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The production of lithium‐ion cells consists of a series of highly interlinked process steps. Calendering, as the last step of electrode manufacturing, has a significant impact on electrode characteristics. The process primarily aims at enhancing the electrode energy density and hereinafter, minimizing the plastic deformability, improving the conductivity, and determining the pore structure of the electrode. So far, electrode characteristics are mainly investigated regarding the impact on cell quality. However, they also affect their subsequent processabilities in the process chain, which is crucial for cost improvement, for example, by reduction of scrap rates. Herein, a methodical identification, description, and categorization of electrode characteristics is conducted based on a literature review, an expert survey, and operating experience. The methodical classification will provide a basis for the modeling of the interaction between the influencing factors (product properties, process parameters, and machine characteristics) and electrode characteristics during calendering.

Seeds of different cultivars of Glycine max (L.) Merr. (soybean) have strikingly different rates of water imbibition. Seeds that readily imbibe water are termed 'soft', while those that remain non-permeable, even after several days in water, are referred to as 'hard', 'stone', or 'impermeable' seeds. What prevents soybean hard seeds from taking up water? Previous work established that the initial imbibition of soft soybean seeds correlates with the presence of small cracks in the outermost cuticle that covers the seed coat, prompting a detailed analysis of soybean seed coat cutin. In this paper, it is shown that the outermost cuticle of the seed coat has an unusual chemical composition, lacking typical mid-chain-hydroxylated fatty acids but being relatively rich in other types of hydroxylated fatty acids. The cuticle of the impermeable cultivar studied contained a disproportionately high amount of hydroxylated fatty acids relative to that of the permeable ones. Moreover, a brief treatment with hot alkali released the omega-hydroxy fatty acid component of the outermost cuticle and created holes in it that caused the seeds to become permeable. This demonstrates that the outermost cuticle of the seed is the critical structure that prevents water uptake by hard seeds.

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Electrodes are usually calendered to enhance the energy density and improve the electrochemical cell performance. However, low porosities can compromise these two important features. To achieve the optimum porosity, a comprehensive process control is of major interest. This study further develops a Heckel‐based compaction model considering the impact of the roll temperature and discusses the effect of the composition. Increasing the temperature of the roll linearly decreases the achievable coating porosity and the line load effort due to the rise of the elastic deformability of the thermoplastic binder PVDF. Reduced contents of simultaneously less‐distributed additives increase the achievable coating porosity. Furthermore, the poor distribution is the main factor for lower line load efforts with lower additive contents. Moreover, the adhesion strength of the coating improves with increasing the temperature of the rolls due to the thermal rising of the elasticity of the binder.

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Soybean [Glycine max (L.) Merr.] plants produce some seeds (called stone or impermeable seeds) that do not take up water for long periods of time. The present investigation confirmed that the stone seed trait is a feature of the seed coat: isolated embryos from both stone and permeable seeds took up water equally quickly. A whole, permeable seed typically imbibed water initially through its dorsal side, forming wrinkles in the seed coat and delivering water to the underlying cotyledons. Later, some lateral movement of water through the coat occurred, presumably through the air spaces of the osteosclereid layer. Imbibition by seeds was a two-phase process, the first dominated by hydration of the seed coat and the second by hydration of the cotyledons, which was rate-limited by the coat. When hydrated, coats of stone seeds were permeable to water but their hydraulic conductivity, as measured with a pressure probe, was smaller than that of coats from permeable seeds by a factor of five. Hydrated coats of both permeable and stone seeds showed weak osmometer properties.