Carla S. Santos, Alexander Botz, Aliaksandr S. Bandarenka, Edgar Ventosa, Wolfgang Schuhmann
The solid-electrolyte interphase (SEI) plays a key role in the stability of lithium-ion batteries as the SEI prevents the continuous degradation of the electrolyte at the anode. We combine the feedback and multi-frequency alternating-current modes of scanning electrochemical microscopy (SECM) for the first time to assess quantitatively the local electronic and ionic properties of the SEI varying the SEI formation conditions and the used electrolytes in the field of Li-ion batteries (LIB).
Ruben Leithoff, Arian Fröhlich, Steffen Masuch, Gabriela Ventura Silva, Klaus Dröder
In today’s cell production, the focus lies on maximizing productivity while maintaining product quality. To achieve this, the lamination of electrode and separator is one key process technology, as it bonds the electrode and separator to form mechanically resilient intermediate products.This paper addresses the investigation of interdependencies and proposes three characterization methods (grey scale analysis, high potential tests, electrochemical cycling and C-rate tests).
Nawfal Al-Zubaidi R-Smith, Manuel Kaspar, Peeyush Kumar, Daniel Nilsson, Björn Marlid, Ferry Kienbarger
Advanced EIS was applied to characterize industrial Ni-Cd batteries and to investigate the electrochemical redox processes. A two-term calibration workflow was used for accurate complex impedance measurements across a broad frequency range of 10 mHz to 2 kHz, resulting in calibrated resistance and reactance values. The EIS calibration significantly improved the measurements, particularly at high frequencies above 200 Hz, with differences of 6–8% to the uncalibrated impedance.
Manuel Kaspar, Arnd Leike, Johannes Thielmann, Christian Winkler, Nawfal Al-Zubaidi R-Smith, Ferry Kienberger
An interlaboratory Round-Robin comparison between three-labs is conducted where calibrated electrochemical-impedance-spectroscopy (EIS) is measured on prismatic cell dummies and prismatic batteries. Advanced EIS calibration workflow is employed allowing for precise measurements of low micro-Ohm impedances in a broad frequency range of 50 mHz to 10 kHz. Significant systematic-error corrections are obtained from the calibration.
Enrique Garcia-Quismondo, Sandra Alvarez-Conde, Guzmán Garcia, Jesús I. Medina-Santos, Jesús Palma, and Edgar Ventosa
In this work, a new, cheap and easily-implementable methodology to analyzes the quality of the Solid Electrolyte Interphase (SEI) on the negative electrode of Li-ion batteries (LIBs) is proposed. First, a redox-mediator is added in the electrolyte after the SEI formation cycle, and the redox mediator leads to an internal self-discharge process that is inversely proportional to the electrically-insulating character of the SEI. Second, a few charge and discharge cycles are applied to the battery and the presence of the redox-mediator provokes a shuttle effect enables by the lack of electrically protecting character of the SEI which consumes charges decreasing the coulombic efficiencies, enhancing the sensibility to the SEI protecting nature. We believe that the findings based on the application of this mediator-enhanced coulometry can be used to accurately predict the cyclic behavior of LIBs under extended operating conditions, which is especially relevant for a better comprehension of future industrial needs for battery R&D in cell components and production fields.
Simon Grall, Ivan Alić, Eleonora Pavoni, Mohamed Awadein, Teruo Fujii, Stefan Müllegger, Marco Farina, Nicolas Clément, Georg Gramse
This publication reports local cyclic voltammetry (CV) measurements at the solid-liquid interface on ferrocene self-assembled monolayer (SAM) with sub-atto-Ampere sensitivity and simultaneous spatial resolution <80 nm.
Nawfal Al-Zubaidi R-Smith, Mykolas Ragulskis, Manuel Kasper, Sascha Wagner, Johannes Pumsleitner, Bob Zollo, Albert Groebmeyer, Ferry Kienberger
This presents sensitive battery tests for large-scale applications using a compact measurement station with 256 multiplexed channels, to measure ACIR and OCV of 256 cells for cell classification and quality inspection.
Stefan Dieckhöfer, Wolfgang Schuhmann, Edgar Ventosa,
The implementation of scanning droplet cell (SDC) for non-aqueous battery research is discussed in this publication as well as the necessary adaptations for operation inside an Ar-filled glovebox in absence of oxygen and moisture.
Louisa Hoffmann, Manuel Kasper, Maik Kahn, Georg Gramse, Gabriela Ventura Silva, Christoph Herrmann, Michael Kurrat and Ferry Kienberger
The detection of defects and poor insulation behavior of the separator is essential for high-quality batteries.This publication shows how high-potential testing is used to analyze the insulation performance of the electrically insulating separator layer in a pouch cell.