This study focuses on developing solvent-free polymer electrolytes for solid-state lithium-ion batteries intended to replace conventional liquid systems. The materials consist of a polysulfone (PSU) backbone chemically bonded to pendant polyetheramine (Jeffamine®) chains and lithium salt. The synthesis consists of four key steps: sulfonation of PSU to obtain PSU-SO3Na (40% and 60% sulfonation), conversion of these groups into sulfonyl chlorides (PSU-SO2Cl), nucleophilic substitution with Jeffamine® M − 2070 to form PSU-Jeff copolymers (40% and 60%), and finally incorporation of LiTFSI as the conducting salt to produce PSU-Jeff-LiTFSI with an O/Li ratio of 20. The conducting copolymers obtained in this way do not require solvents for their use as electrolytes, and their semi-solid gel-like appearance facilitates effective contact with the electrodes. Structural and morphological analyses were performed using 1H NMR and SEM/EDS, while thermal behavior was examined via DSC. Both electrolytes exhibit ionic conductivity ranging from 10−2 to 10−1 mS cm−1 in the temperature range of 10-80 °C, and show oxidative stability above 3.9 V and 4.2 V vs. Li+/Li, for PSU-Jeff40%-LiTFSI and PSU-Jeff60%-LiTFSI, respectively. Preliminary electrochemical evaluation in LiFePO4|Li cells demonstrated the feasibility of employing the synthesized PSU-Jeff-LiTFSI systems as solvent-free polymer electrolytes, although further optimization of electrode/electrolyte interfaces and electrochemical performance under practical operating conditions will be required.

Despite growing interest in metal-organic frameworks (MOFs for protonconductivity applications, monovalent-cation-based MOFs remain comparatively underexplored due to the weaker coordination interactions typically associated with these systems. In this work, we report GR-MOF-28, a novel potassium-based naphthalene tetracarboxylate framework synthesized under mild aqueous conditions at room temperature. Structurally, GR-MOF-28 consists of K2O10 dioctahedra interconnected through tetracarboxylate ligands and coordinated water molecules, generating a confined hydrogen-bond network along the crystallographic channels. The material exhibits proton conductivity values up to 4.3·10-2 S·cm-1 under high relative humidity conditions, placing it among the highest-performing K-based MOFs reported to date. Combined electrochemical impedance spectroscopy and molecular simulations support a water-mediated Grotthusstype proton transport mechanism through the confined hydrogen-bond network. In addition, GR-MOF-28 can be incorporated into a conductive polymer matrix without loss of proton transport properties. These results highlight the potential of underexplored K-based coordination frameworks as proton-conducting materials.

Sodium solid electrolytes combining high ionic conductivity, interfacial stability and long-term durability enable reliable all-solid-state sodium batteries, a promising alternative to lithium-based systems. This work presents a comparative study of three representative families of solid electrolytes: NASICON-type ceramics, cross-linked polymer electrolytes and hybrid polymer-in-ceramic systems obtained via in-situ cross-linking within porous ceramic matrices.Structural and morphological analyses reveal that dense NASICON electrolytes favor bulk Na⁺ transport, whereas cross-linked polymer electrolytes form amorphous networks with homogeneous composition. Hybrid electrolytes successfully integrate both phases, yielding improved interfacial contact and structural integrity and handling stability. Thermal characterization shows excellent stability for NASICON, delayed degradation for polymer electrolytes due to cross-linking, and significantly enhanced thermal stability for hybrids (>370 °C), attributed to strong organic-inorganic interactions. Broadband Electric Spectroscopy (0.03–107 Hz; −100 to +150 °C) clarifies conduction mechanisms, where Vogel-Tamman-Fulcher behavior confirms coupling between ion transport and matrix dynamics. Na⁺ migration distances increase with temperature, reaching ∼4 nm (NASICON), ∼10 nm (NPC1000-NaX), and up to 100 nm (HSE-NaX). Favorable interdomain pathways and ClO4⁻ anions enhance structural–dynamic coupling and long-range sodium transport in hybrids. Electrochemical cycling in Na/FePO₄ cells reveals a balance between initial capacity and durability. NASICON displays modest initial capacity (∼85 mAh·g⁻¹) but progressive increases to ∼113 mAh·g⁻¹ after 500 cycles (∼96 % retention), whereas polymer and hybrid electrolytes deliver higher initial capacities (>100 mAh·g⁻¹) but experience capacity decay during prolonged cycling. In summary, NASICON-type electrolytes offer superior long-term durability and stability, whereas polymeric and hybrid systems favor higher initial performance, revealing a trade-off governed by electrolyte architecture.

Solid-state sodium batteries based on polymer electrolytes offer a sustainable solution to overcome current and near-future needs regarding the growing energy and transport electrification issues. In this work, we propose the development of solvent-free polymer electrolytes based on an unsaturated polyether, which, once cross-linked, leads to an amorphous structure at room temperature that favors ionic transport towards reliable and robust solid-state sodium batteries operative at moderate temperatures. Using NaClO4 and NaPF6 as sodium salts, the best polymer electrolyte reaches an ionic conductivity in the range of 0.02 mS & centerdot;cm-1 (30 degrees C)-0.90 mS & centerdot;cm-1 (100 degrees C) with a lifetime superior to 2000 h after plating and stripping. Regarding electrochemical performance, a maximum specific capacity of 110.2 mAh & centerdot;g-1 (C/20) is obtained for the polymer electrolyte including NaClO4, using Na and C/FePO4 as anode and cathode, respectively, which represents about 65% of the theoretical value expected for FePO4. In view of more sustainable energy storage devices, a life cycle assessment is also applied. While the polymer matrix is identified as the main environmental hotspot, the choice of Na salt significantly affects the overall impact, with NaClO4 exhibiting lower climate change and particulate matter impacts than NaPF6.

This work presents the modeling and characterization of novel LFP-LTO lithium-ion cells with thick electrodes specifically designed for low-power applications, such as cardiac pacemakers. The selected cells, manufactured in a 2032 coin format with a nominal voltage of 1.9 V and a capacity of 15 mAh, were modeled using equivalent circuit models (ECMs), including both a basic first-order RC (1RC) and an enhanced three-RC-branch (3RC) Thevenin model. A multiobjective optimization strategy was employed to balance accuracy and computational complexity. To capture the dynamic behavior of the cells, a pulse-PRBS (Pulse-Pseudo-Random Binary Sequence) identification signal was applied, enabling precise parameter extraction over a broad frequency spectrum. Experimental results demonstrate that the 3RC model achieves voltage errors below 0.1%, making it suitable for accurate modeling under dynamic load conditions. Furthermore, the series configuration of two LFP-LTO cells reaches a nominal voltage of 3.7 V, matching the requirements of conventional pacemaker batteries. In addition, aging analysis was conducted by applying the same PRBS signal to the cells both before and after accelerated cycling and then modeling the results. These findings confirm that the 3RC model can also serve as a predictive tool for estimating battery aging and health. The proposed modeling methodology offers a reliable and efficient framework for integrating new thick-electrode technologies into biomedical applications.

This work focuses on the development and production of additive-free Li4Ti5O12 thick electrodes with carbon nanotubes processed by powder extrusion moulding to be applied as anodes in high energy density lithium-ion batteries. Li4Ti5O12 is a safer alternative to graphite, featuring a stable solid electrolyte interphase and minimal lattice parameters changes upon lithiation ("zero-strain" behaviour) though its low conductivity necessitates conductive additives, such as carbon nanotubes. Firstly, the commercial pristine powder in terms of composition, particle size distribution, microstructure, and density was characterized. Rheological analysis identified an optimal 50:50 vol% ratio of powder to binder for extrusion. After shaping, the green parts underwent binder removal and sintering at 850 degrees C and 900 degrees C to produce dense, thick electrodes without additional additives. The resulting electrodes were similar to 500 mu m thick, with porosities of 28.5 % (122 mg cm(-2) mass loading) and 22.8 % (132 mg cm(-2) mass loading), respectively. Electrochemical characterization in coin cells against Li and LiFePO4 demonstrated excellent performance. In Li4Ti5O12/Li half-cells, volumetric and areal capacities of 375 mA h cm(-3) and 19 mA h cm(-2) were achieved at C/ 24 (0.89 mA cm(-2)). In full Li4Ti5O12//LiFePO4 cells, the electrodes showed stable cycling over 80 cycles at C/24, delivering similar to 18 mA h cm(-2) and 350 mA h cm(-3), with energy values of similar to 280 mW h g(-1) and 35 mW h cm(-2). These results highlight the potential of powder extrusion moulding for the scalable fabrication of thick ceramic electrodes with outstanding energy and power densities, paving the way toward next-generation lithium-ion batteries.

In this work, an electrochemical study of the iron fumarate metal-organic framework structure MIL-88a was carried out. This MOF exhibits an exceptional characteristic: it alters the parameters of its crystal lattice in response to temperature variations and the specific guest molecules present. Through impedance spectroscopy, we investigated how guest molecules within the pores of MIL-88a influence the material's ionic conductivity and its responsiveness to changing environmental conditions. Based on the data obtained, hybrid membranes based on sulfonated multiblock copolymers of polysulfone and polyphenylsulfone (SPES) doped with MIL-88a were prepared. The distribution of crystallites in the membrane was assessed by using scanning electron microscopy. It was found that crystallites agglomerates reduce the tensile strength of the membrane from 87 to 69 MPa, and from 56 to 42 MPa in the dry and wet forms, respectively. The presence of this MOF doubles the water absorption of the hybrid membranes compared to the pure one, resulting in an improvement of their ionic conductivity from 15.8 to 26.5 mS/cm at 80 degrees C. Hybrid membranes show a high maximum power density (1040 mWcm(-2)) in the fuel single cell test that is comparable to that obtained for commercial perfluoro-sulfonic acid PEMs such as Nafion (R).

To address the growing demands for energy density, power, lifetime, and safety in Li-ion batteries, innovative processing techniques for high-capacity electrodes are essential. This study explores the additive manufacturing of ultra-thick LiFePO4 (LFP) electrodes (similar to 800 mu m) using robocasting, as an alternative to traditional methods like screen printing or pressing. 3D LFP-based electrodes with cellular architectures and high mass loading (similar to 20 mg) are designed to enhance ion transport and energy density by increasing the surface area. Eco-friendly, aqueous-based printable inks are optimized for suitable rheological properties (viscosity, modulus, yield strength), in agreement with scalable and sustainable production. To improve mechanical strength and conductivity, 3 wt% of graphene oxide (GO) or graphene nanoplatelets (GNP) are incorporated to the ink formulation. After printing, 3D structures undergo thermal debinding and sintering to remove inactive components, yielding additive-free electrodes. Microstructural, mechanical, and electrical characterizations reveal that GO incorporation increases Vickers hardness by 50 % without compromising compressive strength. Electrochemical testing with Li4Ti5O12 (LTO) as the anode demonstrates promising performance, with LFP-GO electrodes achieving areal capacities up to 11 mA h cm(-2) (21 mW h cm(-2)) at C/25. These results highlight the potential of robocasting to produce robust, high-performance thick electrodes for next-generation Li-ion batteries.

All-solid-state sodium batteries emerge as an excellent alternative to the conventional Li-ion ones towards more reliable, sustainable and safer large-scale energy storage systems able to overcome the current challenges related to climate change and decarbonization. In this study, we present novel sodium hybrid solid electrolytes based on a sintered porous NASICON structure infiltrated with a polymer electrolyte that crosslinks, via radical polymerization, inside the porous microstructure. The porous ceramic material (Na3.16Zr1.84Y0.16Si2PO12) is obtained by combining tape-casting with low-temperature hot pressing, whereas the polymer electrolyte is based in a polycondensate polymer and two different sodium salts (NaClO4 and NaPF6). The hybrid electrolytes are characterized in terms of microstructure, thermal stability and electrochemical behavior. The galvanostatic cycling was performed at 80 degrees C for both approaches, using a coin cell with configuration Na Hybrid electrolyte FePO4, obtaining a higher discharge capacity of 160.7 mAh g-1 (C/20) with the hybrid electrolyte based on the NaPF6 salt, which corresponds to 90 % of the theoretical capacity value of FePO4, value higher than that obtained using a dense ceramic electrolyte (Na3.16Zr1.84Y0.16Si2PO12), demonstrating the synergistic effect of both electrolytes (ceramic and polymer). The proposed rigid hybrid electrolytes pave the way for the development of safer electrolytes for all-solid-state batteries.

The growing demand for electric vehicles and renewable energy storage has intensified the need for Li-ion batteries with higher energy density. One effective strategy is the use of high mass loading electrodes, which increase the ratio between active and inactive materials. However, conventional tape casting techniques face challenges in producing thick electrodes as mechanical consistency deteriorates beyond a certain thickness. Alternative methods have been explored but often require changes in additives or compromise electrochemical performance. In this work, we present a simple and scalable modification of the traditional electrode fabrication process. By drying the NMP solvent before pressing and applying low-temperature hot pressing (190 °C), we obtain thick (150-650 μm), homogeneous, and mechanically robust electrodes that retain the use of standard additives such as carbon black and polyvinylidene fluoride (PVDF). A full cell composed of LFP/LP30/LTO delivered outstanding results: high areal capacities (17 and 13.5 mAh cm-2 at C/25 and C/4), and exceptional cycling stability with no capacity loss over 300 cycles at C/12, despite a high loading of 120 mg cm-2 (650 μm). This approach requires minimal changes to current industrial processes, offering a promising route for next-generation Li-ion batteries with improved energy density and performance.

Lithium-ion batteries are the most efficient electrochemical energy storage devices. However, there is still room for improvement in terms of safety and energy density, presently limited by conventional tape-casting electrode processing. In this study, a blend of the anodic material Li4Ti5O12 with 2 wt% carbon black has been processed through powder injection moulding (PIM) yielding, after subsequent debinding and sintering processes, to ultra-thick (>500 mu m) ceramic binder-free electrodes. The mixture of Li4Ti5O12 with the thermoplastic binder composed of polypropylene, paraffin wax, and stearic acid is investigated to identify a rheologically suitable feedstock for the PIM process. The resulting disk-type green parts contain 50 vol% of ceramic powder. After removing the binder with solvents and subsequent thermal treatment, the parts are sintered at 900 degrees C, aiming for a relatively high porosity, i.e., 25.7%. The resulting electrodes show very high areal and volumetric capacities up to 26.0 mAhcm(-2) and 403 mAhcm(-3) at C/24, respectively, in a half-cell against lithium metal.

Lithium-ion batteries are widely used in portable electronic devices because of their high energy and power density. To enhance the energy density of these batteries, one strategy involves increasing the active material loading by increasing the thickness of the electrodes. In previous studies, we demonstrated that powder extrusion moulding (PEM) is a scalable and efficient method for producing additive-free LTO and LFP ceramic electrodes, which exhibit remarkable electrochemical performance with thicknesses up to 500 mu m. This study focuses on the preparation and optimisation of the entire manufacturing process for thick ceramic electrodes of LiCoO2 (LCO) with a high mass loading of 180 mg cm-2 using the PEM process. Different powder loadings of mixtures of LCO and a thermoplastic multi-component binder were explored to obtain a formulation suitable for rheology. The optimal formulation comprises 60 vol% of powder. After binder removal via a combination of solvent and thermal treatment, followed by air sintering, parts with varying porosities were obtained. Striking a balance between porosity and thermal degradation is crucial for achieving optimal electrochemical behaviour. Electrochemical evaluations of the electrodes sintered at 900 degrees C and 1000 degrees C revealed areal capacity values as high as 17 mAh cm- 2 at C/25 and 7 mAh cm-2 at C/6.25, respectively. These values far exceed the 1-2 mAh cm-2 obtained from commercial LCO electrodes. These results indicate a strategy for the production of electrodes to fabricate lithium-ion batteries with a low ratio of inactive materials and, therefore, with higher energy densities.

Despite the progress made in Li-ion battery components, technology still faces major challenges. Among them, the development of novel electrolytes with promising characteristics is required for next-generation energy storage devices. In this work, rigid hybrid electrolytes have been prepared by infiltration of an ionic liquid solution (Pyr(14)TFSI) with a lithium salt (LiTFSI) into a sintered LATP ion-conducting porous ceramic. The porous ceramic 3D network was obtained via solid-state sintering of LATP powders mixed with a small amount of corn starch as pore former. A synergetic effect between the ionic liquid and support was evidenced. The resultant quasi-solid-state hybrid electrolytes exhibit high ionic conductivity (similar to 10(-3) Scm(-1) at 303 K), improved ion transfer number, t(Li)+, and a wide electrochemical window of 4.7-4.9 V vs Li+/Li. The LATP porosity plays a critical role in the free Li+ charge because it favors higher TFSI- confinement in the ceramic interfaces, which consequently positively influences t(Li)+ and ionic conductivity. Electrochemical tests conducted at room temperature for Li/LiFePO4 cells using the hybrid electrolyte exhibited a high capacity of 150 mAhg(LFP)(-1) at C/30, and still retained 60 mAhg(LFP)(-1) at 1 C, while bare LATP does not perform well at low temperatures. These findings highlight this hybrid electrolyte as a superior alternative to the ceramic LATP electrolyte and a safer option compared with conventional organic electrolytes.

Lithium-ion batteries are widely used in portable electronic devices because of their high energy and power density. To enhance the energy density of these batteries, one strategy involves increasing the active material loading by increasing the thickness of the electrodes. In previous studies, we demonstrated that powder extrusion moulding (PEM) is a scalable and efficient method for producing additive-free LTO and LFP ceramic electrodes, which exhibit remarkable electrochemical performance with thicknesses up to 500 μm. This study focuses on the preparation and optimisation of the entire manufacturing process for thick ceramic electrodes of LiCoO2 (LCO) with a high mass loading of 180 mg cm−2 using the PEM process. Different powder loadings of mixtures of LCO and a thermoplastic multi-component binder were explored to obtain a formulation suitable for rheology. The optimal formulation comprises 60 vol.% of powder. After binder removal via a combination of solvent and thermal treatment, followed by air sintering, parts with varying porosities were obtained. Striking a balance between porosity and thermal degradation is crucial for achieving optimal electrochemical behaviour. Electrochemical evaluations of the electrodes sintered at 900°C and 1000°C revealed areal capacity values as high as 17 mAh cm−2 at C/25 and 7 mAh cm−2 at C/6.25, respectively. These values far exceed the 1−2 mAh cm−2 obtained from commercial LCO electrodes. These results indicate a strategy for the production of electrodes to fabricate lithium-ion batteries with a low ratio of inactive materials and, therefore, with higher energy densities.

Sodium-ion batteries (NIBs) can use elements that are abundantly present in Earth's crust and are technologically feasible for replacing lithium-ion batteries (LIBs). Hence, NIBs are essential components for sustainable energy storage applications. All-solid-state sodium batteries are among the most capable substitutes to LIBs because of their potential to have low price, great energy density, and consistent safety. Nevertheless, more advancements are needed to improve the electrochemical performance of the Na3V2(PO4)(3) (NVP) cathode for NIBs, especially with regard to rate performance and operational lifespan. Herein, a core-shell NVP/C structure is accomplished by adopting a solid-state method. The initial reversible capacity of the NVP/C cathode is 106.6 mAh/g (current rate of C/10), which approaches the theoretical value (117.6 mAh/g). It also exhibits outstanding electrochemical characteristics with a reversible capacity of 85.3 mAh/g at 10C and a cyclic retention of roughly 94.2% after 1100 cycles. Using synchrotron-based operando X-ray diffraction, we present a complete examination of phase transitions during sodium extraction and intercalation in NVP/C. To improve safety and given its excellent ionic conductivity and broad electrochemical window, a Na superionic conductor (NASICON) solid electrolyte (Na3.16Zr1.84Y0.16Si2PO12) has been integrated to obtain an all-solid-state NVP/C||Na battery, which provides an exceptional reversible capacity (95 mAh/g at C/10) and long-term cycling stability (retention of 78.3% after 1100 cycles).

Nonfluorinated polymers have been widely proposed to replace Nafion as raw materials for redox flow battery ion-exchange membranes. Hereby, block copolymers based on polysulfone (PSU) and polyphenylsulfone (PPSU) are synthesized and employed as precursors of membranes for vanadium redox flow batteries. A series of copolymers with varying molar proportions of PSU (75/25, 60/40, 50/50 mol %) were prepared. The 60/40 and 75/25 copolymers exhibit concentrated sulfonic groups predominantly in the PSU unit, favoring the formation of hydrophobic and hydrophilic domains. The 50/50 copolymer presents a balanced degree of sulfonation between the two units, leading to a homogeneous distribution of sulfonic groups. An ex situ study of these materials comprising vanadium ion permeability and chemical and mechanical stability was performed. The best performance is achieved with 50/50 membranes, which exhibited performance comparable to commercial Nafion membranes. These results signify a promising breakthrough in the pursuit of high-performance, sustainable membranes for next-generation VRFBs.

PurposeThis study aims to develop a highly loaded filament with spherical metallic particles for fused filament fabrication (FFF) technology. The research focuses on optimizing powder loading, printing parameters and final processes, including debinding and sintering, to produce successful metal parts.Design/methodology/approachThe optimal powder loading was identified by measuring mixing torque and viscosity at various temperatures. The filament was extruded, and printing parameters - particularly printing speed to ensure proper material flow - were optimized. Different filling patterns were also examined. After printing, the polymeric binder was removed and the parts were sintered to form the final metal components.FindingsThe optimal powder loading was determined to be 55 vol.%. The best surface quality was achieved with an optimized printing speed of 5 mm/s. Parts printed with various infill patterns were studied for differences in open, closed and total porosity, showing a strong link between porosity and infill pattern.Originality/valueThis comprehensive study provides new insights into manufacturing metal parts using FFF technology. It fills a gap in the literature regarding feedstock viscosity and shear rate in highly loaded metal filaments during FFF. Additionally, it uniquely examines the open, closed and total porosity of metal parts printed with different infill patterns.