bluuebunny/crossref_metadata_2025_split huggingface dataset:
Alkaline Exchange Fuel Cell Membrane Ionomers Containing Spirocyclic Repeat Units in an All Carbon Backbone for Enhanced Durability
Authors: Strasser Derek , Meek Kelly M , Neyerlin Ami , Antunes Christopher M , Pivovar Bryan S. 
Published: February 2020

Alkaline exchange membrane fuel cells (AEMFC)s continue to gain interest as a potential lower cost alternative to the commercially available proton exchange membrane fuel cells (PEMFC)s. Recently there have been significant advances in the performance of AEMFC systems achieving greater than 1 1-2, albeit with PGM catalysts. However, the incorporation of non PGM catalyst materials will significantly reduce costs. One of the more significant challenges to the commercialization of AEMFCs is demonstrating long term durability under operating conditions and over startup/shutdown cycles. Improving the durability of the ionomers employed in alkaline exchange membranes and catalyst ink formulations will enhance the long term durability of AEMFCs.
Enhancing the durability of alkaline ionomers has focused on the installation of more stable cationic head groups3. Previous research has demonstrated the incorporation of spirocyclic repeat units into multiblock copolymers of polysulfone4. The research presented demonstrates the incorporation of the spirocyclic polymer poly(diallylpiperidinium hydroxide) into an all carbon backbone of hydrophobic/hydrophilic block copolymers. The synthesis, characterization and performance is pesented.

Omasta, T. J.; Peng, X.; Miller, H. A.; Vizza, F.; Wang, L.; Varcoe, J. R.; Dekel, D. R.; Mustain, W. E., Beyond 1.0 W cm-2 performance without platinum: the beginning of a new era in anion exchange membrane fuel cells. J. Electrochem. Soc. 2018, 165 (15), J3039-J3044.

Omasta, T. J.; Zhang, Y.; Park, A. M.; Peng, X.; Pivovar, B.; Varcoe, J. R.; Mustain, W. E., Strategies for Reducing the PGM Loading in High Power AEMFC Anodes. J. Electrochem. Soc. 2018, 165 (9), F710-F717.

Marino, M. G.; Kreuer, K. D., Alkaline Stability of Quaternary Ammonium Cations for Alkaline Fuel Cell Membranes and Ionic Liquids. ChemSusChem 2015, 8 (3), 513-523.

Strasser, D. J.; Graziano, B. J.; Knauss, D. M., Base stable poly(diallylpiperidinium hydroxide) multiblock copolymers for anion exchange membranes. J. Mater. Chem. A 2017, 5 (20), 9627-9640.
(Invited) Enabling Cost Effective Hydrogen at Low Temperatures
Authors: Mukerjee Sanjeev , Kolla Praveen , Jia Qingying , Kendrick Ian , Yan Yushan 
Published: February 2020

This presentation will focus on durable, high-performance materials and interfaces for advanced water splitting, enabling a clear pathway for achieving <$2/KgH2 (on scale) with efficiency of 43 KWh/Kg using anion exchange membrane interface. Advances via fundamental understanding of both hydrogen and oxygen evolution reactions (HER/OER) leading to novel materials will be in conjunction with critical improvements in membrane and ionomers and gas evolution electrodes with corresponding characterization and testing. Progress towards these goals under a three-year multifaceted and comprehensive effort will be described wherein Northeastern University (NEU) will present catalyst development and characterization (both in situ and ex situ). University of Delaware (UD) will showcase improvements in ionomer and membrane materials. In addition, close collaboration with National Laboratory partners with Lawrence Berkeley National Lab (LBNL) participating in multiscale modeling and computation in close concert with Sandia National Laboratory (SNL) providing MD simulations of the membrane catalyst interface and National Renewable Energy Laboratory (NREL) providing advanced ionomers, durability protocols and validation will be described.
Anion exchange membrane electrolyzers (AEMELs) are ideally suited with a low-cost profile enabled by platinum group metal (PGM)-free catalysts, low fluorine content membranes, and a less corrosive environment for cell separators. This presentation will showcase state of the art stable, high-conductivity, and high-strength AEMs, stable and active PGM-free catalysts for hydrogen and oxygen evolution reaction (HER/OER), and high performance electrode architectures that together can unlock the cost advantages of AEMELs. If successful, the developed technology can meet FCTO efficiency targets, delivering carbon-neutral hydrogen at $2/kg while simultaneously enabling higher penetrations of wind and PV electricity on the grid.
The overall goal is cell level performance of 1.62 V at 1 A/cm2, which meets the FCTO efficiency target of 43 kWh/kg. Component performance targets have been established using a porous electrode model to support the overall cell performance target. This is at the modeled scale of 50,000 kg/day and operating at 1 A/cm2 resulting in hydrogen cost at $2.15, $1.82, or $1.76/kg, respectively (2, 20, 200 plants). In the low-volume manufacturing case, it is still possible to meet the cost target by operating near 2 A/cm2, sacrificing some efficiency.
Spray-Deposited Al2O3 for Rear Passivation and Optical Trapping in Silicon Solar Cells
Authors: Shin Woo Jung , Huang Wen-Hsi , Tao Meng 
Published: February 2020

Si passivated emitter rear contact (PERC) are expected to become the dominant cell technology in the near future [1]. In PERC cells, a thin layer of Al2O3 is deposited on the rear of the Si cell to reduce rear surface recombination on p-type Si by chemical and field-effect passivation [2]. Optically the Al2O3 film is supported by a thicker SiNx layer stacked on Al2O3, and the low refractive index of SiNx improves light trapping in the Si cell by rear reflection [3]. In commercial production, the Al2O3 film is prepared by atomic layer deposition (ALD). ALD is a slow process and the precursor for Al2O3, Al2(CH3)6, is expansive and pyrophoric. For these reasons the thickness of the Al2O3 film in PERC cells is limited to ~10 nm and the 80-nm SiNx layer is deposited on Al2O3 by plasma-enhanced chemical vapor deposition (PECVD). It is noted that the refractive index of Al2O3 is lower than that of SiNx, 1.6 vs. 2.0 [4,5], so a thicker Al2O3 film on the rear of the PERC cell should provide better rear passivation and optical trapping than an Al2O3/SiNx stack. This requires a low-cost process to deposit thicker Al2O3 on Si.
In this talk, we report the suitability of spray-deposited Al2O3 for rear passivation and optical trapping in Si PERC cells. Electrical, optical and structural properties of spray-deposited Al2O3 are investigated and compared to the industrial standard ALD Al2O3/PECVD SiNx stack. It was found that spray-deposited Al2O3 has a negative charge density of 3.19×1012 cm–2 for an 80-nm film, indicating that spray-deposited Al2O3 can serve as the passivation layer. Optical properties of spray-deposited Al2O3 are identical to the ALD Al2O3/PECVD SiNx stack, suggesting that spray-deposited Al2O3 can also serve as the optical trapping layer. It was also found that spray-deposited Al2O3 is crack and pore free, and its surface roughness has a root-mean-square value of 0.42 nm for an 80-nm film. Spray-deposited Al2O3 is amorphous and its composition is slightly Al rich. The resistivity and breakdown field of 80-nm spray-deposited Al2O3 are ~1014 Ω-cm and 3.28 MV/cm, respectively. These properties suggest that spray-deposited Al2O3 is a promising candidate to replace the ALD Al2O3/PECVD SiNx stack in Si PERC cells.
[1] C. Roselund, International Technology Roadmap for Photovoltaic (ITRPV), 7, 21, (2016).
[2] N. Batra, J. Gope, R. Singh, J. Panigrahi, S. Tyagi, P. Pathi, S. K. Srivastava, C. M. S. Rauthan, P. K. Singh, Phys. Chem. Chem. Phys., 16(39), 21804 (2014).
[3] B. Vermang, H. Goverde, L. Tous, A. Lorenz, P. Choulat, J. Horzel, J. John, J. Poortmans, R. Mertens, Prog. Photovolt. Res. Appl., 20(3), 269 (2012).
[4] M. D. Groner, F. H. Fabreguette, J. W. Elam, and S. M. George, Chem. Mater., 16(4), 639 (2004).
[5] J. Schmidt and M. Kerr, Sol. Energy Mater. Sol. Cells, 65(1-4), 585 (2001).
Characterizing Lithiation/Delithiation of Thick Electrodes without Binders and Conductive Additives Using Neutron Imaging
Authors: Koenig Gary , Nie Ziyang , Ghosh Dipankar , Parai Rohan 
Published: February 2020

The advantages of thick electrodes in improving energy density at the cell level has been reported in many lithium-ion battery papers. Thick electrodes increase energy density by reducing the fraction of the cell dedicated to inactive components, in particular current collectors and separators. However, thick electrodes increase electron and ion transport path lengths through the electrode which increases cell resistance and can result in limited current densities of battery operation.
In this presentation the fabrication and characterization of cells with thick electrodes will be described. These electrodes are produced via hydraulic pressing and mild thermal treatment of active material powders as opposed to conventional casting of composite slurries. These electrodes thus have no binders or conductive additives, which would be expected to increase the diffusion of ions through the electrolyte-impregnated void regions within the electrode. However, these all active material electrodes can now have multiple processes that might limit their rate of charge/discharge, including transport of ions through the electrode microstructure, transport of ions through the solid active material particles, and transport of electrons through the all active material electrode matrix to the current collector. To provide insights into the processes that are limiting the current density in the high energy electrodes, we will describe the use of neutron imaging. Neutron imaging is highly sensitive to the lithium concentration within the battery cell, and thus regions undergoing lithiation/delithiation can be interrogated in operando during charge/discharge of the cell. The lithiation/delithiation profiles provide insights into what process limits the cell and opportunities to improve the performance of these thick electrodes fabricated with less common processing routes.
(Invited) Structure Design and Property Enhancement of Electrode Materials of Lithium-ion Battery
Authors: Sun Shi-Gang 
Published: February 2020

is communication will report our recent progresses made on the design and synthesis of electrode nanomaterials of lithium ion battery for efficient energy storage.
Lithium-ion batteries (LIB) are widely used today. The fast development of high-technologies (such as 5G and artificial intelligence (AI)) and electric vehicles demands increasing as much as possible energy and power density of LIBs. The key issue is to develop electrode nanomaterials with high capacity and high rate property, as the property of both anode and cathode nanomaterials is determined by their structure, especially the surface structure which relates to the energy barrier of surface reaction and the density of lithium ion transportation. Based on a thorough analysis of structure-functionality, we have achieved to design and tune the structure and property of electrode nanomaterials, including anode of metal oxides (such as Co3O4, MnO) and cathode of lithium rich oxide, NCM and Layered/Spinel heterostructure nanomaterials. All the designed and well-controlled electrode materials were tested in LIB cells, and superior capacity, high rate property and excellent cycleability were confirmed.
Acknowledgements: The study was supported by NSFC (21621091) and the MOST (2016YFB0100202).
References:

G.Z. Wei , X. Lu , F.S. Ke et al. Adv.Mater. 2010, 22: 4364.

G.L. Xu, Li, Huang, Sun et al. Nano Energy 2013, 2(3): 394.

F. Fu, G.L. Xu, Q. Wang et al. J. Mater. Chem. A, 2013, 1, 3860.

G.L. Xu, Q. Wang, J.C. Fang et al. J. Mater. Chem. A, 2014, 2,19941.

J. Liu, Q. Zhang, T. Zhang et al. Adv. Funct. Mater. 2015, 25, 3599.

C.H. Shen, Q. Wang, H.J. Chen et al. ACS Appl. Mater.
& Interfaces, 2016, 8, 35323.

Y.F. Xu, Y. Chen, G.L. Xu et al. Nano Energy, 2016, 28, 63.

8.Y.Q. Lu, J.T. Li, X.X. Peng et al. Electrochem. Commun. 2016. 72, 79–82.

Y.P. Deng, F. Fu, Z.G. Wu et al. ChemElectroChem 2016, 3, 2027.

X.X. Peng, Y.Q. Lu, L.L. Zhou et al. Nano Energy 2017, 32, 503.

Y.P. Deng, Z.W. Yin, Z.G. Wu et al. ACS Appl. Mater. Interfaces 2017, 9, 21065.

Y.F. Wen, J.J. Fan, C.G. Shi, et al. Nano Energy 2019, 60, 162.
How Transition Metals Facilitate Charge-Transfer through the SEI in Li-Ion Batteries
Authors: Harris Oliver Clyde , Tang Maureen H 
Published: February 2020

Transition metal dissolution from a high-voltage Li-ion battery cathode accelerates capacity fade leading to unacceptably short battery lifetimes. After dissolution, metals like Mn, Ni, and Co deposit at the carbon anode and disrupt the formation and performance of the solid-electrolyte interphase (SEI), a vital battery interface responsible for protecting the electrolyte from the highly reductive anode. SEI contamination by metals results in continual Li loss and uncontrolled SEI growth, culminating in severe capacity decay. Fundamental understanding of the role of each metal in undermining SEI passivation is necessary to mitigate this degradation and to enable commercialization of high-voltage Li-ion cathodes.
In this work we interrogate the effects of three transition metals (Mn, Ni, and Co) on charge-transfer through the SEI via in-situ electrochemical characterization. Our approach is to grow an SEI in metal-contaminated electrolyte and then characterize the film via rotating disk electrode voltammetry. Redox mediators deconvolute through-film transport and reaction kinetics to determine physical charge-transfer mechanisms. We find that each metal disrupts the electronic properties of the SEI far more than the morphological properties, and that Mn-contamination is the most detrimental of the three metals. We compare charge-transfer mechanisms based on electron tunneling across the SEI and electrocatalytic metal cycling between redox states and compare experiments to microkinetic models of each mechanism. Our results indicate that reaction thermodynamics and kinetics do not fully capture why Mn facilitates faster through-film charge-transfer than Ni or Co. This suggests that differences in coordination environment between transition metals embedded in the SEI are responsible for the more aggressive disruption by Mn, offering insight into mitigation approaches to inhibit accelerated capacity fade.
Structure and Electrochemistry of SiOx Made By Reactive Gas Milling
Authors: Cao Yidan , Bennett J. Craig , Dunlap R. A. , Obrovac Mark N 
Published: February 2020

SiO
x
is a promising Li-ion battery negative electrode material because of its high capacity and unique microstructure that leads to good cycle life. However, SiO is typically made by high temperature methods that are expensive and difficult to realize, especially at lab scale. Here, SiO
x
negative electrode materials were synthesized by ball milling Si in air. This method allows efficient control of oxygen content, as shown in Figure 1a and results in a similar microstructure as a commercially purchased SiO.
XRD and TEM results show that the SiOx prepared by ball milling in air are composed of nanocrystalline Si embedded in an amorphous silicon oxide matrix (Figure 1b). The very low initial coulombic efficiency (ICE) of conventionally made SiO (measured here to be ~55% for Aldrich SiO) is one of its major drawbacks. In contrast, reactive gas milled SiO
x
have much higher reversible capacities (>1500 mAh/g) and higher ICE values (>70%). Reactive gas milled SiO
x
has a number of attractive features: an inexpensive and simple synthesis process, high capacity, high ICE, high thermal stability (stable microstructure at 800 °C, Figure 1c), and a special microstructure that protects Si from reaction with electrolyte, resulting in excellent cycling performance (Figure 1d).
Here a detailed study will be presented describing SiO
x
synthesis by reactive gas milling, thermal properties, and its electrochemical performance in relation to its composition and microstructure.

Figure 1
Effect of Fast-Charging on Ageing of Energy-Optimized Automotive LiNi1/3Mn1/3Co1/3O2/Graphite Prismatic Lithium-Ion Cells
Authors: Wreland Lindström Rakel , Mussa Abdilbari , Liivat Anti , Marzano Fernanda , Klett Matilda , Philippe Bertrand , Tengstedt Carl , Lindbergh Göran , Edstrom Kristina , Svens Pontus 
Published: February 2020

It is desirable to be able to charge automotive batteries at a fast rate, especially for heavy duty commercial vehicles. In this study [1] the effect of fast charging (1C-4C) on ageing was studied on an energy-optimized 25 Ah prismatic NMC(III)/graphite lithium-ion cell cycled at 35°C and 20-80% SOC. Detailed post-mortemanalysis was carried out using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and electrochemical impedance spectroscopy (EIS). The results show that the effect of charging rate is more complex than earlier described. Even though ageing is more rapid at 3 and 4C charging, no clear trends in degradation with charging rate are observed. Instead, different mechanisms are dominating at the different charging rates. Accelerated lithium plating was observed after cycling at 3C-charging, while extensive gas evolution was the cause to the fast cell impedance rise and capacity fade of the cells cycled at 4C. Graphite exfoliation and accelerated lithium inventory loss point to the graphite electrode as the source of the gas evolution. SEM show cathode particle cracking independent of the charging rate used for the cycling. XPS and EIS generally indicate thicker surface film and larger impedance, respectively, towards the edge of the cells. The results implicate that the ageing rates are too high to be feasible for a battery electric inner-city bus using this type of cell being charged at 3C. However, even though ageing rates for 2C and below are acceptable, it is concluded too slow from the point of view of practical charging time.
Fig. Capacity fade vs. number of equivalent full cycles (inset: capacity fade vs. cycling time).

Fast-charging effects on ageing for energy-optimized automotive LiNi1/3Mn1/3Co1/3O2/ graphite prismatic lithium-ion cells. Abdilbari Shifa Mussa, Anti Liivat, Fernanda Marzano, Matilda Klett, Bertrand Philippe, Carl Tengstedt, Göran Lindbergh, Kristina Edström, Rakel Wreland Lindström, Pontus Svens, Journal of Power Sources 422, 2019, 175-184.
Investigation of « Cross-Talking » Phenomenon within Li-Ion Batteries
Authors: Portalis Guillaume , Simon Bernard , Vivier Vincent 
Published: February 2020

Li-ion batteries are good candidates for energy storage devices in the field of transportation as they grant not only high energy and power densities to the systems but also long cycle-life. The graphite is commonly used as the anode because of its high lithium storage capacity whereas the LiFePO4 (LFP) is a cathode material of choice for transportation applications which require high level of safety. Besides, the LFP is thermally and chemically very stable, enables a good specific capacity (170 mAh/g) and is more environmentally friendly than most of the other materials of positive electrode. Nevertheless, LFP/C(gr) system suffers from a particular undesirable phenomenon, namely the "cross-talking". It consists in the iron dissolution from the LFP, the migration onto the graphite electrode and the subsequent contamination of the Solid Electrolyte Interphase (SEI), which protects the graphite from further reduction of electrolyte and a loss of active lithium. As a matter of fact, changes in physical and chemical properties of the SEI occur. Among possible alterations, permeability to either reducible species or electrons increases, enabling new SEI to grow and thus consuming more lithium. The available charge in the system LFP/C(gr) is then constantly decreased as long as the cross-talking occurs, and so is the cycle-life of the battery. Therefore, this LFP/C(gr)-specific phenomenon is a big concern especially considering the difference of capacity fading with other systems of batteries for which it is much lower.
The aim of this work is to highlight, characterize and understand the cross-talking phenomenon through cycling of LFP/C(gr) coin cells. The Electrochemical Impedance Spectroscopy (EIS) technique will be used in order to assess the changes in physical and chemical properties of the LFP/C(gr) electrodes. EIS spectra from different steps of the electrodes lifetime under different conditions will be compared and discussed. By using symmetrical coin cells (LFP/LFP and C(gr)/C(gr)), it is possible to obtain EIS signal for each material, and a specific attention will be paid to the study of influence of the temperature on the impedance response. Additionally, physical parameters can be determined through EIS spectra such as activation energy of ionic conductivity and SEI thickness (from the complex capacitance representation). These electrochemical analyses will be completed by physical and chemical characterizations such as X-ray Fluorescence (XRF), Glow Discharge Optical Emission Spectroscopy (GD-OES) and RAMAN spectroscopy.

Figure 1
Effects of Porous Material Properties and Operating Conditions on PEM Electrolysis Performance and the Observation of Mass and Heat Transport
Authors: Lopata Joseph Steven , Bender Guido , Kang Zhenye , Young James L. , Shimpalee Sirivatch , Weidner John W. 
Published: February 2020

Polymer electrolyte membrane water electrolysis (PEMWE) is a promising technology for the integration and utilization of renewable energy and hydrogen as an energy carrier. Advancements in catalysis have made the commercial viability outlook very encouraging. Nonetheless, more work is necessary to advance the technology from niche markets towards broad market penetration. Through this study, we increase understanding of transport and interfacial phenomena, which can be used to design more efficient electrolyzers and improve cell performance.
Preventing excessive oxygen accumulation in the catalyst layer (CL) by adjusting the geometry and properties of flow channels, the porous transport layer (PTL), and the CL itself may result in increased catalyst utilization, efficiency, and performance. Controlling feed water to allow a significant increase in CL temperature may also improve efficiency. In order to optimize performance without operating under conditions that may affect cell durability, PEMWE scale-up relies on robust models that accurately predict current and temperature distributions. Such models, particularly 3-D flow models, provide the opportunity to improve electrolysis efficiency through process engineering.
Electrochemical models have been commonly used to fit known relationships to the measured performance of PEMWE devices. Computational modeling is a lean approach to enhancing technology without the cost and duration of experimentation, albeit via the quantitative understanding of prior empirical observations. This work investigated the effects of experimental parameters on transport, highlighting the need to accurately model temperature elevation and gas inhabitation in the CL. This was done in order to develop and validate a 3-D PEMWE model that predicts current distribution and overall cell efficiency using computational fluid dynamics (CFD) simulations. The following experiments examined a PEMWE device under a wide range of conditions in order to uncover information about multiscale phenomena that may improve the model. The experimental parameter space was designed minding the importance of the through-plane pressure drop in the PTL and the temperature rise in the CL. It included variation of current density, inlet water flow rate, temperature, and properties of cell components. Polarization curves and complimentary Nyquist plots from electrochemical impedance spectroscopy (EIS) were used in addition to inlet/outlet temperatures and cell pressure drop to observe mass and heat transport. A summary of the findings from the main validation experiments and their interpretations will be discussed.