bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lithium-Ion Battery State of Charge and Health Estimation – Electrochemical or Equivalent Circuit Model– a Review
Authors: Enoch-Oghene Samuel , Yesufu Thomas Kokumo , Olayiwola Pipeloluwa Samuel , Akhigbe Godswill Ehimengbale 
Published: February 2020

With the advent of the fourth (4th) industrial revolution, energy needs are increasing. For this revolution which is expected to improve the quality of human lives to succeed – energy that is reliable, affordable and sustainable is a sine qua non. At the heart of energy storage are electrochemical devices of which batteries are key. However, batteries require monitoring in order to accurately estimate the states of charge (SOC) and health (SOH).
To effectively monitor SOC and SOH – there is a need to develop smart models which can accurately track and capture battery dynamic and static characteristics.
Two main classes of models are used in battery modeling are electrochemical and electrical models (equivalent circuit models, ECMs). The electrochemical models tend to be accurate but computationally expensive. They have also been reported as impractical for online usage. The reverse happens with ECMs but they are much less accurate.
This paper reviews models reported in previous works for Lithium-ion battery SOC & SOH estimation in battery management systems (BMS). Comparison is made of ELECTROCHEMICAL models as well as ECMs on the Lithium-ion batteries. This gives a working overview of how practical smart-battery models can be developed. This is in order to track accurately parameters such as film resistance and diffusion coefficients etc which are beneficial for accurate SOC and SOH estimation.
Structural Change of the Discharge Products in Lithium Sulfur Battery during Storage
Authors: Noh Hyungjun , Kim Yun-Jung , Lee Jinhong , Kim Hee-Tak 
Published: February 2020

Lithium-Sulfur (Li-S) battery has been regarded as one of the most promising candidates to commercialize electric vehcles (EVs). Compared to Ni-Cd or commercialized Li ion battery, Li-S battery possesses many advantages, including high theoretical capacity (1,675 mAh/g) and low price of active materials. Energy density, rate capability, and cycling stabilities are regarded as key performances of any next generation secondary batteries, however, memory effect, which is history-dependent variation in battery state, is also a highly important battery chacteristic to be considered. As exampled with Ni-Cd battery, memory effect often leads to an accelerated cell deterioration [1]. In recent years, it was also reported that LiFePO4,which is a promising cathode material for EV applications, has memory effect [2] and it could result in a severe error of battery managment system (BMS). In spite of its importance, such memory effect has not been issued for Li-S battery.
In this work, the structural change of discharge products during storage and its influence on the subsequent cycle was studied. Structural changes with different storage time were clearly observed with ex-situ X-ray diffraction (XRD) and X-ray photoeletron spectroscopy (XPS) analysis. The XRD results demonstrated that the discharge products with a low crystallinity is converted to a more crystalline structure during a storage at room temperature. In addition, the XPS spectra collected at different storage time suggest that the structural change observed in XRD originates from a compositional change of the solid discharge products. The structural evolution of the discharge products significantly influence the overpotential of the subsequent charging step. This small perturbation in voltage profile can induce severe error in battery management system in EVs because it can lead to mis-estimate state of charge. The mechanism for the behavior and the impact on the Li-S performances will be presented and discussed.
Synthesis of Cu Nanowires Using Ascorbic Acid in Aqueous Solution and Their Applications for Flexible Transparent Conductive Films
Authors: Yokoyama Shun , Motomiya Kenichi , Jeyadevan Balachandran , Tohji Kazuyuki 
Published: February 2020

Cu nanowires (NWs) have been extensively studied to produce flexible, low-cost and high-conductivity transparent films because of their flexibility, low cost and high conductivity. Most synthetic procedures are based on chemical reduction, which often requires high temperature, organic solvents, and toxic reagents such as N2H4. It is desirable to develop a cost-efficient and environmentally friendly synthetic procedure for practical use. Furthermore, Cu NWs with high aspect ratios are required to improve performances of the transparent conductive films. Previously, we synthesized Cu nanoparticles based on chemical aqueous reduction employing ascorbic acid (vitamin C) as a reducing agent instead of commonly used toxic reducing agents. The key to the wire-like morphologies is the adsorption of surface ligands to metal crystal facets during the nucleation of NWs. Surface ligands selectively adsorbs onto {100} facets and consequently the anisotropic growth along the <110> direction occurs. In addition, reaction speed control and additives are also important for syntheses of NWs with high aspect ratios. In this study, we examined to synthesize Cu NWs by chemically reducing aqueous Cu chloride complexes using ascorbic acid as a mild reducing agent instead of the commonly employed toxic reducing agent. We chose polyvinylpyrrolidone (PVP) and NaCl as a surface ligand and an additive, respectively. In addition, we controlled aspect ratios of Cu NWs by changing type of capping agent, optimizing additives and atmosphere.
Cu chloride complexes were reduced to Cu metal through CuCl by ascorbic acid. The shape of the Cu metal particles highly depended on pH in the presence of PVP. Cu NWs were synthesized in the pH range of 3 to 4 while Cu nanoparticles were synthesized above pH 4. The reduction speed accelerated with increasing pH because the reduction capability of ascorbic acid increased with increasing pH. In fast reduction, all Cu chloride complexes were reduced to Cu particles before the anisotropic growth. In slow reduction, PVP effectively stabilized {110} facets of Cu rather than {111} facets, resulting in Cu NWs. The length and diameter of the Cu NWs were affected by atmosphere rather than additives and type of PVP. In the case of using ascorbic acid in aqueous solution, dissolved oxygen reacted with ascorbic acid to form hydrogen peroxide. Subsequently, hydrogen peroxide oxidized Cu metal surface and consequently prevented the anisotropic growth, resulting in Cu NWs with low aspect rations. By changing atmosphere from air to N2, we synthesized Cu NWs (length: 36 µm, diameter: 124 nm) from the reaction using ascorbic acid in aqueous solution. In our presentation, detailed results and discussion about the synthesis mechanism and performances as transparent conductive films will be introduced.
(Invited) Effect of Electrolyte Electrode Interface Design on Lto Cell Performance
Authors: Ma Chengsong 
Published: February 2020

Li plating on graphite electrode is a well-known issue which consumes active li and cause capacity loss and increase cell impedance. It also triggers degradation of active material and electrode conductive network. Cold temperature and high rate charge on graphite electrode can easily cause Li plating. The carbon anode is coated on Cu current collector and Cu will be oxidized at 0V cell potential. LTO is 1.5V separated from Li plating so it can be used for very fast charge and cold temperature charge. Al foil can be used as current collector for LTO electrode thus makes 0V cell storage feasible. Using LTO anode in Li ion cell can reduce or eliminate battery thermal management for weight reduction.
Saft has been studying LTO since 2010 and developed different LTO based cells for DOD, Rail, USABC. Recently Saft started to develop LTO cells for space application. The high DOD discharge capability make LTO cell have similar or higher usable energy than graphite cells in some space missions. Details of the cells and cell performance data will be presented.
Sulfide Based Solid Electrolyte for Lithium-Sulfur Batteries
Authors: Lu Dongping , Wang Yuxing , Xiao Jie , Zhang Ji-Guang , Liu Jun 
Published: February 2020

Lithium-sulfur (Li-S) batteries have the potential to deliver higher energy at lower cost compared to state-of-the-art Li-ion batteries. Greatest obstacles for deployment of Li-S batteries lie in polysulfide dissolution/shuttle and high Electrolyte/sulfur ratio required for stable long term cycling. In all-solid-state Li-S batteries (ASSLiS), S conversion undergoes the solid-state route therefore excludes the problems of polysulfide dissolution and high E/S ratio. Sulfide-based solid electrolytes are most suitable for ASSLiS and excellent performance of S cathode has been demonstrated.1

Due to the insulating nature of S particles, short diffusion length is needed to realize high S utilization. Liquid phase synthesis of sulfide-based solid electrolyte has advantages of easy preparation of nanosized particle, great flexibility and tunability, better scalability, and thus is desired for sulfur electrode preparation. It was found in our study the crystalline Li7P3S11 forms through a two-step reaction: 1) formation of solid Li3PS4∙ACN and amorphous ‘Li2S∙P2S5’ phases in the liquid phase; 2) solid-state conversion of the two phases.2 The other significant obstacle of ASSLiS is lack of solid state electrolytes that support stable Li metal cycling at relevant current density and cycling depth. We developed a sulfide-based solid electrolyte that has extremely high ionic conductivity of 4.7 mS/cm and kinetically stable, low-impedance interface (< 10 Ω cm2) with Li metal anode. Long term Li/Li symmetric cell cycling was achieved at 0.5 mA/cm2. In addition, the material remains stable in structure and ionic conductivity within two hours exposure in the dry room environment. In this talk, we present our progress on the sulfide-based solid electrolytes for ASSLiS.
References

H. Nagata, Y. Chikusa. Journal of Power Sources 264 (2014) 206-210

Y. Wang, D. Lu, Z Deng, J Xiao, J. Zhang and J. Liu. Chemistry of Materials 30 (3):990-997. doi:10.1021/acs.chemmater.7b04842
Analysis of Interfacial Processes at Tin Anodes Using in situ Enhanced Raman Spectroscopy (SHINERS) and Advanced Electrochemical Techniques
Authors: Torres Bautista Blanca Estela , Bignaud Charles , Fillaud Laure , Perrot Hubert , Sel Ozlem , Lucas Ivan 
Published: February 2020

As Li-ion batteries (LiBs) have become on one of the most reliable power sources, new electrode materials with higher lithium-retention capacity such as tin and silicon-based anodes as well as high voltage oxide or polyanion-type cathodes materials already stand as promising candidates to address the growing need of inexpensive, efficient energy storage systems for the forthcoming energy transition. Despite their initial promising capacity, continuous cycling ineluctably leads to a fading of their performances. The comprehension of failure mechanisms during operation will pave new routes for the design of battery electrode and electrolytes.
This work focusses on the study of interfacial processes at tin anodes, specifically on the dynamics of formation and composition of the solid electrolyte interphase upon cycling. The strategy proposed herein consists in associating enhanced Raman spectroscopy and advanced electrochemistry techniques derived from electrochemical impedance techniques (Quart crystal microbalance and AC electrogravimetry).
We report the compositional study of the SEI (1) by SHINERS using the plasmon resonance of gold nanoparticles which enhances the Raman signal of the compounds in close vicinity and compensates for the low Raman scattering cross section of the compounds forming the SEI (2). Using SHINs on tin electrodes, Raman signature of the SEI were successfully extracted ex-situ but also in situ through the electrolyte. Composition data are compared to structural information of the SEI extracted by EQCM (3,4). Influence of the electrolyte composition on the SEI properties will be detailed during the presentation.
References:
[1] F. Shi, et al, J. Phys. Chem., vol 118, 2014, 14732.
[2] S. Hy, et al, J. Pow. Sour., vol 256, 2014, 324.
[3] J.-T. Li, et al, Langmuir, vol 23, 2007, 13174
[4] Z. Yang, et al, Appl. Mater. Interfaces, vol 7, 2015, 26585

Figure 1
(Invited) Kinetics-Controlled Degradation Reactionsat Lipon/Li(x)CoO(2) and LiPON/Li-Metal Interfaces
Authors: Leung Kevin , Pearse Alexander J , Talin Albert Alec , Fuller Elliot James , Rubloff Gary W , Modine Normand A. 
Published: February 2020

All-solid-state batteries are safe and viable approaches to energy storage. Detailed understanding of solid-solid interface structure-function relations is critical for the improvement and wide deployment of such batteries. The interfaces between lithium phosphorous oxynitride ("LiPON") solid electrolyte material, and lithium metal anode and Li(x)CoO(2) cathode surfaces, have been reported to generate solid electrolyte interphase ("SEI")-like products and/or disordered regions. Using electronic structure calculations, we predict that "defective" P-O-P sequences in disordered LiPON regions react with Li metal in battery operational timescales, but in general LiPON is kinetically inert towards lithium at room temperature. In contrast, transfer of oxygen atoms from low-energy Li(x)CoO(2) (104) surfaces to LiPON is much faster under ambient conditions. The mechanisms of the primary reaction steps, experimental results to partially corroborate these predictions, and possible mitigation strategies to reduce degradations are discussed. LiPON interfaces are found to be useful case studies in terms of addressing challenges in modeling redox-active oxide interfaces; differentiating electrochemical from interfacial chemical reactions; and highlighting the importance of kinetics-controlled processes during battery assembly, which often involves moderate processing temperatures.
This work was supported by Nanostructures for Electrical Energy Storage (NEES), an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number DESC0001160. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of EnergyâNational Nuclear Security Administration under contract DE-NA0003525.
(Invited) Evaluating Strategies for Dendrite Prevention in Li Metal Anodes
Authors: Srinivasan Venkat , Barai Pallab , Higa Kenneth 
Published: February 2020

With the resurgence of interest in lithium metal anodes, the long-standing problem of dendrite prevention has once again gained popularity as a research focus. There is significant debate as to the actual cause of dendrite growth with different mechanisms observed in polymer and ceramic cells, and different morphologies observed when changing operating conditions.
Over the last year, we have been developing mathematical methods that combine electrochemical effects (kinetics, mass transfer and ohmic) with mechanical interactions (elastic deformation, plastic deformation, and fracture) to understanding the role of material properties and operating conditions on dendrite growth. We have used this model to examine dendrite formation in polymer electrolytes, both single-ion conducting and non-single-ion conducting. In addition, we have been examining the formation of dendrites in ceramic materials.
This talk will use this combined electrochemical/mechanical approach to provide insights into the cause of dendrite formation in polymer electrolytes, the effect of changing operating conditions like current density, the effect of pressure, and the effect of changing material mechanical and transport properties. We also examine the impact of grain boundaries on dendrite formation in ceramics and provide insights into the challenges that need to be solved to enable this system.
Predicting and Optimizing the Performance of Thick Battery Electrodes
Authors: Tang Ming , Wang Fan 
Published: February 2020

The use of thick electrodes in Li-ion batteries has received widespread interest in recent year as a promising way for energy densisty enhancement and cost reduction, but it faces the instrinsic challenge of slow transport kinetics due to the increased ion diffusion distance between cathode and anode. It is thus important to carefully optimize the microstructure of thick electrodes to improve their rate performance for specific applications. Here we report an efficient computational approach to predict and optimize the performance of thick electrodes as an alternative to the pseudo-2D simulation technique, which is the de-facto modeling method for battery design at the cell-level. We derived an analytical model for predicting the charge/dicharge capacity of the battery cells based on the observations that a pseudo-steady state of ion transport in electrolyte is typically established in thick electrodes during discharge/charge process. As shown in Figure 1a, the model provides predictions on the depth of discharge of battery cells within a range of discharge rate and cell configuration that are in very good agreement with the psedudo-2D battery simulations, but only consumes a negligible amount of computational cost. As a demonstration of its utility, the model is used to efficiently predict the dependence of a cell's specific energy on the cathode porosity and thickness given a required specific power and identify the optimal parameter values (Figure 1b). Our method makes it feasible to design and optimize non-uniform electrode structures that involves a large number of parameters in the design space.
Figure 1 (a) Comparison of depth of discharge (DoD) predicted by pseudo-2D simulation and our analytical model for various electrode thickness in half or full cell configurations. (b) Contour plot of cell-level specific energy of a full cell as a function of cathode porosity and thickness at a given power density. The thick line represents the maximal specific energy at different cathode thicknesses.

Figure 1
Mathematical Modeling of Electron and Hole Tunneling through the Deposit Layers in Li-Oxygen and Li-Sulfur Batteries
Authors: Andrei Petru 
Published: February 2020

The main discharge products in Li-oxygen and Li-sulfur batteries, as evidenced by x-ray microscopy, are predominantly crystalline lithium peroxide, lithium superoxide, and lithium sulfide [1, 2]. These products have a high electric resistivity and, practically, the only conduction mechanism in these materials is electron and hole tunneling. In this presentation we develop a mathematical model to describe the tunneling current density in Li-oxygen and Li-sulfur batteries. The model is based on the WKB approximation, which is used to model the electron and hole tunneling probability through the insulating layer. The derivation of the tunneling current is relatively similar to the derivation by Simmons [3], which analyzed metal-insulator-metal systems (MIM) but, in our case, the mathematical derivation is carefully modified to describe metal-insulating-electrolyte systems (instead of MIM systems). More importantly, we derive closed-form equations for the tunneling current density that can be readily used in finite element simulations or in the mathematical modeling of the ohmic losses across the discharge layer in Li-oxygen and Li-sulfur batteries. As we expect the tunneling current density depends on the shape of the conduction and valence bands, applied voltage, and permittivity (because of the image charges created in the carbon). At normal applied voltages (below 0.5 V) the tunneling currents are negligibly small, however, they can become large enough to affect the discharge characteristics of the batteries for low discharge rates (e.g. below 0.1 C) if the barrier heights of the valance band in the case of holes and conduction band in the case of electrons are small. More details about the mathematical derivation, the approximations used in the derivation, the closed-form equations, and a comparison with current models in the literature will be presented at the meeting.
[1] N. Cañas, S. wolff, N. Wagner, K. Andreas Friedrich, In-situ X-ray diffraction studies of lithium-sulfur batteries, 2012.
[2] K.R. Ryan, L. Trahey, J.S. Okasinski, A.K. Burrell, B.J. Ingram, In situ synchrotron X-ray diffraction studies of lithium oxygen batteries, Journal of Materials Chemistry A, 1 (2013) 6915-6919.
[3] J.G. Simmons, Generalized Formula for the Electric Tunnel Effect between Similar Electrodes Separated by a Thin Insulating Film, Journal of Applied Physics, 34 (1963) 1793-1803.

Figure 1
Carbon Nano-Onions Synthesized By Laser Pyrolysis As Catalyst Support in Proton Exchange Membrane Fuel Cells
Authors: Yeon JeHyeon , Choi Indae , Choi Mansoo 
Published: February 2020

Proton exchange membrane fuel cells (PEMFC) typically utilize nanostructured carbon (such as carbon black, carbon nanotubes, graphene and porous carbon) as the support material for catalysts. The durability and electrical conductivity of the material are important contributors to the fuel cell performance, as well as the structural design to maximize the triple phase boundary between the fuel, the catalyst and the electrolyte membrane. In view of engineering the structure and composition of the carbon catalyst support, a versatile manufacturing method with flexibility in size, shape, structure, and properties (such as electrical conductivity) of the carbon material would open up a chance to investigate an expansive composition matrix for potential improvements of the cell performance. In addition, for potential commercialization, processes that are clean and high-throughput are desired.
Laser pyrolysis of hydrocarbons has been established as a widely adopted gas phase production of carbon nanoparticles. In particular, multilayered particles with concentric graphitic shells, commonly called carbon nano-onions, are of interest as the size, shape and the number of graphitic shells are easily tuned by adjusting the experimental parameters. In this work, we present a CO2 laser induced pyrolysis of gaseous hydrocarbons (such as acetylene and ethylene) that generates various types of carbon nanoparticles, and demonstrate that these carbon nano-onions have superior durability and electrical conductivity to commonly used commercial carbon materials such as Vulcan XC-72. Platinum-decorated carbon nano-onions have been used to fabricate PEMFCs and they are shown to have comparable performance to conventional cells, and the accelerated stress test reveals that the durability of the cells have improved.