Solid-state electrolytes are a promising family of materials for the next generation of high-energy rechargeable lithium batteries. Polymer electrolytes (PEs) have been widely investigated due to their main advantages, which include easy processability, high safety, good mechanical flexibility, and low weight. This review presents recent scientific advances in the design of versatile polymer-based electrolytes and composite electrolytes, underlining the current limitations and remaining challenges while highlighting their technical accomplishments. The recent advances in PEs as a promising application in structural batteries are also emphasized.

To effectively use (Li) lithium metal anodes, it is becoming increasingly necessary to create membranes with high lithium conductivity, electrochemical and thermal stabilities, as well as adequate mechanical properties. Composite gel polymer electrolytes (CGPE) have emerged as a promising strategy, offering improved ionic conductivity and structural performance compared to polymer electrolytes. In this study, a simple and scalable approach was developed to fabricate a crosslinked polyethylene oxide (PEO)-based membrane, comprising two different glass fiber reinforcements, in terms of morphology and thickness. The incorporation of a solvated ionic liquid into the developed membrane enhances the ionic conductivity and reduces flammability in the resulting CGPE. Galvanostatic cycling experiments demonstrate favorable performance of the composite membrane in symmetric Li cells. Furthermore, the CGPE demonstrated electrochemical stability, enabling the cell to cycle continuously for more than 700 h at a temperature of 40 °C without short circuits. When applied in a half-cell configuration with lithium iron phosphate (LFP) cathodes, the composite membrane enabled cycling at different current densities, achieving a discharge capacity of 144 mAh·g⁻¹. Overall, the findings obtained in this work highlight the potential of crosslinked PEO-based composite membranes for high-performance Li metal anodes, with enhanced near room temperature conductivity, electrochemical stability, and cycling capability.

This study explores the preparation of lithium iron phosphate (LFP) electrodes for lithium-ion batteries (LIBs), focusing on electrode loadings, dispersion techniques, and drying methods. Using a three-roll mill for LFP slurry dispersion, good electrochemical properties were achieved with loadings of 5–8 mg·cm⁻² (0.8–1.2 mAh·cm⁻² areal capacity). Adding polyvinylidene fluoride (PVDF) during the final milling stage reduced performance due to premature solidification in-between rolls. Vacuum-free drying improved ionic conductivity, stability against lithium metal, and discharge capacity, whereas vacuum-dried samples exhibited higher initial resistance and lower capacity retention. These findings highlight critical parameters for enhancing LFP electrode performance, paving the way for high-performance, and sustainable energy-storage solutions.

Ischemic stroke is a leading cause of mortality and morbidity worldwide. Nevertheless, current treatments are very ineffective as they only restore the blood flow, lacking neuroprotective properties. Excitotoxicity, primarily mediated by the overaccumulation of glutamate in the synaptic space, plays a key role in infarct expansion. Therefore, we propose a novel neuroprotective strategy to limit excessive glutamate release using the light-chain (LC) of Botulinum neurotoxin type A (BoNT/A), known to block neurotransmitters exocytosis, transported and delivered with proprietary fully biodegradable PEG-dendritic block copolymers (fbB). Here, the synthesis of 'taggable' dendrimers at their PEG end was further explored, where a Cy5.5 molecule was tagged through this point to allow for the tracking of nanoparticles in complex biological systems. A highly pure and catalytically active LC protein was produced and successfully complexed with the fbB dendrimers, forming DETOX nanoparticles. These systems, with nanosizes and mildly positive net charges, achieved up to 84 % LC-loading efficiency. DETOX significantly enhanced the cleavage of SNAP-25 - the LC's target - in neurons compared to BoNT/A and demonstrated a faster onset of action than the full-length neurotoxin, without inducing cytotoxicity. Importantly, DETOX capacity to reduce glutamate exocytosis was demonstrated in an in vitro model of ischemia. Moreover, DETOX nanoparticles showed their remarkable ability to permeate a 3D full-human blood-brain barrier model, indicating their promising application in humans. These findings position DETOX nanosystems as a groundbreaking neuroprotective strategy, offering a novel, clinically relevant approach for mitigating excitotoxicity in ischemic stroke, paving the way for advanced CNS therapeutics.