TY - JOUR A1 - Toigo, Christina A1 - Arbizzani, Catia A1 - Pettinger, Karl-Heinz A1 - Biso, Maurizio T1 - Study on Dfferent Water-Based Binders for Li4Ti5O12 Electrodes JF - Molecules N2 - In this study, Li4Ti5O12 (LTO) electrodes with different types of water-soluble binders are successfully coated upon aluminum foil. Electrodes containing solely sodium alginate (SA) as a binder or a mixed PVDF/carboxymethyl cellulose (CMC) binder show the most stable performance in 1 M LiPF6 in EC/DMC 1:1 in half cell vs. Li, with respect to cycle stability over 100 cycles at 1 C. The electrodes processed with a mixture of PVDF/SA show considerable fading and slightly worse values for rate capability. Each one of the different binders used is eco-friendly, and the whole processing can be performed without the use of organic solvents. Further advantages covering the whole production and recycling process, as well as safety issues during operation, encourage deeper research in this area. Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:860-opus4-2798 VL - 25 IS - 2443 ER - TY - JOUR A1 - Zugschwert, Christina A1 - Dundálek, Jan A1 - Leyer, Stefan A1 - Hadji-Minaglou, Jean-Régis A1 - Kosek, Juraj A1 - Pettinger, Karl-Heinz T1 - The Effect of input parameter variation on the accuracy of a Vanadium Redox Flow Battery Simulation Model JF - Batteries N2 - Accurately predicting battery behavior, while using low input data, is highly desirable in embedded simulation architectures like grid or integrated energy system analysis. Currently, the available vanadium redox flow battery (VRFB) models achieve highly accurate predictions of electrochemical behavior or control algorithms, while the optimization of the required input data scope is neglected. In this study, a parametrization tool for a DC grey box simulation model is developed using measurements with a 10 kW/100 kWh VRFB. An objective function is applied to optimize the required input data scope while analyzing simulation accuracy. The model is based on a differential-algebraic system, and an optimization process allows model parameter estimation and verification while reducing the input data scope. Current losses, theoretical storage capacity, open circuit voltage, and ohmic cell resistance are used as fitting parameters. Internal electrochemical phenomena are represented by a self-discharge current while material related losses are represented by a changing ohmic resistance. Upon reducing input data the deviation between the model and measurements shows an insignificant increase of 2% even for a 60% input data reduction. The developed grey box model is easily adaptable to other VRFB and is highly integrable into an existing energy architecture. Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:860-opus4-2809 VL - 7 IS - 7 ER - TY - JOUR A1 - Schälicke, Gerrit A1 - Landwehr, Inga A1 - Dinter, Alexander A1 - Pettinger, Karl-Heinz A1 - Haselrieder, Wolfgang A1 - Kwade, Arno T1 - Solvent-Free Manufacturing of Electrodes for Lithium-Ion Batteries via Electrostatic Coating JF - Energy Technology N2 - This work demonstrates the feasibility of a novel solvent-free anode production for lithium-ion batteries. It combines a modified dry-mixing procedure with an innovative electrostatic coating process. The mixing is divided into two steps. At first, carbon black and binder are deagglomerated and recombined to a matrix structure by intensive mixing. In a second less intensive step, this matrix is blended with graphite. The powder mixture is fluidized and then transferred to the current collector by inducing a high voltage. After a subsequent hot pressing step, the powder coating is permanently fixed on the current collector. This procedure is presented with three different fluorinated binders. Furthermore, effects of different mixing intensities on the powder and electrode properties are examined. The electrodes are investigated in the three-electrode T-cell setup versus lithium metal to examine their C-rates and cycle stabilities. The produced anodes offer comparable electrochemical performance to conventional wetcoated ones on electrode and cell levels. Overall, this new process is a suitable alternative to the conventional electrode production techniques. Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:860-opus4-2819 ER - TY - CHAP A1 - Zugschwert, Christina A1 - Göschl, Sebastian A1 - Ibanez, Federico Martin A1 - Pettinger, Karl-Heinz T1 - Development of a multi-timescale method for classifying hybrid energy storage systems in grid applications N2 - An extended use of renewable energies and a trend towards increasing energy consumption lead to challenges such as temporal and spatial decoupling of energy generation and consumption. This work evaluates the possible applications and advantages of hybrid energy storage systems compared to conventional, single energy storage applications. In a mathematical approach, evaluation criteria such as frequency, probability of power transients, as well as absolute power peaks are combined to identify suitable thresholds for energy management systems on a multi-timescale basis. With experimental load profiles from a municipal application, an airport, and an industrial application, four categories, clustering similar roles of the VRFB and the SC, are developed. KW - Hybrid Energy Storage System KW - Vanadium Redox Flow Battery KW - Supercapacitor KW - Peak Shaving KW - Distribution Grid Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:860-opus4-3039 SP - 1 EP - 7 ER - TY - JOUR A1 - de Giorgio, Francesca A1 - La Monaca, Andrea A1 - Dinter, Alexander A1 - Frankenberger, Martin A1 - Pettinger, Karl-Heinz A1 - Arbizzani, Catia T1 - Water-processable Li4Ti5O12 electrodes featuring eco-friendly sodium alginate binder JF - Electrochimica Acta N2 - Electrodes based on Li4Ti5O12 (LTO) with sodium alginate (SA) binder featuring high percentage of active material and operating in glyme-based electrolyte are here proposed for the first time. Three electrode formulations operating in ethylene carbonate: dimethyl carbonatee1M LiPF6 (LP30) and 1m lithium bis(trifluoromethane) sulfonimide - tetraglyme were tested in half-cell vs. Li and compared to conventional 80% LTO and 10% polyvinylidene fluoride binder. Electrodes with 87% LTO and 3% SA binder show the best performance, with good rate capability and excellent cycling stability over 600 cycles at 1C in both electrolytes. The use of SA is beneficial as it allows made-in-water electrode manufacturing in absence of N-methyl-2-pyrrolidone, a toxic and expensive solvent required by fluorinated binders. SA also permits to decrease its amount to 3% increasing the active material percentage, and to develop a final device with higher specific energy. Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:860-opus4-2723 VL - 289 SP - 112 EP - 119 ER - TY - JOUR A1 - Kazhamiaka, Fiodar A1 - Keshav, Srinivasan A1 - Rosenberg, Catherine A1 - Pettinger, Karl-Heinz T1 - Simple Spec-Based Modelling of Lithium-Ion Batteries JF - IEEE Transactions on Energy Conversion N2 - Lithium-ion battery models that estimate their energy content after a series of charge and discharge operations are essential in the optimal design, analysis and operation of batterybased systems. We focus on the class of battery models that can be calibrated entirely from the battery’s manufacturer-provided specifications (spec). Such models are simple to calibrate and are therefore widely used in practice. The best-known model in this category was proposed by Tremblay et al. in 2007. This model, however, has several shortcomings, including low fidelity at high C-rates, and the fact that it does not model the battery management system.We propose an alternative, called the Powerbased Integrated (PI) model that is also completely spec-based, yet has much higher fidelity. We perform two types of validation, the first one uses the voltage profiles in the spec while the other is based on laboratory experiments. Both validations confirm that our model, which we have publicly released as a Simulink system block, has a mean absolute voltage error of less than 0.1 V across a wide range of C-rates. Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:860-opus4-2732 VL - 33 IS - 4 SP - 1757 EP - 1765 ER - TY - JOUR A1 - Toigo, Christina A1 - Singh, Madhav A1 - Gmeiner, Benjamin A1 - Biso, Maurizio A1 - Pettinger, Karl-Heinz T1 - A Method to measure the swelling of water-woluble PVDF Binder System and its electrochemical performance for Lithium Ion Batteries JF - Journal of The Electrochemical Society N2 - Water-soluble CMC/PVDF binder systems were used to prepare graphite anodes and compared mechanically and electrochemically with CMC/SBR binder systems. The effect of crystallinity of PVDF binder on the mechanical and electrochemical performance of the anodes is studied. A contact free method easy to operate and equipped with high accuracy was developed by using capacitance measurement. The swelling of graphite electrodes was controlled and showed different results for different binder crystallinities (no swelling of binder with high crystallinity vs 12% for medium crystallinity and 17% for low crystallinity binder). The discharge capacity depends on the crystallinity of the binders and half-cells delivered a capacity in the range of 230–360 mAh g−1. The binder with medium crystallinity in particular exhibited the best mechanical and electrochemical performance and showed an excellent C-rate stability with specific capacities up to 10 C. Full cell tests showed good cycling stability over 180 cycles. The water-based PVDF binders seem to be a promising alternative to solvent-based binders. Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:860-opus4-2766 VL - 167 IS - 2 ER - TY - JOUR A1 - Frankenberger, Martin A1 - Trunk, Markus A1 - Seidlmayer, Stefan A1 - Dinter, Alexander A1 - Dittloff, Johannes A1 - Werner, Lukas A1 - Gernhäuser, Roman A1 - Revay, Zsolt A1 - Märkisch, Bastian A1 - Gilles, Ralph A1 - Pettinger, Karl-Heinz T1 - SEI Growth Impacts of Lamination, Formation and Cycling in Lithium Ion Batteries JF - Batteries N2 - The accumulation of solid electrolyte interphases (SEI) in graphite anodes related to elevated formation rates (0.1C, 1C and 2C), cycling rates (1C and 2C), and electrode-separator lamination is investigated. As shown previously, the lamination technique is beneficial for the capacity aging in graphite-LiNi1/3Mn1/3Co1/3O2 cells. Here, surface resistance growth phenomena are quantified using electrochemical impedance spectroscopy (EIS). The graphite anodes were extracted from the graphite NMC cells in their fully discharged state and irreversible accumulations of lithium in the SEI are revealed using neutron depth profiling (NDP). In this post-mortem study, NDP reveals uniform lithium accumulations as a function of depth with lithium situated at the surface of the graphite particles thus forming the SEI. The SEI was found to grow logarithmically with cycle number starting with the main formation in the initial cycles. Furthermore, the EIS measurements indicate that benefits from lamination arise from surface resistance growth phenomena aside from SEI growth in superior anode fractions. Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:860-opus4-2770 VL - 6 IS - 21 ER - TY - JOUR A1 - Springer, Bernhard A1 - Frankenberger, Martin A1 - Pettinger, Karl-Heinz T1 - Lamination of Separators to Electrodes using Electrospinning JF - PLOS ONE N2 - This study shows the feasibility of the Electrospinning method as a process step for advanced and fast production Li ion cells. Lamination is a key technology for Lithium-ion battery production. It bares different advantages, such as a fast production line speed by fixing the separator to the electrodes. Unfortunately, this technology is inapplicable for separator and electrode formulations not based on thermoplastic binders. Using Electrospinning, this disadvantage can be overcome. In our study, beaded PVDF polymer nanofibres were spun onto a fibre-reinforced, inorganic-filled separator. This modified separator was then laminated onto a NMC111-cathode using a temperature profile of 110/110/120˚C within the laminator. After Lamination, the separator was pulled-off again and placed in a SEM to see the adhesive behaviour of the applied polymer. The information gathered with SEM clearly shows a successful lamination of the separator to the electrode. Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:860-opus4-2783 IS - 15 ER -