In literature, the ionic conductivity of solid electrolytes is often discussed as one of the most important properties of an all solid-state battery. However, the behavior of the electrolyte inside a composite electrode and the influence of electrode structure on the ionic conductivity is neglected in most of the studies. In this work we manufactured model electrodes with clearly defined structures by using electrochemically inert glass particles as model active material with six different volume fractions and four different particle sizes, respectively. Higher volume fractions and smaller particles led to a decrease of ionic conductivity down to two decades due to emerging pores and a rise of tortuosity. Beneath the ionic conductivity the interface resistance between Li-metal and model electrodes was investigated, clearly indicating that high volume fractions of small active materials led to higher interface resistances. Finally, a model is introduced to predict the effective ionic conductivity of a solid electrolyte within an all solid-state battery electrode by just knowing the volume fraction of active material.

This work is about the possibility to enhance the lithium ion conductivity of a polymeric solid-state electrolyte via scalable production processes which can directly be utilized for series production. The solid electrolyte consists of PEO, LiTFSI and SiO 2 and achieved a maximum ionic conductivity of σ Ion = 2.4 •10 −3 S cm −1 at 90 °C and σ Ion = 1.26 •10 −3 S cm −1 at 80 °C. For that, we present a scalable completely dry process chain consisting of granulation, plastification and calendering without the need of any solvents. Within these production processes the influence of process parameters like specific energy input, production temperature and filling degree to the properties of the polymeric solid electrolyte components (among others lithium ion conductivity, chain length, density) are investigated. One key finding is that a suitable process window in terms of specific energy input during plastification is very small and can be quantified for the given process geometry. Under-or overshooting these barriers can directly lead to a degradation of the whole system and as a result directly decreased lithium ion conductivities. Besides process parameters, we also investigate material and formulation parameters, like salt concentration, annealing time and measurement temperatures. Finally, a model is presented to describe the maximum achievable lithium ion conductivity as a function of the specific energy input during production.

All-solid-state batteries constitute a very promising energy storage device. Two very important properties of these battery cells are the ionic and the electrical conductivity, which describe the ion and the electron transport through the electrodes, respectively. In this work, a numerical method is presented to model the electrical conductivity, considering the outcome of discrete-element method simulations and the intrinsic conductivities of both the active material particles and the conductive additive particles. The results are calibrated and validated with the help of experimental data of real manufactured electrodes. The tortuosity, which strongly influences the ionic conductivity, is also presented for the analyzed electrodes, taking their microstructure into account.

For the development of all‐solid‐state batteries (ASSBs), it is of major importance to identify scalable process routes, to define limits of the processing technologies, and to investigate how the electrochemical performance can be influenced by the manufacturing process. Herein, two scalable and sustainable production chains are presented, extrusion‐ and direct calendaring of composite cathode granules, which are suitable for industrial series production. Both process routes start with a melt granulation step to desagglomerate the carbon black to homogenize the cathode components. By adjusting the granulation process parameters the process time and, thus, the production costs can be reduced. The polymer solid electrolyte distribution induced by the process shows a considerable influence on the rate capability of the ASSB cells. The manufactured pouch cells reach ≈140 mAh g−1 at 0.1C and 75/50 mAh g−1 at 1C discharge rate and 80 °C for extruded‐calendered and directly calendered electrodes, respectively, which is comparable to other recent publications on laboratory scale.

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