bluuebunny/crossref_metadata_2025_split huggingface dataset:
Finite Element Simulation of Electrochemical Impedance Spectra in Li-S Batteries
Authors: Shen Chao , Andrei Petru , Zheng Jim P. 
Published: February 2020

It is well-known that electrochemical impedance spectra (EIS) can provide important information about the diffusion and reaction processes in Li-S systems. While there is a large amount of experimental characterization of Li-S batteries using EIS, the theoretical modeling is mostly limited to simplified models based equivalent circuits. While these simplified models provide important information about the resistance of the electrolyte, the charge transfer resistance, and double layer capacitance, they fail to provide a more detailed physical understanding of the electrochemical processes inside the battery. Such an understanding can be provided by physics-based models, in particular by finite element models.
In this work we present for the first time a numerical method for the computation of electrochemical spectra in Li-S batteries based on finite element simulations. The model has the advantage that it is entirely framed in terms of measurable quantities, such as ion mobilities and diffusivities, reaction rate parameters, and double layer capacitance. The model is formulated in the form of a nonlinear system of partial differential equations derived from our previous work1 and which can be easily implemented numerically in standard battery simulators. In addition, the model can accurately describe the depressed semicircles of the EIS. More details about the numerical implementation of the method and a comparison with experimental results will be presented at the conference.
References

P. Andrei, C. Shen, and J. P. Zheng, Electrochim. Acta, 284, 469–484 (2018)
Experimental Measurement of the Local Current Density in the Vicinity of a Lithium Protrusion: Plating and Stripping
Authors: Maslyn Jacqueline A. , McEntush Kyle D. , Harry Katherine J. , Balsara Nitash P. 
Published: February 2020

Successful prevention of lithium dendrite growth would enable the use of lithium metal as an anode material in next-generation secondary batteries. Mechanically stiff solid polymer electrolytes have been shown to prolong the life of lithium metal cells by partially suppressing lithium dendrite growth. However, we lack fundamental knowledge about the nature of lithium electrodeposition and stripping as a function of time, as direct observation of this phenomenon is non-trivial.
Synchrotron X-ray microtomography was used observe lithium metal plating and stripping through these solid polystyrene-block-poly(ethylene oxide)-LiTFSI electrolyte membranes in the vicinity of lithium protrusions. Local current density was calculated from these experimental measurements and mapped on the top and bottom electrode under conditions of lithium metal plating and stripping. Local current density at one electrode was correlated to local current density at the other electrode and to electrode thickness. We show quantitatively how lithium protrusions are stripped at a faster rate than planar lithium and gain insight into the lithium ion transport governing protruding lithium growth in a cycled lithium metal electrode.
Highly Conductive Li7La3Zr2O12/PVDF Composite Polymer Electrolyte for Rechargeable Lithium Ion Batteries
Authors: Li Junhao , Wang Ruigang 
Published: February 2020

Commercialized LIBs have disadvantages such as overheating and catching on fire due to the utilization of liquid organic electrolytes. To expand the applications of LIBs, the development of solid-state lithium-ion conductive electrolyte materials, which are nonflammable, more durable for high temperature, more resistive to lithium dendrite and have wider electrochemical operating voltage window, is urgently needed.
Among the various types of solid-state lithium-ion conductive electrolyte candidates, the garnet-type Li7La3Zr2O12 (LLZO) has attracted significant attention due to its high ionic conductivity and superior electrochemical stability corresponding to a wide electrochemical window. By combine the sol-gel synthesis and high energy ball milling, we investigated the phase transition from tetragonal Li7La3Zr2O12 to cubic Li7La3Zr2O12 without subsequent high-temperature calcination. For the sample calcined at 900 °C for 6 h, X-ray diffraction measurement revealed that the ball milling treatment induces a direct phase transition from tetragonal Li7La3Zr2O12 to cubic Li7La3Zr2O12 without high-temperature heat treatment. However, in a comparative study, cubic Li7La3Zr2O12 can only be obtained after high-temperature calcination above 1180 °C. We hypothesize that the high energy ball milling promotes the accumulation of Li+ vacancy leading to this easy phase transition. This study establishes an efficient way to transform tetragonal Li7La3Zr2O12 to cubic Li7La3Zr2O12 at lower calcination temperature via high energy ball milling treatments.
In addition, dispersing cubic Li7La3Zr2O12 powders as active inorganic electrolyte fillers in polymer matrix to synthesize flexible and easy-to-process Li7La3Zr2O12/PVDF composite polymer electrolytes (CPEs) is also being investigated in order to enhance not only ionic conductivity but also mechanical properties and thermal stability of polymer electrolytes.
Graphene Mesosponges for the Conductive Additive of Cathode Composites in Lithium−Sulfur All-Solid-State Batteries
Authors: Yamamoto Masanori , Nishihara Hirotomo , Goto Shunsuke , Yoshioka Youichi , Ito Masashi , Mitsuyama Tomohiro , Morooka Masahiro , Kyotani Takashi 
Published: February 2020

All-solid-state lithium−sulfur batteries are a class of promising energy storage technologies because of the low cost of sulfur as the active material, high safety due to no use of volatile organic solvents, high theoretical energy density (2600 Wh kg−1), and being operative at high temperature. However, they suffer from the limited utilization of sulfur when the rate of charge/discharge processes is fast, partly because the active material is highly insulating with s of 10−30 S cm−1. Moreover, it is highly desired to use as much sulfur in the cathode composite as possible while maintaining the electrochemical performance for the practical application, but the literatures reported thus far utilized lower surface loading of sulfur ranging from 9 to 50wt%. The choice of conductive additive such as activated carbons in the cathode composites will be crucial in improving and controlling the electrochemical processes. In this regard, graphene mesosponges (GMS) are a class of unprecedentedly functional carbon materials having the high electrochemical stability, electric conductivity, structural flexibility, and mesostructured nanopores (Nishihara, H. et al. Adv. Funct. Mater.
2016, 26, 6418–6427; Energy Environ. Sci.
2019 DOI: 10.1039/C8EE03184C), and therefore, are promising as the conductive supports in cathode composites of lithium−sulfur all-solid-state batteries.
The utilization of GMS as the conductive additive indeed showed a good electrochemical performance with a gravimetric capacity of 690 mA h g−1 at 80 ºC at a rate of 0.2C even with 50wt% of sulfur loaded in the cathode composites. The elastic nature with the bulk modulus of ca. 0.8 GPa and large pore volume (~5 mL g−1) of the 3D graphene materials will be suitable for the charging/discharging processes that require a large volumetric change of the cathode composites (ca. 80%) as going from sulfur (~2 g cm−3) to lithium sulfide (1.66 g cm−3) with the following equation 2Li++S+2e− ⇄ Li2S. Moreover, the phase segregation in micrometer scale occurred with high loading of the active material (50−60wt%) was suppressed by the confinement of insulating sulfur into the mesopore of the elastic 3D graphene, achieving the durable three-phase contact between a solid-electrolyte, insulating sulfur, and the electric conductive carbon. As a result, both the rate characteristic and durability of the all-solid-state batteries were higher than those with a typical activated carbon, and the electrochemical operation was feasible under the harsh operation conditions up to 80 ºC with the specific charge/discharge capacities of 3.4 mA h cm−2 (2 C) even with the unprecedentedly high sulfur-loading (60wt%).
Preparation of Three-Dimensional Nitrogen-Doped Hollow Fiber Carbon and Its Application to Electrochemical Energy Device
Authors: Lim Katie Heeyum , Kim Hansung , Park Heeyoung , Park Hyun S. , Jang Jong Hyun 
Published: February 2020

Three-dimensional nitrogen-doped carbon materials are prepared using thermally decomposable polystyrene(PS) and mussel-inspired polydopamine(PDA), as a sacrificial template and a nitrogen-doped carbon precursor, respectively. By virtue of the versatile coating ability associated with the high nitrogen content, dopamine was demonstrated to be an effective precursor for the preparation of nitrogen-doped carbon. In previous studies, PDA has been used as a nitrogen source by coating its layer onto a main carbon source. Herein, however, the PDA is utilized not only for the nitrogen precursor but also for the carbon source, without any additional carbon source, in order to achieve the higher nitrogen content and simple synthetic procedure. As a result, nitrogen content on carbon increased to over 4 at. %, which was limited to under 1 at. % when PDA was just coated onto the other carbon source. Moreover, due to highly moldable characteristics of polymer ingredients, three-dimensional carbon structures with various configurations could be prepared such as micron-sized hollow carbon fiber.
First, nitrogen-doped hollow carbon fiber with μm-sized diameter was synthesized by coating PDA around the electrospun PS fiber and following pyrolysis for PS removal and PDA carbonization. The length of hollow carbon fiber was also able to be controlled from several μm to hundreds of μm, using ultra-sonication. Completely hollow carbon fiber with about 3-μm diameter was successfully obtained and analyzed its physical characteristics from XPS, Raman and Mercury porosimeter. Nearly 4 at. % of nitrogen was detected on the hollow carbon fiber and the over 68 % of nitrogen-doping structure is revealed to be graphitic-N, which is known as the most effective nitrogen-doping structure for oxygen reduction reaction.
Since both PDA-derived carbon materials have relatively high nitrogen content and can form a self-supporting network, endowing high applicability as a binder-free electrode, they can be effectively applied to electrochemical energy device, specifically polymer electrolyte membrane fuel cell (PEMFC) and Li-O2 battery system where the oxygen reduction reaction is the dominant reaction.
(Plenary) Layered Oxides in Li- and Na- Batteries: Structural and Electronic Effects
Authors: Delmas Claude 
Published: February 2020

At the end of the 70’s, Huggins, Whittingham, Murphy, Armand and then Rouxel research groups open the way to reversible Lithium batteries with aprotic liquid electrolytes. Most of the researches was devoted to chalcogenides at the positive electrode. Concerning Na battery, only intercalation in TiS2 and WO3 was considered.
Working on layered potassium and sodium layered oxides, only from the solid state chemistry point of view, I decided to study intercalation processes in the NaxCoO2 system because various structural types could be obtained by high temperature chemistry depending on the Na amount. This led to the first paper on the Na//NaxCoO2 battery. Simultaneously, J. Goodenough do the same in the homologous Li system (he made the good choice). Then my work was extended to the NaxMO2 (M = Ti, Mn, Ni, Nb) materials and to mix Co,Ni phases. Various systems were explored with Li and Na intercalation. This led, for example to the first intercalation in Nasicon phases.
At this time only alkali metals were used as negative electrode; therefore, the applications were limited. When Sony proposed in 1989 the first Li-ion Battery a fantastic market opened and most of the researches were then focused on materials with promising applications. In 1991, we proposed the LiNi1-xCoxO2 system which is used till now in most of the batteries for spatial applications. The Ni-rich phases, which are now very promising for EV, where intensively studied in my group till 2005, then followed by the lithium-rich system.
Recently, we revisited the Na layered phases with V and Mo. These ions with d2 and d3 configurations like to form M-M bonds via their t2g orbitals, therefore the study of the structural changes upon Na intercalation (deintercalation) was interesting.
In the perspective of the development of very large scale renewable energy systems the prevailing parameters are the lifetime, the price and the material availability. A general investigation was undertaken on Na layered oxides with several transition metal ions. The studies were focused on P2-type layered phases. One of the main interests of this structure is the existence of an ion conduction plane made of face sharing trigonal prims which exhibits a high ionic diffusivity thanks to the existence of a large bottleneck (oxygen rectangle) for sodium diffusion. This structure is able to accommodate a lot of transition metal cations, allowing the optimization of the properties by cationic substitution.
In all our studies we try to use a solid state chemist approach: structural and physical properties characterization in addition to the electrochemical characterization. The electrochemistry is a probe inside the material which is able to detect all changes (structural or electronic). The solid state chemistry is able to understand what is going on.
Several examples will be given in this general overview.
(Invited) Advanced Lithium Ion Batteries with Cobalt Free Cathode Materials
Authors: Axmann Peter , Mancini Marilena , Gabrielli Giulio , Balasubramanian Prasanth , Wohlfahrt-Mehrens Margret 
Published: February 2020

Lithium ion batteries are widely used in many applications and are the most promising energy storage systems for future mobility. The development of cobalt free cathode materials with high capacity and high voltage can contribute significantly to further cost reduction and better safety compared to lithium ion batteries with Nickel rich layered oxides like NMC622 or NMC811 as cathode material.
We report the synthesis and characterization of a series of Co-free, Li-rich Li1+xNi0.5Mn1.5O4 (0<x<1) cathode materials obtained via a low-temperature synthesis method. These materials give high reversible capacities up to 250 mAh/g cycled between 2.4 and 4.9 V vs. Li/Li+, high rate capability and good cycling life. Th cycling stability can be further improved by optimizing morphology, particle size distribution and additional surface coating and proper selection of electrolyte.
Full cell data of these cathode materials in combination with graphite or silicon/carbon composites as anodes demonstrate 15 to 20% higher specific energy compared to reference cells using NCM622 as cathode material, excellent rate capability, better safety and good cycling life.
Negative Electrodes for Longer Life, High Energy Li-S Batteries
Authors: Ulissi Ulderico , Rikarte Jokin , Carboni Marco , Locke Jacob 
Published: February 2020

As we approach the limits of lithium-ion batteries, new alternative chemistries are required[1]. Those that involve the sulfur conversion reaction at the positive electrode are among the most promising to move beyond Li-ion[2]. The conversion reaction of sulfur to form lithium sulfide is characterized by a high theoretical specific capacity of 1672mAh g-1, translating in a theoretical energy density of c.a. 2500 Wh kg-1, a value 2.5 times higher than that of commercial state-of-the-art Li-ion cells, using transition metal oxide based cathodes[3].
There are well-documented challenges associated with the traditional Li-S system which have been demonstrated to restrict the practical energy density and the cycle life[4]. Soluble polysulfides are generally formed, resulting in the shuttling mechanism, a major issue causing low coulombic efficiency, high self-discharge rates and negative electrode corrosion[4]. This reaction is also associated with large volume changes. This can lead to cell failure, due to the alteration of the cathode and anode structure and the favoured formation of lithium dendrites[5].
Strategies to enhance cycle life, while maximizing practical energy density, require a holistic approach. This includes optimization of the positive electrode (e.g., selection of conversion reaction catalyst, use of polysulfide adsorbents, binder selection); the negative electrode (e.g., lithium coating, functionalization and protection); the separator (e.g. functional barriers and polymeric membranes); the electrolyte (e.g. use of alternative solvents and salts, additives).
This work will focus on the recent negative electrode advances at OXIS Energy Ltd, the pioneer in the research and development of large-scale, high-energy, longer cycle life lithium-sulfur batteries.
[1] D. A. J. R. Ronald M. Dell, Lithium Batteries, John Wiley & Sons, Inc., Hoboken, NJ, USA, 2013.
[2] B. Scrosati, J. Hassoun, Y.-K. Sun, Energy Environ. Sci.
2011, 4, 3287.
[3] M. S. Whittingham, Proc. IEEE
2012, 100, 1518.
[4] A. Manthiram, Y. Fu, S. H. Chung, C. Zu, Y. S. Su, Chem. Rev.
2014, 114, 11751.
[5] X. Liu, J.-Q. Huang, Q. Zhang, L. Mai, Adv. Mater.
2017, 29, 1601759.
Titanosilicate Sitinakite Compound As a Low-Potential Anode for Sodium-Ion Battery
Authors: Liu Yao , Xia Yong-Yao 
Published: February 2020

Sodium-ion batteries (SIBs) have been considered as a promising candidate for large-scale energy storage applications, because of the low cost of sodium element and a broad choice of cathode materials which do not contain the expensive raw materials. However, a lack of promising anode materials still hinders the development of SIBs technology. Herein, we for the first time report a one dimensional tunnel-structure titanosilicate sitinakite compound with an ideal formula of Na1.68H0.32Ti2O3SiO4·1.76H2O employed as a new type anode material in SIBs. This material can deliver a reversible capacity of 110 mAh g-1 at a current density of 20 mA g-1 and with an average working voltage of 0.4 V vs. Na+/Na. The structure changes of this material during discharge/charge processes were investigated by using in-situ laboratory X-ray diffraction. The results indicated that sodium insertion proceeds via a topotactic intercalation pathway. We also identified pre-dehydration as an effective avenue to further improve the capacity of Na1.68H0.32Ti2O3SiO4·1.76H2O anode (reversible capacity of 131 mAh g-1 at a current density of 20 mA g-1 after pre-dehydration process). In addition, cation Nb doped Na1.68H0.32Ti2O3SiO4·1.76H2O compounds have been synthesized and systematically investigated the electrochemical performances in SIBs.
Reference
[1] Liu, Y.; Xia, Y., Na1.68H0.32Ti2O3SiO4·1.76H2O as a Low-Potential Anode Material for Sodium-Ion Battery. ACS Applied Energy Materials
2018, doi:10.1021/acsaem.8b01412.
Exploring Cobalt-Based Lithiated Spinel Cathodes
Authors: Lee Eungje , Croy Jason R. , Thackeray Michael M. 
Published: February 2020

Over recent years, our group has demonstrated that the incorporation of a spinel (S) component into ‘layered-layered’ (LL) composite electrode structures serves, as a stabilizing unit, to slow transition metal migration during electrochemical cycling.[1] However, unraveling the mechanism by which the S component operates in actual ‘layered-layered-spinel’ (LLS) materials is a challenging task because of the highly complex, inhomogeneous arrangements of the cations (typically Li, Mn, Ni, and Co) within multiple nano-domains. Moreover, relatively little is known about the structure and electrochemical properties of Co-based spinel materials, which were first reported in early 1990s[2,3], compared to Mn-based spinels. The lithiated spinel Li2Co2O4 is particularly attractive as a stabilizing agent in LLS composite electrodes for two reasons. First, cobalt has a lower propensity to migrate during electrochemical Co3+/4+ redox reactions and, second, lithium extraction from Li2−zCo2O4 (0 ≤ z ≤ 1), occurs at a potential (∼3.6 V) that is significantly higher than that of its lithiated manganese-oxide spinel analogue, Li2Mn2O4 (∼2.9 V). In this presentation, we will discuss the structure and electrochemical properties of substituted lithiated spinel materials that are easier to produce as a single phase, thereby eliminating the propensity for Li2Co2O4 samples to be contaminated by some layered LiCoO2.

References

[1] M.M. Thackeray, J.R. Croy, E. Lee, A. Gutierrez, M. He, J.S. Park, B.T. Yonemoto, B.R. Long, J.D. Blauwkamp, C.S. Johnson, Y. Shin, and W.I.F. David, “The quest for manganese-rich electrodes for lithium batteries: strategic design and electrochemical behavior,” Sustainable Energy & Fuels
2, 1375-1397, (2018).
[2] R.J. Gummow, M.M. Thackeray, W.I.F. David, S. Hull, “Structure and electrochemistry of lithium cobalt oxide synthesized at 400oC," Mater. Res. Bull.
27, 327-337, (1992).
[3] E. Lee, J. Blauwkamp, F.C. Castro, J. Wu, V.P. Dravid, P. Yan, C. Wang, S. Kim, C. Wolverton, R. Benedek, F. Dogan, J.S. Park, J.R. Croy, M.M. Thackeray, "Exploring Lithium-Cobalt-Nickel Oxide Spinel Electrodes for ≥3.5 V Li-Ion Cells," ACS Appl. Mater. Inter.
8, 27720-27729, (2016).
Electrothermochemical Behavior of External Short of Lithium Ion Batteries
Authors: Doh Chilhoon , Ha Yoon-Cheol , Eom Seung Wook 
Published: February 2020

Yazami1 reports on the thermodynamics of lithium ion battery. The understanding on heat generation of battery during charge and discharge and on heat dissipation is very important to maintain within appropriate temperature range2-4. Especially, it is highly important in the case of the battery of large capacity.
Here, drastic discharge with external resistance was studied with experimental and computational approach applying evaluated parameters of entropy, internal resistance, specific heat and open circuit cell potential. The coulombic capacity of used cell was ca 100 Ah. A case of external short was presented as below figure.
Acknowledgment: This study was supported by the KERI R&D program of MSIP/NST (18-12-N0103-01) and 18-02-N0108-02.
References:

Kazunori Ozawa, Lithium Ion Rechargeable Batteries, Ch. 5, Wiley-VCH Verlag GmbH & Co. KGaA, 2009.

K. Maher, R. Yazami, Electrochimica Acta, 101 (2013) 71.

K. Jalkanen, T. Aho, K. Vuorilehto, Journal of Power Sources 243 (2013) 354.

D.H. Jeon, S.M. Baek, Energy Conversion and Management 52 (2011) 2973

Dong Hyup Jeon, Current Applied Physics 14 (2014) 196.

Figure 1