Symposium FD
Materials Demands Towards New Generation Electrochemical Energy Storage Systems

Session FD-1 - Batteries

FD-1:IL01  Advances in Na-ion Batteries 
T. ROJO, Department of Inorganic Chemistry. Faculty of Science and Technology. University of the Basque Country (UPV/EHU), Bilbao, Spain; and CIC energiGUNE, Parque Tecnológico de Álava, Miñano, Spain

With the ever-increasing demands of modern societies, energy generation, storage, and distribution are becoming increasingly important research fields. Currently, one of the most promising areas of research and development is Sodium ion Battery (SiB) technology, which has a range of potential applications but remains particularly suited for use in stationary systems. Here we will discuss SiB systems in terms of what may be considered its three most significant components: anodes, electrolytes, and cathodes. SiB anodes are mainly based on hard carbon materials, due to their attractive combination of low cost and high energy density. However, there has also been interest in other systems, such as intermetallic alloying materials and metal oxides, as well as exploiting specific electrolyte co-solvation effects so as to enable the use of graphite. In general, the SiB research community uses organic electrolytes which are analogous to already existing Lithium ion batteries (LiB). However, recently there has been growing interest in developing new electrolytes which are specifically tailored for use in SiBs, such as optimized liquid and solid electrolytes. At the present time, cathodes are one of the most explored SiB components - with a plethora of options to choose from, including Prussian blue and organic materials. However, the most promising are polyanionic and layered materials, with their good combinations of electrochemical performance, low cost, stability and available constituents. Although interest in SiB technology has only relatively new, when compared to LiBs, it has been already developed at the prototyping level. A general overview of the most interesting electrode and electrolyte materials for Na-ion batteries paying special attention to those related to the current prototypes will be presented. By examining this topic in detail, it will be shown that there exists a strong drive to exploit this technology and that there are a wide range of opportunities to develop new and improved SiB technologies.


FD-1:IL02  Materials for Advanced Lithium and Lithium-ion Batteries for NASA’s Future Missions
R. BUGGA, M. SMART, W. WEST, E. BRANDON, R. EWELL, R. SURAMPUDI, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA

Lithium-ion batteries offer higher specific energy and energy density and longer lifetimes compared to the aqueous nickel-based chemistries used in the past, and have contributed to a significant enhancement or even enablement of several space missions in the last two decades. In contrast to the terrestrial applications, the planetary space missions require batteries to perform well under extreme operating conditions, i.e., low or high temperatures, micro-gravity and high radiation environments. Further, NASA’s future missions, e.g., planetary landers, rovers, probes and Cubesats need batteries with even higher specific energies and energy densities. Additionally, the planetary surface missions need batteries with good low (or high for inner planets) temperature performance, while the Jovian missions require batteries to be radiation-tolerant. Commentate with these unique needs, we have been developing advanced battery chemistries, including low-temperature and high specific energy Li-ion batteries and high specific energy lithium-sulfur cells. In this paper, we will describe some of our recent efforts on these advanced chemistries with high specific capacity cathodes and anodes, and electrolytes for improved low-temperature capability.


FD-1:L03  MgH2-TiH2 Nanocomposites as a Conversion Material for Conventional or Solid State Li-ion Battery Anodes
F. CUEVAS, J. ZHANG, M. LATROCHE, Université Paris Est, ICMPE, CNRS-UPEC, Thiais, France

Lithium-ion batteries are today largely used in portable electronics but their expansion towards large-scale energy applications requires novel electrode materials with higher energy density. Enhanced battery performances are expected from conversion material anodes. Owing to their high capacity, suitable potential and low polarization, metal hydrides are attractive anode materials [1]. However, reaction kinetics and cycle-life need to be improved for practical applications. In this context, we have recently focused our efforts on MgH2-TiH2 nanocomposites, whose hydride phases exhibit synergic effect for hydrogen storage [2]. Their electrochemical properties as anodes of Li-ion batteries using either conventional liquid organic electrolytes or solid electrolytes have been studied [3, 4]. For the first time, a hydride-based solid-state full cell has been successfully built including MgH2-TiH2 as anode, lithiated sulfur as cathode and LiBH4 as electrolyte [4].
[1] Y. Oumellal et al., Nat. Mater. 7 (2008) 916. [2] F. Cuevas et al., 14 (2012) 1200. [3] N. Berti et al., Int. J. Hydrogen Energy, 42 (2017) 22615. [4] P. López-Aranguren et al., J. Power Sources, 357 (2017) 56.


FD-1:IL04  Complex Hydrides as Electrolytes for Lithium-ion Batteries
D. GREGORY, WestCHEM, School of Chemistry, University of Glasgow, Glasgow, UK

With the continued depletion of fossil fuels, concerns over climate change and the necessity for secure sources of fuel supply, the need to explore alternatives to a carbon-based economy is becoming more urgent. One could consider storing sustainably generated electrical energy directly (for example in batteries) or indirectly using an energy vector, such as hydrogen. In fact, some materials with similar origins can serve both these purposes and the release of hydrogen from a number of complex hydrides, such as lithium borohydride, is linked to a transition to a fast ion conducting state. Partial anion replacement with appropriate halides can stabilize the high temperature structures of such hydrides, engendering fast ion conductivity at room temperature and enabling the design of potential new solid-state electrolyte materials for secondary batteries. This contribution will consider how one might design and produce new fast ion conducting complex hydride materials, taking lithium borohydride, LiBH4, as a basis. In contrast to their use in hydrogen storage applications, the hydrides should be thermodynamically robust enough to allow operation over a range of working temperatures. “Soft chemistry” synthesis and the ionic conductivity of these materials will be described.


FD-1:L05  Li Insertion into Li4Ti5O12 Spinel Prepared by Low Temperature Solid State Route: Charge Capability vs Surface Area
M. ZUKALOVA, L. KAVAN, J. Heyrovsky Institute of Physical Chemistry, CAS, Prague, Czech Republic; M. FABIAN, Institute of Geotechnics, SAS, Košice, Slovak Republic; M. KLEMENTOVA, Institute of Physics of CAS, Prague, Czech Republic; M. SENNA, Faculty of Science and Technology, Keio University, Yokohama, Japan

Li4Ti5O12 spinel powders with different surface areas are prepared by a novel low temperature solid state route. XRD proves the presence of majority of Li4Ti5O12 phase with small rutile and WC impurities. TEM analysis evidences the presence of two morphologies, larger Li4Ti5O12 crystals surrounded by nanocrystals of Li4Ti5O12. Cyclic voltammetry of Li insertion and galvanostatic chronopotentiometry at 1C and 2C rates confirms the highest charge capacity for Li4Ti5O12 spinel with surface area of 21 m2 g-1. Due to optimized two-phase morphology this material exhibits excellent long time cycling stability during galvanostatic chronopotentiometry at 1C and 2C. Its discharge capacity at 2C reached 180 mAh g-1 in the 1st cycle and dropped by less than 3% after 50 cycles. This exceeds even the discharge capacity of the same material at 1C. Hence, Li4Ti5O12 spinel prepared by our synthetic route represents promising material for fast Li-ion batteries.
This work was supported by the Ministry of Industry and Trade of the Czech Republic (contract TRIO FV20471) and by V4-Japan Joint Research Program AdOX granted from Visegrad fund and Japan Science and Technology Agency.


FD-1:IL06  Aluminum Batteries: Sustainable Alternative to Lithium-ion Systems
G.A. ELIA, Technische Universität Berlin, Research Center of Microperipheric Technologies, Berlin, Germany

The sustainability of energy storage systems is a keystone for the development of the “Green” energy economy. The use of electrochemical storage systems employing abundant and low-cost materials can allow the development of sustainable and environmental friendly electrochemical storage systems. In particular, the aluminum system appears as an interesting candidate for the next generation of electrochemical storage systems. Due to its high volumetric capacity (8040 mAh cm-3 for Al vs 2046 mAh cm-3 for Li), abundance and low cost, aluminum secondary batteries could be a viable alternative to the present Li-ion technology. In our work, we investigate the suitability of possible cathode materials for application in advanced aluminum batteries.


FD-1:L07  High-nickel Layered Oxide Cathodes for Next-generation Lithium-ion Batteries
A. MANTHIRAM, Materials Science and Engineering Program and Texas Materials Institute, The University of Texas at Austin, Austin, TX, USA

With enormous desire to increase the energy density beyond the current levels of 200 Wh/kg, layered oxides with high nickel contents are attracting much attention as cathodes for next-generation lithium-ion batteries for portable electronics, electric vehicles, and grid storage. However, their adoption in practical cells is hampered by serious scientific and technological challenges due to the chemical instability and catalytic activity of tetravalent nickel in the charged state in contact with the organic electrolytes, microcracks caused by phase transitions during charge-discharge, and the consequent rapid capacity fade. The high-nickel layered oxides also suffer from reactivity with ambient air, which increases rapidly with increasing nickel content and complicates the electrode fabrication process. This presentation will focus on the challenges as the nickel content increases and on the approaches to overcome them. Advanced surface and bulk characterizations of high-nickel cathodes and graphite anodes retrieved from full cells subjected to cycling over thousands of cycles will be presented to develop a clear understanding of the challenges. Utilizing the understanding gained, tailored cathode compositions and surface chemistry as well as optimized electrolyte compositions developed will then be discussed.


FD-1:L08  High-temperature Reactivity of Li7La3Zr2O12-based Garnets with Cathode Active Materials
V. TARNOPOLSKIY, O. HAJNDL, S. CHOMETTE, P. AZAIS, Commissariat à l'Energie Atomique et aux Energies Alternatives, Grenoble, France; M. Chakir, Renault, France

The market of lithium-ion batteries for electric vehicles will increase in near future. The next generation of batteries for electric transport will have to meet strict requirements on energy density, power and cost. At the same time, the safety of batteries becomes critical. Non-flammable ceramic solid electrolytes are promising candidates to replace the existing technology. Most persistent challenges to implement ceramic electrolytes include high grain-boundary ionic resistance and complicated cell assembly. No standard method exists to build an all-solid cell with ceramic electrolyte. Garnet-type Li7La3Zr2O12-based (LLZO) ceramics are promising solid electrolyte having high Li-ion conductivity, wide electrochemical stability and compatibility with Li metal. However, high temperatures are needed to densify ceramics for perfect contact between particles. This may induce unwanted reactions between components during densification of composite electrodes. Here we optimized the densification protocol of the LLZO ceramics by a hot pressing technique and studied the side reactions with cathode active materials. The ultimate goal is the cathode half-cell assembly in one single step without side reactions.


FD-1:IL09  Electrochemical Properties of Highly Concentrated Aqueous Na-ion Battery
SHIGETO OKADA, RYO SAKAMOTO, KOSUKE NAKAMOTO, AYUKO KITAJOU, DAIKI MURAKAMI, HARUKA HIRAI, MASARU TANAKA, Institute for Materials Chemistry and Engineering, Kyushu University, Kasuga, Fukuoka, Japan

For large-scale batteries, the cost per performance is more important issue than the energy density. In addition to the cost and environmental impact, another important issue for the large-scale cell is safety. In such game-changing situation, solid-state Na-ion battery and aqueous Na-ion battery without minor-metal are promising candidates as post Li-ion battery. Especially, in the viewpoint of the cost, aqueous electrolyte is more attractive than solid-state electrolyte. Since the 1.2 V theoretical electrochemical window of water is narrower than many solid electrolytes, the voltage limitation is more severe for aqueous batteries. But, the voltage restriction is a little bit eased in real aqueous battery system by the charge/discharge overvoltage. Recently, more than 2 V operations have been reported in some highly concentrated aqueous Li-ion batteries. In this presentation, high voltage operation will be presented for highly concentrated aqueous Na-ion battery with Na2MnFe(CN)6 hexacyanoferrates cathode and NaTi2(PO4)3 NASICON-type anode. In addition, the free water molecule amounts in various concentrated aqueous electrolytes are estimated by the DSC measurement below room temperature.


FD-1:IL10  Layered Oxide Electrode Materials for Sodium-ion Batteries
C. DELMAS, J. YOSHIDA, B. MORTERMARD, L. VITOUX, M. GUIGNARD, D. CARLIER, ICMCB, Pessac France; J. YOSHIDA, Toyota Motor Europe NV/SA, Zaventem, Belgium

In the perspective of the development of renewable energy systems, which have an intermittent character, the electricity supply and demand must be balanced in real time. This requires very large high capacity and power batteries. In this context, the prevailing parameters are the lifetime, the price and the material availability. From these points of view, sodium based batteries have to be investigated. Our research group studied layered oxides as positive electrode 30 years ago. In recent years, many research groups are involved in these studies. A general overview of their structure and electrochemical properties will be presented with a special focus 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 prisms, which exhibits a high ionic diffusivity thanks to the existence of a large bottleneck for sodium diffusion. This structure is able to accommodate many transition metal cations, allowing the optimization of the properties by cationic substitution. Recent results on the Nax(Fe,Mn)O2, Nax(Mn,Fe,Ni)O2 and Nax(Mn,Co,Ni)O2 systems will be discussed. Study of Na-battery is also a way to discover new materials. The original behaviour of the NaxMoO2 phases will be presented.


FD-1:IL15  Singlet Oxygen in Non-aqueous Battery Chemistries
N. MAHNE, L. SCHAFZAHL, E. MOURAD, Y. PETIT, B. SCHAFZAHL, C. SLUGOVC, S. BORISOV, S.A. FREUNBERGER, Graz University of Technology, Graz, Austria; O. FONTAINE, University of Montpellier, France; D. KRAMER, University of Southampton, UK

The redox chemistry of O2 moieties has come into the focus of much of the forefront battery research such as metal-O2 batteries and Li-rich layered oxides. O2 evolution is in either case a critical yet not fully understood phenomenon. For example, operation of the rechargeable metal-O2 batteries depends crucially on the reversible formation/decomposition of metal (su)peroxides at the cathode on discharge/charge. The greatest challenge arises from severe parasitic reactions, which so far have been ascribed to the reactivity of superoxide and peroxide. Yet, their reactivity cannot explain the observed irreversible processes. Here we discuss our recent insights into irreversible parasitic reactions caused by the highly reactive singlet oxygen during cycling of non-aqueous batteries that have so far been overlooked and that account for the majority of the parasitic products on discharge and nearly all on charge in metal-O2 cells (Nature Energy 2017, 17036; Angew. Chem. 2017, in press). We discuss their detection via newly developed methods and strategies to suppress them effectively. Awareness of singlet oxygen gives a rationale for future research towards achieving highly reversible cell operation.


FD-1:IL16  New Developments in Three-dimensional Microbatteries
E. COHEN¹, S. MENKIN¹, H. RAGONES¹, M. LIFSHITS¹, Y. KAMIR ², G. KOSA², D. GOLODNITSKY¹, ¹School of Chemistry, Tel Aviv University, Tel Aviv, Israel;  ²Department of Biomedical Engineering, University of Basel, Switzerland

Miniature power sources are needed for a variety of applications, including implantable medical devices, remote microsensors and transmitters, “smart” cards, and IOT systems. Today’s rechargeable lithium-ion batteries - with the best performance on the subject of energy density and with a reasonably good power efficiency - dominate the consumer market. Insufficient areal energy density from thin-film planar microbatteries inspires a search for three-dimensional microbatteries (3DMB) with the use of cheap and efficient micro- and nano-scale materials and techniques. The exclusive capabilities of the 3D-printing technology enable the design of different shapes and high-surface-area structures, which no other manufacturing method can do easily. We present a novel quasi-solid rechargeable 3D microbattery assembled on a 3D-printed perforated polymer substrate (3DBPS) with interconnected channels formed through XYZ planes. Simple and inexpensive electrophoretic-deposition routes are applied for the fabrication of all the thin-film active-material layers of the microbattery. Taking advantage of thin films, which conformally follow all the contours of the 3D substrate and are composed of nanosize electrode materials, like modified LFP, NCA, LTO, and original polymer-in-ceramic electrolyte, our 3D microbatteries offer high reversible specific capacity, high pulse-power capability, and intrinsic safety.


FD-1:IL17  Liquid and Solid State NMR Investigations of Low MW Polyether and Non-polyether Polymer Electrolytes for Supercapacitor and Battery Applications
M. GOBET, JING PENG, S. MUNOZ, D. MORALES, S.G. GREENBAUM, Hunter College of CUNY, New York, NY, USA; L. CARBONE, J. HASSOUN, University of Ferrara, Ferrara, Italy; R. RUTHER, J. NANDA, Oak Ridge National Laboratory, Oak Ridge, TN, USA; M. ZIMMERMAN, R. LEISING, Ionic Materials, Inc. Woburn, MA, USA

Nuclear magnetic resonance (NMR) has been productively employed to investigate ion transport and solvation in Li ion battery liquid electrolytes and in solid polymer electrolytes based on poly(ethylene oxide). Future electrochemical power sources require new electrolytes to adapt to disruptive changes in battery chemistry, such as moving to Na ion, or to Li metal. We highlight several recent collaborative activities on electrolytes. Variable chain length glymes containing lithium or sodium salts were studied by NMR methods including (i) natural abundance ¹⁷O; (ii) pulsed field gradient diffusion of solvent (via ¹H), cation (⁷Li or ²³Na), and anion (¹⁹F). Correlations between both solvent and anion ¹⁷O chemical shifts and chain length yield insight into solvation structures and ion pairing tendencies which are supported by the diffusion measurements. We next discuss a novel solvent-free solid polymer with room temperature ionic conductivity exceeding 1 mS/cm, which can be extruded into non-flammable thin films, has attractive mechanical properties for lithium dendrite suppression, and is compatible with Li metal as well as a wide variety of cathodes. It is based on semicrystalline polyphenylene sulfide and Li salts familiar to the battery community. The ionic transport mechanism is decoupled from polymer host motion, and NMR measurements reveal Li self-diffusion coefficients at room temperature that are the highest reported in any known solid, with a Li⁺ transport number greater than 0.6.


FD-1:L18  Polymeric Electrode Materials for Organic Batteries
A. LEX-BALDUCCI, S. MÜNCH, C. FRIEBE, R. BURGES, M.D. HAGER, U.S. SCHUBERT, Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Jena, Germany; Center for Energy and Environmental Chemistry Jena (CEEC Jena), Friedrich Schiller University Jena, Jena, Germany

According to a study of the European Commission the market value of the internet of things (IoT) is expected to exceed one trillion euros by 2020. In this context, objects and devices like smart clothes, sensors and active RFID tags call for thin, flexible batteries with the ability to be processed by roll-to-roll (R2R) techniques. Additionally, these batteries should not contain any toxic or harmful metals, while displaying high rate performance. In contrast to common battery technologies (e. g., lithium-ion batteries), organic batteries based on polymeric redox-active materials can meet all the above-mentioned criteria. While having comparable theoretical capacities they are superior not only regarding the availability, toxicity and environmental friendliness of the active materials but also in terms of flexibility and processability via R2R techniques. Another advantage of batteries based on polymeric active materials is the rich diversity of organic chemistry, which allows the realization of devices with capacities and cell voltages adjusted to the particular application. In this presentation new n- and p-type materials are presented. These polymeric active materials, based on stable radicals as well as on anthraquinones, can be used as active materials in organic batteries.


FD-1:IL19  Challenging the Fabrication of Ultra-thick Electrodes for Higher Energy Density Batteries
L. ZOLIN, W. PORCHER, CEA Grenoble - Liten, Grenoble, France; J. GAUBICHER, D. GUYOMARD, B. LESTRIEZ, IMN CNRS/University of Nantes, Nantes, France

Lithium-ion batteries are a commercially established reality that is able to ensure an effective solution for a green electric future. Nevertheless, different research strategies are needed to enhance performance and reduce costs of Li-ion batteries. One of the most efficient one consists in increasing the surface capacity of the electrodes. Indeed, the latter allows to increase both the volumetric and mass energy density and to reduce the cost by reducing the relative amount of passive elements. Today, the maximum loading achievable by the current industrial reference process, the “slot die coating”, is limited at around 5 mAh.cm^-². This communication deals with the production of ultra-thick negative and positive electrodes by an innovative process based on filtration. Upon optimization, ultra-thick electrodes with loading up to 25 mAh.cm^-2 were achieved. In addition, this approach was also found to be versatile as it can be readily transferred to post Li-ion technologies and to different materials. Despite their unconventional thickness (around 1 mm before compression), electrodes show robust mechanical properties. Electrochemical performance of full ultra-thick prototypes will be disclosed along with the analysis of advantages and limitations of this innovative process.


FD-1:IL20  Ions, Electrons, and Phonons: On the Movement of Charge through Solids
B.C. MELOT, Department of Chemistry, University of Southern California, Los Angeles, CA, USA

Li-ion batteries are ubiquitous; powering our cell phones, tablets, and laptop computers. Yet, we’ve almost exclusively relied on materials that adopt the same ordered rock salt structure type for over 20 years. What makes these materials so special and why is it so hard to move past them? This talk will present work our group has done to create a deeper understanding of the fundamental materials criterion required to move Li-ions through densely packed solids and outline new design principles for the development of next-generation intercalation hosts.


FD-1:IL21  Ionic Liquid-based Electrolytes for Safe Lithium-ion Batteries
A. MORETTI, S. PASSERINI, Helmholtz Institute Ulm, Karlsruhe Institute of Technology, Ulm, Germany

The state-of-the-art electrolytes for Li-ion batteries remain those based on Li salts, e.g., LiPF6, dissolved in organic carbonates. Although the use of these electrolytes gives good cell performances, the volatility and flammability of the organic solvents results, upon cell abuse and/or thermal runaway, in a significant risk of gas release and combustion.[1] In an effort to combat these safety issues, ionic liquids (ILs) with dissolved Li salts have been proposed as electrolytes because of their properties such improved thermal, chemical and electrochemical stabilities, wider useable temperature range, and low volatility and flammability. However, ILs have a relatively high viscosity and subsequently lower lithium-ion mobility, which limits the rate capabilities of IL-based batteries. Recently an alternative approach, based on the use of high concentration electrolytes, e.g., IL-in-salt (analogous to solvent-in-salt) systems, has been explored.[4-8]
References: 1. J. Kalhoff, et al, ChemSusChem, 2015, 8, 2154. 2 G. M. A. Girard, et al, Phys. Chem. Chem. Phys., 2015, 17, 8706. 3. M. J. Marczewski, et al, Phys. Chem. Chem. Phys., 2014, 16, 12341. 4. H. Yoon, et al, Phys. Chem. Chem. Phys., 2015, 17, 4656. 5. G.A. Giffin, et al, J. Power Sources, 2017, 342, 335.

 
Session FD-2 - Supercapacitors

FD-2:IL01  Cost-effective and High-capacity Spinel Pseudocapacitive Oxides
NAE-LIH WU, M. ABDOLLAHIFAR, Y.C. LIN, Department of Chemical Engineering, National Taiwan University, Taipei, Taiwan

Supercapacitors (SCs) are currently being developed as high-efficiency and high-power electrochemical energy storage devices for future portable-electronics and electric-vehicle applications. SCs require rapid charge-discharge rates, a long cycle life (>10,000 cycles), excellent reversibility, low maintenance requirements and high operational safety. The electrochemical performance of SCs is strongly related to their electrode-materials’ composition, surface area, and porosity. The use of binary metal oxides- particularly spinel structures, represented by AB₂O₄ (containing two transition metals A and B)- as pseudocapacitive electrode materials in SCs has been gaining increasing attention because of their potential superior electrochemical performance as compared with single component oxides because of their multiple available oxidation states and richer redox processes. In this presentation, the development of new spinel pseudocapacitive electrode materials containing low-cost and abundant transition metal elements, such as Mn, Fe, Cu, and Zn, and using either aqueous or organic electrolytes will be presented.


FD-2:IL02  Environmentally Friendly Materials for Supercapacitors
A. VARZI, S. PASSERINI, Karlsruhe Institute of Technology (KIT) - Helmholtz Institute Ulm (HIU), Ulm, Germany

The role of binders is often underrated in the field of Electrochemical Double Layer Capacitors (EDLC), as they are merely considered as “dead weight” with the only function of holding together the electrode components. However, choosing the right polymer is fundamental for lowering the environment impact of EDLCs. In fact, the binder determines the solvent needed for the electrode production and, in turn, the overall process' sustainability. Polyvinylidene fluoride (PVdF) and Polytetrafluorethylene (PTFE) have represented for decades the state-of-the-art binders for EDLCs. Nowadays, however, with the growing market of such devices, fluoropolymers are being questioned for several reasons. Besides containing fluorine, which makes them difficult to dispose at the end-of-life, PVdF, for example, requires the use toxic solvents (e.g., N-methyl-2- pyrrolidone) that need to be properly handled to avoid health hazards. For these reasons, many efforts are put into developing greener alternatives. This paper will provide a comprehensive overview about the recent developments in the field of fluorine-free and water-processable binders. Advantages and open challenges of natural polymers (and their derivatives) such as cellulose, starch and casein will be thoroughly discussed.


FD-2:L03  3D-printing Electrodes for Electrical Energy Storage
M. WORSLEY, Lawrence Livermore National Laboratory, Livermore, CA, USA

Aerogels are monolithic high surface area structures with great potential as electrodes for electrical energy storage applications. However, the random, uncontrolled nature of their porous networks can hinder mass transport and negatively impact device performance. 3D printing provides a means to synthesize aerogels in a manner that can mitigate the mass transport issues by intelligently incorporating macroporous channels into the native nanoporous aerogel structure. This advance in electrode fabrication has the potential to provide an even greater level performance for these hierarchical functional materials. Here we present our recent efforts to 3D print aerogel materials. The 3D printed aerogels exhibit many of the same properties as bulk aerogels, but with some enhancements in mass transport as well as mechanical properties. Energy storage devices based on 3D printed electrodes, which exhibit great rate capability, synergistic capacity, and cycling stability, will be presented.
This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.


FD-2:IL04  Buffered Solutions as New Electrolytes for Aqueous Supercapacitors
WATARU SUGIMOTO, SHO MAKINO, DAI MOCHIZUKI, Shinshu University, Faculty of Textile Science and Technology, Ueda, Japan

Nanostructured ruthenium oxides show extremely high capacitance of ~700 F/g in acidic electrolytes, and is considered as the 'gold standard' for pseudocapacitive materials. Nonetheless, information on the electrochemical behavior in near neutral media is scarce. Here we report the charge storage behavior of poorly-crystalline hydrous RuO2 nanoparticles and highly-crystalline RuO2 nanosheets in acetic acid-lithium acetate (AcOH-AcOLi) buffered solutions with pH near neutral. It is shown that capacitance values as high as 1,040 F/g can be achieved in AcOH-AcOLi buffered solutions with RuO2 nanosheets, which is almost 1.5 times higher than the benchmark RuO2·nH2O in H2SO4 electrolyte (720 F/g−1). The mechanism of the pseudocapacitive charge storage is discussed based on the difference in the surface redox behavior with the different RuO2 nanomaterials in acid, neutral, buffered solutions, and in weak acid.


FD-2:IL05  Novel Electrolytes for Supercapacitors
A. BALDUCCI, L. HENNING HEß, C. SCHÜTTER, J. KRUMMACHER, Friedrich-Schiller-University Jena, Institute for Technical Chemistry and Environmental Chemistry, Center for Energy and Environmental Chemistry, Jena (CEEC Jena), Jena, Germany

The state-of-the-art organic electrolytes of electrochemical double layer capacitors (EDLCs) consist of solutions containing 1M of the salt tetraethylammonium tetrafluroroborate (Et4NBF4) in acetonitrile (ACN) or propylene carbonate (PC). These electrolytes display good transport properties, and their use makes possible the realization of EDLCs with operative voltage in the order of 2.7-2.8 V, able to work in a rather broad temperature range. Nevertheless, when used in devices operating at more than 3 V, these electrolytes are not able to guarantee the performance (especially in term of cycle life) required for EDLCs. Since the development of high voltage (>3V) devices is a prerequisite for the realization of high energy EDLCs, which is ultimate goal of this technology, it is evident that the introduction of new electrolytes, able to work at high voltage, is presently considered one of the priorities for this technology. In this presentation novel electrolytes suitable for the realization of high voltage and high energy EDLCs, based on carbonates, nitriles and cyano-ester solvents, will be presented. Furthermore, an innovative strategy for the identification of novel electrolytes components, based on computational screening, will be introduced and discussed.

 
Session FD-3 - Application Engineering

FD-3:IL02  Materials Engineering Challenges for Viable Li-S Battery Electrodes and Cells
S. TRABESINGER, Electrochemistry Laboratory, Paul Scherrer Institute, Villigen PSI, Switzerland

The prospect of low-cost battery with high energy-density drives the research in Li–S batteries, which are the most promising candidates for practical next-generation post-Li-ion systems, despite the numerous challenges. These challenges are not only materials or chemistry related, such as insulating nature of sulphur and of its lithiation end-product, lithium sulphide, or polysulphide dissolution and reactivity, but also involve engineering ones on both electrode and cell levels. In this talk the sensitivity of Li–S battery performance to experimental parameters, related to electrode composition and cell assembly will be discussed, clearly calling for standardized testing not only within Li–S but also in wider rechargeable battery field. The exquisite sensitivity of the Li–S system to many experimental parameters speaks to the importance of directing future research towards the entire Li–S-battery set-up, rather than just some of its components, and a need to dedicate more research to cell engineering. In addition, commercial viability study of novel cell components, such as interlayers and membranes, designed to alleviate one of the most challenging issues of Li–S batteries, — polysulphide shuttle, — will be presented.


FD-3:IL03  Economic and Ecological Sustainability Analysis of Batteries for Stationary Applications
M. WEIL, M. BAUMANN, KIT/ITAS, Karlsruhe, Gemany; J. PETERS, KIT/HIU, Ulm, Germany

The German energy turnaround is a big challenge, due to the goal of the integration of a high share in fluctuating renewable energy within the energy grid. Experts are convinced that energy storage will play an important role with the future grid. But the predictions how much energy storage capacity is needed for short, mid, and long term until 2050 differ significantly, but will depend on the cost development per kWh. For batteries a strong production cost reduction is predicted until 2030, with potentially costs below 200 €/kWh. But production costs are not sufficient to compare on an economic base energy storage options with different technology performance. Instead cost has to be analysed over the whole life cycle (including e.g. use phase). For the investigation four stationary applications are considered: • Electric time shift (ETS)/ , “Arbitrage” (Energy/Power = 4) • Increase of photovoltaics self-consumption (PVSC, Energy/Power = 3,2) • Primary regulation (PR, Energy/Power = 1) • Renewables support (RS, Energy/Power = 10) The presented work compare the economic an ecological performance of 8 different battery options, including diverse Li-Ion and redox flow batteries. The effects of parameter variations are investigated within a sensitivity analysis.