bluuebunny/crossref_metadata_2025_split huggingface dataset:
Field Assisted Sintering of Li7-3xLa3Zr2AlxO12 Solid Electrolyte and the Influence of the Microstructure on the Electrochemical Performance
Authors: Botros Miriam , Djenadic Ruzica , Hahn Horst 
Published: February 2020

To enable large-scale applications of lithium ion batteries for transportation and storage of renewable energy high energy densities, high power, reduced costs and, most importantly, safety are required. The use of liquid organic electrolytes that exhibit high vapor pressures and flammability poses a substantial safety issue in particular for large-scale systems. Solid electrolytes offer a potential solution due to their inherent chemical stability. Recently, several material systems such as Li7-3x
La3Zr2Al
x
O12 (LLZO) have been identified that exhibit a large electrochemical window, ionic conductivities similar to those of liquid electrolytes at moderate temperatures and are stable against lithium metal, paving the way to the integration in high energy density battery cells.
In this work the synthesis and processing of fine-grained Li7-3x
La3Zr2Al
x
O12 solid electrolyte is performed for the first time using a combination of nebulized spray pyrolysis (NSP) and field assisted sintering technique (FAST). The microstructure, i.e. grain size and microstrain, has a crucial influence on the electrochemical properties of the solid electrolyte and thereby on the all-solid-state battery performance. During sintering using FAST, the grain growth is suppressed and dense ceramics with 93 % of the theoretical density are obtained. The microstructure and the phase composition are characterized using scanning electron microscopy and X-ray diffraction, respectively. The total lithium ion conductivity of the solid electrolyte at room temperature is found to be in the order of 10-4 Scm-1, which is in very good agreement with the literature values. The total conductivity is determined in a wide temperature range from 220 K to 393 K for the determination of the activation energy. Galvanostatic cycling of symmetrical cells using lithium electrodes shows a good cycling stability over 100 hours. The interfacial resistance in contact with lithium metal is determined using alternating current impedance spectroscopy and is amongst the best reported values so far. Several techniques for the integration of Li7-3x
La3Zr2Al
x
O12 solid electrolyte in an all-solid-state battery are presented and discussed.
Solid State Electrolytes Based on Doped Li7La3Zr2O12 Garnets: Crystal Chemistry, Ion Transport and Implementation into Li Batteries
Authors: Llordés Anna , Buannic Lucienne , Manalastas William Wang , Aguesse Frédéric , López del Amo Juan Miguel , Carrasco Javier , Kilner John A. 
Published: February 2020

Solid-state batteries could greatly boost current Li-ion technologies; they are expected to endure tens of thousands recharges, pack 2-3 times more energy as well as being safe from combustion and non-toxic. However, a widespread application of solid-state batteries is still far from being achieved owing mainly to limitations of the solid electrolyte component. Key challenges are achieving high ionic conductivity-in the range of 1 mS/cm-, good interfacial contact with the electrodes and easy/cost efficient processing. Among ceramic electrolytes, the garnet family Li7La3Zr2O12 (LLZO) is one of the most promising because of its high lattice conductivity for Li ion and its wide electrochemical stability [1],[2]. Unfortunately, these garnet-type materials often show highly resistive grain boundaries and have proven difficult to process into dense ceramic bodies.
In this presentation I will show our research on developing high-performance LLZO solid electrolytes. By using a wide variety of techniques, such as solid-state NMR, XRD, SEM and EIS, as well as DFT simulations, we investigate the role of crystal chemistry, doping and processing to the total conductivity and sintering properties of the ceramic electrolyte. I will particularly focus on the fundamental understanding and enhancementof ionic conductivity via substitutional doping of Li+ by Ga3+, which led to values as high as 1.3 mS/cm for Li6.55Ga0.15La3Zr2O12 at room temperature[3]. Alternative substitutions on the Zr4+ site can lead to a wider range of compositional possibilities and even higher conductivity values. The implementation of these LLZO garnet electrolytes into full cell devices, with LFP or LCO as cathode and Li metal as anode, will be also presented.
Finally I will report on a novel solid electrolyte concept based on the combination of doped LLZO garnets and polymeric Li-ion conductors, such as polyethylene oxide (PEO). These ceramic-polymeric composites show great promise as solid electrolyte membranes given the superior mechanical and interfacial properties compared to pure ceramics.
[1] R. Murugan, V. Thangadurai, W. Weppner. Angew. Chem. Int. Ed. 46, 7778-7781 (2007).
[2] M. Nakayama, M. Kotobuki, H. Munakata, M. Nogamia and K. Kanamura. Phys. Chem. Chem. Phys., 14, 10008-10014 (2012).
[3] Bernuy-Lopez, C.; Manalastas, Jr. W.; Lopez del Amo, J-M.; Aguadero, A.; Aguesse, F.; Kilner, J. A. Chemistry of Materials, 26, 3610 (2014).
Ceramic Polymer Hybrid Electrolyte Based on Li7La3Zr2O12 for Solid-State Batteries
Authors: Langer Frederieke , Glenneberg Jens , Bardenhagen Ingo , Kun Robert 
Published: February 2020

Solid-state lithium-ion batteries are a promising type of batteries for future applications. While replacing flammable liquid electrolytes with solid alternatives gives advantage to improved safety, the higher density of these solids compared to the currently used liquids is detrimental to the gravimetric energy density. Therefore, for sufficient battery cell performance thin and dense electrolyte layers of highly Li+ conductive material are needed. Currently, materials investigated for solid electrolyte application include ceramics, glasses and polymers.
Ceramic Li7La3Zr2O12 (LLZO) with cubic garnet like crystal structure has emerged as one of the most promising materials as electrolyte. Its advantages include high Li+ conductivity and chemical stability vs. lithium metal anodes. The material can be synthesised by solid state reactions as well as various wet chemistry routes. The product usually obtained from all methods is a powder. Processing this powder into a thin electrolyte layer that is suitable for battery production proofs to be difficult. Physical vapour deposition methods (e.g. pulsed laser deposition or sputtering) have been used to create thin film layers of LLZO, but these methods are limited and not suitable for large scale production. Easier processing techniques (e.g. tape casting and extrusion) are found for solid polymer electrolytes, but so far ionic conductivities of solid polymer electrolytes fall short of ceramic and glass electrolytes.
The objective of this study is to combine the advantages of ceramic and polymer electrolytes by fabrication of a hybrid solid state electrolyte. The hybrid mainly consists of LLZO and employs a polymer electrolyte as a binder. The aim is to produce a hybrid electrolyte for easier processing of solid-state batteries. Therefore, LLZO powder obtained from a facile wet chemistry synthesis route is mixed with solid polymer electrolyte. Thin hybrid electrolyte membranes are obtained using the tape casting method. Ceramic content of the hybrid electrolyte is varied up to 80-wt %.
Both LLZO powders and the hybrid electrolytes are characterized in regard to structure and electrochemical performance. Phase composition and crystal structure of the prepared powder are checked using X-ray diffraction (XRD). Morphology of powders and microstructure of the hybrid electrolytes are investigated with scanning electron microscopy (SEM). Thermal behavior of the hybrid electrolytes is examined using differential scanning calorimetry (DSC). Electrochemical impedance spectroscopy (EIS) is used to evaluate the ionic conductivity and special attention is paid to the ceramic polymer interaction. Its influence on lithium ion transport is discussed in detail.
We show that the combination of LLZO with polymer greatly simplifies the production of thin solid state electrolytes for lithium-ion batteries with only small losses in conductivity.
Iron and Titanium Substituted LiCoTixMn1-XO4/ LiCo1-yFeyMnO4: High-Voltage Spinels As Cathode Materials for Li-Ion Batteries
Authors: Dräger Christoph , Indris Sylvio , Ehrenberg Helmut 
Published: February 2020

Mn-based spinel materials are highly promising high-voltage cathode materials for Li-Ion batteries due to their structural peculiarity, resulting in their high rate capability and excellent room temperature cycling stability. The energy density of these Mn spinel based materials can be further increased by substituting Mn with electrochemically active 3d transition metals like nickel, iron or cobalt, so that the operating potential of the cathode is further increased1,2. This substitution is also reducing the Mn3+ content in the spinel and should therefore stabilize the cathode-material during cycling. In the present work, the high-voltage spinel LiCoMnO4 and its titanium or iron substituted derivatives LiCoTixMn1-xO4 (0.02 ≤ x ≤ 0.16) / LiCo1-yFeyMnO4 (0.05 ≤ y ≤ 0.2) are in the spotlight.
To investigate these compounds, our research is focused on the synthesis, structural and electrochemical characterization as well as spectroscopic methods in order to compare their properties and capabilities. Therefore, several techniques such as thermogravimetry in different states-of-charge (SOC), NMR spectroscopy in different SOC, and in situ powder synchrotron diffraction during electrochemical cycling and also during heating are applied.
Galvanostatic cycling reveals that about 70% of the lithium can be extracted and reinserted electrochemically in the voltage window from 3.5 to 5.3 V against Li from/into LiCoMnO4, LiCoTi0.06Mn0.94O4 or LiCo0.90Fe0.10MnO4 (Fig. 1). In situ synchrotron powder diffraction results show that Li extraction/insertion occurs via a single-phase mechanism over the whole range of Li contents and over the whole voltage-range for Ti substituted and unsubstituted LiCoMnO4 spinels (Fig. 2).
Financial support from the Federal Ministry of Education and Research (BMBF) within the DESIREE project, grant no. 03SF0477B, is gratefully acknowledged.
(1) Alcántara, R.; Jaraba, M.; Lavela, P.; Tirado, J. L. Chem. Mater.
2003, 15 (5), 1210–1216.
(2) Bhaskar, A.; Mikhailova, D.; Kiziltas-Yavuz, N.; Nikolowski, K.; Oswald, S.; Bramnik, N. N.; Ehrenberg, H. Prog. Solid State Chem.
2014, 42 (4), 128–148.

Figure 1
All-Solid State Rechargeable Batteries: Manufacturing of Composite Cathodes
Authors: Peters Fabian , Andre Felix , Schwenzel Julian 
Published: February 2020

All-solid-state batteries have great potential for both improvement of cell safety and increase of energy density. Safety improvements are obviously attained by removing the flammable liquid electrolyte. For the energy density, values up to 400Wh/kg are often claimed. Results of theoretical calculations reveal that specific energies beyond 400 Wh/kg and energy densities of more than 1200 Wh/L can be reached with all solid state Li-ion cells.
Great challenges remain in manufacturing of the components and the cell stack. All-solid battery cells as presented here typically consist of a lithium metal anode, a thin all-solid separator and a composite cathode. While the Lithium metal anode and the separator can probably be single-phase, the composite cathode requires a much more complex structure to ensure both good electrical and ionic conductivity. In addition, the contact resistance at the components’ interfaces needs to be minimized. Such cathodes ideally consist of evenly dispersed particles in solid electrolyte, with no remaining porosity.
In this work, a practical approach for manufacturing of all-solid composite cathodes is presented. The impact of different compositions and manufacturing technologies on the electrode structure and conductivity is shown. Composite cathodes comprising active material, polymer based electrolytes and conductive agents are manufactured by dry mixing, hot pressing and extrusion, respectively. SEM and TGA-DSC analysis reveal the structure of the resulting electrodes. Results of density and porosity measurements are also shown. Ionic and electrical conductivities are measured as well.
In conclusion, the impact of composition and processing on the quality of all-solid state composite cathodes is shown and discussed in this work. Recommendations towards improved manufacturing routes are derived.

Figure 1
Garnet Based Electrolytes Based on Li6.75La3-XMXZr1.75Ta0.25O12-D for All Solid State Lithium Batteries: Systematic Doping on the Lanthanum Site with Two and Three-Valent Cations
Authors: Struzik Michal , Genta Jessica , Pfenninger Reto , Garbayo Inigo , Rupp Jennifer L. M. 
Published: February 2020

Lithium stuffed garnet oxides such as Li7La3Zr2O12 have attracted considerable attention as promising candidate for solid electrolytes for All Solid State Lithium Ion Batteries. Their high Li-ion conductivity of ca. 1x10-3 Scm-1, wide temperature stability window, stability against metallic lithium and compatibility with high voltage new electrode materials implies new perspectives for large-scale applications for elevated temperatures as well new cell designs for thin film chip-integrated micro-batteries. The key to a successful application of Li-garnets is to ensure high Li-ion conductivity and electrochemical stability with other battery components.
Despite the great interest on this class of materials, there is still uncertainty on the role of La- and Zr-sites co-doping on the structural stability and phase as a function of ionic radii of the dopant and Li-transport properties. Here we present extensive study on structural properties and ionic transport of the Li6.75La3-xMxZr1.75Ta0.25O12 system, where M=Er3+, Y3+, Nd3+, Gd3+, Sr2+, Ba2+, Ca2+. Utilizing X-Ray diffraction, Raman spectroscopy and electron microscopy we discuss crystal structure properties and stability of the materials with respect to the ionic transport properties analysed by impedance spectroscopy in wide temperature window for future electrolyte applications in all solid state batteries.
NMR Studies of Ion Transport in Ultra-Concentrated Aqueous Lithium Electrolytes
Authors: Peng Jing , Xu Kang , Wang Chunsheng , Suo Liumin , Gobet Mallory , Munoz Stephen , Greenbaum Steven 
Published: February 2020

The electrolytes currently used in lithium ion batteries are a source of many cost and safety issues, which can be mitigated by a switch to aqueous electrolyte. This was, until recently, precluded by the narrow electrochemical stability window of the aqueous electrolyte, a problem which severely limited the practical voltage and energy density of the battery. However, recent developments have shown that it is possible to open up this stability window by increasing concentration of the salt (LiTFSI), enabling the formation of an interphase. This opens the door for a fresh focus on the properties of aqueous electrolytes. (1)

Nuclear Magnetic Resonance (NMR) is a powerful tool for exploring ionic and molecular transport in electrolytes. The nuclei in question (7Li , 19F, and1H) are particularly well-suited to measurement by NMR, due to their gyromagnetic ratios and abundances.
We performed NMR measurements on a range of concentrations of LiTFSI aqueous electrolyte, varying from 1 m to 21 m. In particular, pulsed gradient spin-echo self-diffusion experiments were performed on a 300 MHz spectrometer. Self-diffusion coefficients for both ions and water molecules were obtained over a range of temperatures from 20°C to -60°C. The diffusion results are displayed in Figs. 1 and 2. As expected, we note a general trend of smaller diffusion coefficients with lower temperature, as well as smaller diffusion coefficients with higher salt concentration. Cation transference numbers were determined directly from the diffusion measurements and those results are listed in Table 1. The cation transference number increases as the temperature falls and the salt concentration rises, as well. Although this investigation focuses on the transport properties of the liquid phase, ongoing work will address SEI formation on a variety of anodes in contact with this unusual aqueous system.

References

1. Liumin Suo et al. "Water-in-salt" electrolyte enables high-voltage aqueous lithium-ion chemistries. Science.
350, 938 (2015).

Figure 1
Graphite-Si Based Cell Performance in Alternative Electrolytes
Authors: Dzwiniel Trevor L , Pupek Krzysztof Z. , Krumdick Gregory , Abraham Daniel P 
Published: February 2020

In the quest to increase energy density of lithium-ion cells, graphite-silicon composite electrodes have been extensively investigated. The long-term performance of these electrodes is limited due to the instability of the electrode-electrolyte interface that is continually disrupted during the charge-discharge cycles. In order to improve the performance of silicon-based negative electrodes, researchers have developed various strategies that include novel electrolyte formulations among many others.
We conducted a comparative study of several electrolyte formulations based on LiFSI, LiTFSI, LiPF6, and mixtures thereof in fluorinated carbonates like methyl 3,3,3-trifluoroethyl carbonate, bis(3,3,3-trifluoroethyl) carbonate, 3,3,3-trifluoropropylene carbonate, and monofluoropropylene carbonate.
Comprehensive data from rate study, impedance and cycle life evaluation in NCM523//Gr-Si CR2032 full cells will be presented and discussed.
Investigation on Electrochemical Behavior of Rhombohedral Lithium and Sodium Vanadium Phosphate Cathode for Ion Storage System
Authors: Yang Junghoon , Kim Soo Young , Kang Yong-Mook 
Published: February 2020

Sodium ion batteries have attracted extensive interest based on its low cost and its similarity to lithium ion batteries. However, unlike what would be assumed that sodium storage mechanism is similar as lithium, recent reports show that sodium storage mechanisms in most materials could be significantly different from the corresponding lithium counterpart materials. These are mainly come from unexpected and unpredictable structure differences caused by different ionic radius between lithium ion and sodium ion. Recently, researchers are interested in the structural differences and their electrochemical behavior of lithium containing materials and sodium counterparts.
Li3V2(PO4)3 ­(LVP) and Na3V2(PO4)3 (NVP) are promising cathode materials for both lithium and sodium ion batteries, respectively. However, they have different structure when they are prepared by synthetic process. LVP prefers monoclinic structure but NVP formed rhombohedral structure and this difference caused different electrochemical behavior for lithium ion and sodium ion. The most distinguishing difference of the materials is available number of ions that participate in electrochemical reaction. Monoclinic LVP utilize whole lithium ions, thus LVP exhibits high theoretical capacity of 197 mAh/g. However, rhombohedral NVP only can use two sodium ions in the structure that limits it theoretical capacity of 118 mAh/g. The limitation mainly contributed to different crystallographic position of sodium ions in the structure that caused different migration energy. Thus, we need to approach to the problem with structural view point to overcome the electrochemical limitation of NVP.
To deduce the electrochemical behavior limitation of NVP with structural viewpoint, we prepared LVP materials with rhombohedral structure to observe the differences between the samples. The materials which have similar rhombohedral type structure LVP could be prepared from rhombohedral NVP by ion exchange method. From the rhombohedral LVP, we observed that more than two lithium ions can be extracted from the structure and new voltage plateau at high voltage which are not observed in NVP case. In this study, we will suggest different electrochemical behavior of LVP and NVP cathode materials based on different cation type and detailed structural studies during electrochemical reaction which will give the clues for understanding the different electrochemical behavior. The derived structural difference would also give new insights for modifying the structural features of NVP to enhance the electrochemical performances.
High Performance Sodium-Ion Batteries Based on Prussian White Electrode
Authors: Lu Yuhao , Vail Sean , Zhao Xin , Song Jie , Pan Wei , Lee JJ 
Published: February 2020

Sodium-ion batteries (NIB) consisting of a Prussian White (PW) cathode, a hard carbon anode and an organic electrolyte were prepared using conventional Li-ion battery (LIB) fabrication protocol. The Na2MnFe(CN)6 (Prussian White) was synthesized via a co-precipitation approach, which contains a Mn (III)/(II) redox couple and two Na ions in each unit cell. Attributed to the high Na concentration, fast ion transfer kinetics and mechanical robustness, the Prussian White cathode demonstrated a high capacity beyond 160 mAh/g, along with superior rate capability and cycling stability. The excellent performance and economical production method makes the NIB a promising alternative to lithium-ion batteries (LIB) in many application fields.

Figure 1
MSn2 (M= Mn, Fe, Co) Intermetallics As Anode Materials for Na-Ion Batteries
Authors: Vogt Leonie O , Marino Cyril , Villevieille Claire 
Published: February 2020

Tin is a promising anode material for the storage of large amounts of lithium and sodium; it currently boasts one of the highest specific charges: 990 mAh/g and 846 mAh/g in lithium-ion and sodium-ion batteries upon conversion to Li4.4Sn and Na3.75Sn, respectively1. However, storing such large quantities of these ions is typically accompanied by large volume expansions of up to 400%, which leads to particle fracture and thus electrical isolation resulting in rapid capacity fade with cycle number. By alloying an active metal with an inactive metal the reaction mechanism can be modified, allowing substantial specific charge to be achieved while mitigating the detrimental effects of the volume expansion.
Here, we alloy Sn with inactive transition metals Mn25, Fe26 and Co27 to form the tetragonal intermetallic MSn2 (I4/mcm). Since none of the three transition metals form alloys with Na on their own, they are expected to be inactive in the storage of Na; however the three MSn2 materials (M = Mn, Fe, Co) do not behave identically during cycling in sodium ion batteries, demonstrating that the transition metal in fact plays an “active role” in such systems. With the three materials being isostructural and the transition metals being adjacent to each other in the periodic table, the precise influence of the electronic structure of the supposedly inactive transition metal on the active system (here Sn) could be identified.
Using electrochemical measurements (CV, GITT, galvanostatic cycling and rate capability), ex situ and operando X-ray powder diffraction (XRD) data and X-ray absorption spectroscopy (XAS) we elucidate the reaction mechanism of all three materials and uncover that the reaction between Na and MSn2 (M = Mn, Fe, Co) is facilitated by intermediate state formation, dependent on the transition metal. The results of this study give an insight into designing the most effective combinations of active and inactive metals that may be selected as suitable alloy hosts for the next generation of novel battery materials.

References:

(1) Komaba, S.; Matsuura, Y.; Ishikawa, T.; Yabuuchi, N.; Murata, W.; Kuze, S. Electrochemistry Communications
2012, 21, 65.

Acknowledgment:

The Swiss National Science Foundation is thanked for financial support (Project 200021_156597). This work was performed within the Swiss Competence Center of Energy Research Heat and Storage (SCCER) framework.

Figure 1