bluuebunny/crossref_metadata_2025 huggingface dataset:
High-Pressure Electrochemistry: The Electrochemical Reduction of Carbon Dioxide into Usable Fuels and Chemicals
Authors: McKee Austin , Rassoolkhani Alan , Koonce Jonathan G , Alsaedi Sattar , Cheng Wei , Mubeen Syed
Published: February 2020

Currently, the United States ranks second internationally in terms of absolute carbon dioxide (CO2) emissions per year, exceeded only by China. Nearly 30% of these emissions come from coal- and natural gas-fired power plants. Carbon capture and storage (CCS) technologies can potentially reduce net CO2 emissions from power sectors; however, efforts, to date, have not been widely adopted due to high CO2 sequestration cost (over $60 per metric ton of CO2 captured). Electrochemical fixing of CO2 in stable high value marketable chemical products can potentially reduce net CO2 capture costs. Further, electrochemical systems can be powered by renewable electricity sources, thereby ensuring that no additional CO2 is produced in the process of CO2 removal. At present, all electrochemical-based carbon utilization technologies suffer from low product yield and rates, making them impractical for commercial applications. This poster will summarize our recent findings on CO2 reduction obtained from a high pressure electrochemical reactor. The motivation for using a high-pressure electrochemical reactor is to overcome two major limitations: (1) the low-current density caused by low CO2 solubility in ambient conditions; and (2) the low selectivity for CO2 reduction caused by the competing proton reduction to hydrogen. Particularly, the poster will summarize the results on CO2 reduction currents on Cu and Ag electrocatalysts as a function of CO2 partial pressure, co-solvent volume fraction, inter electrode spacing, and salt concentration.
Electrochemical Study of Photocatalytic Activity Enhanced By Plasmon Resonance
Authors: Velasco Tinajero Esteban
Published: February 2020

Titanium oxide has been proven the most promising material for water treatment via Advance oxidation process (AOP) due to its low recombination rate and high capacity to generate hydroxyl radicals, its most important downside is restricted photocatalytic activity to the UV range. Enhancing photocatalytic activity under visible light has been the objective of a lot of researchers around the world. Plasmon resonance in conjunction with traditional semiconductor photocatalyst provides an opportunity to understand and improve on the already useful properties of titanium oxide. The present study is focused on the interaction of an anodized titanium surface (ATS) and silver nanoparticles (Ag-NP) deposited on the ATS by photo electrochemical electroless reduction. Photocatalytic activity enhanced by plasmon resonance is expected to improve the material activity in two fronts, via the metal semiconductor junction where the electron hole (e/h) separation and fast lane charge transfer are induced, and a second front where localized surface plasmon resonance (LSPR) benefit photocatalysis by enabling visible light response, enhancing Visible/UV absorption, local electric fields reducing (e/h) diffusion length, generation of LSPR powered (e/h), local heating effects, lastly molecule polarization.

ATS was form by anodic oxidation of a titanium sheet at 30 V for 120 minutes in an organic electrolyte compose of ethylenglicol, NH4F and water at 5%. Subsequently Ag-NP were deposited by photoreduction of 0.1 M AgNO3, The material was characterized by cyclic voltammetry and scanning electron microscopy. The photo response to visible and UV light was evaluated by zero-current chronopotenciometry. The ATS/ Ag-NP system was successfully fabricated showing a porous titanium oxide surface, decorated by Ag-NP with a uniform size of around 60 nm. Results shows an increase in the visible light response provoked by the silver deposit, the way the photocatalytc response is affected appears to be dependent on the amount of silver deposited, and the size of the particles. Further studies on the effect of the nanostructures over the photocatalytic activity are being conducted.

Figure 1
A Comparative Study on the Corrosion Properties of Self-Piercing Riveted CFRP/Steel and CFRP/Al Joints
Authors: Bae Jin-Hee , Park Yeong-Do , Karim Md Abdul , Kam Dong-Hyuck , Kim Cheolhee , Jeong Chanyoung
Published: February 2020

This work aims to investigate the corrosion properties of CFRP/Steel (carbon fiber reinforced plastic) and CFRP/Al SPR (self-piercing riveting) joints by an Almac®-coated steel rivet. The corrosion behavior of all samples was evaluated by open-circuit potential and potentio-dynamic polarization tests in 3.5 wt% NaCl solution. Meanwhile, the samples were exposed to continuous a salt spray test up to 90 days. Furthermore, single-lap shear tests were carried out in order to assess the mechanical performance of these SPR joints before and after the salt spray test. The results show that the lap shear strength of the CFRP/Steel SPR joints was decreased drastically as a function of increasing exposure time, whereas the strength of CFRP/Al SPR joints remained relatively unaffected for the entire exposure time. It is also observed that the Almac®-coated steel rivet in the CFRP/Steel SPR joint was affected by severe galvanic and/or crevice corrosion as a result of the rivet head deterioration as the exposure time increased. On the other hand, the Al sheet of CFRP/Al SPR joint experienced noticeable pitting corrosion.
Study of Influence of Crystalline Phase of TiO2/MWCNT Novel Materials on the Photoelectrochemical Activity
Authors: Rosado Gabriel , Verde Gómez Ysmael , Alonso-Vante Nicolas , Valenzuela-Muñiz Ana Maria
Published: February 2020

Titanium dioxide is a low cost material, environmental friendly and one of the most attractive semiconductors, due to this it has a wide spectrum of applications in photocatalysis and photoelectrocatalysis. In this work, TiO2 nanoparticles in anatase and anatase-brookite phases were synthetized by sol-gel method, and deposited on multi-walled carbon nanotubes (MWCNT). A solution of Titanium (IV) Isopropoxide was mixed with MWCNT by ultrasonication, the suspension was kept in an ice bath (around 0o C), and water was added for the hydrolysis reaction. Anatase phase was obtained placing the so-gel product in a thermal treatment at 4000C during 2 hours. For anatase-brookite mixture, the sol-gel product was placed in a reflux system at 800C during 5 hours. Once the solution was cooled at room temperature, the pH was adjusted to 2. Finally, after a filtration process, the obtained material was dried and thermally treated at 4000C. In order to compare, anatase and anatase-brookite nanoparticles without MWCNT were synthesized. The materials were physically and chemically analyzed by scanning and transmission electron microscopy, energy dispersive X-ray spectroscopy, thermogravimetric analysis, Raman spectroscopy, surface area analysis (BET method) and X-ray diffraction. For the photoelectrochemical measurements, a three electrode cell assembly was used having 0.5M H2SO4 as base electrolyte. The working electrode was prepared by depositing the synthetized materials in a conducting glass substrate. Ag/AgCl (KCl sat) electrode and a Pt wire was used as reference and counter electrode respectively. During the analysis the working electrode was irradiated with UV light and linear sweep voltammetry (LSV) was performed in order to obtain photocurrent values. Photocurrents transients were obtained by light chopping with on-off periods of 5s. An extensive analysis and discussion of the obtained physicochemical results as well as the photocatalytic performance will be presents at the conference.
(Invited) Investigation of Solid Electrolyte Interphase on Amorphous Siox/Si Films Using Tip Enhanced Raman Spectroscopy
Authors: Nanda Jagjit , Yang Guang , Voylov Dmitry N. , Sokolov Alexei P. , Veith Gabriel M.
Published: February 2020

The composition, morphology and thickness of solid electrolyte interphase (SEI) on silicon anodes are dictated by multiple factors such as surface chemistry, electrolyte composition, chemical passivation effects etc. Further the SEI constantly evolves, as it is electrochemically lithiated (delithiated) during the enormous volume changes. SEI on silicon typically is reported to be in the range of tens of nanometers and can be compositionally heterogeneous. Normal vibrational spectroscopy techniques such as micro-Raman and FT-IR while pretty useful, provide chemical information at a relatively bulk scale, typically much > 100 nm from the sample surface.This makes it harder for getting information from the real SEI, which can be only order of tens of nanometer. Tip Enhanced Raman Spectroscopy (TERS) is based on the field enhancement of Raman active signal locally at regions close to the tip. The Raman cross section is enhanced at least several orders of magnitude due to resonance coupling between surface plasmon modes (of the tip) and the electromagnetic field of the excitation laser. TERS enables simultaneous chemical mapping and topography at a nanoscale spatial resolution. TERS mapping of cycled amorphous silicon show the SEI composition and morphology changing as a function of electrochemical cycles. These observations will be compared with results from other techniques such as X-ray photoelectron spectroscopy
Theoretical Analysis of Li Insertion/Desorption Reaction at Li
x
C6/1M LiPF6 EC Solution Interface Using Density Functional + Implicit Solvation Model
Authors: Haruyama Jun , Ikeshoji Tamio , Otani Minoru
Published: February 2020

A fundamental approach to solve energy-related issues is the development of a stable energy storage device. Lithium-ion batteries (LIBs) are one of the most promising candidates because of their high energy density and long cycle life. Charge transfer reactions at electrode/electrolyte interfaces is regarded as a main factor limiting the performance of LIBs.1,2 In this study, we focus on Li insertion/desorption reaction R at the interface between graphite anode and 1 M LiPF6 EC solution:

Li
n
C6m
→ Li
n

-1C6m
+ Li+(EC) (R).

Methods

We applied density functional theory (DFT) + effective screening medium (ESM) method3 combined with reference interaction site method (RISM);4 ESM-RISM calculation treats graphite surface (Li
x
C6 slab + Li+) and liquid solution (1 M LiPF6 EC) by quantum mechanics and implicit solvation model, respectively.5 ESM-RISM calculations were performed on the configuration of a vacuum/slab/solvent system as shown in Figure 1, where the DFT slab domain is on the left-hand side, and the RISM solvents (EC, Li+, and PF6
−) treated by the RISM equations are on the right-hand side. The Li insertion/desorption path (reaction R) was assumed as a combination of one or two straight lines, as indicated in Figure 1. The reacting Li was moved from the stable Li site in the graphite layer (r = 0) to the interior region of the solution. In the ESM-RISM calculations, the distribution function of the solvation is automatically formulated for the solvation/desolvation structures.

Results

We successfully obtained the energy landscapes of reaction R under the various constant chemical potentials of electron; a profile of the grand potential Ω along the reaction R path as indicated in Figure 1. The activation energy of reaction R at the equilibrium potential is approximately 0.6 eV, which is consistent with the experimental measurements.1,2 In the presentation, we will discuss changes of the activation energy and the surface charge density with changing the Li content x of Li
x
C6 (x=0, 0.5, 1) on two differently tilted graphite (30 and 90 degrees).

References

T. Abe, H. Fukuda, Y. Iriyama, Z. Ogumi, J. Electrochem. Soc.
151, A1120 (2004).

K. Xu, A. von Cresce, U. Lee, Langmuir
26, 11538 (2010).

M. Otani, O. Sugino, Phys. Rev. B
73, 115407 (2006).

F. Hirata, P. J. Rossky, Chem. Phys. Lett.
83, 329, (1981).

S. Nishihara, M. Otani, Phys. Rev. B
96, 115429 (2017).

Figure 1
Elucidating Decomposition Mechanisms of Ethylene Carbonate on Layered Cathode Material Surfaces in Lithium Ion Batteries
Authors: Qin Xueping , Shao Minhua , Balbuena Perla B
Published: February 2020

During the charge/discharge cycling processes in lithium ion batteries (LIBs), degradation reactions of organic solvents would be inevitable at the electrode-electrolyte interface because of the instability of electrolyte components,1,2 leading to electrode degradation, capacity fade, poor cycling stability, and even safety issues. Since the reductive decomposition mechanisms of electrolytes at the anode-electrolyte interface have been extensively studied by theoretical simulations,3 it is critical to understand the interfacial reaction mechanisms at the cathode-electrolyte interface to provide more effective strategies to help design interfacial layer in LIBs, alleviating capacity fading and improving the cycle performance of batteries.

First-principles calculations were conducted to study the oxidative decomposition reactions of ethylene carbonate (EC) on the (110) surface of LiNi1/3Co1/3Mn1/3O2 (NCM333). All the possible oxidative decomposition reaction steps of EC on cathode surfaces, including H-abstraction reaction and ring-opening reactions caused by Cc-Oe and/or Ce-Oe bond cleavage, were analyzed from both thermodynamic and kinetic aspects. We found that EC decompositions are initiated by the ring-opening reaction (Cc-Oe bond cleavage) as the first step with an activation barrier of 0.57 eV and reaction energy of -0.70 eV. Afterwards, the H-abstraction reaction is quite easily to occur with an activation energy of only 0.26 eV. Figure 1 shows the reaction energies (ΔE) and activation energies (Barriers) for four possible reaction pathways as the first decomposition step for EC on NCM333 (110) surfaces. Another layered cathode material LiCoO2 (LCO) was also considered, and the similar decomposition steps were found for EC decomposition on (110) surfaces.

In a further study, lithium salt anions (PF6
-) and solvent molecules (EC) as well as Mn cations were introduced into the model. These molecules showed significant effects on the reaction pathways.

References

(1) Aurbach, D.; Gofer, Y.; Langzam, J. Journal of the Electrochemical Society
1989, 136, 3198.

(2) Etacheri, V.; Marom, R.; Elazari, R.; Salitra, G.; Aurbach, D. Energy & Environmental Science
2011, 4, 3243.

(3) Martinez de la Hoz, J. M.; Leung, K.; Balbuena, P. B. ACS Applied Materials & Interfaces
2013, 5, 13457.

Figure 1. Reaction energies (ΔE) (black filled circles) and activation energies (Barriers) (red empty circles) for four possible reaction pathways as the first decomposition step for EC on NCM333 (110) surfaces. Color code: lithium, green; carbon, brown; oxygen, red; hydrogen, white; Co, dark blue; Ni, silver gray; Mn, purple.

Figure 1
Granular Dendrite Free Effect of CsPF6 as an Electrolyte Additive for Micro Patterned Lithium Metal Anode
Authors: Kim Seokwoo , Ryou Myung-Hyun
Published: February 2020

To increase lithium secondary batteries energy density, lithium metal with high theoretical specific capacities, low densities, and lowest negative values of electrochemical potential should be used for anode material. However, despite their advantages, the unpredictable lithium deposition of lithium metal anode generating low Coulombic efficiency and safety problem has limited their commercialization until now. So, in order to solve this problem, our group developed regular sized micro patterned lithium metal anode for lithium secondary batteries. This micro patterned lithium metal anode demonstrated great electrochemical performance. But, above specific current density (about 2.4 mA cm-2) cycling, the cell with patterned lithium metal anode gradually lost their original capacity and showed low Coulombic efficiency due to forming granular lithium depositions in the micro patterned lithium metal holes. Luckily, additionally, micro pattern lithium metal anode is simply able to apply others lithium dendrite suppressed methods such as protection layer, electrolyte additive and so on. To remove these potential risk of electrochemical performance, CsPF6 electrolyte additive was introduced in our patterned lithium metal anode. This additive was known for suppressing lithium dendrite growth due to their Self-Healing Electrostatic Shield (SHES) Mechanism. Herein, LMO/Pattern lithium metal coin cells with CsPF6 additive in electrolytes show well protected patterned lithium metal anode surface, enhanced rate capability and extended cycling stability. This is mainly because CsPF6 can relatively help forming dense lithium deposition in pattern lithium metal hole so that bulk electrolyte consumption was suppressed.
Non-Carbonate Based Electrolytes for High Energy Lithium-Rich Manganese-Based Positive Electrodes with Excellent Cyclability
Authors: Xia Lan , Chen George
Published: February 2020

The demand for high specific-capacity positive electrode materials has become a high priority for the integration for high-energy density rechargeable lithium-ion batteries (LIBs) in transportation and grid storage applications. With the advantages of high capacity of >280 mAh g-1, high operating voltage (>3.2 V vs. Li+/Li on average) and low cost, Li-rich Mn-based layered oxides xLi2MnO3-(1-x)•LiMO2 (M= Ni, Co, Mn) have emerged as a potential next-generation positive electrode materials for high-energy density Li-ion batteries. However, a poor cycling stability observed in Li-rich cathodes is regarded as a major obstacle to commercialization. It is now well recognized that the use of conventional carbonate-based electrolytes in current Li-rich positive electrodes, which can react with oxygen evolved from the lattice of Li-rich positive electrodes during cycling, is a major cause for theirs poor cycling stability. Therefore, here we select several non-carbonate based electrolyte solvents including ethers, crown ethers, fluorinated ethers (1, 1, 1, 3, 3, 3-hexafluoroisopropyl methyl ether, HFPM), sulfones and phosphates and prepare some electrolytes based these non-carbonated solvents. The results indicate that the Li-rich electrodes with non-carbonate electrolyte show good performance in galvanostatic cycling, confirming their potential as rich-Li positive materials with enhanced longevity and safety.

Figure 1
(Invited) Electrochemical Characteristics of Lithium-Ion Cells Employing Different Additives at Low Temperature
Authors: Kim Dong-Won , Kim Sang-Hyung , Park Seung Hark , Han Dong-Kwan , Kim Soojin , Kim Myung-Hoon , Park Jung Joon
Published: February 2020

Significant attention has been paid to lithium-ion batteries (LIBs) with high energy density and excellent cycle life, because new applications such as electric vehicles (EVs) and energy storage systems (ESSs) are rapidly emerging into the market. However, current LIBs cannot satisfy the low temperature performance for further applications of EVs in cold climates. It is common that the LIBs lose most of their reversible capacity and power density as the temperature decreases below 0 oC.1,2 Therefore, improving low temperature performance has been an important subject for many researchers. In our study, we firstly try to investigate the factors that limit the low temperature performance of LIBs by using electrochemical impedance spectroscopy (EIS) analysis. Furthermore, we examine the electrochemical characteristics of LIBs with electrolyte solution containing small amounts of different low-temperature additives. X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) analyses have been also implemented to identify and inspect the detailed mechanism for improving the low temperature performance.

References

S.S. Zhang, K. Xu and T.R. Jow, Electrochim. Acta, 49, 1057 (2004).

K. Xu, Chem. Rev., 104, 4303 (2004).
Electrochemical Reactions at the Electrolyte–Electrode Interfaces in All-Solid-State Batteries Elucidated By Operando X-Ray Photoelectron Spectroscopy
Authors: Wu Xiaohan , El Kazzi Mario , Villevieille Claire , Novák Petr
Published: February 2020

All-solid-state lithium ion batteries (SLiB) represent a promising battery technology thanks to the replacement of the volatile and flammable state-of-the-art liquid electrolyte by a non-flammable solid electrolyte (SE).[1] Recent progress in the development of SE with high ionic conductivity moves the battery performance, i.e. energy and power density closer to the state-of-the-art Li-ion technology.[2] Despite the significant improvement of the bulk materials properties, degradation phenomena at the electrode/electrolyte interface remain to be understood in order to ensure long-term cycling stability of the batteries. Post-mortem XPS has proved to be a powerful and appropriate technique for monitoring the chemical states of elements at the interfaces between the SE, the active materials, and conductive carbon.[3] However, it still suffers from experimental limitations to explore the full picture of the surface and interface reaction mechanisms.

We present here operando X-ray photoemission spectroscopy (XPS) as an advanced methodology to assess the interfacial (electro-) chemical reactivity between active materials (AM), conductive carbon and SE during battery cycling leading to the formation of interphases at the nanoscale which critically affects the ion transport within the SLiB. Starting from the working principles of electron spectroscopy, we derive a model to assign the observed binding energy (BE) shift to different electronic properties of the materials. This way, in addition to the observed chemical reactions in real-time, we gain further knowledge on the surface potential by analyzing the voltage dependent spectra evolution. Through an efficient experimental implementation, this method enables simultaneous monitoring of the chemical and electronic properties of the electrode-electrolyte interphases during battery operation. These fundamental knowledge will be applied and demonstrated in several case studies: i) using a mixture of amorphous (Li2S)3-P2S5 (LPS) as SE with conductive carbon, the redox reaction mechanism of the SE is fully revealed, ii) using LiCoO2 and amorphous (Li2S)3-P2S5 as SE, this methodology allows to determine precisely the oxidation potential of the SE, the interfacial reaction products as well as the cross reaction mechanisms between LCO and LPS and iii) using a mixture of In, LPS and carbon, the chemical and electrochemical reaction within a commonly used counter electrode composite is elucidated.

Reference
s
:

[1] Y. Kato, S. Hori, T. Saito, K. Suzuki, M. Hirayama, A. Mitsui, M. Yonemura, H. Iba, R. Kanno, Nature Energy, 1 (2016) 16030.

[2] N. Kamaya, K. Homma, Y. Yamakawa, M. Hirayama, R. Kanno, M. Yonemura, T. Kamiyama, Y. Kato, S. Hama, K. Kawamoto, A. Mitsui, Nat Mater, 10 (2011) 682-686.

[3] J. Auvergniot, A. Cassel, J.-B. Ledeuil, V. Viallet, V. Seznec, R. Dedryvère, Chemistry of Materials, 29 (2017) 3883-3890.

Figure 1
Interfacial Kinetics and Ionic Diffusivity of Electrodeposited MoS2 Film a Battery Electrode
Authors: Amin Md Ruhul , Hossain Md. Anower
Published: February 2020

The MoS2 is deployed in various fields of applications including rechargeable battery, hydrogen storage, solar cell, catalysis and electronic transistors. The ionic diffusivity and interfacial exchange current density, are important parameters, play a vital role for the optimization of device performances which are not systematically studied for this material. Additive-free dense film of MoS2 has been fabricated by electrodeposition technique and annealed at different temperatures in argon and sulfur atmosphere. The as-deposited and heat treated film is characterized by XRD, SEM, SIMS and XPS. The measurements of interfacial charge transfer kinetics and lithium ion diffusivity is performed in the half cell configuration (Li/separator/LixMoS2 film) as a function of lithium content. The exchange current density at the electrode/electrolyte interface is found to be barely vary with the degree of lithiation (~0.09-0.08mA/cm2) at (x=0.01-0.25). The ionic diffusivity of the phase is found to be ~5x10-12cm2s-1 and ~5x10-11cm2s-1, respectively, and does not vary much with the degree of lithiation. From the obtained results it appears that the charge transfer resistance during electrochemical measurement is limited by the interfacial kinetics over the measured state-of-charge. Down size particle with higher surface area is required to be used as a battery electrode of the material for real life application.
(Invited) Direct Recycling of Lithium-Ion Batteries
Authors: Sloop Steven E , Xu Wei , Lerner Michael M. , Kim Joon , Lee Myongjai
Published: February 2020

By 2025, the lithium-ion battery and disposal markets are forecast to reach $ 93 billion and $14 billion respectively. Logistics contribute to these costs, but processing takes its toll with energy intensive industrial smelting and/or hydrometallurgical technologies. As traction and storage cathode materials use less cobalt, these recycle technologies require centralized, large scale facilities to meet economic viability based upon the metal. Cobalt dilute or cobalt free applications may therefore require disposal fees, which is not helpful for circular economic sustainability for the advanced lithium-ion battery industry.

Another technological approach is necessary to address this challenge for the industry. Direct recycling has potential for cost effective recycling of lithium-ion cathodes, which is demonstrated for NMC532 and NMC622 in this work.

In the first example, NMC 532 electric vehicle grade cells were faded to 80% of their original capacity. The cells were pulverized and cathodes captured and treated and packaged. Afterwards, in a manufacturing setting, 2.2 Ah cells were built using the recycled cathode and graphite. Recycled cathode demonstrated both performance and manufacturability like new material. In side by side cycle testing, both tallied 2,500 cycles at C/10 to reach 80% of original capacity.

In the second example, starting with faded cells, NMC 622 is similarly regenerated to original capacity and rate capability. Physical characterization of NMC622 before and after processing shows the treatment reverses ageing in the surface region of the electrode particles resulting in renewed performance.

These examples show the ease and flexibility of hydrothermal and calcination processes to restore electrochemical performance to NMC cathode materials. A comparable industrial process is alumina production from bauxite, which has a world-wide production over 60,000 tons and demonstrates the scalability and low cost potential for direct recycling. The development of distributed direct recycling services reduces both logistical and production costs relative to the current approach. Direct recycling technologies provide a viable foundation for the future waste management services for the lithium-ion battery market.

Figure 1
(Invited) Evaluating the Impact of Initiation Methods on Propagating Thermal Runaway in Lithium Ion Batteries
Authors: Lamb Joshua , Torres-Castro Loraine , Karulkar Mohan , Stanley June , Grosso Christopher
Published: February 2020

The evaluation of lithium ion battery safety has traditionally focused on the performance of single cells exposed to abusive conditions. As lithium ion batteries are fielded in increasingly large and complex systems, the system level safety performance is becoming of greater concern. Testing laboratories and battery end users have begun to consider the hazards associated with a localized thermal runaway event, a single cell or small group of cells, propagating to the bulk of a large battery system. Evaluating this propagating failure requires initiating thermal runaway of a single cell or group of cells and observing how that failure affects the surrounding system.

A major uncertainty in this testing is the impact of the initial thermal runaway initiation. The common means of initiating this testing is through abusive battery tests, but the intensity of failure may vary with the test performed and the surrounding cells potentially influenced, which in turn leads to uncertainty in the test results. This work looks at the potential impact of various failure initiating methods on the results of a propagating battery failure. Figure 1 shows a comparison of overcharge failure (left) and a nail penetration failure (right) on a 5 cell pouch cell pack. This particular result shows some change in the initial failure intensity, and the time required to initiate a failure is significantly increased in the case of the overcharge test. However, once failure is initiated the propagating behavior is similar in this case. We take a systematic look at similar affects both amongst similar construction and as the same methodology is applied across various formats and cell chemistries.

Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.

Figure 1 Data showing a propagating battery failure initiated through overcharge (left) and nail penetration (right). While the failure of the initial cell is more energetic, other aspects of the propagating battery failure remain similar between each test.

Figure 1
(Invited) Safe Design of GS Yuasa Large Format Lithium Ion Cells for Industrial Applications
Authors: Inoue Takefumi , Matsubara Takehito , Yamamoto Yuzo , Aldrich Curtis , Moll William
Published: February 2020

Since the 1990’s, GS Yuasa has developed and produced large-format Li ion cells for a variety of applications including satellites, rockets, electrified vehicles, trains, AGVs, energy storage systems, UPS, submarines, and others. Through these activities, safer Lithium-ion cell designs have evolved not only through the careful selection of electrode chemistry, but also cell shape, case materials and cell orientation within the module or battery pack. Lithium iron phosphate, for example, is stable and often considered a “safe” material for use in the positive electrodes of lithium-ion cells; however, there have been many lithium iron phosphate cell fires in the field. Fires may be caused by leakage of a flammable electrolyte in proximity to an ignition source. GS Yuasa considers the combination of using a metal cell case with laser-welded seal and a terminals-up orientation of cells in the module or battery pack to drastically decrease the risk of electrolyte leakage. Figure 1 shows the typical cell design of our large lithium ion cells for electrified vehicles and other industrial applications such as trains, AGVs, energy storage systems and UPS. The metal case with laser-welded seal offers high reliability with respect to the prevention of electrolyte leakage. This approach to cell design and orientation locates the more sensitive potential leak paths such as the rupture disk, terminal seal and case welds in the top of the cell and away from free electrolyte. In this presentation, we will detail GS Yuasa’s cell and battery systems and discuss our field experiences.

Figure 1
Smart Microcapsule for Enhancement of Li-Ion Battery Separator
Authors: Lee Kyung Jin , Cha Sang-ho
Published: February 2020

Safety issue for Li-ion batteries have attained great attention as increasing the capacity and power of battery. In particular, development of functional separator which can retard flame generation or have shut-down properties has been focused steadily in recent years. One of method will be addition of functional microparticles or capsules on separator. Herein we attempted to prepare smart microcapsules and the capsules were coat on Li-ion battery separator in order to enhance Li-battery safety. The shell polymer can melt down under certain condition, so that induce shut-down of Li-ion battery operation. In addition, frame retardant materials can be inserted into core materials to prevent unexpected fire generation.
Infrared Microscopy for Characterizing Thermal Transport in Lithium-Ion Batteries
Authors: Kantharaj Rajath , Sun Yexin , Marconnet Amy
Published: February 2020

Thermal management of lithium-ion batteries is crucial for safe and reliable performance. Quantification of thermal transport in lithium-ion batteries is challenging due to the heterogeneous and multi-scale nature of the constituent materials. The electrodes themselves typically consist of particles with micro- and nano-scale features, and the structure and composition of the electrodes evolve with charging and discharging, and degrade with repeated cycling. Integrating thermal sensors within batteries is challenging due to the confined geometry and possibility of shorting the electrodes if using thermocouples within the closely packed electrode stacks. Here, we focus on quantifying thermal transport in batteries using infrared microscopy through the design of battery cells with infrared transparent windows for viewing the internal thermal distributions. In parallel, we measure the thermal conductivity of the battery cells in an open cell configuration without charging and discharging. These new data provide insight into the performance, heat generation, and thermal transport within the battery cells. Ultimately, these properties are required for understanding thermally driven failure modes, for designing systems with improved safety and reliability, and to prevent thermal runaway.
(Invited) The Role of Variability in Failure for High Energy and High Power Batteries
Authors: Nagpure Shrikant C. , Dufek Eric J. , Tanim Tanvir R , Liaw Boryann , Dickerson Charles C
Published: February 2020

The demand for higher power and higher energy Li-ion and Li metal batteries continues to increase. In order to meet expectations the utilization of materials and cell designs need to be optimized. The result of the need for high utilization is that small variations within a group of cells can create significant difference in performance and failure.

As part of an effort to advance the performance of Li metal batteries and specifically to increase specific energy closer to 500 Wh/kg recent work looking at the ability to more clearly understand and define the role that cell variability has on the performance of Li metal batteries has been undertaken. This work has shown that significant impact to performance arises as a set of cells, which at the beginning of life had low variability, age. Refined analysis of the electrochemical data enables key variation in Li utilization and other fade mechanisms to be clearly identified and quantified across the different cells.

Complimentary work looking at the ability to fast charge, Li-ion cells in 10 minutes or less has also begun. This presentation will discuss the analysis methodology, key similarities in identifying the role of variability and how a more refined understanding can significantly impact the technology development pathway.
Semi-Empirical Cycle Life Model with Electrolyte Depletion Function for Long Cycle Prediction of Lithium-Ion Battery
Authors: Park Joonam , Appiah Williams Agyei , Byun Seoungwoo , Jin Dahee , Ryou Myung-Hyun , Lee Yong Min
Published: February 2020

Lithium-ion batteries (LIBs) have already been adapted for the applications of electric vehicles (EVs) and energy storage systems (ESSs) thanks to their high power density (~1500 W/kg), high energy density (~250 Wh/kg), long cycle life, low self-discharge and among secondary batteries. However, in general, tens of years or thousands of cycles are too long to evaluate the electrochemical performance or reliability of large-format LIBs. moreover, since high-current cyclers are much more expensive in comparison with those for small LIB cells for small device, available channels for long-term tests must be limited. That is why high-level modeling and simulation technologies must be developed for the battery industry. In this study, we developed a new semi-empirical cycle life model for predicting long-term cycle life considering an electrolyte depletion function for the first time. Consequentially, we are able to predict capacity fade depending on operating conditions such as c-rate and depth-of-discharge (DOD), which should be pre-estimated before building up the battery management system for EVs and ESSs application.
First-Principles Study of Electrolyte Decomposition at the Lithium-Metal Anode
Authors: Camacho-Forero Luis E , Balbuena Perla B
Published: February 2020

In the search for batteries for the next generation of energy storage systems, one of the most promising candidates for the next generation of energy storage and conversion devices is the Li–sulfur battery. Here, the lithium-metal anode is a critical component of the battery due to its low density and extremely high theoretical specific capacity. However, several challenges have prevented lithium anodes from becoming viable to be used in commercial batteries. Some of these issues are related to the continuous decomposition of the electrolyte when it is in contact with the Li surface, which leads to the formation of an inhomogeneous Solid-Electrolyte Interphase (SEI) layer. It has been suggested that a controlled SEI growth on the anode surface can enhance the performance of the battery. Therefore, a comprehensive understanding of how the electrolyte components react with the Li-metal may help us elucidate improvements in performance and provide some guidelines for enhanced materials to extend battery life. In this work, we use density functional theory (DFT) and ab initio molecular dynamics (AIMD) simulations to investigate the decomposition of a series of electrolyte mixtures including pure solvent (1, 2-dimethoxyethane - DME) and 1M solutions of LiFSI (Lithium bis(fluorosulfonyl)) or LiTFSI (Lithium bis(trifluoromethanesulfonyl)imide) in DME. From a rigorous analysis of the AIMD simulations, the reaction pathways, distribution of charge, and structure of the SEI are characterized in detail. In addition, in order to corroborate the decomposition mechanisms predicted from the dynamics, some insights on thermodynamics and kinetics of the reactions are presented.
Towards First-Principles Design of Battery Components for Current and Next-Generation Li-Ion Batteries
Authors: Viswanathan Venkatasubramanian
Published: February 2020

Complete electrification of transportation and aviation requires more energy-dense batteries and requires a much more rapid design iteration loop.[1,2] Computation and data will play a crucial role towards achieving this goal. The design of Li-ion batteries components - anode, electrolyte and cathode require simulation capabilities at varying length and time scales. Here, we will discuss our group's progress in using first-principles modeling and data-driven methods for designing liquid electrolytes, solid electrolytes and cathodes. We highlight the importance of open source methods, especially in the context of phase-field modeling for describing Li metal based anodes. We will show the crucial role played by a tight integration between atomic scale and continuum scale simulations to identify material targets for various use-cases. We believe that a vertically integrated modeling approach is necessary to enable rapid development of next-generation Li-ion batteries to power electric semitrucks and aircrafts.

[1] S. Sripad, V. Viswanathan, J. Electrochem. Soc. 164 (11), E3635-E3646.

[2] S. Sripad, V. Viswanathan, ACS Energy Lett. 2 (7), 1669-1673.
Multiscale Modeling of Nanostructured Electrodes and Interfaces in Li-Ion Batteries
Authors: Bedrov Dmitry , Hooper Justin B. , Gritton Chris , Berzins Martin , Kirby Robert M.
Published: February 2020

In this talk we will discuss interdisciplinary efforts on multiscale modeling of electrochemical devices undertaken at the Alliance for Computationally-guided Design of Energy Efficient Electronic Materials (CDE3M). Specifically, we focus on our recent results in modeling components of Li-ion batteries, including solid electrolyte interphase (SEI), SEI/electrolyte interfaces, and nanostructured Si anodes. The coupling of electrochemical and mechanical processes inside electrodes and at electrode/SEI interfaces is one of the key challenges that has to be addressed in order to provide efficient materials-by-design of novel batteries. Most of the current modeling tools only consider these system at the continuum level. We have focused on the development of multiscale modeling tools that allow us to couple the atomic, molecular and nanoscale electrochemical and mechanical processes with continuum level modeling. In this talk we will discuss i) mechanisms of Li-ion transport through bulk SEI and SEI/electrolyte interfaces, ii) mechanical properties of SEI and its failure mechanism under large deformations, and iii) chemical/mechanical coupling during lithiation of nanostructured Si-based electrodes.
(Invited) Mesoscale Understanding of Lithium Electrodeposition
Authors: Mukherjee Partha P. , Hao Feng , Verma Ankit , Mistry Aashutosh N
Published: February 2020

The burgeoning demand for high-performance electrical energy storage has precipitated into the revival of research into lithium metal anode for battery systems. Traditional graphite-metal oxide systems are reaching their upper theoretical limits for capacity, with further improvements only resulting in incremental benefits. Consequently, the shift to lithium metal anode is inevitable for a major overhauling of battery performance. Lithium metal anodes are, however, fraught with undesirable electrodeposition. Based on the operating conditions and material properties, various morphologies are observed in experiments, including film, island, needle-like and fractal-like lithium electrodeposition. Amongst these, dendritic lithium morphology has the most deleterious consequences on battery safety and cyclability, which is still a critical challenge. This presentation aims to provide mesoscale insights into the fundamental understanding of lithium electrodeposition characteristics and electrochemistry-transport interactions.
(Invited) Rational Design of Battery Cathode Materials
Authors: Cho Kyeongjae
Published: February 2020

We will discuss about applying ‘materials by design’ and validation experimental research on high capacity cathode materials for Li and Na ion batteries (LIB and NIB). Using the first-principles density functional theory (DFT) method, we have designed electrode materials for battery cathodes, and subsequently performed experimental studies to validate the material designs. Through an integrated material design - experiment research, we have developed highly efficient cathode materials for NIB. [1] Furthermore, using the DFT based stability analysis of Li(Ni,Mn,Co)O2 (NMC) cathode materials, the underlying mechanisms of stability change in Ni-rich NMC cathodes are elucidated over the range of 30 – 100 % Ni concentration in metal composition. [2-6] Surface analysis of Ni-rich NMC has also provided insights on the degradation mechanisms (both chemical and mechanical) facilitating to develop a design strategy to improve the stability of Ni-rich NMC over 80% Ni contents. [7]

This work was also supported by the International Energy Joint R & D Program (No. 20168510011350) of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Ministry of Knowledge Economy, Korean government.

[1] D. Kim, M. Cho, K. Cho, “Rational Design of Na(Li1/3Mn2/3)O-2 Operated by Anionic Redox Reactions for Advanced Sodium-Ion Batteries,” Adv Mater 29(33), 1701788 (2017).

[2] Chaoping Liang, F, Kong, R. Longo, Santosh KC, Jeom-Soo Kim, SangHoon Jeon, SuAn Choi, K. Cho, “Unraveling the Origin of Instability in Ni-Rich LiNi1−2xCoxMnxO2 (NCM) Cathode Materials,” The Journal of Physical Chemistry C 120(12), 6383–6393 (Mar. 31, 2016)

[3] R. C. Longo, F. Kong, C. Liang, D. -H. Yeon, J. Yoon, J. -H. Park, S. -G. Doo and K. Cho, “Transition Metal Ordering Optimization for High-Reversible Capacity Positive Electrode Materials in the Li-Ni-Co-Mn Pseudoquaternary System,” Journal of Physical Chemistry C 120(16), 8540-8549 (Apr. 28, 2016).

[4] F. Kong, C. Liang, L. C. Roberto, D.-H. Yeon, Y. Zheng, J.-H. Park, S.-G. Doo and K. Cho, “Conflicting Roles of Anion Doping on the Electrochemical Performances of Li-ion Battery Cathode Materials”, Chem. Mater. 28(19), 6942–6952 (Oct. 11, 2016)

[5] Chaoping Liang, Roberto C. Longo, Fantai Kong, Chenxi Zhang, Yifan Nie, Yongping Zheng, Jeom-Soo Kim, SangHoon Jeon, SuAn Choi, and K. Cho, “Obstacles toward unity efficiency of LiNi1-2xCoxMnxO2 (x=0~1/3) (NCM) cathode materials: Insights from ab initio calculations” Journal of Power Source 340, 217-228 (2017).

[6] C. Liang, F. Kong, R. Longo, C. Zhang, Y. Nie, Y. Zheng, K. Cho, “Site-dependent multicomponent doping strategy for Ni-rich LiNi1-2yCoyMnyO2 (y=1/12) cathode materials for Li-ion batteries,” J. Mater. Chem. A 5(48), 25303-25313 (Dec. 2017).

[7] C. Liang, R. Longo, F. Kong, C. Zhang, Y. Nie, Y. Zheng, K. Cho, “Ab initio Study on Surface Segregation and Anisotropy of Ni-rich LiNi1-2yCoyMnyO2 (NCM) (y ≤ 0.1) Cathodes,” ACS Appl. Mater. Inter. (2018).
(Invited) Recent Advances in the DFT-Based Search of Cathode Materials for Ca Batteries
Authors: Torres Arturo , Casals Jose Luis , Luque Javier , Tortajada José , Arroyo-de Dompablo M. Elena
Published: February 2020

In the last years, concerns on Li availability have prompted the search for suitable alternatives to rechargeable Li-ion batteries. Batteries based on multivalent charge carriers (Mn+) can exhibit advantages in terms of energy density since for a certain amount of M carriers the capacity is doubled (n=2) or tripled (n=3) when compared to single valent carriers like Li+ or Na+. Calcium is an attractive candidate due to its low cost, natural abundance and low reduction potential. At this very early stage of the Ca-batteries technology, the quest for a high specific energy cathode material is an active field. The general goal of our work is the identification of materials able to function as positive electrode in Ca batteries.

DFT is a unique tool to quickly screen a variety of structures and compositions to identify potential cathode materials for this novel technology. The general strategy is firstly to calculate average voltage and volume changes associated to the Ca insertion reaction. Further, DFT theory could be applied to gather additional information regarding electronic and ionic conductivities, crystal structure of intercalated phases and precise voltage-composition-curves at various temperatures. In this communication, we will present a survey of recent results for oxides, silicates and sulphides as cathode for Ca batteries. Special attention is given to the calculation and analysis of Ca migration pathways using the NEB method. In good agreement with parallel experimental investigations [1-3], we found that the low ionic mobility is the main handicap for the insertion/deinsertion of Ca ions in most structures. Yet, for some materials, Ca intercalation is predicted at low C rates.

Acknowledgments: Authors are grateful for financial support from European Union H2020-FETOPEN funded project CARBAT-766617.

References;

[1]. M.E. Arroyo-de Dompablo, C. Krich, J. Nava-Avendaño, M.R. Palacin, F. Barde. Phys. Chem. Chem. Phys. 18 (2016) 19966.

[2]. M.E. Arroyo-de Dompablo, C. Krich, J. Nava-Avendaño, N. Biskup, M.R. Palacin, F. Barde. Chem. Mater. 28 (2016) 6886.

[3]. D. Tchitchekova, A. Ponrouch, R. Verrelli, T. Broux, C. Frontera, A. Sorrentino, F. Barde, N. Biskup, M.E. Arroyo-de Dompablo, M.R. Palacin. Chem. Mater. 30 (2018) 847.
Novel Carbon Nanomaterials for 3rd Generation Solar Cells
Authors: Wei Wei
Published: February 2020

Recently, we invented various types of 3D carbon nanomaterials, including 3D graphene and highly conductive porous carbon. Those novel materials possess high electrical conductivity and large accessible surface area, which are required for ideal electrode materials. In this presentation, the design and synthesis of those materials will be discussed and their excellent performance as counter electrodes for dye-sanitized solar cells and perovskite solar cells will be highlighted.