundamental limit on the performance of these materials. An inverse correlation between cation transference number and cation conductivity indicates that homogenous solid polymer electrolytes may have intrinsic limitations that prevent their ability to meet commercial performance targets. The analysis presented here is compared with an extensive literature survey to validate the theoretical relationship developed.