bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Fast-Charging on Ageing of Energy-Optimized Automotive LiNi1/3Mn1/3Co1/3O2/Graphite Prismatic Lithium-Ion Cells
Authors: Wreland Lindström Rakel , Mussa Abdilbari , Liivat Anti , Marzano Fernanda , Klett Matilda , Philippe Bertrand , Tengstedt Carl , Lindbergh Göran , Edstrom Kristina , Svens Pontus
Published: February 2020

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

Fig. Capacity fade vs. number of equivalent full cycles (inset: capacity fade vs. cycling time).

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

Li-ion batteries are good candidates for energy storage devices in the field of transportation as they grant not only high energy and power densities to the systems but also long cycle-life. The graphite is commonly used as the anode because of its high lithium storage capacity whereas the LiFePO4 (LFP) is a cathode material of choice for transportation applications which require high level of safety. Besides, the LFP is thermally and chemically very stable, enables a good specific capacity (170 mAh/g) and is more environmentally friendly than most of the other materials of positive electrode. Nevertheless, LFP/C(gr) system suffers from a particular undesirable phenomenon, namely the "cross-talking". It consists in the iron dissolution from the LFP, the migration onto the graphite electrode and the subsequent contamination of the Solid Electrolyte Interphase (SEI), which protects the graphite from further reduction of electrolyte and a loss of active lithium. As a matter of fact, changes in physical and chemical properties of the SEI occur. Among possible alterations, permeability to either reducible species or electrons increases, enabling new SEI to grow and thus consuming more lithium. The available charge in the system LFP/C(gr) is then constantly decreased as long as the cross-talking occurs, and so is the cycle-life of the battery. Therefore, this LFP/C(gr)-specific phenomenon is a big concern especially considering the difference of capacity fading with other systems of batteries for which it is much lower.

The aim of this work is to highlight, characterize and understand the cross-talking phenomenon through cycling of LFP/C(gr) coin cells. The Electrochemical Impedance Spectroscopy (EIS) technique will be used in order to assess the changes in physical and chemical properties of the LFP/C(gr) electrodes. EIS spectra from different steps of the electrodes lifetime under different conditions will be compared and discussed. By using symmetrical coin cells (LFP/LFP and C(gr)/C(gr)), it is possible to obtain EIS signal for each material, and a specific attention will be paid to the study of influence of the temperature on the impedance response. Additionally, physical parameters can be determined through EIS spectra such as activation energy of ionic conductivity and SEI thickness (from the complex capacitance representation). These electrochemical analyses will be completed by physical and chemical characterizations such as X-ray Fluorescence (XRF), Glow Discharge Optical Emission Spectroscopy (GD-OES) and RAMAN spectroscopy.

Figure 1
Improving the Electrochemical Performance of Li4Ti5O12 Anode By Phosphorus Reduction at a Relatively Low Temperature
Authors: Deng Wenwen
Published: February 2020

The current commercial Li ion battery composed of a transitional-metal oxide cathode and graphite anode cannot meet the demands of these vehicles due to the poor rate capability and safety issues (dendritic lithium) of the graphite anode. Li4Ti5O12(LTO) is used to replace graphite because it is lithium dendrite free and shows a long cycle life as a result of its minimal lattice expansion (less than 1%) during the charge/discharge process. However, its intrinsically poor electronic conductivity has restricted LTO from showing high rate performance. Reducing Ti4+ in LTO to more conductive Ti3+ can help increase the conductivity. There are two main ways to reduce Ti4+ in LTO to Ti3+, one method is done by using a transition metal, such as Cr, Mo, Cu, Co, or Ta, to partially replace Li or Ti in the lattice, and another approach is to use reducing reagents. Almost all the reported methods require high temperature (higher than 600 oC), which limits the application of these approaches. In this work, A novel and efficient method is demonstrated to improve the electrochemical performance of LTO. In contrast to other methods, inexpensive red phosphorus powder is used as a reducing reagent, and the reduction is conducted at a relatively low temperature of 400 oC. Charging/discharging test results show that the phosphorus treated LTO (LTO/P) can deliver a capacity of 75mAh g-1 at 16 C (1 C=170 mAh g-1), while the LTO electrode can only deliver less than 50 mAh g-1. After 160 cycles at 1C, LTO/P electrode can maintain a capacity retention of 96%, while the LTO only maintain 90% capacity, demonstrating a much-improved electrochemical performance. Cyclic voltammetry at different scan rates and EIS results disclose that both Li+ diffusion and electronic diffusion are enhanced for the LTO/P electrode. In addition, this simple, inexpensive, and efficient method can also be expanded to improve the electrochemical performance of other metal-oxide anode materials such as MoO3, offering a low cost and effective way for Li4Ti5O12 and metal-oxide anode applications.
Free-Standing Flexible FeF­­3-C Cathodes for Sodium-Ion Batteries
Authors: Sun Zifei , Liu Michael , Fu Wenbin , Lu Peilin , Zhao Enbo , Magasinksi Alexandre , Liu Mengting , Luo Shunrui , McDaniel Jesse , Yushin Gleb
Published: February 2020

Abstract: Sodium-ion batteries (SIBs) have recently attracted great attention as a potential alternative to lithium-ion batteries due to ubiquity of sodium reserves. Conversion-type iron trifluoride (FeF3) may become a particularly interesting cathode due to low cost and abundance of Fe and extremely high theoretical capacity of this material (712 mAh g-1). Unfortunately, prior studies showed rather poor capacity and cycling performance of FeF3 due to significant volume changes, morphological changes and various side reactions. Here we demonstrate that by the confinement of FeF3 nanoparticles in flexible carbon nanofibers (CNFs) to mitigate structural changes during cycling and by utilizing a novel electrolyte salt, substantial performance improvements could be attained. This novel (for SIB) cell design facilitated electron and ion transport and additionally led to the formation of a thin cathode electrolyte interphase (CEI) layer on the FeF3-CNF surface. The assembled cells show high discharge capacity of up to ~200 mAh g-1 at the rate of 100 mA/g (up to ~230 mAh g-1 at 20 mA/g) and capacity retention up to ~ 70% after 100 cycles, which represent the best results reported on FeF3 in Na-ion electrolytes. We acknowledged the funding support from ARO (Grant No. W911NF-17-1-0053), W.F. M.L. and S. Luo acknowledge the fellowship support of China Scholarship Council.
Effects of Porous Material Properties and Operating Conditions on PEM Electrolysis Performance and the Observation of Mass and Heat Transport
Authors: Lopata Joseph Steven , Bender Guido , Kang Zhenye , Young James L. , Shimpalee Sirivatch , Weidner John W.
Published: February 2020

Polymer electrolyte membrane water electrolysis (PEMWE) is a promising technology for the integration and utilization of renewable energy and hydrogen as an energy carrier. Advancements in catalysis have made the commercial viability outlook very encouraging. Nonetheless, more work is necessary to advance the technology from niche markets towards broad market penetration. Through this study, we increase understanding of transport and interfacial phenomena, which can be used to design more efficient electrolyzers and improve cell performance.

Preventing excessive oxygen accumulation in the catalyst layer (CL) by adjusting the geometry and properties of flow channels, the porous transport layer (PTL), and the CL itself may result in increased catalyst utilization, efficiency, and performance. Controlling feed water to allow a significant increase in CL temperature may also improve efficiency. In order to optimize performance without operating under conditions that may affect cell durability, PEMWE scale-up relies on robust models that accurately predict current and temperature distributions. Such models, particularly 3-D flow models, provide the opportunity to improve electrolysis efficiency through process engineering.

Electrochemical models have been commonly used to fit known relationships to the measured performance of PEMWE devices. Computational modeling is a lean approach to enhancing technology without the cost and duration of experimentation, albeit via the quantitative understanding of prior empirical observations. This work investigated the effects of experimental parameters on transport, highlighting the need to accurately model temperature elevation and gas inhabitation in the CL. This was done in order to develop and validate a 3-D PEMWE model that predicts current distribution and overall cell efficiency using computational fluid dynamics (CFD) simulations. The following experiments examined a PEMWE device under a wide range of conditions in order to uncover information about multiscale phenomena that may improve the model. The experimental parameter space was designed minding the importance of the through-plane pressure drop in the PTL and the temperature rise in the CL. It included variation of current density, inlet water flow rate, temperature, and properties of cell components. Polarization curves and complimentary Nyquist plots from electrochemical impedance spectroscopy (EIS) were used in addition to inlet/outlet temperatures and cell pressure drop to observe mass and heat transport. A summary of the findings from the main validation experiments and their interpretations will be discussed.
Electrochemical Synthesis of Conductive Polymers to Enhance Carbon Supports for Metal Catalysts
Authors: Vargas Pérez Brenda Lee , Cunci Perez Lisandro
Published: February 2020

In this project is based on the synthesis of electrically conductive polymers as supports for metal catalysts using the rotating disk slurry electrode (RoDSE) technique, in which isolated atoms, clusters and metal nanoparticles are deposited on an unsupported nanocarbon material. The aim of the research is the use of RoDSE to electrochemically synthesize nanoparticles based on polypyrrole as support for metallic catalysts. This technique will also be used to produce coatings of polypyrrole-based conducting polymers on nanocarbon supports to increase their surface. The first step is the synthesis of nanodiamonds to carbon nano-onions (CNO) using a thermal process. Once the product was obtained, it was characterized using the Raman and XRD technique. In the Raman, the signals are observed approximately 1300 cm-1 and 1700 cm-1, whereas in the X-ray diffraction diffractograms the peaks are observed approximately at 25° and 40°. Second, a synthesis was performed with the CNO to oxidize the layers of CNO particles with sulfuric acid. The follow step will be using RoDSE to deposit polypyrrole as support. To confirm these results, infrared Fourier transform spectroscopy and Raman techniques will be used to identify support materials. The techniques of cyclic voltammetry and electrochemical impedance spectroscopy will be used to identify the conductive polymers for their electrochemical properties. The dynamic light scattering technique will also be used to determine the size of the particles and the interactions with the polymers. Finally, the scanning electron microscopy technique will be used to obtain images of the analyzed surface.
Enabling High-Energy Lithium Metal Batteries through Electrolyte Strategy
Authors: Xu Wu , Zhang Ji-Guang
Published: February 2020

Lithium (Li) metal has been regarded as an ideal anode material for high-energy rechargeable batteries because metallic Li has an ultrahigh theoretical specific capacity (3860 mAh g-1) and a very low standard electrochemical redox potential (-3.040 V), thus the potential to double the specific energy density of the state-of-the-art Li ion batteries. However, the safety concern from Li dendrite growth and the short cycle life due to low Li Coulombic efficiency still hinder the application of rechargeable Li metal batteries. In the past six years, lots of great progresses have been made in stabilizing Li metal anode including smoothening Li deposition morphology and increasing Li Coulombic efficiency during repeated deposition/stripping processes, which have made the application of rechargeable Li metal batteries very promising although there are still many challenges to overcome. Among these progresses, one of the most important things is the development of electrolytes which can not only protect Li metal anode with high safety and good stability, but also to stabilize high voltage cathodes. The mechanisms for these advancements by the new electrolytes are the formation of high quality Li/electrolyte and cathode/electrolyte interface layers. More details of the electrolytes on advancing Li metal anodes and Li metal batteries will be discussed during the presentation.
(Invited) Millimeter-Thick All Organic Based Electrodes for Low Cost Aqueous Batteries
Authors: Perticarari Sofia , Soudan Patrick , Pellegrin Yann , Guyomard Dominique , Odobel Fabrice , Poizot Philippe , Gaubicher Joël
Published: February 2020

Aqueous ionic batteries are a promising technology for environmentally friendly grid storage systems as they reduce cost, risk and environmental impact, although this is at the expense of energy density.[1] Designing such batteries from inexpensive, abundant, recyclable and non-toxic organic active materials provides a way towards improving both the environmental and economic impact of these systems.

Herein, the first battery materials that work with simultaneous uptake and release of both cations (Na, Mg) and anions are proposed by designing mixed p-type and n-type “di-block” oligomers[2,3]. It demonstrates optimal potential, extremely fast kinetics and highly competitive capacity and cyclability in both neutral Na and Mg electrolytes, including ocean water. Through a combination of UV-Vis spectroelectrochemistry, EQCM, and operando synchrotron-XRD a simultaneous cation/anion insertion mechanism was proven and rationalized. The surprisingly fast kinetics of this di-block oligomer allow to attain an unmatched specific capacity of near to 60mAh/g per gram of electrode while entirely devoid of conducting additives, and more than 80mAh/g per gram of electrode with 10% carbon additive.

Based on these findings, full organic cells with millimeter-thick electrodes were assessed [4]. These findings may well provide a viable option, thereby promoting the design of cutting-edge, low-cost, rocking-chair dual-ion aqueous batteries.

[1] Wu Li, J. R. Dahn, D. S. Wainwright, Science. 1994, 264, 1115-1118

[2] S. Perticarari, Y. Sayed-Ahmad-Baraza, C. Ewels, P. Moreau, D. Guyomard, P. Poizot, F. Odobel and J. Gaubicher, Adv. Energy Materials, 2018, 8 (8), 1701988

[3] S. Perticarari, T. Doizy, P. Soudan, C. Ewels, C. Latouche, D. Guyomard,F. Odobel, P. Poizot, J. Gaubicher, Adv. Energy Materials, 2019, in press

[4] S. Perticarari, E. Grange, T. Doizy, Y. Pellegrin, A.-J Fernandez-Ropero, D. Guyomard, P. Poizot, F. Odobel and J. Gaubicher, Chem
.
Mater. 2019, (10.1021/acs.chemmater.8b03282
Fabrication and Characterization of High Capacity and Long Cycle Life Lithium-Sulfur Battery Using Porous Material As a Polysulfide Adsorbent
Authors: Zegeye Tilahun Awoke , Su Wei -Nien , Jeffrey Kuo Chung-Feng , Hwang Bing-Joe
Published: February 2020

The need for large-scale energy storage, improved safety, and sustainable transport are driving research into alternative battery technologies with higher specific energies. Rechargeable Li-S batteries have high capacities (1675 mAh g-1) and theoretical energy densities as high as 2600 Wh kg-1 making them promising candidates for the next-generation of energy storage systems. However, due to its insulating nature, polysulfide dissolution and poor cycle life, it has been challenging to achieve the existing technology requirement.

Herein we choose porous carbon as conducting agent and TiO2 nanotube as polysulfide adsorbent and forming hybrid nanostructured materials to overcome active material utilization and polysulfide dissolution problems. The porous host materials for sulfur was produced by a low cost, hydrothermal and annealing process with one step green synthesis approach. The process is facile, cheap, scalable and environmental friendly. The material was characterized and examined by XRD, BET, XPS, SEM, TEM, Raman, TGA, CV, EIS and galvanostatic charge-discharge tastes. It is found that the materials are highly porous and show both the characteristics of microporous and mesoporous behavior and contain large pore volume to impregnate large amount of sulfur. Moreover, the microporous carbon can effectively adsorb smaller sulfur (S2-4) molecules in their narrow pores with increasing the electrical conductivity of the cathode by decreasing the resistance of sulfur and enhance active material utilization. Meanwhile, mesoporous carbon doped TiO2 nanotube were placed on the surface to prevent the overflow of sulfur as well as the dissolution of polysulfides in the electrolyte effectively and improve the strength of the entire electrode thereby enhancing the electrochemical performance. As a result, using the porous host-sulfur nanocomposite as a cathode material, we demonstrate excellent cycle stability with initial discharge capacity of 916 mAh g-1 with coulombic efficiency of over 98.6% at a current density of 0.2 C after 140 cycles. This improved performance is due to the unique design of the porous host materials and the good dispersion of sulfur in the narrow pores of microporous host with TiO2 support. Thus, our approach is a promising strategy to control the dissolution of polysulfides and cycle life problems of the battery.

Key words: porous materials, lithium-sulfur battery, polysulfide adsorbent, cycle stability
Facet Engineering of Low-Cost Transitional Metal Oxides for Tunable ORR/OER Kinetics
Authors: Yuan Yifei , Yao Wentao , Tan Guoqiang , Liu Cong , Cheng Meng , Yurkiv Vitaliy , Bi Xuanxuan , Long Fei , Friedrich Craig , Amine Khalil , Lu Jun , Shahbazian-Yassar Reza
Published: February 2020

To meet future needs for industries from personal devices to automobiles, energy storage devices are transitioning into the next-generation advanced battery systems beyond lithium ions with higher energy density. Among them, lithium-oxygen (Li-O2) battery stands out due to its highest theoretical energy density among all rechargeable ion battery systems. Yet, its application is severely disabled by the sluggish reaction kinetics during oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). To address this problem, various catalysts have been developed with the most promising materials being the noble metals (Pt, etc.) and transitional metal oxides (TMOs such as CoxOy, MnxOy, etc.). While the noble metal catalysts offer superior performance in terms of improving the reaction kinetics, the high cost and environmental sensitivity prevent the large-scale application.

As an alternative, TMOs are attracting more and more interest because they exhibit satisfactory catalytic performance while their cost and cycling durability are much better than that of noble metals. While most studies have focused on the development of different TMO structures, phases and compositions, few studies have reported the advancement in the crystalline facet engineering, particularly for the low-cost TMOs such as manganese oxides, and its effect on ORR/OER kinetics.

In this work, beta-(β-)MnO2 crystals with either octahedron or rod-like shapes were successfully synthesized separately using a simple hydrothermal method. Combining various electron microscopic methods, the octahedron’s surface is seen to mostly occupied by MnO2-{111} facets, while rod’s surface is occupied by MnO2-{100}. As the cathode for Li-air batteries, the β-MnO2 with {111} facets and {100} facets catalyzed the formation of Li2O2 into large toroids and thin film, respectively. For the first time, we revealed that the control of crystal facets can switch the Li2O2 formation mechanism from the surface mode to the solution mode even in the low donor number TEGDME electrolyte. To further understand the formation kinetics of Li2O2, we referred to operando liquid cell transmission electron microscopy, by which a LiO2 phase was identified to function as the intermediate discharge products which significantly affect the formation of Li2O2 as the final product. Following this finding, DFT results further showed that the different catalytic properties were due to the different adsorption free energies for the LiO2 intermediate on the {111} and {100} facets of MnO2. Our findings revealed that facet-engineering of the low-cost TMO catalysts would open a new way for the design of lithium-air batteries with high stabilities and long cycle life.

Figure 1
Advanced Nanoporous Separators for Stable Lithium Metal Electrodeposition at Ultra-High Current Densities in Liquid Electrolyte
Authors: Yang Jingling , Mou Chung-Yuan , Wu Heng-Liang
Published: February 2020

Lithium (Li) metal is considered as the ultimate anode material for the development of next-generation batteries.1 However, Li metal electrode forms dendritic structure after cycling which causes an internal short circuit.2, 3 In this work, we grew mesoporous silica thin film (MSTF) with perpendicular nanochannels and ultra-small pore diameter (~5 nm diameter) onto the anodic aluminum oxide (AAO) membrane as the MSTF⊥AAO separator. The nanoporous MSTF⊥AAO separator with novel inorganic structures shows stable Li deposition for more than 1600 h of operation in Li-Li cells under a very high current density and capacity of 10 mA cm–2 and 5 mAh cm–2. The separator gives improved rate capability in Li-NMC batteries. The excellent performance of the MSTF⊥AAO nanoporous separator is due to good wetting of electrolytes, straight nanopores, uniform deposition of Li and blocking the finest dendrite. Our designed separators provide a groundbreaking model to regulate Li plating/stripping behavior.

References

Cheng, X.-B.; Zhang, R.; Zhao, C.-Z.; Zhang, Q., Toward Safe Lithium Metal Anode in Rechargeable Batteries: A Review. Chem. Rev.
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117 (15), 10403-10473.

Xu, W.; Wang, J.; Ding, F.; Chen, X.; Nasybulin, E.; Zhang, Y.; Zhang, J.-G., Lithium metal anodes for rechargeable batteries. Energy Environ. Sci.
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7 (2), 513-537.

Zhang, S. S., A review on the separators of liquid electrolyte Li-ion batteries. Power Sources
2007,
164 (1), 351-364.
Electrochemical Behavior of Lithium Chloride/Polymer Hybrid Layer Coated Lithium Powder Anode
Authors: Lee Seung Taek , Go Nak Gyu , Yoon Woo Young
Published: February 2020

Lithium metal anode is considered to be ultimate anode material because of its high theoretical specific capacity(3860mAh/g) and low redox potential(-3.04V vs H/H+). However, lithium metal suffers from dendrite growth and low coulombic efficiency. Lithium metal powder synthesized by droplet emulsion technique has 6 times higher surface area than lithium foil. So it can lower the effective current density thus prevent the dendrite growth. However, low coulombic efficiency still exists due to unstable Solid Electrolyte Interphase(SEI) layer. Here in, we propose a stable artificial protection layer to lithium powder anode by using perchloroethylene(PCE). PCE reacts with LiOH which is naturally passivated on lithium surface. Then, LiCl nanoparticle within the polymer matrix will form on the surface and act as a high lithium conducting, flexible artificial layer. The structure, morphology, and electrochemical properties will be investigated by the implementation of X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), transmission electron microscope (TEM), and energy dispersive spectroscopy (EDS). The result was analyzed by electrochemical impedance spectroscopy (EIS).
New Fast Li-Ion Conducting Solid State Electrolyte
Authors: Allen Jan L
Published: February 2020

Solid electrolytes are the key to realize future, energy-dense, intrinsically-safe solid-state batteries. It is therefore of great interest to explore and report novel fast Li-ion solid electrolyte compositions. Here we report the synthesis and preliminary characterization of a new oxide solid electrolyte. We detail the compositions that were explored and give the results of the synthesis, densification and the structural, physical and electrochemical characterization. The properties of the new material will be compared and contrasted to well-known solid Li electrolytes such as garnet and NASICON structured materials.
Lithium Metal Solid State Batteries: In Situ SEM Detection of Carbide Nature of Dendrites
Authors: Zaghib Karim , Golozar Maryam , Paolella Andrea , Bouchard, Patrick , Demers Hendrix , Gauvin Raynald
Published: February 2020

Li metal batteries suffer from dendrite formation which causes short circuit of the battery. Therefore, it is important to understand the chemical composition and growth mechanism of dendrites that limit battery efficiency and cycle life. In this study, in situ scanning electron microscopy was employed to monitor the cycling behavior of all-solid Li metal batteries with LiFePO4 and NMC cathodes. Chemical analyses of the dendrites were conducted using a windowless energy dispersive spectroscopy detector, which showed that the dendrites are not metallic lithium as universally recognized. Our results revealed the carbide nature of the dendrites with a hollow morphology and hardness greater than that of pure lithium. These carbide-based dendrites were able to perforate through the polymer, which was confirmed by milling the polymer using focused ion beam. Deep analysis of lithium surface of edge and grain boundary will be discussed

It was also shown that applying pressure on the battery can suppress growth of the dendrites.
Solid State Batteries
Authors: Allie Lazbourne , Johnson Lonnie
Published: February 2020

The quest for a better battery to meet the needs of applications such as electric vehicles and consumer electronics has been ongoing for many years. The need for higher energy density, safer lithium batteries that are low cost are the main performance criteria for the industry. This has led many researchers to attempt the modification and optimization of the lithium ion battery, but there is limited energy density to be obtained from the lithium ion battery, and there is still a safety challenge as the separator used in these batteries does not suppress lithium dendrites. Higher energy density can be achieved by developing a solid-state lithium metal battery instead of a lithium ion, in which a thin lithium metal anode is used instead of graphite, increasing the energy density from 700 Wh/L (250-300 Wh/Kg) to about 1200 Wh/L (400-500Wh/Kg). In order to enable the use of a thin lithium metal anode, the separator must suppress dendrites. It is well known that porous or even solid polymers do not suppress dendrites and therefore the challenge is to find a dense highly conductive lithium ion conductor that can be used for the separator of solid-state batteries. Recent study and review of these electrolyte materials by Oakridge National Lab (ORNL) suggests that their new goal is to develop a glass-like material that is highly conductive, electrochemically stable, low electronic conductivity and low cost. These enabling materials as well as our material and solutions to developing a high energy density, safe solid state battery will be discussed and presented in this study.
Comparison of Correlated Li+ Diffusion from Molecular Dynamics of Promising Solid Electrolytes
Authors: Adelstein Nicole , Wei Vanessa Yi Zhen , Mehmedović Zerina , Grieder Andrew , Leclerc Nima , Musaelian Alby , Kahle Leonid , Marzari Nicola , Kozinsky Boris , Udovic Terrence John , Mehta Prateek , Stavila Vitalie , Borodin Oleg , Akhade Sneha A , Shea Patrick , Kweon Kyoung , Varley Joel Basile , Wood Brandon C.
Published: February 2020

Li-ion batteries (LIBs) have been steadily improving since the first LIBs were commercially developed in the 1990s. Batteries with higher volumetric and gravimetric energy density using all-solid-state materials could revolutionize the LIB market. However, known superionic solid electrolytes are limited by a number of materials properties. Engineering better materials is especially limited by the lack of understanding of diffusion mechanisms, demanding novel analysis of diffusion using molecular dynamics.

Molecular dynamics (MD) provides insight into correlated motion between Li-ions and correlated motion with the lattice. Correlated motion of Li-ions is common in the most promising superionic electrolytes. The results presented will be a broad survey of correlated motion using novel analysis tools developed by the authors and their collaborators. Diffusion in some of the most promising electrolytes, such as lithium borohydrides, lithium germanium thiophosphate, amorphous lithium thiophosphate, lithium lanthanum zirconium oxide, and the lithium rich anti-perovskites will be compared. Molecular dynamics of these systems will be performed either by ab-initio MD or classical MD. The Haven ratio and the Distinct Van Hove Analysis will be presented for each material. The novel analysis will focus on computational atomistic insights into the diffusion mechanisms of Li-ions, especially correlated motion.
(Invited) In Situ Imaging of Interphase Evolution and Degradation Processes in Solid-State Batteries
Authors: McDowell Matthew T
Published: February 2020

Understanding the electrochemical interface between alkali metals and solid-state electrolytes is key for developing stable, high-energy density solid-state batteries. The vast majority of solid-state electrolyte (SSE) materials are unstable in contact with lithium metal, and (electro)chemical reactions between SSEs and lithium result in the formation of an interphase region. Understanding the growth kinetics and chemo-mechanical consequences of interphase formation is key for controlling solid-state interfaces, and this knowledge may enable the use of a wider variety of SSE materials within lithium metal batteries. Here, we investigate NASICON-structured L1+xAlxGe2-x(PO4)3 (LAGP), as well as sulfide-based SSEs. For LAGP, electrochemical experiments combined with multi-modal in situ investigation of interfacial reactions reveal how the formation of the interphase is linked to cell failure. In situ transmission electron microscopy (TEM) shows that the reaction of LAGP with lithium is similar to a conversion reaction, in which lithium insertion causes amorphization and volume expansion of ~130%. The interphase is a mixed ionic-electronic conductor, resulting in continuous growth. In situ X-ray tomography experiments of operating LAGP-based cells reveal that the growth of the interphase causes fracture of the SSE, and quantification of the crack network shows that the extent of fracture with time is directly correlated to impedance increases within the cell. Finite-element analysis is used to model stress evolution during interphase formation, and the initial fracture locations predicted from modeling correspond well to experimental observations. Operation of cells at different currents between 100 and 500 mA/cm2 causes the interphase to grow in different ways: higher currents result in highly non-uniform interphase growth deep into the SSE pellet, resulting in rapid fracture and cell degradation. Interestingly, we have found that interphase growth trajectories can be modulated through the deposition of interfacial protection layers. Controlling the morphology of the interphase with protection layers results in the ability to extend cycling stability of symmetric cells from ~30 hours with unprotected SSEs to >1000 with protected materials. Overall, these results provide fundamental insight into interfacial transformations in solid-state batteries, and they show that control over interfacial transformation processes could enable a wider variety of materials to be used in solid-state lithium metal batteries.
Tracking Percolation and Transport Pathways in Hybrid Solid Electrolytes for All Solid State Batteries
Authors: Zaman Wahid , Hortance Nicholas , Dixit Marm , De Andrade Vincent , Hatzell Kelsey B.
Published: February 2020

Hybrid solid electrolytes are composed of organic (polymer) and inorganic (ceramic) ion conducting materials and are promising options for large-scale production of solid state lithium metal batteries. Combining an inorganic conductor with a polymer electrolyte improves the mechanical properties and limits dendrite growth in metal batteries (i.e. short circuiting). However, hybrid electrolytes are comprised of numerous interfaces. There are intrinsic interfaces that form between material junctions in the solid electrolyte between the inorganic and organic ion conducting materials. Depending on the loading of the inorganic material, the electrolyte can experience different mechanical and electrochemical properties. There are two percolation thresholds that exist in hybrid electrolytes: (1) long-range connectivity of inorganic particles (contact mode) and (2) long-range connectivity of space charge layers. The former is achieved at high loadings of 33 vol% (ceramic:polymer) and the later is achieved at ~4 vol% (ceramic:polymer). There is currently a critical lack in understanding regarding transport in these inorganic/organic electrolyte systems, but there is clear evidence that it is reliant on the underlying structure of the inorganic particles. At minimal loading, the superior ion conduction is generally attributed to the rapid interphase conduction. Although this addition of active/passive ceramic nanofillers within polymer matrix showed better ionic conductivity, this is often hindered by unwanted particle agglomeration at higher loadings. Nano-CT allows us to look in to the structural heterogeneity of PEO-LLZO composite systems which is beneficial in understanding the continuous percolated network for ion conduction (Fig. 1). This presentation intends to use a multi-modal approach which couples physics-based modeling with electrochemical, and synchrotron x-ray nanotomography experiments to probe the origin of low ionic conductivity in these hybrid electrolyte systems.

Figure 1
Characterization of Na4P2S6 and Li2Na2P2S6 As Potential Electrolytes for Na Ion Batteries
Authors: Li Yan , Hood Zachary David , Holzwarth Natalie A. W.
Published: February 2020

Solid-state electrolytes are anticipated to enable the construction of batteries with increased volumetric energy densities. However, depleting reserves of sources of lithium has motivated the exploration of next-generation alkali-metal-conducting solid-state electrolytes such as solid-state sodium-ion conductors. We recently explored a water-mediated synthesis of Na4P2S6, which could allow for the scalable fabrication of this Na ion conductor.1 Na4P2S6 has been shown to crystalize2 in the based-centered monoclinic structure C2/m (#12) and its room temperature ionic conductivity has been measured1 to be 3x10-6S/cm. Previous simulations3 suggested that the monoclinic structure is meta-stable relative to structures found for the similar material Li4P2S6, but further work reported here shows that vibrational free energy contributes to the stabilization of the C2/m structure of Na4P2S6 at room temperature. Our analysis also investigates the mixed alkali electrolyte Li2Na2P2S6 which may have increased Na ion conductivity compared with that of Na4P2S6.

Z. D. Hood et al., to be published.

A. Kuhn et al., Z. Anorg. Allg. Chem.,
640, 689–692 (2014)

E. Rush Jr. et al., Solid State Ionics,
286, 45-50 (2016)

Acknowledgements: YL and NAWH were supported by NSF grant DMR-1507942. A portion of the work by ZDH was conducted at the Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility.
4.2V Cost Effective All-Solid-State Na Ion Batteries with a Na3PS4 Electrolyte Operating at Room Temperature
Authors: Banerjee Abhik , Tang Hanmei , Wu Erik , Nguyen Han , Zhang Minghao , Ong Shyue Ping , Meng Shirley
Published: February 2020

Cost effective all‐solid‐state sodium‐ion batteries that operate at room temperature are appealing candidates for use in large‐scale energy storage systems. Although low voltage sulfur was primarily used as cathode for fabrication of all solid-state Na ion battery, limited research was done for cost effective high voltage layered oxide cathode. Here we developed a bulk-type Na-ion all-solid-state battery, fabricated using a high voltage layered oxide cathode Na0.8[Li0.12Ni0.22Mn0.66]O2(NLNMO, 4.2V vs. Na/Na+) and Na3PS4(NPS) glass-ceramic as the solid electrolyte, is expected to have high energy density and improved safety over batteries containing liquid electrolytes. However, the observed interfacial chemical reactions between the oxide cathode and sulfide solid electrolyte as well as electrochemical decomposition of NPS limits the high voltage electrochemical performance. Such reactions were probed using Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). To improve the performance, the surface of NLNMO was modified by applying a cost-effective, solution-processed and computationally guided resistive coating of additional oxide layer. STEM revealed that coating layer is amorphous about 5nm thick. After optimizing the coating process, the electrochemical performance of the cell dramatically improved, achieving a specific capacity comparable to that of the liquid cell while exhibiting 80% capacity retention after 300 cycles. This coating method can be an effective strategy for achieving higher electrochemical performance in room temperature all-solid-state Na-ion batteries.
Carbon Nanofiber Composites As Anode Materials in Li+ and Na+ Batteries
Authors: Liu Xinyang , Indris Sylvio , Ehrenberg Helmut
Published: February 2020

Carbon nanofibers (CNFs) are well known by their one-dimensional (1D) nanostructure, high conductivity and large surface area, which can provide direct and short pathways for ion transport. These unique properties have facilitated their application as anode materials in both lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). Electrospinning, as a versatile and controllable method of CNFs manufacturing, has been widely investigated in the battery field. Electrospun CNFs still have limited capacity and rate capability. To further improve their performance, additives such as nickel metal nanoparticles and macromolecular Pluronic were added in this work.

Pure CNFs derived from polyacrylonitrile (PAN) and two composite systems: CNFs/Ni and CNFs/Pluronic were synthesized. Morphology of the electrospun fibers and their electrochemical performance in both LIBs and SIBs were studied. Metallic nickel plays the role of an electronic conducting agent, while Pluronic serves as a template to generate micropores, which is favorable for sodium ion transport.

Nanofibers with diameters around 200 nm were successfully prepared. Nanoparticles of nickel were observed on the surface of these CNFs by scanning electrode microscope (SEM). A high capacity of 460 mA h g-1 of pure CNFs when cycled at 100 mA g-1 in LIBs has been achieved with an outstanding stability. After 300 cycles, the capacity stays above 400 mA h g-1. With the addition of nickel particles, an even higher capacity of around 800 mA h g-1 was obtained. CNFs/Pluronic showed the best capacity retention among all composites with a steady capacity at around 600 mA h g-1. The influence of porosity and carbonization temperature on overall electrochemistry performance in LIBs and NIBs are being investigated.

In summary, introduction of additives of Ni and micropores can effectively improve capacity of CNFs as anode materials. Charge/discharge profiles did not vary a lot which can prove that the additives are electrochemically inert. Electrospinning is a flexible method to develop 1D nanostructured electrode materials for both LIBs and SIBs. The outstanding electrochemical properties of such electrospun anodes will further stimulate their applications in LIBs and SIBs.
Chemical Doping of Cellulose Nanocrystal
Authors: Choi Sukyung , Park Nae-Man , Oh Jee Eun
Published: February 2020

Cellulose nanocrystal (CNC) has received great interest as sustainable green materials, owing to their intrinsic properties such as renewability, and abundance. It has attractive features, such as large specific surface area, low density, transparency, high tensile stiffness and strength, high thermal stability, and biocompatibility. CNC is extracted from forest and agro-biomass by mechanical or chemical treatments, which has rod-like shape with lengths varying between 100 and 600 nm, and diameters ranging between 2 and 20 nm. However, CNC is basically an insulator due to its high band gap, its applications to electronic devices are limited. We have investigated a doping method that can improve the electrical conductivity of CNC for electronic applications. Among carbon based materials, such as carbon nanotube or graphene, reduced sheet resistance and improved electrical conductivity by chemical doping have been reported. Based on the results of these studies, we designed chemical doping experiments to CNC. Generally, molecules with electron-withdrawing groups adsorbed on the surface of carbon materials serve as p-type dopants. The selected materials for p-type dopants were doped to CNC and the optical- and electrical properties were characterized. We believe this work is a valuable concept demonstrating that CNC plays a new material for future electronic applications.

-This work was supported by Electronics and Telecommunications Research Institute(ETRI) grant funded by the Korean government (19ZB1510).
(Invited) Nanotubular Fullerenes: Part Buckyball, Part Nanotube
Authors: Seeler Tiffany L. , Koenig Ryan M. , Tepper Katelyn R. , Franklin Hannah M. , Stevenson Steven
Published: February 2020

Many thousands of papers are published on the spheroidal fullerene cages (e.g., C60, C70) and carbon nanotubes (e.g., SWNT, MWNT). What if there existed a family of nanocarbons that was 1/2 tubular and 1/2 fullerene? What properties would they exhibit? Theoretical calculations do predict a family of tubular fullerenes having C60 endcaps but with sequential additions of 10 belt carbons for elongation. Such a pattern would be C60, C70, C80, C90, C100, C110, C120 and so forth. With C60 and C70 already well-characterized, we searched for other family members. To date, we have developed a chemical-based method that selectively separates tubular versus spheroidal species. In this presentation, I will discuss our newly isolated nanotubular C90-D5h(1) and nanotubular C100-D5d(1) fullerenes and how we purified them.....29 years after the electric-arc synthesis had made them. We believe these nanotubular fullerenes were hidden in fullerene soot by their low yields (<0.05% of the soluble extract). Now, they are finally purified.
Optimization of Laser-Reduced Graphene with Automated Parameter Tuning: Towards Human-Less Advanced Manufacturing
Authors: Wahab Hud , Jain Vivek , Tyrrell Alexander , Kotthoff Lars , Johnson Patrick
Published: February 2020

Graphene-derived materials are of significant interest in the manufacturing of functional devices due to their exceptional physical and chemical properties. The challenge in standardizing the synthesis of pristine graphene layers makes patterning of carbon materials a more favorable fabrication method. However, the graphene patterning process is often impeded due to high temperatures or toxic chemicals. Thus, it is paramount to find a straightforward and reproducible processing technique in a large scale. Laser reduction of graphene oxide and polymers have gained attention since it is a one-step chemical-free process to fabricate graphene circuits on-the-fly down to micrometer scales. The selective and locally confined laser-reduced circuits can be written on almost any solid or flexible substrate, showing promising potential in the manufacturing of advanced devices such as supercapacitors, energy storage devices and biosensors. In our work, we investigate strain effects on the electrical properties of graphene circuits on flexible substrates. We also utilize in-situ Raman and optical analysis with a view to automate the fabrication process in a closed-feedback loop. Furthermore, we present results of state-of-the-art model-based optimization in materials science. In particular, we use surrogate models for automated parameter tuning to optimize the manufacturing of laser-reduced graphene circuits. Our results are reproducible even with sparse training data and we discuss possibilities of human-less advanced manufacturing.