bluuebunny/crossref_metadata_2025_split huggingface dataset:
Understanding the Pseudocapacitive Behavior of RuO2 from First Principles
Authors: Keilbart Nathan D. , Dabo Ismaila 
Published: February 2020

The ever increasing power of electronic devices creates a taxing demand on energy storage technology to increase the energy and power density available. Typical energy storage devices that have met this demand in the past are batteries and capacitors. A growing need for high energy and power dense materials leads to a new set of devices called pseudocapacitors, typically made from battery electrode materials but on a nanometer scale, which push the limit of both energy and power density available in a single device. The charge storage system of pseudocapacitors can be broken into several parts: double-layer capacitance, underpotential deposition, redox and intercalation pseudocapacitance which occurs through quick intercalation and surface redox reactions on the electrode.1 Therefore, to maximize the capabilities of pseudocapacitors the surface area must be increased for double-layer capacitance as well as allowing fast and reversible faradaic reduction-oxidation reactions. The exact nature of these redox reactions are not fully understood with respect to the oxidation state of the atoms. A typical pseudocapacitor material is Ruthenium Oxide (RuO2) which exhibits great pseudocapacitor properties but becomes expensive when looking to make on a large scale. The goal of this work is to better understand the material properties of pseudocapacitive materials, such as RuO2, that permit them to have the qualities of a pseudocapacitor as opposed to that of a battery. To do this work, the use of highly efficient and high throughput computation models, such as density functional theory (DFT), are used to proficiently calculate material properties in order to exclude material systems that do not meet designated outcomes. A particular method of interest for this process is the Self-Consistent Continuum Solvation model (SCCS)2 which allows DFT to correctly model the dielectric properties of a solvent. From the values calculated in DFT we are able to predict the change in the Gibbs free energy as well as the change in the chemical potential of the system as the surface of the material is covered with ions. Furthermore, charged surface calculations allow for the prediction of the change in the material properties at different levels of coverage3 and charge. For future and current work we would apply these models to pseudocapacitor systems to examine if they have intrinsic properties or if the material could be manipulated on the structural level to have the abilities of an extrinsic pseudocapacitor.

References

1. Augustyn, V., Simon, P. & Dunn, B. Pseudocapacitive oxide materials for high-rate electrochemical energy storage. Energy Environ. Sci.
7, 1597 (2014).
2. Andreussi, O., Dabo, I. & Marzari, N. Revised self-consistent continuum solvation in electronic-structure calculations. J. Chem. Phys.
136, 064102 (2012).
3. Bonnet, N. & Marzari, N. First-principles prediction of the equilibrium shape of nanoparticles under realistic electrochemical conditions. Phys. Rev. Lett.
110, 1–5 (2013).
(Invited) The Use of Modeling to Reveal Root-Cause and Quantify Degradation Effects in Electrochemical Systems
Authors: Fuller Thomas F 
Published: February 2020

Electrochemical systems are characterized by coupled, non-linear behavior of several phenomena. Typically, thermodynamics, kinetics, and mass-transfer all come in to play in describing the current voltage response of a system. This strong coupling can make interpretation of experimental results confounding and cause our intuition to fail us. Through, mathematical modeling, the nature of the response is more easily revealed. This concept is explored through two real-world applications of electrochemical systems: start-stop phenomena in fuel cells and power fade in lithium-ion batteries.
Corrosion of carbon support during start-up and shut-down of proton-exchange-membrane fuel cells is well-known and widely reported in the literature. Today, this is an accepted degradation mechanism. However, the journey from severe performance loss observed in a fuel-cell vehicle to our present understanding was difficult. In fact, measurements of cell potential and current did not help elucidate the mechanism at all. It was only through mathematical modeling that the corrosion process was clarified. No new physics was needed, just the careful assembly of existing knowledge of kinetics and transport for a start-up transient.
Capacity fade in lithium-ion batteries is also a well-known issue. Generally, the formation and slow growth of the solid electrolyte interphase (SEI) results in irreversible consumption of lithium. This loss of cyclable lithium translates into a reduced capacity of the battery with age. In addition to capacity fade, power fade is critical for many applications. A prime example is the battery for a charge-sustaining hybrid-electric vehicle. Here, the energy storage system is used for recovering energy and power assist, not sustained propulsion of the vehicle. Therefore, power capability is at least if not more important than capacity. The power capability is characterized by “cell resistance.” As the SEI thickness grows, the ohmic resistance of the cell increases. However, the magnitude of the increase cannot explain the power fade. Typically, for a pulse of current of ten or so seconds is used in practice to measure “cell resistance.” For transients of this length, this quantity is not simply the ohmic resistance of the cell--concentration polarizations are significant. This behavior is explored with well-established mathematical models of lithium-ion cells. Again, a mathematical model that uses existing physics is able to shed light on the nature of the power fade.
(Invited) New Li Ion Cells with Extended Temperature Range
Authors: Ma Chengsong , Peres Jean-Paul 
Published: February 2020

Saft developed a new Li ion cell limiting cell aging between -40oC and 85oC. It avoids Li deposition, electrodes de-percolation & swelling.
This new cell design address issue of the state of art Li ion cell which are not able to work both at LT (-20°C and below) and at HT (+60°C to +85°C), without a strong cell electrical performances degradation. It sustains a long calendar life or floating period at 4.1V-4.2V @ 60°C, without a strong electrical performances degradation, and/or a rapid opening of the circuit breaker in link with internal cell gas generation. It limits cell self heating at end of discharge during high rate discharge at elevated temperature environment. It has 10 years life floating at 4.2V. This cell has three layers of safety protection and compliance to international safety standard.
(Invited) Aqueous Interphase Enables Safe, Green and Low Cost Li-Ion Chemistry
Authors: Suo Liumin , Borodin Oleg , Wang Chunsheng , Xu Kang 
Published: February 2020

The interphases play a key role in enabling Li-ion intercalation chemistries in non-aqueous electrolytes, in which solvents reduction mainly contribute the chemical building blocks 1, 2. Recently Suo et al discovered for the first time that such protective interphases could be formed in aqueous media via manipulation of the Li-ion solvation structure 3. This discovery opened a window to an entirely new world, and makes it possible to employ aqueous electrolytes to replace the inflammable and toxic non-aqueous components that induces huge cost in processing, safety management as well as packaging 4. This talk will summarize the newest progress achieved in this new direction.

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2004, 104, 4303

K. Xu, Chem. Rev.,
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L. Suo, O. Borodin, T. Gao, M. Olguin, J. Ho, X. Fan, C. Luo, C. Wang, and K. Xu, Science,
2015, 350, 938

L. Smith, and B. Dunn, Science,
2015, 350, 918
Lithium Plating: Root Cause, Post-Mortem Characterization, and Key Parameters to Exclude It in Automotive Applications
Authors: Waldmann Thomas , Hogg Bjoern-Ingo , Kasper Michael , Wohlfahrt-Mehrens Margret 
Published: February 2020

Deposition of metallic Li on graphite anodes is a critical aging mechanism happening in Lithium-ion cells during charging at low temperatures, high C-rates and high states-of-charge [1,2]. Furthermore, Li deposition can also have negative effects on cell safety [3]. The cause for deposition of Li on anodes are negative anode potentials vs. (Li/Li+). Unfortunately, anode potentials are not accessible in commercial cells since they do not contain a reference electrode. In half cells such measurements are also not possible, since the interaction between anode and cathode is absent. Furthermore, the position of the reference electrode between anode and cathode is very important to measure anode potentials correctly [4] (Figure (a)).
In the present talk, we show that it is possible to reconstruct both, anodes (graphite) and cathodes (NMC/NCA) from commercial cells (16Ah pouch/3.25Ah 18650-type) into 3-electrode full cells with an additional Li reference electrode (Figure (a)). With these 3-electrode cells, it is possible to measure the anode potentials vs. (Li/Li+) for all important combinations of operating parameters: (i) temperature, (ii) charging C-rate, and (iii) end-of-charge voltage. Data evaluation results in parameter sets which can exclude Li deposition on anodes (Figure (b)). The data extracted from the 3-electrode full cells are in agreement with long-term cycling tests and with Post-Mortem analysis of the original commercial cells. Furthermore, the data from the 3-electrode full cells allow to extend the cycle life of the original commercial cells significantly.
References:
[1] J.C. Burns, D.A. Stevens, J.R. Dahn, J. Electrochem. Soc. 162 (2015) A959-A964.
[2] T. Waldmann, M. Kasper, M. Wohlfahrt-Mehrens, Electrochim. Acta 178 (2015) 525-532.
[3] M. Fleischhammer, T. Waldmann, G. Bisle, B.-I. Hogg, M. Wohlfahrt-Mehrens, J. Power Sources 274 (2015) 432–439.
[4] B.-I. Hogg and M. Wohlfahrt-Mehrens, in Meeting Abstracts, The Electrochem. Soc. (2015), 343 .

Figure 1
(Invited) Dry Electrode Process Technology
Authors: Duong Hieu , Suszko Arek , Feigenbaum Haim 
Published: February 2020

Within this decade, there has been immense effort focused on reducing the cost of energy storage devices. The goal towards energy independence through electrification of automobiles for widespread adoption has greatly incentivized this endeavor. Strategies ranging from novel materials investigation to advanced device manufacturing development span the cost reduction effort. Maxwell Technologies is actively engaged in this global effort from the direction of dry electrode fabrication technology. Maxwell dry electrode technology offers manufacturing cost and performance competitiveness, and novel battery chemistry enablement. This paper provides the initial foundation and validation for the application of dry coated electrode in lithium-ion batteries.
Maxwell Technologies is a San Diego based ultracapacitor manufacturer that uses a proprietary liquid-free electrode production process. Advanced process development without the need for solvents has enabled Maxwell’s dry electrode production lines to operate at high throughput using a minimal manufacturing footprint. This unique electrode manufacturing process does not introduce any volatile waste products into the atmosphere or require complex manufacturing plant arrangement. It begins with dry raw materials compounding and maintains its liquid-free state throughout the subsequent processing steps to ultimately produce a robust high-performance ultracapacitor electrode. Since this process produces a dry active material free-standing film, the scrap is collected and reused in the successive processing batches.
Maxwell is currently engaged in research and development efforts to expand the application space of its dry electrode process technology to include battery electrode manufacturing. Cell performance using prototype dry coated lithium-ion battery electrodes has been demonstrated under two DOE funded programs. Electrode configuration with various architectures using a wide range of materials can be produced at thicknesses ranging from about 50 microns to about 1 millimeter. In addition to manufacturing flexibility, the cohesion and adhesion properties of electrodes derived from the dry process are superior in the presence of electrolyte at high temperatures compared to those produced using the wet coating technology.
This unique electrode process technology offers significant saving in manufacturing cost and helps curb CO2 pollution during the battery electrode manufacturing process. By eliminating the use of any liquids/solvents, and the associated coating and drying complexity inherent in wet processing, the dry electrode process is environmentally friendly, and can be readily installed and commissioned with a much lower start-up capital investment. Thus, dry electrode manufacturing is economically attractive and socially responsible.
This paper will provide insight into dry electrode coating technology and its capacity for the enablement of advanced battery chemistries, and cell performance results derived from dry coated lithium-ion battery electrodes.
Two-Dimensional Layered Materials with Expanded Interlayer Distance for Rechargeable Magnesium Batteries
Authors: Li Yifei , Liang Yanliang , Yao Yan 
Published: February 2020

Mg rechargeable batteries (MgRBs) stand out as a promising candidate beyond lithium ion battery technologies due to high volumetric energy density, resource abundance, and the dendrite-free deposition behavior of Mg, which ensures safe operation. Many of the advantages of MgRBs originate from the divalent nature and small ionic size of Mg ions; however, these properties also render the cation too polarizing to diffuse easily in most ion- intercalation materials. To overcome this challenge, we recently adopted an interlayer expansion approach via insertion of external pillars to transform two representative two-dimensional layered materials (MoS2 and V2O5) into efficient Mg storage host materials.
To boost the Mg storage performance of MoS2, we intercalated appropriate amount of poly(ethylene oxide (PEO) to expand MoS2 structure through an exfoliation and restacking process. [1,2] The Mg solid state diffusivity and capacity increased accordingly with increasing amount of PEO. PEO2L-MoS2 (two layers of PEO in between MoS2 layers) showed the best performance with Mg2+ diffusivity increase by two orders of magnitude and capacity increase of about 300% compared with bulk MoS2. The flexible PEO serves as a structure pillar, which can increase the interlayer spacing but not block the diffusion of Mg2+ ions. In the case of V2O5, we turned to insert small water molecules in the layered structure to take advantage of the shielding effect of H2O.[3] We prepared graphene decorated V2O5 aerogel nanowires, and demonstrated it to be an effective cathode material, with specific capacity of 330 mAh g-1 at low rate, stable cyclability and good rate performance. The performance enhancement compared with bulk V2O5 is due to the increased space and charge shielding effect of crystal water in the aerogel to enhance the Mg2+ insertion and the porous structure of aerogel allowing easy access of electrolyte into the active material. Moreover, various interlayer spacing and crystal water amount were also studied and we found that the as-prepared sample with the highest amount of water and interlayer spacing showed the best performance.
The merit of the interlayer expansion lies at the enlarged space for enhanced Mg2+ ion mobility and weakened interaction between Mg2+ ions and the electrode frameworks. This approach could be further extended to a wide range of host materials for the storage of Mg2+ ion and other multivalent ions.
1. Yanliang Liang, Hyun Deog Yoo, Yifei Li, Jing Shuai, Hector A. Calderon, Francisco Carlos Robles Hernandez, Lars C. Grabow, and Yan Yao, Nano Lett.
2015, 15, 2194-2202.
2. Yifei Li, Yanliang Liang, Francisco C. Robles Hernandez, Hyun Deog Yoo, Qinyou An, Yan Yao, Nano Energy
2015, 15, 453-461.
3. Qinyou An, Yifei Li, Hyun Deog Yoo, Shuo Chen, Qiang Ru, Liqiang Mai, and Yan Yao, Nano Energy
2015, 18, 265-272.
Polyimide Derivative As Electrolyte Additive to Improve Electrical Performance and Safety in Lithium-Ion Batteries
Authors: Chang Max Yu-hao , Chu Peter Po-jen 
Published: February 2020

A new type of electrolyte additive, the hyperbranched polyimine derivative (p-BPMI) is prepared from 1,3-dimethyl-barbituric acid (1,3-DBTA), copolymerizing of bismaleamic acyl imide (BMI) and N-phenylmaleimide(PMI). The p-BPMI powder is dissolvable in electrolyte (1M LiPF6 in EC+DMC+EMC 1:1:1 V/V %), and administered similarly as other electrolyte additives. The interface composition and SEI structure after pre-cycling the coin cells using the Li(Ni1/3Mn1/3Co1/3)O2/Li half cell were characterized by SEM、EIS and XPS techniques and confirmed that the hyper-branched p-BPMI participated with the growth of SEI, where both the electrolytes and salt decomposition are reduced, leading to the formation of thinner and more robust SEI coating.
With addition of 1wt% p-BPMI in electrolyte, the capacity retention is improved from 85.21% to 96.53% compared with the base electrolyte after 0.5C-rate for 80 cycles at 25°C. Cycling at 0.5C-rate at 60oC for 30 cycle, the capacity retention is improved from 93.71% to 96.43% when compared with 1wt% VC. NMC/graphite pouch full cell (500mA) with 1wt% p-BPMI-added electrolyte in the fully charged state at 4.3V shows no sign of combustion or explosion after induce internal shortage by puncturing the cell, while the regular cell with only VC additive is exploded. This new type of electrolyte additive p-BPMI not only improved the room and high temperature cycling performance, it also assured LIBs safety.

Figure 1
Tuning Ionic Clusters in Sulfide Glass-Ceramics for Superior Solid-State Electrolytes
Authors: Kim Hyoungchul , Cho Soo-Young , Lee Yoon-Sung , Jung Hun-Gi , Lee Jong-Ho , Lee Hae-Weon 
Published: February 2020

The all-solid-state lithium batteries (ASSLBs) have drawn increasing interests and demands as the next-generation rechargeable batteries for electric vehicles and energy storage devices since they have much more potentials (e.g., higher safety, reliability, power density, and design flexibility) than conventional lithium batteries. However, all we know any further advances in ASSLBs are not possible without solving the current raising issues of ASSLBs, such as low lithium ion conductivity, structural instability, and high resistance of electrode/electrolyte interface. Especially, the unveiling the mechanism of lithium ion conduction in solid electrolytes, and the development of a superior solid-state lithium ion conductor are required.
Here we present the recent advances and understandings in Li-P-S based solid electrolytes for the next-generation ASSLBs using a novel atomistic alloying and annealing process. Employing the low-temperature milling and quantitative bulk/surface analyses, we demonstrate the tuning ionic structures in sulfide glass-ceramics for superior solid-state electrolytes, and unveil the roles of atomistic alloying in the mechanochemical pulverization and high-temperature annealing in the amorphous-crystal transition to seek the highly active, stable, and versatile Li-P-S based solid electrolytes. Controlling ionic structures and understanding such atomistic alloying and annealing effects of lithium super-conducting sulfides provides insights for designing advanced solid electrolyte materials. We also believe these research activities lead to the promising technological advances and provide new guidelines in developing the sulfide based solid electrolyte for ASSLBs.
A Vanadium Redox Flow Battery for Hydrogen Production
Authors: Girault Hubert 
Published: February 2020

A vanadium/cerium redox flow battery is used with two external circuits to ensure a chemical discharge of the electrolytes to maintain on optimum state-of-charge of the battery even in the case of electricity overproduction.
A first reactor is dedicated to hydrogen production whilst the second is dedicated to oxygen evolution.
In the first reactor, the Vanadium(II) solution in sulfuric acid is passed over a catalyst made of Mo2C to generate hydrogen under pressure.
In the second reactor, theCerium (IV) solution in sulfuric acid is apssed over a catalyst made of RuO2 to generate oxygen.
The theory underlying these electrochemical reactions on a floating catalyst will be discussed. Experiments on a 10 kWh scale will be presented.
In addition, we shall present our experience at coupling a 50 kW alkaline electrolyser with a 200kW Vanadium redox flow battery to run a service station for electric vehicles and hydrogen fuel cell cars.
Thin Film Li-Ion Microbatteries Using Self-Supported Titania Nanotubes
Authors: Djenizian Thierry 
Published: February 2020

Nowadays, lithium-ion batteries (LIBs) are widely used to power portable devices, microelectronics, vehicles, etc. With many advantages such as high surface area and improved charge transport, self-supported 3-D nanostructured metal oxides are promising electrode materials for LIBs and their impact is particularly significant when considering the miniaturization of energy storage systems and the development of 3D microbatteries [1-3].
During this talk, it will be presented the fabrication and use of materials derived from self-organized titania nanotubes (TiO2nts) as negative 3D self-supported electrodes for microbatteries [4–8]. This kind of 3D nanostructured electrodes is particularly interesting due to better electrochemical performance in terms of kinetics and stability during cycling.
Then, the fabrication of an all-solid-state Rocking-chair battery composed of vertical arrays of TiO2nts as anode, a polymer thin film as electrolyte, and a LiNi0.5Mn1.5O4 (LNMO) layer as cathode will be shown [9]. According to the electrochemical tests, this 2D full-solid microbattery showing an operating voltage of 2.1V exhibits high performance such as good discharge capacity and good capacity retention.
Finally, the current approaches developed to achieve the fabrication of a full 3D microcell will be highlighted. Particularly, the conformal electrodeposition of polymer electrolytes into tha titania nanotubes and their potential filling will be discussed [10-12].
References
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[2] L. Baggetto, J.F.M. Oudenhoven, T. van Dongen, J.H. Klootwijk, M. Mulder, R. a. H. Niessen, M.H.J.M. de Croon, P.H.L. Notten, J. Power Sources 189 (2009) 402.
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[4] G. Ortiz, I. Hanzu, T. Djenizian, P. Lavela, J.L. Tirado, and P. Knauth, Chem. Mater. 21 (2009) 63.
[5] N.A. Kyeremateng, C. Lebouin, P. Knauth, T. Djenizian, Electrochim. Acta 88 (2012) 814.
[6] N.A. Kyeremateng, V. Hornebecq, P. Knauth, T. Djenizian, Electrochim. Acta 62 (2012) 192.
[7] T. Djenizian, I. Hanzu, P. Knauth, J. Mater. Chem. 21 (2011) 9925.
[8] N.A. Kyeremateng, N. Plylahan, A.C.S. dos Santos, L. V Taveira, L.F.P. Dick, T. Djenizian, Chem.Commun. 49 (2013) 4205.
[9] N. Plylahan, M. Letiche, M. Barr, and T. Djenizian, Electrochem. Commun., 43, 121 (2014).
[10] N. Plylahan, N.A. Kyeremateng, M. Eyraud, F. Dumur, H. Martinez, L. Santinacci, P. Knauth, T. Djenizian, Nanoscale Res. Lett. 7 (2012) 349.
[11] N. Plylahan, A. Demoulin, C. Lebouin, P. Knauth, T. Djenizian, RSC Adv., 5, 28474 (2015).
[12] N. Plylahan, M. Letiche, M. Barr, B. Ellis, S. Maria, T. N. T. Phan, E. Bloch, P. Knauth, and T. Djenizian, J. Power Sources, 273, 1182 (2015).