Intraparticular Heterogeneity Limits Capacity in Lithium–Sulfur Batteries With Carbonate Electrolyte

The formation of a stable cathode‐electrolyte interphase (CEI) is critical for the performance of lithium–sulfur (Li–S) batteries with carbonate‐based electrolytes, as it suppresses parasitic polysulfide reactions and enables solid‐state sulfur conversion. In nanoporous carbon hosts, the CEI together with nanopore confinement plays a key role in capacity retention and long‐term cycling. Yet, its spatial formation, stability, and contribution to electrochemical performance remain poorly understood, partly due to challenges in characterization caused by beam and air sensitivity. Here, we employ cryogenic transmission electron microscopy (cryo‐TEM) with electron energy loss spectroscopy and energy‐dispersive X‐ray spectroscopy, X‐ray photoelectron spectroscopy and electrochemical testing together with galvanostatic intermittent titration technique measurements to elucidate how carbon particle size affects CEI formation and electrochemical performance. We find that the CEI is not a uniform surface film but extends heterogeneously into the particle bulk. Mass transport during the first discharge dictates CEI development, and larger particles suffer from inactive regions due to the preferential CEI formation only in the outer regions of the particles. During extended cycling, charge transfer resistance at confined CEI/active material/carbon interfaces emerges as the dominant performance‐limiting factor. These findings show that particle size controls CEI formation during initial discharge, offering guidance for designing carbon hosts from nano‐ to micrometer length scales in Li–S battery cathodes

Correction to “Acid-Free Electrochemical Regeneration of Sandrose-like Aluminum Layered Double Hydroxide Electrodes for Selective Lithium-Ion Recovery in Mixed Ion Solution”

In the original Article, Figure 1C shows an image from a different, morphologically similar sample rather than the sample investigated in the other panels and throughout the manuscript. A corrected version of Figure 1 (with the correct image for panel C) is provided below. This correction does not affect the results, discussion, or conclusions of the Article

The Pivotal Step of Structure Formation and Oil-Binding Capacity of Polyglucosamine

For decades, polyglucosamine (PGA), also known as chitosan, has been used as an active ingredient in medical devices intended for body weight reduction and the control of blood lipid levels in obese patients, even though the exact mechanism of lipid binding still remains unclear. The binding capability of polyglucosamines towards dietary lipids is well documented in the literature and has been studied in-depth with respect to the physicochemical properties of the biopolymer. However, only a limited number of reliable correlations between the oil-binding capacity and material properties have been reported. In contrast, the morphology and structural nature of oil-polyglucosamine sponges have not received much attention and have been investigated only rudimentarily. Our work closes this gap and shines light on the pivotal step of structure formation and morphology in relation to oil-binding capacity. After the characterization of three batches of polyglucosamine via elemental and thermal analysis, infrared spectroscopy, and size exclusion chromatography, the oil binding capacity was determined over a range of oil-to-PGA ratios for one selected batch PGA21 (Mw = 251.6 kDa, DA = 4.3%). From the resulting oil-binding capacity, which turned out to be as high as 3,750 goil/g, a combination of variables C100 and Cmax was derived for more reliable material characterization. Furthermore, the prepared sponges were subjected to morphology investigations. Mild electron microscopy techniques, as well as confocal microscopy, were utilized to resolve the native three-dimensional network of polyglucosamine embedded in the oil matrix. After oil removal using a tailored solvent-exchange method, we were successful in resolving a highly porous, sponge-like structure featuring nanofibrils as the structural subunit. This delicate structure offered a high surface area, resulting in increased oil-binding capacity. From these findings, we derived that an interplay of morphological characteristics and molecular interactions leads to the ultra-high and structurally rigid oil-binding capacity of polyglucosamine

FAK modulates immune response and fibroblast activation in biomaterial-induced fibrosis

Fibrotic capsule formation remains a major barrier in the clinical performance of biomedical implants. Here, we demonstrate that synthetic hydrogels mimicking the mechanical properties of fibrotic tissue trigger stromal cell activation and immune remodeling via focal adhesion kinase (FAK)-mediated mechanotransduction. Using a mechanically tunable poly(ethylene glycol) hydrogel platform and subcutaneous implantation in mice, we show that pharmacological inhibition of FAK activity significantly reduces α-smooth muscle actin (α-SMA)-positive myofibroblast activation, collagen I deposition, and fibrotic capsule thickness in a hydrogel stiffness-dependent manner. Flow cytometry and cytokine profiling revealed that FAK inhibition alters the fibrotic niche by reducing CD163-positive M2c macrophages and significantly downregulating pro-fibrotic cytokines including IL-6, and VEGF, while transiently increasing regulatory T cells and elevating IL-10 levels. Importantly, these changes occurred without parallel increases in canonical pro-inflammatory cytokines, indicating selective modulation rather than global immune suppression or activation. These findings position FAK as a central hub translating mechanical cues into coordinated stromal and immune responses. Targeting FAK mechanotransduction may provide a therapeutic strategy to mitigate foreign body responses and improve implant integration across regenerative applications

Synthetic Cell‐Based Tissues for Bottom‐Up Assembly of Artificial Lymphatic Organs

Synthetic cells have emerged as a novel biomimetic approach for studying fundamental cellular functions and enabling new therapeutic interventions. However, the potential to program synthetic cells into self‐organized 3D collectives to replicate the structure and function of tissues has remained largely untapped. Here, self‐assembly properties are engineered into synthetic cells to form millimeter‐sized 3D lymphatic bottom‐up tissues (lymphBUTs) with mechanical adaptability, metabolic activity, and hierarchical microstructural organization. It is demonstrated that primary human immune cells spontaneously infiltrate and functionally integrate into these synthetic lymph nodes to form living tissue hybrids. Applying lymphBUTs, it is shown that structured 3D organization and mechanical support drives T cell activation and the application of lymphBUTs for ex vivo expansion of regulatory CD8 + T cells is demonstrated. The study highlights the functional integration of living and non‐living matter, advancing synthetic cell engineering toward 3D tissue structures

Local networks of electrical conductance in hybrid gold nanoparticle–polymer films

Inks of gold nanoparticles with stabilizing and conducting polymer shells are promising materials for printed electronics. Local measurements of their electrical properties at the single-particle scale are required to understand the relationship between the particle network and electrical functionality. Herein, we report on conductive atomic force microscopy (cAFM) on films produced from hybrid Au nanoparticles that carry a covalently bound shell of the conducting polymer poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) and are distributed in a non-conductive matrix of polyvinyl alcohol (PVA). Current maps reveal the clustering of particles into electrically well-connected local networks and allow us to quantify the contact resistance between particles or clusters of particles. We find that the contact resistance between particles inside clusters is lower than those between clusters, indicating a hierarchical layer structure. By comparing inkjet-printed thicker bulk films and drop-cast films of single- or few-layer thickness, the experimental results offer valuable insights into the relationship between the structure of nanoparticle networks and the electrical conductance in these hybrid systems

Revealing the Hidden Electrochemical Pathway for Cathode Electrolyte Interface Formation in Lithium–Sulfur Batteries with Carbonate-Based Electrolytes

This study investigates the role of microporous carbons and carbonate-based electrolytes in addressing challenges related to polysulfides dissolution and electrolyte compatibility in lithium–sulfur (Li–S) batteries. By employing microporous carbons and varying the sulfur content, we investigate the formation of the cathode-electrolyte interphase (CEI) during the first discharge process. We propose an electrochemical nucleophilic mechanism for the formation of the CEI involving polysulfides and solvent molecules in the confined small pores of the cathode. This interphase, primarily composed of LiF, effectively seals the carbon pores, preventing further solvent intrusion and stabilizing the system. Furthermore, it allows the use of wider pores without compromising the system. Our findings reveal that an increased sulfur content within the micropores enhances cycling stability, contradicting trends observed in ether-based systems. These insights highlight the potential of designing Li–S systems with optimized pore structures and electrolyte compositions to achieve greater stability and capacity retention, marking a significant step forward in the development of practical Li–S batterie

Conductive emulsions with selective filler distribution as volume exclusion strategy in electrofluids

A classical approach to reduce the percolation threshold in conductive polymer composites is the so-called volume exclusion. While this method proved to lower the filler concentration required to achieve electrical conductivity in solid composites, it remains unexplored for liquid conductive composites such as electrofluids (EFs). We propose the combination of emulsions and conductive particles to create EFs with reduced filler content. Conductive emulsions were prepared based on two immiscible liquids, glycerol and polydimethylsiloxane (PDMS), and carbon black (CB) as the conductive filler. The structural characterization of stable emulsions revealed a selective distribution of CB in the PDMS phase (continuous phase), around glycerol droplets (dispersed phase). This configuration led to a decrease in percolation threshold proving the viability of volume exclusion as strategy in EFs. The combination of the CB network and the glycerol droplets resulted in unpredictable mechanoelectrical properties such as a reduced stiffness scaling compared to CB-EFs in the pure solvents and the reduction of a strain thickening behavior with increased filler concentration. We evaluated the role of the CB in the emulsion formation and its impact on the droplet size and size distribution and concluded that this effect must be synergetic with the creation of a stress-carrying filler network that absorbs the elastic energy from the droplet deformation at large strains

An Inkjet‐Printed Platinum‐Based Temperature Sensing Element on Polyimide Substrates

In this work, we present a proof‐of‐concept demonstration of inkjet‐printed resistive temperature sensors based on nanoparticle platinum ink on flexible polyimide substrates. The resistive temperature sensors are designed as meander structures with a target nominal resistance of 100 and 1000 Ω to be compared to conventional bulk Pt100 and Pt1000 resistors. Thermogravimetric analysis and in situ resistance measurements identified 250°C as the optimal sintering temperature, enabling sufficient solvent removal for conductive structure formation while avoiding Pt surface oxidation and polyimide substrate degradation. Electrical characterization in the 20°C–80°C range revealed a linear relationship between resistance and temperature with effective temperature coefficients of resistance (~48%/57%) and sensitivities (~72%/87%) compared to Pt100/Pt1000 standards, respectively. Mechanical testing over 400 bending cycles showed less than 1% change in electrical resistance, confirming robust flexibility. This study demonstrates the feasibility of translating nanoparticle Pt‐based resistive temperature sensors into flexible and automotive sensing applications, offering low‐temperature processability, stable temperature coefficients of resistance, linear sensitivity, mechanical robustness, and chemical stability across 20°C–80°C range

Acid-Free Electrochemical Regeneration of Sandrose-like Aluminum Layered Double Hydroxide Electrodes for Selective Lithium-Ion Recovery in Mixed Ion Solution

The demand for lithium production has seen a significant rise, with the growing electric vehicle and stationary battery markets requiring further development of sustainable and scalable extraction methods. Direct lithium extraction technologies have been developed to address potential shortages, with adsorption emerging as a key method due to its efficiency and low environmental impact. Given that Al(OH)3 is already utilized as an adsorbent in various industrial applications, the practical importance of Al-based alternative systems for lithium ion extraction is increasing, yet lithium ion recovery requires harsh chemicals. In this study, we report a novel lithium extraction method combining chemical adsorption and electrochemical release using a synthesized aluminum layered double hydroxide (Al-LDH) material, developed under mild reaction conditions. The performance of the Al-LDH electrode was evaluated against a commercial Al(OH)3 adsorbent. Comprehensive characterization using techniques such as X-ray diffraction, Fourier-transform infrared spectroscopy, and scanning electron microscopy revealed detailed insights into the crystalline structure, particle size distribution, and surface morphology of the materials. The Al-LDH electrode exhibited a lithium ion adsorption capacity, achieving an average chemical uptake of lithium ions of 57.6 mg/g. In contrast, lithium-ion uptake capacity for Al(OH)3 was 1.0 mg/g over 15 cycles. Notably, this method operates under pH-neutral conditions, eliminating the need for harsh acidic or basic eluents. As a result, it prevents structural degradation and minimizes secondary pollution for potential future applications of lithium-ion recovery. The material’s layered structure selectively allowed lithium ion intake while blocking sodium ions, demonstrating its high selectivity and utility in lithium ion recovery processes. The integration of pH-neutral regeneration and high selectivity shows that Al-LDH electrodes as viable candidates for next-generation, green lithium extraction technologies