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Povzetek: The ZnOrgBAT project aims to develop next-generation zinc-based energy-storage systems by combining highly cyclable Zn anodes with high-capacity organic cathodes. Since the performance and durability of these batteries are critically influenced by the behaviour of the zinc anode, a fundamental understanding of its degradation mechanisms is essential for guiding electrode and cell design. This contribution first provides an overview of the most common challenges associated with zinc anodes, together with the corresponding mitigation strategies typically adopted. It then presents an integrated summary of recently published studies by the co-authors, covering a range of different anode architectures and additive chemistry. Across these works, X-ray microtomography (XμCT) and microradiography (XμR) played a central role in elucidating key morphochemical processes, such as dead-metal formation, redistribution of active phases, gas-induced mechanical degradation, and in correlating these structural dynamics with electrochemical behaviour.
Ključne besede: zinc-organic batteries, zinc-anodes, stationary energy storage, 3D and 4D microtomography
Objavljeno v DiRROS: 09.04.2026; Ogledov: 187; Prenosov: 130
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Povzetek: Zinc-based batteries are promising for sustainable energy storage due to their low cost and environmental friendliness. However, challenges such as passivation, low cycle life, and limited zinc utilization hinder practical commercialization. In this study, we address these challenges using ZnO@C nanoparticles (NPs) as anode active material, optimizing slurry formulation and electrode architectures. PTFE and CMC were employed as complementary binders to enhance mechanical integrity, wettability, and zinc utilization, while reducing the reliance on fluorinated binders. Two electrode fabrication methods — blade coating and hot pressing — were evaluated to assess the effects of active layer thickness on performance and durability. Full-cell Zn/Ni tests were run under harsh testing condition: closed cell, low amount of electrolyte and no additive or ZnO saturation. We found that thinner (ca. 100 μm), blade-coated ZnO@C anodes outperformed thicker (ca. 400 μm) hot-pressed electrodes in both cycle life and specific capacity. Blade-coated electrodes maintained a discharge-specific capacity exceeding 400 mAh g−1 for over 200 cycles and achieved a maximum of 524 mAh g−1, approximately 80 % of ZnO theoretical capacity. Post-mortem X-ray computed microtomography analyses revealed that the crucial electrode architecture parameters are ZnO particle accessibility and even utilization in the electrode bulk. These resulted to be optimal in blade-coated electrodes, while heterogeneities and untransformed ZnO volumes were found in the hot-pressed ones. Additionally, in view of concrete device implementation, the often overlooked role of cell casing materials was explicitly addressed. Specifically, the galvanic coupling among electrode material, current collector and cell casing was positively measured and rationalized. By integrating innovations in slurry formulations, electrode design, and practical testing setups, this work provides guidelines to transfer nanostructured Zn anodes to the practical device environment.
Ključne besede: Zn anode, zinc-alkaline batteries, nanostructured electrodes, electrode architecture, ZnO nanoparticle, X-ray microtomography
Objavljeno v DiRROS: 13.01.2026; Ogledov: 346; Prenosov: 368
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Povzetek: The importance of thermal modification is increasing worldwide. Increased use of thermally modified timber (TMT) has resulted in a need for reliable quality control, comprising control of variation of the production within defined limits, allowing third-party control in the case of certification and the regulation of customer complaints and claims. Techniques are thus needed to characterise the modification of quality in terms of improved target properties of TMT during industrial production, and of TMT products that have been in service for an arbitrary time. In this study, we aimed to utilise dynamic vapor sorption (DVS) for this purpose. Norway spruce (Picea abies) and European beech (Fagus sylvatica) samples were thermally modified at different temperatures according to different heat treatment techniques: (1) the Silvapro process based on an initial vacuum; (2) an air heat treatment, whereby samples were wrapped in aluminium foil; (3) thermal modification of wood samples in the ambient atmosphere in a laboratory oven. Wood samples from closed processes were analysed for validation. TMT was characterised with respect to mass loss, colour and density. Mass loss of wood due to modification (MLTM) was correlated with factors derived from DVS analysis. The present DVS measurements suggest that the equilibrium wood moisture content (EMC95% RH), the time to reach 10% wood moisture content (t10% MC), and the elongation factor, c, derived from a logarithmic function, can serve as alternative parameters to characterise the quality of several thermal modification processes. Further studies are recommended using other wood species, different modification processes and further parameters gained from DVS measurements to understand the robustness and the predictive power of the applied technique
Ključne besede: thermal modification, quality control, dynamic vapour sorption, wood, moisture content
Objavljeno v DiRROS: 31.08.2023; Ogledov: 1634; Prenosov: 1062
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Povzetek: The development of non-biocidal and environmentally friendly systems to protect wood against biological decay has become a high priority in recent years. In the present study the impact of an innovative modification procedure, combining two environmentally friendly modification methods: thermal modification and mineralisation, using an aqueous solution of calcium acetoacetate as a precursor, on the fungal durability of wood was evaluated. European beechwood (Fagus sylvatica) and Norway sprucewood (Picea abies) were selected as model wood species. Wood samples were treated using either a single or combination of both methods and exposed to four different fungi: Gloeophyllum trabeum, Rhodonia placenta, Trametes versicolor and Pleurotus ostreatus. The effect of the different modifications on moisture content, dynamic vapour sorption, contact angle and pH value was also evaluated. Overall, the highest durability against Rhodonia placenta, Trametes versicolor and Pleurotus ostreatus was achieved through thermal modification in both wood species, while the combination of mineralisation and thermal modification has a synergistic effect against degradation by Gloeophyllum trabeum. In the case of beechwood the mass loss decreased from 41% for native to 6% for combined modified samples. We proved that the effectiveness of different treatment against fungal decay of wood were in strong dependence of their moisture content, dynamic vapour sorption, contact angle and pH values. The role of fungi on the morphology of the wood and on crystal structure of formed carbonate was investigated using SEM-EDS analysis.
Ključne besede: thermal modification, wood mineralization, fungal durability, environmentally friendly modification methods
Objavljeno v DiRROS: 20.06.2023; Ogledov: 2041; Prenosov: 1704
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