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Solid-state and sol-gel syntheses were selected as easy and scalable methods to prepare a lithium-rich cathode material for lithium-ion batteries. Among the extended family of layered oxides, Li1.2Ni0.2Mn0.6O2 was chosen for its low nickel content and the absence of cobalt. Both synthesis methods involved two heating steps at different temperatures, 600 and 900 °C. The first step is needed to decompose the metal acetates, which were selected as precursors, and the second step is needed to crystallise the material. To obtain a material with well-defined defects, the rate of heating and cooling was carefully controlled. The materials were characterised by X-ray diffraction, SEM coupled with EDS analysis, and thermal analysis and were finally tested as cathodes in a lithium semi cell. The solid-state synthesis allowed us to obtain better structural characteristics with respect to the sol-gel one in terms of a well-formed hexagonal layer structure and a reduced Li+/Ni2+ disorder. On the other hand, the sol-gel method produced a material with a higher specific capacity. The performance of this latter material was then evaluated as a function of the discharge current, highlighting its good rate capabilities. [ABSTRACT FROM AUTHOR]

In light of the growing interest in printed batteries, we recently demonstrated the possibility of employing industrial gravure printing in battery manufacturing. Gravure is the most appealing printing technique for the low-cost production of functional layers, but it is rarely investigated since the necessity to use diluted inks makes it difficult to obtain proper functionality, especially in the case of composites, and an adequate mass loading of the printed layer. For this reason, the ink formulation represents one of the main challenges; ruling on it could strongly boost the use of such a technique in industrial manufacturing. It is known that a viable method for obtaining good gravure printing quality is based on the Capillary number approaching unity. Taking into account such methods for the choice of ink and the process parameters, here a study of the printing quality influence on the functionality and the performances of the gravure printed layer is proposed in the case of an LFP-based cathode for Li-ion batteries. Good printing quality is necessary to obtain proper layer functionality, but specific parameters have to be considered for achieving high performance. [ABSTRACT FROM AUTHOR]

Nanostructured titania is one of the most commonly encountered constituents of nanotechnology devices for use in energy-related applications, due to its intrinsic functional properties as a semiconductor and to other favorable characteristics such as ease of production, low toxicity and chemical stability, among others. Notwithstanding this diffusion, the quest for improved understanding of the physical and chemical mechanisms governing the material properties and thus its performance in devices is still active, as testified by the large number of dedicated papers that continue to be published. In this framework, we consider and analyze here the effects of the material morphology and structure in determining the energy transport phenomena as cross-cutting properties in some of the most important nanophase titania applications in the energy field, namely photovoltaic conversion, hydrogen generation by photoelectrochemical water splitting and thermal management by nanofluids. For these applications, charge transport, light transport (or propagation) and thermal transport are limiting factors for the attainable performances, whose dependence on the material structural properties is reviewed here on its own. This work aims to fill the gap existing among the many studies dealing with the separate applications in the hope of stimulating novel cross-fertilization approaches in this research field. [ABSTRACT FROM AUTHOR]

A study was conducted to explore the effects of Sr doping on the electrical properties of perovskite LaFeO3 thin-film protective conversion coatings grown onto a K41 ferritic stainless steel, a typical interconnect material for intermediate temperature solid oxide cell (SOC) applications. The Sr-doped coatings were prepared in La2O3- and SrO-containing molten carbonate baths with minor added amounts of nitrate salt for accelerated coating formation. For comparison purposes, undoped coatings were obtained using the same carbonate bath, with the only difference being that SrO was replaced by inert MgO. SEM/EDX and XRD analyses were used for coating characterization and confirmed the effective incorporation of Sr but not of Mg into the LaFeO3 layer. Although both the Sr-doped and undoped coatings consisted of a LaFeO3 layer grown above an inner Fe-Cr spinel, the coating thickness of the Sr-doped coating was distinctly higher, approximately 2 µm, which is twice that of the undoped coating. Electrical measurements in terms of Area-Specific Resistance (ASR) were conducted at 700 °C in air and showed that Sr-doping significantly improved the electrical conductivity of the coated K41 steel. Due to the Sr-doping, the ASR values of the coated steel dropped from 60 to 37 mΩ cm2 after 300 h of exposure, in spite of the higher Sr-doped coating thickness. The study concludes that Sr-doped thin-film perovskite coatings appear to be a promising solution for improved SOCs steel interconnect stability at intermediate temperatures. [ABSTRACT FROM AUTHOR]