A novel approach to state/parameter estimation and optimal fast-charging
This work investigates a novel approach to joint state-parameter estimation and prediction of the optimal fast-charging current. The approach is based on a global optimisation technique, recently developed in the mathematical field of measure-moment theory. This global (rather than discretised) approach to optimisation offers convergence guarantees even when tackling nonlinear problems with non-convex constraints, which […]
Dual lithium salts mediated lithium transfer in viscous cellulose acetate gel-polymer electrolyte
Since gel polymer electrolytes (GPEs) have been introduced by Feuillade and Perche in 1975 [1], the studies on electrolytes based on biopolymers have been actively progressed due to the desirable properties of biopolymers and the concern on environmental issues. Furthermore, GPEs enable improved safety and mechanical stability as well as design flexibility, which meet the […]
Combined polarization-KPFM method to determine changes of the surface potential of ceria-spinel-based dual phase composites.
Dual phase composites, consisting of doped ceria as oxygen conductive phase and an iron-cobalt-based spinel (Fe3-xCoxO4) as electron conductive phase can be used as oxygen permeation membranes working at high temperatures above 800 °C [1-3]. The defect chemistry of these materials is well analyzed for temperatures between 600-1200 °C, whereas for other applications, for example […]
Impact of Thermal Material Properties on the Temperature Distribution within a Lithium-Ion Pouch Cell
Lithium-ion batteries are well established as energy storage devices for a wide range of mobile applications from cell phones through power tools to electric vehicles. The different types of usage lead to distinct requirements concerning the battery system, resulting in customized dimensioning of the single components. For the sustainable, technically and economically efficient battery production […]
Polymeric backbone eutectogel hybrid solid-state electrolytes for lithium-ion batteries
The need for sustainable mobility leads to a growth of the market of electric cars. In all roadmaps for battery development, solid-state batteries are the next step after advanced lithium-ion batteries (LIBs). They offer the potential to significantly increase the energy density, combined with a higher safety due to the absence of a flammable liquid […]
Interactions of cation disordered rocksalt cathodes with various electrolytes
Despite them missing a layered structure, cation disordered rocksalt (DRX) cathode materials have risen in research interest in the last couple of years, not only because of their high specific capacity but also for the possibility to lift the limitation on specific transition metals like Ni, Co and Mn.(1-3) Many of them involve the combination […]
Diagnosis of cell properties by electrochemical impedance spectroscopy during formation
The formation of lithium-ion batteries is an important and time-consuming process step in battery production. Good formation can positively influence cell properties and save process time. Within the scope of the investigations, tests will be carried out on special three-electrode cells. Among other things, the effects of the separators and electrolyte quantities used will be […]
Atomistic modeling of silicon–carbon-based nanocomposite anodes for lithium-ion batteries
Silicon–carbon nanocomposites have recently established themselves among the most promising next-generation anodes for lithium-ion batteries. Indeed, they can exist either as a two-host system combining silicon’s high energy density with the good electrochemical response of graphitic carbon or as a single-host system consisting of silicon carbide with a very high mechanical stiffness. However, selecting the […]
Investigation of lithium plating in commercial lithium-ion batteries
One of the challenges in the automotive industry is to provide fast charging of batteries. On the other hand, the safe operation of including low temperatures is indisputable. During cycling in such conditions, many undesirable phenomena may occur in the lithium-ion cell, such as low electrochemical performance of the system, e.g., high voltage drop, thermal […]
Battery Entropic Heating Coecient Testing and Use in Cell-level Loss Modelling for Ultra Fast Charging
To achieve an accurate estimate of losses in a battery it is necessary to consider the reversible entropic losses, which may constitute more than 20% of the peak total loss. In this work, a procedure for experimentally determining the entropic heating coefficient of a lithium-ion battery cell is developed. The entropic heating coefficient is the […]