bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Morphological Effect of Cobalt Oxide Nanocatalysts on the Electrochemical Performance of Lithium-Air Battery
Authors: Song Kyeongse , Cho Eunbi , Jung Jaepyeong , Kang Yong-Mook 
Published: February 2020

Next generation rechargeable batteries are required to have higher energy density compared to the state-of-art battery. The energy density of the commercial lithium ion battery cannot meet the stringent requirements, whereas the lithium-air battery has high theoretical specific energy coming up to 11700 Wh/kg because lithium–air battery is based on discharge reaction between Li and oxygen to yield Li2O2. However, very little is known about the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in the cathode of lithium-air battery. Moreover, lithium oxides like Li2O and Li2O2 are formed in cathode, which are thermodynamically difficult to decompose finally leading to an enormous irreversible reaction. Therefore, many efforts to overcome this problem have focused on finding proper catalysts having significantly improved ORR and OER. As reported previously, because versatile nanomaterials such as nanowires, nanocubes or nanosheet have shown unique chemical or physical properties due to the change of surface area, size confinement effects and etc., their electrochemical properties or catalytic effects were quite different from bulk counterparts when they were applied to various energy devices like fuel cell, lithium ion battery and solar cells. So, we judged that the morphological change of nanomaterial-based catalysts can be one of the main keys for controlling ORR and OER activities of lithium-air battery.
In this study, diverse cobalt oxide-based nanocatalysts in the form of nanocubes and so forth were synthesized, and their catalytic activities were compared in the morphological or structural viewpoint.
Lithium-Sulfur Cells: State of the Art, Electrolyte/Sulfur Ratio, Silicon Anodes and Safety Tests
Authors: Hagen Markus , Quiroga-González Enrique , Dörfler Susanne , Tübke Jens , Fanz Patrik , Althues Holger , Krampfert Matthias , Frohberg Jens 
Published: February 2020

Lithium-sulfur cells are potential high gravimetric energy density cells with 200-500 Wh/kg. Unfortunately typical used ether based electrolytes are not stable towards Li and degrade during cycling next to a decreasing active Li mass. Typical Li-S publications therefore work with an excess of electrolyte and Li combined with relatively low sulfur loads allowing high cycle numbers at the cost of low practical relevance.
High cell energy densities can only be obtained with a low electrolyte/sulfur ratio (ml/g) next to high sulfur utilization, fraction and load. Unfortunately low amounts of electrolyte typically decrease the sulfur utilization negatively and most sulfur cathodes need electrolyte/sulfur ratios between 5:1 and 10:1 to deliver maximum sulfur utilization. Unfortunately these ratios are too high to surpass the energy density of commercialized Li-Ion technology. We therefore suggest that the reserach focus should be switched away from maximizing only the sulfur utilization to optimization of the whole electrode capacity incl. the electrolytes weight. But even with such electrodes the obtainable cycle number will be low because of the electrolyte degradation. Since no superior, stable electrolytes exist up to now a good strategy might be the use of (lithiated) Si anodes instead of Li metal anodes. Si anodes face severe volume changes during cycling but are at least not completely converted like Li metal anodes. Thus, the electrolyte degradation might be slowlier with Si anodes and allow higher cycle numbers and also higher safety compared to Li metal anodes.
In the talk we would like to give a short overview about state of the art Li-S research, discuss the impact of the electrolyte/sulfur ratio on cell energy density, show some S8-LixSiy full cell results with very high active material loads (Si > 2mg/cm²!) and conlude with safety test results of small Li-S multi layer pouch cells.
New Cell Configuration with Carbon Interlayers for High Cycle Stability Lithium Sulfur Batteries
Authors: Chen Biao , Guo Rui , Li Yong , Liu Wen , Pei Hai Juan , Xie Jingying 
Published: February 2020

Lithium sulfur batteries are the most promising next-generation energy storage system due to their high energy density and low cost[1]. Although the studies on Li-S batteries have been ongoing over many years, commercialization of Li-S battery has not been successful due to many problems including the significant capacity fading.
The diffusion of polysulfides causes fast capacity decay of Li-S battery[2]. In this work, a well-designed carbon interlayer was used between the separator and the sulfur electrode for accommodating the migration of polysulfides during cycling. This Li-S cell configuration delivers excellent cycle stability, retaining a reversible discharge capacity of 850.7mAh·g-1 after 50 cycles with a retention rate of 80.5% when the sulfur loading of the cathode is 5.2mg·cm-2(Figure 1). The result indicates that this configuration is highly practical for the lithium sulfur batteries.
References:
[1]P.G.Bruce, S.A.Freunberger, L.J.Hardwick, and J.M.Tarascon, Nature materials., 11, 19(2011).
[2] Y. Yang, G. Zheng, and Y. Cui, Chemical Society Reviews
.,42, 3018(2013).
Structural Investigation of Na2MnSiO4, a Novel Cathode Material for Rechargeable Sodium Ion Batteries
Authors: Murphy Denissa Tjiadarma , Schmid Siegbert 
Published: February 2020

Lithium ion batteries dominate the world’s requirements of portable power storage due to their superior energy and power capability. However, as the focus of battery applications shifts towards larger scale energy storage, placing pressure on the declining amount of usable lithium, research interests shift towards the development of sodium ion batteries. Recently, various sodium based cathode materials have been based on structures that allow lithium insertion. Mixed-polyanion lithium compounds have been shown to be suitable precursors as they have the structural stability required for the complete exchange of lithium with sodium.1 The silicates Li2
MSiO4, (M = Mn and Fe), fulfil today’s requirements of safe, cheap and sustainable cathode materials especially due to the abundance of iron, manganese and silicon. The relatively higher theoretical capacities for these materials arise due to the possible extraction of two lithium ions accessing the M
2+/M
3+ and M
3+/M
4+ redox couples.2 The clear advantages of Li2
MSiO4, (M = Mn and Fe), over other lithium insertion compounds have made these materials attractive as possible analogues for cathode materials in Na-ion batteries.
While the structure of Na2MnSiO4 (monoclinic, space group Pn) has been reported previously employing conventional X-ray diffraction technique,3 the possibility of this compound to be utilised as a cathode material in sodium ion batteries has not been explored. To date, we have been able to synthesise the Na2MnSiO4 and investigated the structural parameters of the compounds through the combination of synchrotron X-ray and neutron powder diffraction studies. This contribution will also address the electrochemical behaviour of this compound, including structural changes which occur in Na2MnSiO4during electrochemical cycling and the connection of these structural changes to the observed properties.
References:
[1] Zhu, Y.; Xu, Y.; Liu, Y.; Luo, C.; Wang, C. Nanoscale, 2013, 5, 780.
[2] Islam, M. S.; Dominko, R.; Masquelier, C.; Sirisopanaporn, C.; Armstrong, A. R.; Bruce, P. G. Journal of Materials Chemistry, 2011, 21, 9811.
[3] Duncan, H.; Kondamreddy, A.; Mercier, P. H. J.; Le Page, Y.; Abu-Lebdeh, Y.; Couillard, M.; Whitfield, P. S.; Davidson, I. J. Chemistry of Materials, 2011, 23, 5446.
Synthesis and Electrochemical Characterization of NaxMO2 as Electrode Materials for Sodium-Ion Batteries
Authors: Huynh L.T. Nguyen , Ramos J.P. Pereira , Baddour-Hadjean Rita , Nguyen V. Hoang , Tran V. Man , Le Phung My Loan 
Published: February 2020

Nowadays, Na-ion batteries have been largely investigated for large scale applications such as grid storage and transportation because of the huge availability of sodium, its low cost and the similarity of both Li and Na insertion chemistries[[i]]. Some efforts have also been devoted to meet requirements in electric and portable devices such as cell phone or laptop. To do this, we must solve problems involving structural collapse due to high volume change during insertion/deinsertion. A good way to design the sodium electrode materials is by starting with analogue ones that function well for Li-ion batteries[i]. Layer structure of NaxMO2 composition seem to be greatly promising[i] due to its high capacity as well as good structural stability.

This work presents structure study and electrochemical behaviors of NaxMO2 (M = Mn, Ni and Co) as positive electrode materials synthesized by solid state reaction at 800oC. X-ray diffraction showed that structure of cobalt-based compound was the same as layer P2-Na0.74CoO2
[[ii]]. The single phase of Na0.44MnO2 was obtained by using difference manganese precursors (carbonate, acetate and electrolytic manganese dioxide) and the compound used acetate precursor revealed the best crystallinity. Ni-based compound could not form without O2 oxidation atmosphere. Cyclic voltammetry and charge/discharge testing in Swagelok cell with Na metal as anode between 2 - 3.8 V vs Na+/Na exhibited a series of phase transitions. We also determined the diffusion of sodium ion into tunnel structure by GITT Technique. The results will be further discussed.

Acknowledgements

This work was supported by National Foundation for Science and Technology Development (Nafosted) through Project Fund granted of 104.03-2012.46.

References

[i] Simon Engelke, Storage4, 2013, 1, 1.
[ii] J.J. Ding, Y.N. Zhou, Q. Sun, X.Q. Yu, X.Q. Yang, Z.W. Fu, Electrochemica Acta, 87, (2013), 488-393.
Ionic Liquid Based Electrolyte Systems Enabling Operation of High Voltage Cathode Materials
Authors: Snook Graeme Andrew , Huynh Thuy Diem , Ruether Thomas , Best Adam Samuel 
Published: February 2020

Lithium batteries are becoming increasingly important in hybrid and electric vehicle applications. The common cathode materials for these batteries, when based on metal oxides, are reaching their limits in terms of gravimetric capacity (mAh/g). In an effort to push the boundaries in energy density (Wh/kg) for these devices, there is an increasing push to higher voltage cathode materials such as LiMn0.33Ni0.33Co0.33O2 and the LiNi0.5Mn1.5O4 type materials, where the highest capacities of the materials are accessed at potentials greater than 4.6 V vs. Li|Li+. With this push for higher energy and higher voltage there is a limit to the types of electrolytes that are compatible with these materials and allow for the higher operating voltages. Standard battery electrolytes such as (1.2 M LiPF6 in EC/DMC) are well known to be unstable at these high voltages as well allowing severe Aluminium current collector corrosion. A key enabler to increasing the energy density of a lithium battery is an improved electrolyte.
At CSIRO, we have been at the forefront of developing new ionic liquid based electrolytes to enable the next generation of high voltage electrodes. The key factors to consider besides essential properties such as solution conductivity, Lithium ion diffusivity, viscosity, etc are the electrochemical windows of these solvents (i.e. stability at high cathodic voltages), the stability of the Aluminium current collector (i.e. limited corrosion in the solvent) and the compatibility of the high voltage cathode materials in these electrolytes (i.e. limited solubility of charge/discharge products in the solvent). At this time, there is a significant effort to identify solvents (blends), lithium salts and / or additives that can stabilize the cathode in contact with the electrolyte and preclude Aluminium current collector corrosion.
Specifically described in this work is our progress in developing ionic liquids electrolytes as well as blends of these with other solvents and additives for high voltage cathode applications. SECM characterisation to detect cathode dissolution and current collector corrosion has been carried out, as well as long term cycling of lithium cells incorporating the high voltage cathodes.
Modeling Lithium Stripping and Plating
Authors: Horstmann Birger , Hein Simon , Latz Arnulf 
Published: February 2020

Lithium-metal anodes are an indispensable ingredient of next-generation lithium battery concepts, as they offer energy densities comparable to those of new cathode chemistries, e.g., Li-O2 and Li-S. However, lithium-metal anodes undergo morphologic changes during battery cycling which reduces battery performance and safety. Lithium plating on standard graphite anodes is a related phenomenon. At low temperatures or high rates, lithium can deposit on the graphite surface as metal instead of intercalating.
Here, we approach crystallization of lithium metal from two directions. On a mesoscopic level, we model the dissolution of lithium metal. Experimentally, droplet formation, i.e., lithium stripping, was observed during the dissolution of lithium dendrites [1]. Based on our models for electrochemically-driven surface growth [2–4] inspired by phase-field modeling [5], we accurately describe lithium dendrite dissolution. In our model, the interaction between SEI and lithium metal is responsible for the nucleation of a Rayleigh-Jeans instability leading to droplet formation [6] driven by the lithium metal surface energy.
On a macroscopic level, we model lithium plating in a three-dimensional thermal transport and reaction model of the full battery cell. Our model accounts for consistent transport [7] and reaction [4] kinetics in electrolyte and electrode particles in order to understand the influence of inhomogeneous nucleation of lithium metal in a graphite anode on the battery performance.

Literature

[1] J. Steiger, D. Kramer, and R. Mönig, To Be Submitt. (2013).
[2] B. Horstmann, B. Gallant, R. Mitchell, W. G. Bessler, Y. Shao-Horn, and M. Z. Bazant, J. Phys. Chem. Lett. 4, 4217–4222 (2013).
[3] M. Z. Bazant, Acc. Chem. Res. (2013).
[4] A. Latz and J. Zausch, Electrochim. Acta 110, 358–362 (2013).
[5] L. Liang, Y. Qi, F. Xue, S. Bhattacharya, S. J. Harris, and L.-Q. Chen, Phys. Rev. E 86, 051609 (2012).
[6] J. Eggers, Rev. Mod. Phys. 69, 865–929 (1997).
[7] A. Latz and J. Zausch, J. Power Sources 196, 3296 (2011).
Influence of the Electrode Morphology on Lithium-Ion Battery Performance
Authors: Indrikova Maira , Golks Frederik , Kwade Arno 
Published: February 2020

In the future the application of lithium ion batteries as an energy carrier for electric and hybrid electric vehicles will become important field in automotive industry. To achieve this aim, the power density, energy density and long term stability of a battery have to be increased. Sophisticated mixing processes as well as the calendaring process (electrode compression) are known to significantly affect the above mentioned criteria, in particular the electrochemical cell performance [1-3]. However, the underlying cause-effect relationships are to a large extend still unclear.
The presented work investigates the influence of the electrode morphology on the electrochemical performance of the lithium ion battery, aiming at a model which correlates the intrinsic electrode design with characteristics, influence and dependencies of the electrode conductive paths. The performed experiments focused on the observation of changes in the electrode morphology upon external compression force using a novel analytical method, “quasi in-situ” compression scanning electron microscopy. For instance, direct insight into changes of particle-particle distances or pore volumes and their distribution may be obtained. Apart from electrode morphology analysis the electronic conductivity at the same compression pressure is investigated. Exemplary, figure 1a illustrates the changes of the electronic conductivity of the electrode as a function of pressure, as measured with the setup shown in figure 1b. While the porosity of the coating is decreased from initially 45% to 40%, the electronic conductivity increases significantly. Additional determination of the electrode compound performance in an electrochemical half cell (discharge rate test, average discharge potential and lifetime) for different compression forces is made. From the entire data set, a model is derived which correlates the morphological changes e.g., conductive additive network change with the resulting electrochemical performance.

Fig.1: (a) Measurement of electrode conductivity for varying force and a schematic illustration of compressed and uncompressed electrode (b)Experimental setup of conductivity measurements for varying force F; a small current (10 mA) is applied to the system, the response in voltage is recorded.

References

[1] H. Y. Tran, G. Greco, C. Täubert, M. Wohlfahrt-Mehrens, W. Haselrieder, A. Kwade, Journal of Power Sources 210 (2012), 276
[2] Y. H. Chen, C. W. Wang, X. Zhang, A. M. Sastry, Journal of Power Sources 195 (2010), 2851
[3] H. Zheng, J. Li, X. Song, G. Liu, V.S. Battaglia, Electrochimica Acta 71 (2012), 258
All-Solid Lithium Metal Polymer Batteries; Effect of LiFePO4 Cathode Density and Thickness on Electrochemical Performance
Authors: Jeong Jiseon , Lee Hoogil , Shin Gyuho , Ryou Mhyung-Hyun , Lee Yong Min 
Published: February 2020

All-solid lithium metal polymer batteries (LMPBs) consisting of lithium transition metal cathode, polymer electrolyte and Li metal anode have been investigated for achieving much higher energy density than lithium-ion batteries (LIBs) or providing special design properties such as flexibility[1-2]. Unfortunately, commercially available LMPBs failed to go to market, because solid polymer electrolytes (SPEs) show low ionic conductivity and poor interfacial stability towards electrodes comparing to liquid electrolytes. However, most of researches on SPEs have been focused for electrolytes themselves without broad cell performance data such as cycle life and rate capability. Moreover, even though the cathode should be developed or optimized for LMPB systems, few researches on cathodes (for example, cathode thickness, density, or composition) unlike LIBs have been done systematically for LMPBs up to now [3].
So, in this work, we investigate the room temperature electrochemical properties of all-solid LMPBs while changing cathode thicknesses and densities. The LMPBs consist of LiFePO4/SPE/Li metal, in which SPEs for electrolyte and cathode binder are manufactured by in-situ thermal polymerization after cathode/high porous separator/Li cell assembly. The optimum thickness and density of LiFePO4 cathodes could be found by evaluating cycle performances at room temperatures and rate capability. At the same time, morphological changes within the cathode and electrochemical changes before and after polymerization are also compared precisely.

Acknowledgements

This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government(MEST)(2010-0025738).

References

[1] J.Y. Lee et al., Journal Solid State Electrochem 14 (2010) 1445–1449
[2] J.Y. Lee et al., Journal of Power Sources 174 (2007) 603–606
[3] J.C. Choi et al., Journal of Electrochemical Science and Technology 4 (2013) 27-33
Microstructural X-Ray Tomographic Analysis of Commercial Lib Electrodes
Authors: Eller Jens , Ebner Martin , Wood Vanessa 
Published: February 2020

Systematic characterization, understanding, and improvement of Lithium Ion Battery (LIB) electrodes at the micro- and nanometer scales is essential to improving LIB capacity, safety and lifetime. The visualization and quantification of LIB electrode microstructures using X-ray tomographic microscopy (XTM) of ex-situ electrode samples [1-4] and using in-operando setups [5] has proved highly valuable for electrode micro-structure understanding and optimization.
Here we present the XTM structural analysis of different commercial carbon based anode LIB electrodes. Electrode samples have been scanned in absorption contrast mode at the TOMCAT beamline of the Swiss Light Source at Paul Scherrer Intitute in Switzerland resulting in voxel edge length of 0.33 micrometer. The segmented XTM data sets were analyzed for the distributions of porosity, tortuosity, effective relative diffusivity, and pore space constrictions.
The cross sections of four different commercial anodes are shown in Figure a) and display distinct microstructures. As shown in the histograms in Figure b), these differences can be quantified by assessing the spread in through-plane (perpendicular to current collector) and in-plane (parallel to current collector) tortuosities calculated for multiple 1050 μm2regions throughout the cell. Such analysis of the electrode microstructure is linked to the corresponding rate capability that is determined using half-cell based three-dimensional electrochemical modeling [6]. Furthermore, because electrodes typically fail at localized weak points, special focus is put on quantifying constrictions in the pore structure and understanding their potential impact on electrochemical performance and cell life.
References
[1] Shearing, P. R., Howard, L. E., Jørgensen, P. S., Brandon, N. P., Harris, S.J., Electrochem. Comm., Vol. 12 (2010), pp. 374-377. [2] Kehrwald, D., Shearing, P. R., Shinha, P. K., Brandon, N. P., Harris, S. J., J. Electrochem. Soc., Vol. 158 (2011), pp. A1393-A1399. [3] Ebner, M., Geldmacher, F., Marone, F., Stampanoni, M. and Wood, V., Adv. Energy Mater., Vol. 3 (2013), pp. 845-850. [4] Ebner, M., Chung, D.-W., García, R. E. and Wood, V., Adv. Energy Mater, (2013). doi: 10.1002/aenm.201301278 [5] Ebner M, Marone F, Stampanoni M, Wood V., Science, Vol. 342 (2013), pp. 716-720. [6] Latz, A. and Zausch, J.,
J. Power Sources, 2011, Vol. 196(6), pp. 3296-3302.
Detailed Comparison of Lib and SIB Electrolytes Via DFT Calculations
Authors: Jónsson Erlendur , Johansson Patrik 
Published: February 2020

While electrolytes for lithium-ion batteries (LIB) have been explored extensively, this is not (yet) the case for sodium-ion battery (SIB) electrolytes – especially true when it comes to detailed modelling efforts.
We have studied both LIB and SIB electrolytes using density functional theory (DFT), both to understand the dissociation ability of the salts used [1] and the solvation of the cations in the electrolyte solvents in detail [2]. By studying these properties for both LIB and SIB electrolytes, the major differences between the two systems can be outlined, and used for further rational design of new electrolytes and to explain experimental features. Here the main observations will be presented and recommendations given on areas to focus on, pertaining to the fundamental differences between LIB and SIB electrolytes. In general we find that the Na-salts have a higher tendency to dissociate into charge carrying species than Li-salts – from a pure ion-ion interaction strength point of view. A set of >50 different salts, i.e. choices of anions, were evaluated against Li+ and Na+. However, when the coordination and solvation of the respective cation, Li+ or Na+, explicitly by carbonate solvents, is taken into account, the ion-solvent interaction is similarly lowered. These observations thus lead almost to a status quo situation, but we stress that some nuances are worthy to consider for further development of SIB electrolytes and batteries.
[1] E. Jónsson, P. Johansson, Phys. Chem. Chem. Phys., 2012, 14, 10774-10779
[2] E. Jónsson, P. Johansson, submitted