bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrochemical Synthesis of Ammonia Using Proton and Hydroxide Exchange Membrane Cells
Authors: Nash Jared , Wang Junhua , Anibal Jacob , Yan Yushan , Xu Bingjun
Published: February 2020

With the development of the Haber process and the subsequent work done by Bosch, ammonia production become an industrially and economically viable way to fix nitrogen. Ammonia used as a fertilizer has helped increase the global food production and estimates put it at about 40% of the global population’s food needs the ammonia fertilizer from the Haber process[1]. However, the Haber-Bosch process is an energy intensive process requiring high pressure (15-30 MPa) and relatively high temperature (430 °C – 480 °C) and is highly centralized with only about 13 companies producing at about 29 plants[2, 3]. Renewable energy resources offer a possible alternative way to fix nitrogen at low temperature and lower pressure to produce ammonia in a decentralized way. High temperature solid proton conductors have been used to produce ammonia selectively, but the high temperature can degrade the ammonia[5]. Low temperature polymer electrolyte membranes can be used which might reduce the overall energy input. Proton exchange membrane (PEM) suffers from conductivity loss due to the ammonia converting to ammonium[6], which reduces the cation conductivity. The other issue is the competing hydrogen evolution reaction (HER) which is especially fast in the acidic environment[7]. By moving to an alkaline environment, ammonia will not affect the conductivity because hydroxide exchange membranes (HEMs) use anions as the charge carriers. HEMs also allow the use of non-precious metal catalysts which could reduce the overall cost of these electrochemical devices. In this presentation, we will discuss the activity of a variety of catalyst, PGMs, metal nitrides, and non-precious metals in both HEM and PEM electrolyzers for their ammonia production. We utilized the hydrogen oxidation reaction (HOR) as the counter electrode which can also be utilized as a reference. This study allows for the direct comparison of PEM and HEM for electrochemical nitrogen reduction.

References:

1. Erisman, J.W., et al., Nature Geosci, 1(10): p. 636.(2008).

2. Mineral Commodity Summaries 2015, U.S.G. Survey, 2015: Reston, Virginia. p. 196.

3. Marnellos, G. and M. Stoukides, Science, 282(5386): p. 98.(1998).

4. Kordali, V., G. Kyriacou, and C. Lambrou, Chem. Commun., (17): p. 1673.(2000).

5. Amar, I.A., et al., J Solid State Electrochem, 15(9): p. 1845.(2011).

6. Lan, R. and S. Tao, RSC Advances, 3(39): p. 18016.(2013).

7. Sheng, W., H.A. Gasteiger, and Y. Shao-Horn, J. Electrochem. Soc., 157(11): p. B1529.(2010).
(Invited Plenary) From Moon Shot to the Battlefield and Under the Sea
Authors: Freese Charles
Published: February 2020

Accelerating Fuel Cell Transition to Commercial Reality

For more than 100 years, the automotive industry fostered prolific technical innovation and business change. Today, the industry is transforming itself in a concentrated effort to create electrified vehicle architectures from both battery and fuel cell technologies. General Motors began its fuel cell journey more than 50 years ago when the Electrovan became world’s first hydrogen-powered fuel cell vehicle, a feat made possible by the first technology transfer from the Apollo Space Program. Although Electrovan was an important milestone, it highlighted technical challenges that had to be solved before fuel cells could become commercially viable. One by one, these barriers were broken over succeeding decades, and as the 20thCentury closed, GM prepared for the first large-scale fuel cell deployment. Project Driveway placed 119 fuel cell vehicles in customer garages and driveways, with more than 5,000 motorists amassing 3.2 million miles of real-world driving. These Generation 0 systems continue to gather useful data though U.S. military collaborations with the U.S. Army and U.S. Navy. Meanwhile, GM is partnering with Honda in a joint venture to mass produce next-generation fuel cell systems. GM’s HydroTec fuel cell technology is undergoing evaluations, on land, under water, and in the air. Incredible progress has been made in reducing the mass and cost, but additional challenges remain, specifically in creating a scalable public fueling infrastructure in the United States, Japan, Germany and Korea.
(Invited Plenary) Latest Research and Development of PEM Water Electrolysis Technology in South Korea
Authors: Moon Sangbong , Moon Changhwan , Jung Hyeyoung , Choi Yunki , Han Changhyun
Published: February 2020

Reduction of CO2 emission has been an issue around the globe, and most countries are considering renewable energy such as solar and wind power to reduce overall CO2 emission. However, the method of maximizing the utilization of renewable energy needs consideration.

Utilizing water electrolysis is one of considered solution. The concept is to create hydrogen through water electrolysis using excess power produced by renewable energy. Then, produced hydrogen can be used in various fields.

In order to maximize utilization of renewable energy with water electrolysis, three attributes should be considered for water electrolysis; High pressure, large surface area, and high current density.

The following presentation contains three topics; 1. An introduction of latest research and development made in Korea on water electrolysis including PEM water electrolysis, 2. PEM water electrolysis research in Korea, led by Elchemtech and 3. Research conducted by Elchemtech on how to reach the target goal; large active area (3,000cm2), high current density (3A/cm2) and high pressure (350bar).
(Invited Plenary) Electrocatalysis in PEFCs – limitations in the Performance of the Hydrogen Oxidation and Oxygen Reduction Reactions
Authors: Kucernak Anthony
Published: February 2020

An alternative approach to the rotating disk electrode (RDE) for characterising fuel cell electrocatalysts has been recently demonstrated[1, 2]. The approach combines high mass transport with a flat, uniform, and homogeneous catalyst deposition process, well suited for studying intrinsic catalyst properties at realistic operating conditions of a polymer electrolyte fuel cell (PEFC). Uniform catalyst layers were produced with loadings as low as 0.16 μgPt cm-2 and thicknesses as low as 200 nm, Figure 1. Such ultra thin catalyst layers are considered advantageous to minimize internal resistances and mass transport limitations leading to very high performance at low platinum loadings. Modelling of the associated diffusion field suggests that such high performance is enabled by fast lateral diffusion within the electrode. The electrodes operate over a wide potential range with insignificant mass transport losses, allowing the study of the oxygen reduction reaction (ORR) and hydrogen oxidation reaction (HOR) at high overpotentials. For the HOR, geometric current densities as high as 5.7 A cm-2
Geo were experimentally achieved at a loading of 10.15 μgPt cm-2 at room temperature (561 A mgPt
-1), which is three orders of magnitude higher than current densities achievable with the RDE. These currents correspond to a specific current densities of 600 ± 60 mA cm-2
Spec, although this maximum appears to be related - to the hydrogen adsorption process. For the ORR, electrodes produced a specific current density of 31 ± 9 mA cm-2
Spec at a potential of 0.65 V vs. RHE (28 A mg-1), Figure 2. The mass activities of Pt/C catalysts towards the ORR was found to exceed a range of literature PEFC mass activities across the entire potential range. This paper will discuss the lessons that can be learnt from these electrocatalytic studies and what they mean in terms of ultimate performance of fuel cells utilising precious metal catalysts.

[1] C.M. Zalitis, D. Kramer, J. Sharman, E. Wright, A.R. Kucernak, Pt Nano-Particle Performance for PEFC Reactions At Low Catalyst Loading and High Reactant Mass Transport, in: Polymer Electrolyte Fuel Cells 13, 2013, pp. 39-47.

[2] C.M. Zalitis, D. Kramer, A.R. Kucernak, Electrocatalytic performance of fuel cell reactions at low catalyst loading and high mass transport, Physical Chemistry Chemical Physics, 15 (2013) 4329-4340.

Figure 1
(Invited) Mixed Conducting Layered Oxides for Energy Storage: Challenges and Their Mitigation
Authors: Manthiram Arumugam
Published: February 2020

Lithium-ion batteries have aided the revolution in portable electronic devices, and they are now being intensively pursued for electric vehicles and grid storage. Cost, safety, cycle life, energy, power, and environmental impact are the major factors for adopting a specific battery chemistry for a specific application, and often tradeoffs among the factors are needed in the selection. Although the layered LiMO2 (M = Ni and Co) oxides with mixed lithium-ion and electronic conductivity were first demonstrated more than 30 years ago as a lithium-insertion host, they still remain to be the dominant candidate for lithium-ion technology due to several appealing features displayed by them. With an aim to increase the charge-storage capacity and energy density, layered oxides with a high Ni content (> 50%) are now at the forefront in the battery industry around the world. However, compositions with high Ni content are hampered by high surface reactivity with the organic liquid electrolyte and the consequent impedance rise and fast capacity fade during cycling. Furthermore, they also suffer from high surface reactivity with ambient air, forming lithium hydroxide and lithium carbonate on the particle surface and thereby hampering the electrode fabrication process. A firm fundamental understanding of the origin of the fast capacity fade with advanced characterization methodologies and design and development of nickel-rich cathode compositions with robustness in contact with the liquid electrolyte and ambient air are critically needed to make the technology practically move forward. Accordingly, this presentation will focus on the characterization of nickel-rich layered oxides with advanced surface techniques and development of less reactive compositions with robust surface structures.

To develop a fundamental understanding of the degradation mechanisms, the nickel-rich layered oxide cathodes are investigated before and after long-term cycling in full cells with X-ray photoelectron spectroscopy (XPS), time-of-flight – secondary ion mass spectroscopy (TOF-SIMS), and high-resolution transmission electron microscopy. In-depth surface characterization as a function of sputtering time and cross-sectional analyses reveal that surface active mass dissolution caused by the acidic species in the electrolyte during cell operation and migration of dissolved metal ions from the cathode to the graphite anode cause impedance rise at the graphite anode, lithium dendrite growth, and capacity fade. Utilizing the in-depth understanding gained, stabilized full cells are designed and the degradation is being mitigated. Promise of cathode compositions with Ni contents as high as 94% and capacities as high as ~ 220 mAh/g with high power capability will be presented. The progress paves the way to design and develop high-power lithium-ion cells with high volumetric and gravimetric energy densities for portable, vehicle, and grid storage applications.
Phase Stability, Electrochemical Activity, and Accelerated Test for SOFC Cathodes
Authors: Dogdibegovic Emir , Wang Yudong , Zhou Xiao-Dong
Published: February 2020

In this presentation, I will use the cathode for solid oxide fuel cells as an example to elucidate the relationship between the phase stability and electrochemical activity. The presentation will focus on praseodymium nickelate (Pr2NiO4), an active electrode for oxygen reduction reaction. Pr2NiO4, however, exhibits phase transition at elevated temperatures or under an electrochemical operation to form PrOx and higher ordered nickelate phase. We will discuss multiple strategies to improve the phase stability via intrinsic dopants and microstructure modification. More importantly, the knowledge gained has been translated to develop accelerated test protocols for nickelate- and perovskite-based cathodes.
(Invited) Robust and Active Mixed-Conducting Electrodes for Intermediate-Temperature Fuel Cells
Authors: Chen Yu , Chen Dongchang , Ding Dong , Liu Meilin
Published: February 2020

Intermediate-temperature solid oxide fuel cells have potential to be the cleanest and most efficient options for cost-effective utilization of a wide variety of fuels, from hydrogen to hydrocarbons, coal gas, and renewable fuels. They are ideally suited for distributed generation (which may be integrated with smart grids). To make these fuel cells economically competitive and commercially viable, however, several materials challenges must be overcome. One of them is the creation of durable, low-cost cathode materials and nanostructures of high electro-catalytic activity for oxygen reduction reaction at intermediate temperatures. Another challenge is the development of multi-functional anodes enabling efficient reforming of hydrocarbon fuels (e.g., methane) and directly operation on readily available fuels (e.g., natural gas) at intermediate temperatures. In this presentation, we will highlight an effective approach to fabrication of high-performance catalysts coated electrodes of dramatically enhanced electro-catalytic activity and durability, as schematically shown in Figure 1. The concept of modifying electrode surface through solution infiltration of a catalyst to create unique hybrid electrode structure (e.g., exsoluted nanoparticles on a conformal coating) are readily applicable to other electrochemical energy storage and conversion systems, including metal-air batteries, supercapacitors, and electrolyzers.

Figure 1. Schematic for a high-performance cathode consists of the state-of-the-art cathode backbone (e.g., LSCF) and a durable catalyst (conformal coating and exsoluted nanoparticles) against various contaminants, making effective use of the best properties of two different materials (backbone and catalyst).

Figure 1
(Invited) Understanding Anode and Cathode Reaction Mechanisms for Proton Conducting Intermediate Temperature Solid Oxide Fuel Cells
Authors: Sun Shichen , Cheng Zhe
Published: February 2020

The anode and cathode reaction processes for conventional solid oxide fuel cells (SOFC) have been widely studied. In comparison, there are many unknowns about the basic electrochemical behaviors and mechanisms for the anode and cathode reactions of proton conducting SOFC, especially at intermediate temperature (IT) range of ~400-700oC when the cells approach ideal proton conducting behaviors. At intermediate temperature, due to the change of the dominating ionic conducting species from oxide ion to proton, the fundamental reaction pathways would change for both the anode and cathode reactions. Accompanied with such changes, many interesting electrochemical behaviors arise for proton conducting IT-SOFC. For example, it is well known that the Ni-based cermet anode for conventional oxide ion SOFC are susceptible to poisoning by sub-ppm level hydrogen sulfide (H2S) and not very sensitive to carbon monoxide (CO). In comparison, literature seems to suggest that the Ni-proton conducting oxide cermet as the anode for proton conducting IT-SOFC shows much better resistance against low ppm-level H2S but is poisoned by percentage level CO. This study aims to understand the fundamental reaction processes for both the anode (hydrogen electrode) and cathode (air electrode) of proton conducting IT-SOFCs. Electrochemical tests are carried out based on the concept of “controlled poisoning”, which is to selectively slow down a specific part of the electrode reaction using a specially chosen “poison” in order to help understand the fundamentals about the electrode reactions for proton-conducting IT-SOFCs. In particular, for the anode, H2S is used as a “Ni poison” and CO2 as a proton conducting oxide poison, while for the cathode, either H2O or CO2 is used. The measured electrochemical behaviors for different anode- or electrolyte-supported full cells and symmetrical cells including those with patterned (metal) electrodes are compared with those of conventional oxide ion based SOFCs. The results for those experiments aimed at understanding the similarity and differences between proton conducting SOFC and conventional oxide ion conducting SOFC will be presented, and their implications on the anode and cathode reaction mechanisms and the roles (including electrocatalytic roles) of proton conducting oxides in those electrode reactions for proton conducting IT-SOFC will be discussed.
(Invited) The ARPA-E Ionics Program: Separators to Enable the Cycling of Lithium Metal
Authors: Albertus Paul S. , Babinec Susan J. , Litzelman Scott J.
Published: February 2020

ARPA-E has funded five themed Programs and spent >$200 million on advancing energy storage technology since its inception. Unfortunately, the ultimate impacts of some of the technical advances made within ARPA-E efforts, as well as advances developed outside of ARPA-E, are hindered by constraints arising from separator cost and performance limitations. In response to this situation, ARPA-E launched the IONICS (Integration and Optimization of Novel Ion-Conducing Solids) program in 2016. The 16 teams in the program are focused on developing breakthrough separators that would be broadly enabling in different areas of electrochemical technology, and also amenable to cost effective manufacturing. The projects include both polymer and inorganic ion conducting separators that enable electrode chemistries that have been previously unsuccessful in practical devices. Project teams are focused on overcoming property tradeoffs to achieve a full set of required attributes, including conductivity, selectivity, stability, mechanical properties, manufacturability, cost, and others. This contrasts with a common approach of optimizing a single variable at the expense of others. The IONICS focus is on solids rather than liquids, due to inherent advantages in selectivity and mechanical properties offered by solids.

The IONICS program has three areas: (1) Li+ conductors that enable the cycling of the lithium metal electrode at 25°C and at conditions required for high-energy cells, (2) highly selective polymer separators for flow batteries, and (3) anion-conducting polymer separators for use in alkaline fuel cells and electrolyzers. This talk will focus on area (1), where the cycling of lithium metal at conditions relevant to high-energy cells still has not been shown, despite decades of research. Highlights of the talk will include: (1) presentation of a new figure depicting state-of-the-art cycling of lithium metal in both industry and research institutions, which reveals tradeoffs among the critical cycling metrics relevant to high-energy cells (i.e., cumulative capacity throughput, current density, and per-cycle areal capacity), (2) suggestion of test protocols that ensure proper interpretation of cycling data, and especially that electronic and ionic currents are distinguished, (3) the economics of film manufacturing, and the pathways to achieve the aggressive IONICS cost targets (<10 $/m2) required for widespread adoption for transportation or grid applications, and (4) the technical approaches being pursued in the program, with a focus on ceramics.
(Invited) Material, Fabrication and Cell Design for High Loading Li-S Batteries Towards Commercialization
Authors: Dai Fang , Xiao Qiangfeng , Yang Li , Cai Mei
Published: February 2020

Development of novel energy storage systems with improved efficiency and reduced cost is highly desired due to the emerging storage applications, such as grid storage system. Lithium-sulfur battery (Li-S) has been recognized as one promising system beyond conventional Li-ion system due to its high gravimetric energy density and low material cost, which is superior to most of current Li-ion batteries.

Unfortunately, the further commercialization was prohibited by some major issues of Li-S system, such as shuttling effect, which are still not fully surpassed after years’ development. In addition, conflict also exists between the overall electrochemical performance and active material loading. Other issues such as electrolyte amount are also critical. Both chemistry and engineering research and development are necessary to address all those issues that delay the large-scale industrial manufacturing and commercialization of the Li-S batteries.

In order to eventually push for further industrial manufacturing and commercialization, we have spent years working on the Li-S chemistry for balanced solution. Here we’d like to share some results from our works on the Li-S system. A well-engineered carbon framework will be introduced and discussed for high sulfur loading electrodes fabrication. Corresponding critical parameters, as well as the performance evaluation of the obtained high loading electrode will be also discussed. The high loading of S on both material (> 75 wt%) and electrode level (> 70 wt %, > 3 mAh/cm2) enables a much improved electrochemical performance of the large size pouch format Li-S cell. A protected Li anode also helps improving Coulombic Efficiency and preventing shuttling effect. In addition, influence of polymer binder and electrolyte on the optimized electrodes will be discussed. Besides the cell performance, we’ll also share the principle on material screening, cell fabrication and cell design.
(Invited) Sulfide-Based Solid Electrolytes for Solid State Batteries
Authors: Liang Chengdu
Published: February 2020

Sulfide
-Based Solid Electrolytes for Solid
State Batteries

Chengdu Liang , Yongsheng Guo, Chengyong Liu

Research Institute,

Ningde Contemporary Amperex Technology Limited，

Fujian Province 352100, China

The energy density of lithium ion batteries is now approaching the theoretical limit. Therefore, the development of next-generation batteries is of great technical interest nowadays. Solid state lithium batteries have attracted considerable attention because the replacement of an organic liquid electrolyte with a safer and more reliable inorganic solid electrolyte simplifies the battery design and improves safety and durability of the battery [1].

A crucial material to develop solid state batteries is a solid electrolyte with high Li+ ion conductivity at room temperature. Among different kinds of solid electrolytes, inorganic sulfide-based solid electrolytes are one of the most promising candidates for solid state lithium batteries due to the high ionic conductivity, wide electrochemical window and ease of forming framework structures [2-3]. However, there are still many challenges for the commercialization of solid state lithium batteries with sulfide-based electrolyte [4-5], for instance, the electrolyte/electrodes interface and air stability of sulfide-based electrolytes need to be further improved, and advanced manufacturing technologies are required as well.

In this presentation, several strategies to enhance ionic conductivity of sulfide-based solid electrolytes are deliberated; an ionic conductivity as high as 3.0 mS/cm has been achieved. We will then summarize the research progresses of solid state lithium batteries with sulfide-based electrolytes based on our work. Future research trends and perspectives for facilitating further improvement on the performance of sulfide-based solid state batteries will also be discussed.

Reference

 

[1] CW Sun, Nano Energy 33 (2017) 363.

[2] ZC Liu, CD Liang, J. Am. Chem. Soc., 135(3) (2013) 975.

[3] D. Liu, Materials Science and Engineering B 213(2016)169.

[4] A. Sakuda, Solid State Ionics 285 (2016) 112.

[5] J. C. Bachman, Chem. Rev. 2016, 116, 140.

*Corresponding author.

Email: LiangCD@Catlbattery.com.
Formate Fuel Production From the Electroreduction of CO2 on Nanostructured SnOx Coated on Gas Diffusion Electrode
Authors: Zhang Qi , Li Yanan , Hou Xiao fan , Jung Joey , Qiao Jinli
Published: February 2020

Due to the extensive use of non-renewable fossil fuels, the crisis in energy is growing, and the gas CO2, which is a product of the burning of hydrocarbons, is contributing to global warming and to acidification of the oceans. Therefore, the issue about carbon dioxide (CO2) capure, sorage and utilization has inspired intensive interests. [2,3] In the various methods of CO2 utilization and recycling, electrochemical reduction of CO2 to transform to useful chemicals or fuels is a potentially efficient way. However, in the procesure of CO2 electroreduction, there is a challenge of the slow kinetic of CO2 electroreduction. [4,5] Overcoming the problems of CO2 reduction under mild conditions would enable solve the energy crisis and the global warming.

In the past few decades, researchers found that many metal oxide nanopowders could be the perfect catalysts in the CO2 electroreduction for their controllable various morphologies.[1] In this work, we report the synthesis of SnOx nanocatalysts loaded on the multi-walled carbon nanotubes (MWCNTs), which electrochemical catalyzed CO2 to formate, HCOOH, on the room-temperature with an electrochemical cell having a catalytic SnOx cathode. We controlled different special morphologies by one-step hydrothermal method from SnCl2 precursors. The highest faradaic and energy efficiencies of 65% and 28% were obtained at −1.40 V vs. SCE with particles that were obtained by KOH reduction from a SnCl2 precursor and showed excellent stability in prolonged electrolysis.

References

[1]C. Zhao, J.L. Wang, J.B. Goodenough Chemical Communication, 52,12175(2016).

[2] R. Williams, R.S. Crandall, A. Bloom, Applied Physics Letters, 33,381 (1978).

[3] A.S. Agarwal, Y. Zhai, D. Hill, N. Sridhar, ChemSusChem, 4,1301 (2011).

[4] M. Gattrell, N. Gupta, A. Co, Energy Conversion and Management, 48,1255 (2007).

[5] N. S. Spinner, J. A. Vega and W. E. Mustain, Catalysis Science & Technology, 2,19(2012).
(Invited) Metal-Supported Solid Oxide Fuel Cells with High Power Density
Authors: Tucker Michael C
Published: February 2020

Metal-supported solid oxide fuel cells (MS-SOFC) display a number of advantages over conventional all-ceramic SOFCs, including low-cost structural materials (e.g. stainless steel), mechanical ruggedness, excellent tolerance to redox cycling, and extremely fast start-up capability. Challenges for MS-SOFCs include: oxidation of the metal support, especially at 800°C and above; the possibility of the stainless steel exacerbating Cr poisoning of the cathode catalyst; fabrication and materials set restrictions arising from the requirement that stainless steel be sintered in reducing atmosphere; and, only moderate performance and lifetime have been demonstrated to date.

These advantages and challenges suggest that MS-SOFCs may be well-suited for portable, ruggedized, fast-start, intermittent-fuel, or other unique and innovative applications. Nissan has developed the world’s first light-duty vehicle with a conventional SOFC stack for traction power, fueled by bio-ethanol reformate. Because of the desire for rapid-start capability, developing MS-SOFC cell and stack technology for this vehicular application is a priority. The small volume allowance for the SOFC stack on-board a small vehicle furthermore demands high power density from the MS-SOFC. In this work, we seek to maximize MS-SOFC power density.

This work is an extension of our previous efforts focusing on co-sintered, YSZ-based MS-SOFCs with porous metal supports on both anode and cathode sides, with catalysts deposited into both electrodes via infiltration. These features provide for a mechanically rugged cell that can be processed with low-cost scalable techniques, and high surface-area catalysts that provide excellent performance by avoiding interdiffusion or coarsening during cell sintering. To support the vehicular traction application, in this work we further develop catalyst infiltration processing for MS-SOFCs to dramatically increase power density. The goal is to increase cell performance by improving infiltration of conventional catalyst compositions (lanthanum strontium manganite (LSM), Ni, doped ceria) into electrode backbones of conventional yttria-stabilized zirconia (YSZ). Various aspects of the infiltration procedure were optimized, including: precursor composition and dilution with water; catalyst loading; and, crystallization temperature. Figure 1 shows the resulting high performance. Peak power of 1.1 and 1.9 W/cm2 is achieved at 700°C and 800°C, respectively, and the 800°C performance is the highest reported for stainless steel-supported MS-SOFCs to date. Figure 2 shows initial stability of the MS-SOFC. Testing is ongoing, and operation for >1000 h and post-mortem analysis will also be presented. Demonstration of redox cycling and rapid-start tolerance will be discussed.

Acknowledgements

Funding for this work was provided by Nissan Motor Co., Ltd. through Strategic Partnership Projects Agreement FP00004436. This work was funded in part by the U.S. Department of Energy under contract no. DE-AC02-05CH11231.

Figure 1
(High Temperature Materials Division J. Bruce Wagner, Jr. Award Address) Disorder and Transport in Pyrochlore Oxides
Authors: Kreller Cortney R. , Valdez James Anthony , Holesinger Terry , Wang Yongqiang , Uberuaga Blas , Tang Ming
Published: February 2020

Numerous avenues are currently being explored to enhance ionic conductivity in solid oxide materials, including dopants, nano-structuring, and strain engineering. Their effect on material properties, specifically mobile carrier concentration and mobility, needs to be understood and ultimately exploited to develop advanced functional materials. Crystalline disorder in complex oxides can have a pronounced effect on mass transport, but the role of disorder within the complex landscape of material and microstructural defects is not uniquely understood.

In this work, we seek to explore the relationship between intrinsic disorder and oxygen ion conduction. We are using radiation damage, not to study the fundamental damage response, but rather as a tool to induce and control the extent of disorder in oxide materials. The pyrochlore compounds, A2B2O7, consist of both ordered cation and anion sublattices. The introduction of anti-site disorder, where the A and B cations switch positions, is accompanied by increasing disorder on the anion sublattice, and complete randomization of the A- and B-site cations results in the defect fluorite phase. Several workers have previously studied the influence of structural disorder on ionic conductivity by introducing disorder through dopants, temperature, or pressure. It has previously been suggested that disorder increases carrier concentration by freeing the fixed vacancy from the ordered anion sublattice of the pyrochlore structure, while order, on the other hand, may serve to increase mobility by providing a preferential ion transport pathway. This is in contrast to recent modeling results that indicate that both carrier concentration and mobility increase with disorder. In the present work we have chosen to investigate the end members of the Gd2(ZrxTi1-x)2O7 system in order to gain a better understanding of the interplay between disorder and ionic transport. Gd2Zr2O7 is an intrinsic fast-ion conductor that is also very radiation tolerant, whereas Gd2Ti2O7 is a poor ionic conductor that is much more susceptible to amorphization under irradiation than the zirconates. Electrochemical Impedance Spectroscopy is used to measure the conductivity of materials with varying degrees of irradiation-induced structural disorder in order to better understand how the underlying transport mechanisms depend on crystalline disorder.

Acknowledgements

This work was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division.
Electric Field-Assisted Pressureless Sintering of Ceramic Protonic Conductors
Authors: Muccillo R. , Esposito Vincenzo , de Florio Daniel Zanetti , Muccillo E. N.S.
Published: February 2020

Gadolinium, yttrium and samarium-doped barium cerate (BCGd, BCY and BCSm, respectively) polycrystalline green pellets were submitted to electric field-assisted pressureless sintering experiments isothermally in the temperature range 800-1200oC under 100-200 V cm-1 electric fields, limiting to 1-5 A the electric current pulse amplitude. The sintering experiments were carried out in ambient atmosphere with the pellets positioned inside a vertical dilatometer furnace with Pt-Ir electrodes connected either to a power supply for applying the electric field or to an impedance analyzer for collecting [-Z''(ω) x Z'(ω)] data to evaluate the bulk and the grain boundary contributions to the electrical resistivity. Near full density was achieved in the sintered samples. The combined results of dilatometry and impedance spectroscopy measurements before and after flash sintering show substantial improvement of the electrical conductivity of flash sintered specimens. Joule heating is assumed to be the primary effect of the electric current pulse through the specimens. Improved grain-to-grain contact and the removal of depleted chemical species due to Joule heating at the space charge region are proposed, respectively, as the reasons for the almost total disappearance of the grain boundary component in the impedance diagrams and the improvement of the bulk electrical conductivity.
Physico- Chemical Effects of Block Copolymer of Polyethylene and Polypropylene Glycol (Pluronic F-127) on Samarium Doped Ceria (Ce0.8Sm0.2O2) Perovskite As Electrolyte for Low Temperature SOFC Application
Authors: Njoku Chima , Owaga Bernard , Ndungu Patrick
Published: February 2020

Sol-gel technique was adapted, and the templating characteristics of Pluronic F-127 surfactant was introduced to produce porous samarium doped ceria (SDC) nanoparticles as electrolyte. The electrolyte material was calcined at 800 °C and this material was analysed for its crystalline, microstructural and electrochemical properties. X-ray diffraction spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and high resolution transmission electron microscopy was used to analyse the crystalline nanostructure, morphology and microstructure of the material. The electrochemical properties were characterised by using Kittec Squadro SOFC testing equipment with air and hydrogen as gases used. Our results show that the nature of the surfactant influenced the particle morphology, pore diameter, pore size, crystallite size, surface area and the electrochemical properties.
Intermediate Temperature Synthesis and SOFC Anode Application of Cerium Silicate-Based Oxy-Apatites
Authors: Lee Sunghwan , Ramanathan Shriram
Published: February 2020

Oxy-apatites based on rare earth silicates (A10x(SiO4)6O2±x, A=rare earth cation) are of increasing interest for solid oxide fuel cell (SOFC) application due to the high conductivity at moderate temperatures (<1000 K). Here, we report on the intermediate-temperature synthesis (973 K) of thin film oxy-apatites and high total conductivity of the cerium silicate-based apatites at temperatures <750 K: the Ce4.67(SiO4)3O-based apatites (~80 nm-thick) were synthesized at 973 K at very low oxygen partial pressure (p(O2)<10-17atm) and the incorporation of ZnO into the cerium silicate system leads to the high total conductivity of ~0.05-0.2 S/cm. The formation of oxy-apatites was identified by in-situ conductivity measurements as a function of p(O2), x-ray diffraction analysis and x-ray photoelectron spectroscopy. In particular, the in-situ conductivity measurements confirm that the dominant conduction mechanisms of this class of materials are mainly dependent on oxygen interstitials.

Since these materials are prepared at low p(O2) and are stable in reducing atmospheres, Ce4.67(SiO4)3O-based thin film apatites exhibiting high conductivity are of relevance as anodes for intermediate temperature thin film SOFC application. In order to evaluate the performance of the apatite anode in SOFC devices, thin film apatites were grown on Sc-stabilized ZrO2/LSCF electrolyte/cathode substrates. Bilayer anode of apatite/Pt and Ni-apatite composite anode were also utilized in the identical electrolyte/cathode system and the performance were compared. The noteworthy SOFC performance (e.g., peak power density of ~100 mW/cm2 at 748 K) and superior stability were observed in Ni-apatite SOFCs due to higher catalytic activity and low contact resistance at the electrolyte/anode interface compared to those with a single layer apatite anode and bilayers of apatite/Pt anode. The present study demonstrating intermediate temperature synthesis of Ce4.67(SiO4)3O-based oxy-apatites and their high conductivity may significantly contribute to the field of intermediate temperature thin film SOFC application.

Figure 1
(Invited) Life-Cycle Comparison of EV Li-Ion Battery Chemistries Under Grid Duty Cycles
Authors: Sprenkle Vincent , Choi Daiwon , Crawford Alasdair , Viswanathan Vish
Published: February 2020

Energy storage is an integral component to ensure the resiliency and efficiency of a future power grid that is adopting a wider array of distributed generation assets and changing customer usage and expectations. Energy storage can provide a vast array of services, such as back-up power, energy management, voltage support, and frequency regulation, that are critical for grid stabilization. Currently, 77% of the electrochemical energy storage systems in operation in U.S utilize Li-ion batteries developed for commercial and EV applications. To date, the highest value market for energy storage has been frequency regulation services. Potentially, the battery packs in EV could also be used to provide these services also when they are connected to a charging station, however, few studies have addressed the potential impact of providing grid services on the estimated lifetime of the EV battery pack. In this study two leading Li-ion battery chemistries: (NCA) LiNi0.8Co 0.15Al0.05O2 and (LFP) LiFePO4 were obtained from leading manufactures and were subjected to different usage scenarios involving frequency regulation and peak shaving duty cycles with and without the baseline electric vehicle duty cycle. In general, the LFP cells show less aging, higher round trip efficiency and better cycling than NCA when operated under both high and low power applications. For high power applications like frequency regulation, NCA cells are slightly better/comparable to LFP, however the NCA cells show greater degradation and self-discharge during rest.
The Effect of Pre-Lithiation Chemistry on Li Inventory in High-Energy Li-Ion Cells
Authors: Dose Wesley , Senguttuvan Premkumar , Blauwkamp James , Johnson Christopher
Published: February 2020

Silicon containing anodes employed in Li-ion cells are known to dramatically boost the energy density of a full LIB battery by providing a high intrinsic capacity via LixSi intermetallic alloy formation/utilization compared to capacity-limited graphite anodes. However, because a >300% volume change takes place between (de)lithiated LixSi states, a irreversible trapping of cyclable Li in the full cell occurs, negatively impacting performance, potentially lowering cycle life. Moreover, electrode slippage happens whereby the lithium inventory in the battery is compromised, and less cathode capacity can be utilized. In this work we (1) first assess Li-inventory trends from the use of LiFePO4 thick electrodes versus thin 15%Si•graphite anodes, (2) evaluate chemically pre-lithiated 4-V and 5-V spinels in full cells, and (3) implement high-capacity (>700 mAh/g) lithium iron oxide Li5FeO4 anti-fluorite materials as a pre-lithiation additive in the cathode. We will report the findings of this study in this presentation.
Concentrated Gradient Cathode Materials with LiNi0.9Mn0.05Co0.05O2 Core and LiNi0.33Mn0.33Co0.33O2 Surface Composition
Authors: Shin Youngho , Kahvecioglu Feridun Ozgenur , Krumdick Gregory
Published: February 2020

Layered nickel-rich cathode material, LiNi0.9Co0.05Mn0.05O2, exhibits high specific capacity of approximately 220 mAh/g-oxide and shows attracted significant interest for use in plug-in hybrid electric vehicles owing to its high capacity and low cost. However, significant challenges remain to improve capacity retention during cycling and thermal-abuse tolerance of this material.

To improve the electrochemical performance and stability of this kind nickel-rich LiNixMnyCozO2 (NMC, x ≥ 0.6, x+y+z=1) cathode material for the usage in practical batteries, concentrated gradient cathode materials have been investigated. This family of materials shows the gradual decrease of nickel concentration and increase of manganese concentration from the center towards the outer layer of the particle [1-2].

Even though concentrated gradient cathode material is one of promising approaches to mitigate the capacity fade during cycling and thermal runaway of layered nickel-rich cathode materials, its working mechanism has not been fully understood yet. In this study, we explore two types of concentrated gradient cathode materials, core-shell and core-gradient, with nickel-rich LiNi0.9Mn0.05Co0.05O2 core and LiNi0.33Mn0.33Co0.33O2 surface composition which have LiNi0.8Mn0.1Co0.1O2 as overall composition. The precursors were synthesized using hydroxide co-precipitation method using a 20L batch reactor and then dried, mixed with lithium source and calcined. We report the characterized physical properties of the prepared core-shell and core-gradient materials. The detailed electrochemical performance comparison of the prepared materials with commercial NMC811 and NMC333 will be discussed.

Acknowledgement

Funding for this work from the Office of Vehicle Technologies of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, is gratefully acknowledged. The submitted abstract has been created by UChicago Argonne, LLC, Operator of Argonne National Laboratory (“Argonne”). Argonne, a U.S. Department of Energy Office of Science laboratory, is operated under Contract No. DE-AC02-06CH11357.

References

Y.-K. Sun, S.-T. Myung, M.H. Kim, J. Prakash and K. Amine, J. Am. Chem. Soc. 127(38), 13411 (2005).

U.-H. Kim, E.-J. Lee, C. S. Yoon, S.-T. Myung and Y.-K. Sun, Adv. Energy Mater. 6, 1601417 (2016)
Evolution of the Cathode-Electrolyte Interface of Li1
-
xNi0.8Co0.15Al0.05O2 Electrodes Due to Electrochemical and Thermal Stress
Authors: Lebens-Higgins Zachary , Faenza Nicholas , Sallis Shawn , Pereira Nathalie , Amatucci Glenn , Piper Louis F.J.
Published: February 2020

The electrode-electrolyte interfaces (EEIs) play important roles in lithium ion batteries, often determining the capacity retention, safety, and lifetime. The EEI of the positive electrode is far less understood than its negative counterpart. In addition to possible electrolyte oxidation products, layered cathodes often exhibit pronounced surface phase transformations that can also limit the performance of the battery. For example, recent experiments have correlated charge-transfer impedance growth with surface phase transformations at Li1-xNi0.80Co0.15Al0.05O2(NCA) surfaces, which result from surface oxygen loss. [1] Electrolyte reactions with the active material play a role in surface oxygen loss as coating layers [2] and electrolyte additives [3] can mitigate impedance growth and capacity fade. Determining reaction pathways that promote surface oxygen loss is essential to optimizing the selection of coating layers or additives that further improve capacity retention.

Here we report on our surface studies of NCA, to examine the evolution of the cathode-electrolyte interface (CEI) for stressed NCA electrodes held at high voltages (≥4.5V). Using a combination of surface sensitive x-ray absorption spectroscopy and x-ray photoelectron spectroscopy, we correlate transition metal reduction with electrolyte decomposition species at the cathode surface. From comparison of NCA electrodes held under various constant voltage conditions, we examine the influence of voltage and temperature on the formation of electrolyte decomposition species. Our work provides insight into possible reaction mechanisms that influence changes of the CEI layer for electrodes under thermal and electrochemical stress.

This work was supported as part of NECCES, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number DE-SC0012583

[1] S. Sallis et al., App. Phys. Lett. 108 (2016) 263902

[2] I. D. Scott et al., Nano Letts. 11 (2011) 414

[3] R. Wagner et al., Appl. Mater. Interfaces. (2016) 30871

Figure 1
Structural Properties and Functional Electrochemistry of Spinel Type Iron Oxide Structures
Authors: Takeuchi Esther S , Marschilok Amy C , Takeuchi Kenneth J
Published: February 2020

In recent years, binary transition metal oxides such as magnetite, Fe3O4, zinc ferrite, ZnFe2O4, magnesium ferrite, MgFe2O4 and copper ferrite, CuFe­2O4, have gained significant attention as prospective electrodes for lithium based batteries. These materials hold interest due to the low cost iron center, their low environmental impact, and in particular for their high theoretical capacities. Through a combined insertion and conversion mechanism theoretical capacities of up to 1000 mAh/g would be possible, thus, storing more energy than typical insertion materials. Interestingly, along with the commonality of the iron metal center, the materials often have spinel or inverse spinel structures. The densely packed structure of these spinel materials has led to the demonstration that smaller crystallite size samples can provide higher practical energy density than larger size samples. This presentation will provide insight into the role of crystallite size as well as the lithiation/delithiation mechanisms of this class of bimetallic iron oxide structures.