bluuebunny/crossref_metadata_2025_split huggingface dataset:
Voltage and Impedance Analysis for the Indirect Detection and Characterization of Lithium Plating in Commercial Lfp//Graphite Li-Ion Cells
Authors: Danzer Michael A. , Petzl Mathias 
Published: February 2020

Lithium plating is one of the most critical ageing mechanisms of lithium ion batteries; it reduces the cell’s lifetime due to a loss of cyclable lithium and it reduces the safety due to the presence of metallic lithium in the cell. The deposition of metallic lithium occurs on the negative graphite electrode during charging preferentially at low temperatures, high currents, and high states of charge (SOC).
A novel approach enables the indirect detection of lithium plating through the analysis of voltage plateaus at discharge immediately after the charging process. Using the method of differential voltage analysis (DVA) [1] the charge amount corresponding to lithium stripping – as the reverse reaction to plating – is calculated [2].
A characterization of the cell behavior and a deeper analysis of the processes that take place at and after plating are performed using electrochemical impedance spectroscopy (EIS). Subsequent impedance spectra measured over a time span of one hour after metallic lithium was deposited on the negative electrode reveal fundamental changes in the polarization of the cell (see Fig. 1). After plating, the graphite electrode exhibits an impedance behavior which is typical for lithium metal electrodes [3]. The mid-frequency impedance arc increases with time (see Fig. 2) and approximates the size of the arc of the spectrum without plated lithium. The low polarization in this frequency range immediately after plating indicates the presence of new electrode surface area [4]. Whereas the increase in polarization over time reveals the formation of additional surface films. The approximation of the impedance arc over time towards the size of the arc without deposited lithium points to the development of a stable surface film. Nonetheless, the absence of the low frequency tail indicates that the electrode still behaves like a lithium metal electrode without solid state diffusion of lithium ions in graphite.
Further model-free analysis of the measured impedance spectra using the distribution of relaxation times (DRT) enables the identification of the underlying processes due to the relevant time constants [5]. It is shown that Li-ion migration through surface films is the rate-determining process in case of a plated graphite electrode.

References

[1]I. Bloom, A. N. Jansen, D. P. Abraham, J. Knuth, S. A. Jones, V. S. Battaglia, und G. L. Henriksen, J Power Sources, 139 (1–2) 2005, 295–303.
[2] M. Petzl und M. A. Danzer, J Power Sources, DOI 10.1016/j.jpowsour.2013.12.060, 2013.
[3] D. Aurbach, J Power Sources, 89 (2), 2000, 206–218.
[4] N. Schweikert, A. Hofmann, M. Schulz, M. Scheuermann, S. T. Boles, T. Hanemann, H. Hahn, und S. Indris, J Power Sources, 228, 2013, 237–243.
[5] J. P. Schmidt, T. Chrobak, M. Ender, J. Illig, D. Klotz, und E. Ivers-Tiffée, J Power Sources, 196 (12), 2001, 5342–5348.
A New Analytical Instrument Combining XRPD, Mössbauer Spectrometry and Electrochemical Analyses
Authors: Sougrati Moulay-Tahar , Leriche Jean-Bernard , Stievano Lorenzo , Fullenwarth Julien , Fraisse Bernard , Jumas Jean-Claude 
Published: February 2020

The research of new electrode materials of high performance for Li-ion batteries requires a better understanding of the electrochemical reaction that take place during the charge/discharge process.
For this objective in situ measurements have been developed using complementary tools such as X-Ray Powder Diffraction (XRPD) and Transmission Mössbauer Spectrometry (TMS) allowing both structural and electronic characterization of materials under the conditions of the electrochemical cycling (operando mode). Up to now these measurements are carried out separately, ie, using a cell to record the X-ray diffraction data and another cell for the Mössbauer data. To overcome the drawback of working on two different cells, a new setup [1] combining XRPD and TMS has been designed allowing an alternative way for recording of these two kinds of data simultaneously. Thus a conventional TMS spectrometer has been associated to a X-Ray Diffractometer of θ-θ geometry (Figure 1) using a specific electrochemical cell derived initially designed for in situ analyse of Li-ion batteries [2].

Figure 1: 1st
prototype of the setup combining XRPD diffractometer and TMS spectrometer.
On this prototype the electrochemical cell is fixed, thanks to the θ-θ geometry of the diffractometer. Connected to a potentiostat which is used to control electrochemical cycling. This cell allows measurements in both reflection mode (XRPD) and transmission mode (TMS). Since Mössbauer detector is saturated by the diffused X-rays, an software has been developed to allow collecting alternatively XRD patterns and Mössbauer spectra. The duration of the collection of each kind of data can be adjusted as a function of the investigated material.
Several examples are presented to illustrate the capabilities of this setup and how it can be used to illucidate complex mechanisms governing the electrochemical behaviour of Li- and Na-ion new electrode materials containing Fe or Sn.

References

[1] J.-C. Jumas, L. Stievano, M.T. Sougrati, J. Fullenwarth, B. Fraisse, J.-B. Leriche, Brevet Français, 12 58086 (2012), PCT/FR2013/051981 (2013)
[2] J.B. Leriche, S. Hamelet, J. Shu, M. Morcrette, C. Masquelier, G. Ouvrard, M. Zerrouki, P. Soudan, S. Belin, E. Elkaïm, F. Baudelet, J. Electrochem. Soc., 157 (2010) A606.

Acknowledgements

The Mössbauer platform has been implemented at the University of Montpellier with supports from the EC (NoE ALISTORE SES6-CT-2003-503532), Région Languedoc Roussillon (Contracts n° 2006-Q086 and 2008-094192). The author is grateful to these institutions and to CNRS and RS2E (FR 3459) for financial supports.
A Novel Conceptual Mg Battery with High Rate Capability
Authors: Zhang Ruigang , Ling Chen , Mizuno Fuminori 
Published: February 2020

Lithium ion batteries (LIBs) are quickly becoming the mainstream power sources for environmentally friendly vehicles such as hybrid vehicles (HV), plug-in hybrid vehicles (PHV) and electric vehicles (EV) due to their high energy density. On the other hand, a battery system with even higher energy density is required for the long-range PHV and EV applications, and therefore, post lithium ion batteries (PLIB) such as Li-sulfur batteries and Li-air batteries have been getting more attention in recent years. Rechargeable magnesium batteries are also a candidate for the PLIB thank to the natural abundance of magnesium and the absence of dendrite formation when magnesium metal is used as the anode. In addition, the magnesium batteries are expected to have high energy density because of its divalent nature. However, there is not much progress on the development of novel cathodes since an innovation of Chevrel phase materials such as MgxMo3S4. The difficulty lies in the strong polarization character of the small and divalent Mg2+ and consequently the intercalation and diffusion of Mg2+ ions is somewhat difficult and complicated.
Here, we report an interesting approach to find another redox reaction on the cathode side that replaces the classic intercalation reaction and balances the electron transfer. The charge transfer is achieved through the simultaneous transport of dual ions in the electrolyte during the electrochemical cycling. Reversibility on the interesting chemistry was confirmed by multiple techniques, such as X-ray diffraction, X-ray photoelectron spectroscopy, Scanning electron microscopy and so on. Figure 1 shows one of the conceptual Mg batteries comprising a Mg metal anode, a AgCl cathode and a Grignard-based electrolyte. As can be seen, fairly flat discharge-charge curves are repeatedly observed. Also, even at a rate of 10 C, the cell works very well and maintains over 100 mAh/g which is over 50 % of the capacity observed at 0.1 C. The significant change in cathode material design gave us a new finding of an impressive Mg battery with high rate capability.

Figure 1
Development of Garnet-Type Li Ion Electrolytes for All-Solid-State Li Ion Batteries
Authors: Narayanan Sumaletha , Thangadurai Venkataraman , Tong Xia , Hitz Gregory , Wachsman Eric D. 
Published: February 2020

The high energy density Li ion batteries require a replacement of currently used organic polymer electrolyte with highly conducting solid-state materials in terms of safety reasons. Solid electrolytes exhibiting high total Li ion conductivity, negligible electronic conductivity and wide electrochemical window (up to 6 V/Li/Li+) are preferable for application in solid-state Li ion batteries [1,2]. Garnet-like oxides, with general formula, Li5La3M2O12 (M = Nb, Ta) are emerged as a promising class of Li+ conductors among several other solid-state materials [1]. The increase in Li content has proven to be increasing the Li ion conductivity of garnets and Li7La3Zr2O12 have a highest conductivity of the order of 10-4 Scm-1 at ambient condition [3]. In this talk, we report the effect of excess Li added during synthesis to avoid Li volatilization on the ionic conductivity of garnet-type materials and discuss the recent developments on optimization of ionic conductivity of garnets.

References

1. V. Thangadurai, H. Kaack and W. J. F. Weppner, J. Am. Ceram. Soc., 86, 437 (2003).
2. J. B. Goodenough and K.-S. Park, J. Amer. Chem. Soc., 135, 1167 (2013).
3. R. Murugan, V. Thangadurai and W. Weppner, Angew. Chem. Int. Ed. Engl., 46, 7778 (2007).
Structural and Electrochemical Characterization of New Hexagonal Form of NaMn2O4 Cathodes for Sodium Ion Batteries
Authors: Jampani Hanumantha Prashanth , Datta Moni Kanchan , Bandi Ramalingam , Elumalai Viswanathan , Manivannan A. , Achary Damodaran Krishnan , Kumta Prashant N 
Published: February 2020

Introduction

Lithium ion batteries have thus far been the torchbearers in the field of electrochemical energy storage for mobile applications. The large scale commercialization of lithium ion batteries, however has the associated ‘cost of business’ including possible socio-economic concerns to various lithium rich nations such as Bolivia(1). There has therefore been a gradual realization in the battery community at large for the need to switch to more abundant raw-material based chemistries. Sodium and magnesium batteries are the fore-runners therein(2). In order for the smooth transition and for Na-ion to compete with the Li-ion batteries, considerable improvements in cathode and anode energy density, cyclability and rate capability are still required.
Nanocrystalline NaMn2O4 has been synthesized by a high energy mechano-chemical milling process (HEMM) using Na2O2 and Mn2O3 as starting materials for use as cathodes for sodium ion batteries. As previously reported by this group(3), the material exhibits a new close packed hexagonal crystalline form, different from the commonly known stable orthorhombic or monoclinic structures in the Na–Mn–O system, identified for the first time.
In this work, we study the stabilization of the hexagonal phase and its evolution to an orthorhombic phase upon heat treatment. Using in-depth solid-state NMR studies in conjunction with detailed electrochemical evaluation, the nature of the charge-storage behavior of this phase is evaluated herein. Figure 1 depicts the evolution of the hexagonal NaMn2O4 to a conventional orthorhombic phase upon heat-treatment. Alteration in sodium co-ordination chemistry and its effect on insertion/deinsertion and capacity will be presented and discussed.

Captions

Figure 1: Evolution of structure of hexagonal NaMn2O4 into the more known orthorhombic phase upon heat-treatment as observed using scanning electron microscopy.

References

1. R. Aguilar-Fernandez, Estimating the Opportunity Cost of Lithium extraction in the Salar de Uyuni, Bolivia, in, Duke University (2009).
2. B. L. Ellis and L. F. Nazar, Current Opinion in Solid State and Materials Science, 16, 168 (2012).
3. M. K. Datta, R. Kuruba, P. H. Jampani, S. J. Chung, P. Saha, R. Epur, K. Kadakia, P. Patel, B. Gattu, A. Manivannan and P. N. Kumta, Materials Science and Engineering: B, 188, 1 (2014).

Figure 1
Microwave-Assisted Synthesis of Graphene-Coated Mn-Doped Lithium Iron Phosphate (LFMP/G) for Electrochemical Capacitor
Authors: Rossouw Claire Angela , Zheng Haitao , Raju Kumar , Mathe Mkhulu K. , Ozoemena Kenneth I. 
Published: February 2020

Lithium Iron Phosphate (LFP) material is widely used to power commercial products such as torches, automotive vehicles and certain laptops. The material is relatively cheap, safe to use and longer life times than some of the other battery chemistry materials; however it suffers from poor electronic conductivity. In order to improve the electronic conductivity of LFP, the material can be doped with transition metals such as manganese (Mn) and coated with a carbon source such as graphene [1]. Various methods can be used to synthesize LFP materials with microwave synthesis being one of the examples [2]. Microwave irradiation allows for rapid synthesis. The experimental processes involved a one-pot design where all the starting materials were added together and underwent ultra-sonication, microwaving, washing, drying and annealing at 700°C. During the microwave irradiation process it was seen that crystalline LFP material was formed with a coating of graphene to form LFP/G and some of the material was doped with Mn to form LFMP/G. The LFP/G and doped LFMP/G material was made up into asymmetrical electrochemical capacitors (AEC). The LFP/G AEC had a much faster charge and discharge response time at 7mA relative to the LFMP/G AEC, however the LFMP/G AEC could be charged and discharged to higher voltages. The LFP/G AEC provided 1.43 mFcm-2 at a current density of 8.85 mAcm¯² over 30 h, whereas the LFMP/G provided 4.63 mFcm-2at a current density of 12.4 mAcm¯² over 50 h. Both capacitors showed very little internal resistance once the testing was completed.
In this presentation, we will discuss in detail our findings on the various microwave-based synthetic strategies adopted for the LFP/G and LFMP/G and their electrochemical properties for the development of efficient cathode materials for lithium ion batteries and asymmetric electrochemical capacitors.

References

(1) I. Bilecka, A. Hintennach, I. Djerdj, P. Novàk, M. Niederberger, J. Mater. Chem.19 (2009) 5125.
(2) D. Jugović, D. Uskoković, J. Power Sources 190 (2009) 538.

Figure 1
Study on Degradation and Failure in Lithographically Patterned Gold/Manganese Dioxide Core/Shell Nanowires Based Supercapacitors
Authors: Thesma Chandran Girija , Le Thai Mya , Penner R. 
Published: February 2020

Nanostructured manganese oxide (MnO2) is one of the widely studied materials for electrochemical capacitors because of the high specific surface area and excellent electrochemical properties leading to improved rate capability and enhanced energy/power densities. Most of the research on MnO2 is aimed at improving the capacitance whereas only a few studies are focused on cycling stability of these electrodes. In this work, degradation in capacitance of arrays of gold core nanowire encapsulated within a hemicylindrical shell of MnO2 will be studied. The horizontal nanowire systems provide an excellent platform for analyzing nanowire performance, such as investigations of the mechanisms contributing to degradation and failure in these systems. Ex-situ Raman spectroscopy, X-ray photoelectron spectroscopy and Grazing incidence X-ray diffraction measurements will be performed on the core/shell nanowires to examine various parameters such as nanowire defects, MnO2 dissolution, mechanical electrode failure behind degradation .
Carbon Nanostructures (CNS): Highly Conductive Matrix for Lithium Ion Battery Electrodes
Authors: Singh Boor , Shah Tushar , Hashaikeh Raed 
Published: February 2020

Traditional conductive carbon and polymer binder plays an important role for fabrication of lithium ion battery electrodes. Conductive carbon provides conductive pathways between the electrode particles specially for low electrical conductivity electrode materials and current collector,at the same time, the binder helps to provide mechanical integrity for electrode material. In this work, carbon nanostructres are presented as a highly conductive matrix material for fabrication of electrode without using any polymer binder. CNS consists of highly crosslinked and covalently bonded carbon nanotubes and forms a free standing films after reassembling from a CNS dispersed solution. CNS have high surface area, high electrical conductivity, low cost and environmently benign synthesis process. CNS/LiFePO4 cathode is fabricated using a facile process using water/ethanol mixture. No organic solvent is used for electrode fabrication. Scanning electron micrograms of the CNS/LiFePO4 electrode shows that LiFeO4 electrode particles are entraped by the entangled carbon nanostructures and provide high electrical conductivity pathways. LiFePO4/CNS electrode shows high electrical conductivity of 9.1 S/cm compared to the 0.4 S/cm for conventional LiFePO4/Carbon electrode. Cyclic voltammetry results show that CNS/LiFePO4 has low polarization potential compared to C/LiFePO4. This is attributed due to highly conductive pathways offered by the CNS. Charge-discharge performance of the CNS/LiFePO4 in half cell demonstrated improved capacity retention at high discharge rates.
Nanocrystaline Beta-Ni(OH)2 Cathodes and Their Nanoelectrofuel Analogs for Flow Batteries
Authors: Li Yue , Aryal Shankar , Sen Sujat , Timofeeva Elena V. , Segre Carlo U , Ramani Vijay K 
Published: February 2020

β-Ni(OH)2 is a discharged form of NiOOH which is common cathode for a family of nickel-based batteries including Ni/Cd, Ni/Fe, Ni/Zn, Ni/MH with theoretical capacity of 289 mAh/g. Previous studies have shown that introduction of nano-size β-Ni(OH)2 could dramatically increase the electrochemical performance, e.g. smaller polarization and better discharge capacity than commonly used micro-sized Ni(OH)2 mainly due to the enhancement of proton diffusion in nickel hydroxide electrode [1, 2]. Ni(OH)2 and NiOOH have been extensively studied before in bulk form including x-ray diffraction (XRD) and x-ray absorption fine structure (XAFS) techniques [3-6]. In situ EXAFS was used to study the progressive structure change during discharge and compare structures of Ni(OH)2in charged and discharged state [7, 8].
Our work focuses on the development of a suspension form of Ni(OH)2electrodes, also called nanoelectrofuels (NEFs). NEFs are stable dispersions of nano-scale battery active materials in the electrolytes that can be used in flow batteries as high energy density liquid energy storage. The main advantage of NEFs compared to traditional flow battery electrolytes is that high concentrations of active materials, and therefore energy density as concentration of nanoparticles in suspensions it is not limited by solubility of redox salts.
The presentation will discuss how different morphologies and crystallinities of β-Ni(OH)2 nanoparticles can be achieved through a simple one-step synthesis method; analysis with scanning electron microscopy (SEM), XRD, and thermogravimetric analysis (TGA) techniques; electrochemical characterization, including cyclic voltammetry, charge/discharge curves and life cycle analysis for different synthesis products in NEF formulations and compare their performance to the solid state analogs. In addition, we will present results from our in situ XAFS study of structural and electronic changes taking place during charge and discharge cycles in β-Ni(OH)2 cathodes.
References
[1] Guan X. Y, Deng J. C., Materials Letters, 61 (2007) 621-625.
[2] Han X. J., Xu P., Xu C. Q., Zhao L., Mo Z. B., Liu T., Electrochemica Acta, 50 (2005) 2763-2769.
[3] Pandya K. I., O’Grady W. E., Corrigan D. A., McBreen J., and Hoffman R. W., J. Phys. Chem., 94 (1990) 21-26.
[4] Ichiyanagi Y., Kondoh H., Yokoyama T., Okamoto K., Nagai K., Ohta T., Chemical Physical Letters, 379 (2003) 345-350.
[5] Morishita M., Kakeya T., Ochiai S., Ozaki T., Kawabe Y., Watada M., Sakai T., Journal of Power Sources, 193 (2009) 871-877.
[6] Capehart T. W., Corrigan D. A., Conell R. S., Pandya K. I., Hoffman R. W., Applied Physics Letters, 865 (1991) 58.
[7] Farley N. R. S., Gurman S. J., Hillman A. R., Electrochemica Acta, 46 (2001) 3119-3127.
[8] Farley N. R. S., Gurman S. J., Hillman A. R., J. Synchroton. Rad., 6 (1998) 198-200.
Degradation Study of Yttria Doped Barium Cerate (BCY) Electrolyte in Protonic Ceramic Fuel Cells Under Various Test Conditions
Authors: Kim Young Jin , Park Mi-Young , Lim Hyung-Tae 
Published: February 2020

Acceptor-doped barium cerate has been considered as a potential electrolyte material in solid oxide fuel cell because of its high proton conductivity at temperatures below 7000C. However, despite its superior transport property, barium cerate cannot be practically used in fuel cell due to its poor chemical stability in the atmosphere of water vapor and carbon dioxide. In the present work, we fabricated two kinds of BCY based anode supported cells, 1) BCY single layer cell and 2) BCY/BZY bi-layer cell, and their stability and degradation mechanism were investigated and compared, especially under severe operating conditions such as a negative voltage and low air flow rate. Constant current (CC) tests were conducted on the cells under various operating conditions such as positive vs. negative cell voltage and high vs. low fuel/air flow rate. Constant current (CC) tests were conducted on the BCY single layer and BCY/BZY bi-layer cells under a negative well as well a positive cell voltage as a function of air flow rate. Before and after the CC tests, I-V curve and impedance spectra were measured and compared to trace any increase in ohmic and/or non-ohmic resistance of the cells. Post-material analyses were conducted using scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS) to find out any change in microstructure and phase after severe operations.
Preparation of Sn-Cu/Graphene Nanocomposite for High-Performance Lithium-Ion Batteries
Authors: Uysal Mehmet , Cetinkaya Tugrul , Algül Hasan , Tokur Mahmud , Kartal Muhammet , Alp Ahmet , Akbulut Hatem 
Published: February 2020

Sn-Cu-graphene composites have been synthesized through a facile one pot co-precipitation method. The Graphene and copper could provide additional mechanical strength to prevent the crack and pulverization of the electrode structure during repeated volume expansion and contraction, which helps to maintain the integrity of the Sn electrodes and the electrically conductive network, and eventually leads to better cycling performance. Graphene can enhance mechanical properties, prevent the aggregation between Sn-Cu nanoparticles, and provide enough void space to buffer volume change of Sn-Cu. The surface morphology of the produced core-shell Sn-Cu/Graphene composite powders was characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS) and Raman spectroscopy X-ray diffraction (XRD) analysis was performed to investigate the structure of the Sn-Cu/Graphene composite powders. The lithium storage capability of the composites electrode is evaluated by cyclic voltammetry and galvanostatic charge-discharge tests. The resistivities of the produced Sn-Cu/Graphene composite electrodes were studied using electrochemical impedance spectroscopy (EIS). The results show that the Sn-Cu composites embedded in graphene exhibit superior lithium storage performance compared to pure Sn, Sn-Cu, Sn-Graphene, Graphene composites due to the buffering effects of Cu and the excellent confinement and conductivity of graphene.