Electrode fabrication process and its influence in lithium-ion battery performance: State of the art and future trends

Lithium-ion batteries (LIBs) are the main energy storage system used in portable devices. Their outstanding characteristics allied to the growing market of portable devices and electric vehicles provides batteries an increasing trend over the next years. During the past decade, improved materials for LIBs have been developed, with less attention being focused on the manufacturing process, despite its critical influence in battery performance. In the present work, the main electrode manufacturing steps are discussed together with their influence on electrode morphology and interface properties, influencing in turn parameters such as porosity, tortuosity or effective transport coefficient and, therefore, battery performance. A state of art on the main steps of the electrode manufacturing process is presented, together with future directions with respect to LIBs fabrication.The authors thank the Fundaçao para a Cíencia e Tecnologia (FCT) and COMPETE 2020 for financial support under the framework of Strategic Funding grants UID/FIS/04650/2021, UID/EEA/04436/2021, and UID/QUI/0686/2021 and under projects POCI-01-0145-FEDER- 028157 and PTDC/FIS-MAC/28157/2017. The authors also thank the FCT for the investigator contracts CEECIND/00833/2017 (RG) and 2020.04028.CEECIND (C.M.C.). Financial support from the Basque Government Industry Department under the ELKARTEK program is acknowledged

Toward Sustainable Solid Polymer Electrolytes for Lithium-Ion Batteries

Lithium-ion batteries (LIBs) are the most widely used energy storage system because of their high energy density and power, robustness, and reversibility, but they typically include an electrolyte solution composed of flammable organic solvents, leading to safety risks and reliability concerns for high-energy-density batteries. A step forward in Li-ion technology is the development of solid-state batteries suitable in terms of energy density and safety for the next generation of smart, safe, and high-performance batteries. Solid-state batteries can be developed on the basis of a solid polymer electrolyte (SPE) that may rely on natural polymers in order to replace synthetic ones, thereby taking into account environmental concerns. This work provides a perspective on current state-of-the-art sustainable SPEs for lithium-ion batteries. The recent developments are presented with a focus on natural polymers and their relevant properties in the context of battery applications. In addition, the ionic conductivity values and battery performance of natural polymer-based SPEs are reported, and it is shown that sustainable SPEs can become essential components of a next generation of high-performance solid-state batteries synergistically focused on performance, sustainability, and circular economy considerations.The authors thank the FCT (Fundação para a Ciência e Tecnologia) for financial support under the framework of Strategic Funding grants UIDB/04650/2020, UID/FIS/04650/2020, UID/EEA/04436/2020, and UID/QUI/0686/2020 and project PTDC/FIS-MAC/28157/2017. The authors also thank the FCT for financial support under grants SFRH/BD/140842/2018 (to J.C.B.) and Investigator FCT Contracts CEECIND/00833/2017 (to R.G.) and 2020.04028.CEECIND (to C.M.C.), as well POCH and the European Union. Financial support from the Basque Government Industry Department under the ELKARTEK program is also acknowledged

Polymer-based membranes for oily wastewater remediation

The compounds found in industrial wastewater typically show high toxicity, and in this way, they have become a primary environmental concern. Several techniques have been applied in industrial effluent remediation. In spite of the efforts, these techniques are yet to be ineffective to treat oily wastewater before it can be discharged safely to the environment. Membrane technology is an attractive approach to treat oily wastewater. This is dedicated to the immobilisation of TiO2 nanoparticles on poly(vinylidene fluoride–trifluoro ethylene) (PVDF-TrFE) porous matrix by solvent casting. Membranes with interconnected pores with an average diameter of 60 µm and a contact angle of 97°, decorated with TiO2 nanoparticles, are obtained. The degradation of oily wastewater demonstrated the high photocatalytic efficiency of the nanocomposite membranes: Under sunlight irradiation for seven hours, colourless water was obtained.This work was supported by the Solar Equipment Development Unit (UDES) Algeria. This work was also supported by the Portuguese Foundation for Science and Technology (FCT) in the framework of the strategic project UID/FIS/04650/2013 by FEDER funds through the COMPETE 2020-Programa Operacional Competitividade e Internacionalizacao (POCI) with the reference project POCI-01-0145-FEDER-006941, and project PTDC/CTM-ENE/5387/2014

Influence of rGO on the Crystallization Kinetics, Cytoxicity, and Electrical and Mechanical Properties of Poly (L-lactide-co-ε-caprolactone) Scaffolds

Biodegradable scaffolds of poly (L-lactide-co-ε-caprolactone) (PLCL) and reduced graphene oxide (rGO) were prepared by TIPS (thermally induced phase separation). The nonisothermal cold crystallization kinetics were investigated by differential scanning calorimetry (DSC) with various cooling rates. The experimental values indicate that nonisothermal crystallization improves with cooling rate, but the increasing rGO concentration delays crystallization at higher temperatures. The activation energies were calculated by the Kissinger equation; the values were very similar for PLCL and for its compounds with rGO. The electrical conductivity measurements show that the addition of rGO leads to a rapid transition from insulating to conductive scaffolds with a percolation value of ≈0.4 w/w. Mechanical compression tests show that the addition of rGO improves the mechanical properties of porous substrates. In addition, it is an anisotropic material, especially at compositions of 1% w/w of rGO. All of the samples with different rGO content up to 1% are cytotoxic for C2C12 myoblast cells.This work was supported by the University of The Basque Center. The authors acknowledge funding by Spanish State Research Agency (AEI) and the European Regional Development Fund (ERFD) through the project PID2019-106099RB-C43/AEI/10.13039/501100011033 and from the Basque Government Industry Departments under the ELKARTEK program. This work has been also supported by FCT–Fundação para a Ciência e Tecnologia (FCT) under the scope of the strategic funding of UID/FIS/04650/2020 and UIDB/04469/2020 units and project PTDC/BTM-MAT/28237/2017

Sustainable Bio-Based Epoxy Resins with Tunable Thermal and Mechanic Properties and Superior Anti-Corrosion Performance

Bio-based epoxy thermoset resins have been developed from epoxidized soybean oil (ESO) cured with tannic acid (TA). These two substances of vegetable origin have been gathering attention due to their accessibility, favorable economic conditions, and convenient chemical functionalization. TA’s suitable high phenolic functionalization has been used to crosslink ESO by adjusting the −OH (from TA):epoxy (from ESO) molar ratio from 0.5:1 to 2.5:1. By means of Fourier-transform infrared spectroscopy, resulting in thermosets that evidenced optimal curing properties under moderate conditions (150–160 °C). The thermogravimetric analysis of the cured resins showed thermal stability up to 261 °C, with modulable mechanical and thermal properties determined by differential scanning calorimetry, dynamical mechanical thermal analysis, and tensile testing. Water contact angle measurements (83–87°) and water absorption tests (0.6–4.5 initial weight% intake) were performed to assess the suitability of the resins as waterproof coatings. Electrochemical impedance spectroscopy measurements were performed to characterize the anti-corrosive capability of these coatings on carbon steel substrates. Excellent barrier properties have been demonstrated due to the high electrical isolation and water impermeability of these oil-based coatings, without signs of deterioration over 6 months of immersion in a 3.5 wt.% NaCl solution. These results demonstrate the suitability of the developed materials as anti-corrosion coatings for specific applications.R.T. wants to thank the Basque Government for funding under an FPI grant (PRE_2023_2_0276). The authors acknowledge the Basque Government for Grupos Consolidados grant IT1756-22, ELKARTEK program KK-2021/00082, KK-2021/00131, and KK-2022/00109

Energy and development kit, a proposal to promote scientific education in Guinea-Bissau

A educação científica encontra-se profundamente intrincada nas dimensões económica, ambiental e social do desenvolvimento. As ações a desenvolver devem visar a formação de cientistas, técnicos e cidadãos esclarecidos e comprometidos com formas de viver e pensar sustentáveis. No entanto, o que se verifica em muitos países africanos, nomeadamente na Guiné-Bissau, é que o ensino das ciências se baseia na memorização de uma ciência culturalmente desenraizada, onde o trabalho prático com resolução de problemas é escasso, não se traduzindo em contributos sociais significativos. Tendo em conta esses pressupostos, foi desenvolvida uma proposta de um kit científico-pedagógico para o estudo da utilização local dos recursos energéticos baseado no aproveitamento do conhecimento local como estratégia de ensino, aprendizagem e desenvolvimento sustentável.Scientific education is deeply involved in economic, environmental and social development. All action taken in this regard should aim at training scientists and technicians, but above all informed, committed citizens who can manage their daily lives better. However, in many African countries, as in Guinea-Bissau, scientific education is based on memorisation of an acultural science, where practical exercises and problem solving are scarce. Science education does not therefore have an impact on social change. In view of this situation, we have developed a proposal for a pedagogical scientific kit based on a study of local use of energy resources as a strategy for teaching, learning and sustainable development

Multicomponent magnetic nanoparticle engineering: the role of structure-property relationship in advanced applications

Combining magnetic nanomaterials with materials of other classes can produce multicomponent nanoparticles with an entire ensemble of new structures and unique, enhanced, synergetic, and/or complementary functionalities. Here we discuss the most recent developments in the synthesis of multicomponent magnetic nanoparticles, describe the resulting structures and their novel properties, and explore their application in a variety of fields, including multimodal imaging, nanomedicine, sensing, surface-enhanced Raman scattering, and heterogeneous catalysis. The current synthetic methods (usu-ally bottom-up approaches) of multicomponent nanoparticles can produce a number of tailored mor-phologies (core@shell, yolk-shell, core-satellite, Janus, nanochains, anisotropic, etc.), making them invaluable for applications in biology, medicine, chemistry, physics, and engineering. But like any new technology, their synthesis methods need to be optimized to be simple, scalable, and as environmentally friendly as possible before they can be widely adopted. In particular, the use of life cycle assessment (LCA) to guide future works toward environmental sustainability is highlighted. Overall, this review not only presents a critical and timely summary of the state-of-the-art of this burgeoning field in both fundamental and applied nanotechnology, but also addresses the challenges associated with under-standing the particular structure-property relationships of multicomponent magnetic nanoparticles.The authors thank funding from the Spanish State Research Agency (AEI) through the project PID2019-106099RB-C43/AEI/10.13039/501100011033 and from the Basque Government Industry and Education Department under the ELKARTEK, HAZITEK and PIBA (PIBA-2018-06) programs, respectively

Dynamic and Self-Healable Chitosan/Hyaluronic Acid-Based In Situ-Forming Hydrogels

In situ-forming, biodegradable, and self-healing hydrogels, which maintain their integrity after damage, owing to dynamic interactions, are essential biomaterials for bioapplications, such as tissue engineering and drug delivery. This work aims to develop in situ, biodegradable and self-healable hydrogels based on dynamic covalent bonds between N-succinyl chitosan (S-CHI) and oxidized aldehyde hyaluronic acid (A-HA). A robust effect of the molar ratio of both S-CHI and A-HA was observed on the swelling, mechanical stability, rheological properties and biodegradation kinetics of these hydrogels, being the stoichiometric ratio that which leads to the lowest swelling factor (×12), highest compression modulus (1.1·10−3 MPa), and slowest degradation (9 days). Besides, a rapid (3 s) self-repairing ability was demonstrated in the macro scale as well as by rheology and mechanical tests. Finally, the potential of these biomaterials was evidenced by cytotoxicity essay (>85%).This research was funded by Spanish State Research Agency (AEI) and the European Regional Development Fund (ERFD) through the project PID2019-106099RB-C43/AEI/10.13039/501100011033, as well as from the Basque Government Industry Department under the ELKARTEK (KK-2021/00040) program

pH-Induced 3D Printable Chitosan Hydrogels for Soft Actuation

Three-dimensional (3D) printing represents a suitable technology for the development of biomimetic scaffolds for biomedical and tissue engineering applications. However, hydrogel-based inks’ printability remains a challenge due to their restricted print accuracy, mechanical properties, swelling or even cytotoxicity. Chitosan is a natural-derived polysaccharide that has arisen as a promising bioink due to its biodegradability, biocompatibility, sustainability and antibacterial properties, among others, as well as its ability to form hydrogels under the influence of a wide variety of mechanisms (thermal, ionic, pH, covalent, etc.). Its poor solubility at physiological pH, which has traditionally restricted its use, represents, on the contrary, the simplest way to induce chitosan gelation. Accordingly, herein a NaOH strong base was employed as gelling media for the direct 3D printing of chitosan structures. The obtained hydrogels were characterized in terms of morphology, chemical interactions, swelling and mechanical and rheological properties in order to evaluate the influence of the gelling solution’s ionic strength on the hydrogel characteristics. Further, the influence of printing parameters, such as extrusion speed (300, 600 and 800 mm/min) and pressure (20–35 kPa) and the cytocompatibility were also analyzed. In addition, printed gels show an electro-induced motion due to their polycationic nature, which highlights their potential as soft actuators and active scaffolds.This research was funded by Spanish State Research Agency (AEI) and the European Regional Development Fund (ERFD) through the project PID2019-106099RB-C43/AEI/10.13039/501100011033, as well as the Basque Government Industry Department under the ELKARTEK programme (KK-2021/00040 and KK-2021/00082)

Silver-Doped Cadmium Selenide/Graphene Oxide-Filled Cellulose Acetate Nanocomposites for Photocatalytic Degradation of Malachite Green toward Wastewater Treatment

Silver-doped cadmium selenide/graphene oxide (GO) (Ag-CdSe/GO) nanocomposites have been synthesized, loaded in cellulose acetate (CA) to form Ag-CdSe/GO@CA heterostructure nanofibers, and characterized in terms of structural, morphological, photocatalytic properties, among others. The photocatalytic degradation of malachite green (MG) was estimated using cadmium selenide-filled CA (CdSe@CA), silver-doped cadmium selenide-filled CA (Ag-CdSe@CA), cadmium selenide/GO-filled CA (CdSe/GO@CA), and silver-doped cadmium selenide/GO-filled CA (Ag-CdSe/GO@CA) nanocomposite materials. The Ag-CdSe/GO@CA nanocomposites exhibit and retain an enhanced photocatalytic activity for the degradation of MG dye. This amended performance is associated with the multifunctional supporting impacts of GO, Ag, and CA on the composite structure and properties. The superior photocatalytic activity is related to the fact that both Ag and GO can act as electron acceptors that boost the separation efficiency of photogenerated carriers and the loading of the combined nanocomposite (Ag-CdSe@GO) on CA nanofibers, which can augment the adsorption of electrons and holes and facilitate the movement of carriers. The stability of Ag-CdSe/GO@CA nanocomposite photocatalysts demonstrates suitable results even after five recycles. This study establishes an advanced semiconductor-based hybrid nanocomposite material for efficient photocatalytic degradation of organic dyes.The Academy of Scientific Research and Technology (ASRT), Egypt, Grant No. 6510, supported this project financially