Simultaneously boosting cycle life and safety of lithium metal batteries through synergistic interphase engineering with gel polymer and fluoroethylene carbonate

This review provides a comparative assessment of the synthesis, better network selection, catalytic applications, and stabilization of silver, gold, palladium, nickel, and cobalt nanoparticles. It focuses particularly on nickel and cobalt, which exhibit high surface energies and tend to aggregate due to van der Waals forces and magnetic dipole–dipole interactions. This aggregation presents a significant challenge for stabilization. Magnetic nickel nanoparticles are particularly susceptible to surface oxidation; therefore, most synthesis protocols utilize organic media and hydrophobic capping agents to prevent agglomeration and oxidation. While cobalt nanoparticles hold promise for magnetic and catalytic applications, they exhibit poor stability against oxidation and hydrolysis, which limits their use in catalytic contexts. The electronic properties also contribute to the stability challenges faced by these five nanoparticles. We review various synthesis methods, including chemical, biological, and green approaches, as well as stabilization strategies such as surfactant capping, confinement within metal-organic frameworks or covalent frameworks, and polymeric gels. Additionally, we summarize advanced characterization techniques and propose a data-driven framework that combines density functional theory, materials databases, and machine learning to predict synthesis parameters and surface modifications. This review highlights that when properly stabilized, nickel and cobalt nanoparticles can serve as cost-effective alternatives to noble metals, providing high catalytic efficiencies in reactions such as the reduction of nitro compounds and the degradation of dyes. By comparing noble and base metal nanoparticles and highlighting the underexplored systems of nickel and cobalt, we provide mechanistic insights and design principles that will facilitate the rational development of durable catalysts for environmental remediation and energy conversion.

Influence of curing temperature on the carbonation products and mechanical performance of reactivated cementitious materials.

Exploiting its exceptional structural tunability and digital manufacturing capability, 3D printing emerges as a transformative technique for the rational design and scalable fabrication of catalytic electrodes tailored for advanced electrochemical energy systems. In this study, hierarchically porous, self-supporting carbon electrodes were fabricated via 3D printing technique in combination with the sequential conformal carbonization. An optimized polymerizable ionic liquid-based ink was employed to produce a 3D printed polymer gel, which was subsequently functionalized with B-containing species. The as-prepared gel was then pyrolyzed to yield B/N-co-doped carbon electrodes with a high surface area possessing micropores, mesopores and macropores. The metal-free cathode demonstrated good performance in electrocatalytic CO 2 reduction, producing syngas with tunable H 2 /CO ratios ranging from 0.37 to 2.6, thereby catering to diverse application requirements. This study naturally integrates 3D printing with ionic-liquid chemistry to fabricate customizable metal-free carbon electrodes for efficient CO 2 -to-syngas conversion, offering a Power-to-X route to store intermittent renewable electricity as chemical energy and to deliver tunable H 2 /CO syngas suitable for downstream fuel and chemical synthesis. • Self-supporting carbon electrode for CO 2 RR is developed by 3D printing. • 3D printing is based on photopolymerization using ionic liquid-based ink. • The hierarchically porous 3Dp-H-BNC has a high S BET of 842 m 2 g -1 . • Composition of as-produced syngas can vary from 0.4 to 2.6 (H 2 / CO).

Biopolymer electrolytes for rechargeable zinc-air batteries: Advancements and challenges

Coupled polymer gelation and cement hydration in the structural build-up of xanthan gum-modified cement pastes

In this paper, we studied the role of ultrafast medium dynamics in determining the conductivity of a representative gel polymer electrolyte system composed of propylene carbonate, lithium perchlorate (LiClO4), and polypropylene glycol (PPG), with a fixed PC:LiClO4 ratio of 10.7, and explored the possible reasons behind the breakdown of Onsager theory in successfully predicting the composition-dependent measured conductivities at different temperatures. For this purpose, we measured the solution dynamical response by employing frequency dependent dielectric relaxation (DR) experiments and a streak camera-based fluorescence dynamics setup. These measurements indicated fast solution dynamics facilitated ion transport, while the slow diffusive dynamics offered frictional resistance. These opposite roles for the fast and the slow dynamics led to viscosity decoupling of conductivity and suggested the presence of non-hydrodynamic modes for ion transport. Our dynamic light scattering measurements suggested the presence of polymer-induced aggregated structures (∼2000-5000nm) in these solutions, hinting at a negligible contribution from the center-of-mass motions of these nanoaggregates to the measured conductivities. Raman spectroscopic measurements indicated PC-PPG interaction and suppression of ion-pair formation upon addition of PPG. Comparison of experimental conductivities to Hubbard-Onsager (HO) predictions reveals a strong sensitivity to the high-frequency dielectric constant (ε∞) and average DR times τDR. Use of a relatively faster τDR in the HO theory significantly improves the predictions, emphasizing the importance of the ultrafast medium dynamics. This demonstrates the overwhelming dominance of the long-wavelength collective medium polarization modes in governing ion transport and suggests a possible route for optimization of solution composition for battery applications.

Gel polymer electrolytes (GPEs) have been extensively explored for safe and flexible supercapacitors (SCs). However, within eutectic-based GPEs, the electrolyte phase is most commonly implemented either as salt/hydrogen-bond donor (HBD)-type deep eutectic solvents (DES) or by using DES as the solvent/plasticizing medium in polymer matrices. These approaches often suffer from high viscosity and consequently limited ionic conductivity, hindering ion transport and device performance. Here, we propose the concept of an ionic-liquid-assisted eutectic electrolyte; the ionic liquid serves as an active eutectic component and directly participates in establishing the eutectic solvation structure for electrolyte design. On this basis, we develop a quasi-solid ion-gel electrolyte by blending inexpensive bioderived urea (hydrogen-bond donor) with 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIMBF4, hydrogen-bond acceptor) at an optimized 3:7 molar ratio, followed by incorporation into a polyvinylidene fluoride-hexafluoro propylene (PVDF-HFP) matrix via solution casting and vacuum drying. The PVDF-HFP/Urea/EMIMBF4 (PUE) gel achieves a high ionic conductivity of 3.52 mS cm-1, a wide electrochemical stability window of 2.6 V, and reliable operation up to 60 °C. Symmetric SCs based on activated carbon electrodes deliver a specific capacitance of 173.1 F g-1 at 1 A g-1, an energy density of 40.7 Wh kg-1, and 80.1% capacitance retention after 5000 cycles (with a 10% capacitance increase at 60 °C). Additionally, the formation of a binary eutectic mixture significantly lowers the solidification point, which also confers intrinsic flame retardancy to the PUE gel. This work offers a facile and effective route to high-safety, wide-temperature, and eco-friendly quasi-solid electrolytes for next-generation energy storage devices.

A polymeric salt-induced gel separator stabilizes Zn anodes via PO43--Zn2+ coordination, forming a robust 3D network. It enables 99.5% CE in Zn||Cu cells and over 2000 h of stable Zn||Zn cycling at 50 mA cm-2/50 mAh cm-2 (89.5% DOD), effectively suppressing dendrite growth and enhancing reversibility of the zinc anode.

Elevating the charging cutoff voltage is critical for practical lithium metal batteries (LMBs); however, this strategy is severely hampered by solvent parasitic reactions. Despite advances in electrode/electrolyte interface engineering, solvent molecules near the interface remain attracted by cathodic parasitic-reaction sites, resulting in solvent decomposition. Here, we propose a separator-adsorbed solvent strategy, establishing a separator-electrolyte interface enriched with adsorption sites that prevents solvent molecules from being captured by cathodic parasitic-reaction sites. The selected polytetrafluoroethylene (PTFE) separator serves to interact with positively charged regions of carbonate solvents. This combination facilitates robust separator-solvent interactions, including C-H···F weak hydrogen bonds and n → π* interactions. Significantly, these interactions generate numerous solvent adsorption sites at the separator-electrolyte interface, which compete with the active cathode surface for solvent molecules. This enables the solvent molecules to escape the attraction of cathodic parasitic-reaction sites and preferentially accumulate on the separator surface, thereby significantly suppressing solvent decomposition and stabilizing the cathode interface. The gel polymer electrolyte with a polytetrafluoroethylene separator (GPE-PTFE) enables a 4.4 V Li||LiNi0.8Co0.1Mn0.1O2 cell to achieve a high-capacity retention rate, maintaining 80% capacity over 671 cycles, nearly double the 368 cycles achieved using a polyethylene (PE) separator. Under an ultrahigh cutoff voltage of 4.7 V, the capacity retention reaches 90% after 100 cycles. This work proposes a paradigm for realizing ultrahigh-voltage LMBs through the separator-electrolyte interface.

During breathing, anatomical structures within the torso move which can result in inaccurate radiation dose delivery. With the introduction of MRI-linear accelerators (MRI-linacs), the ability to simultaneously acquire high-contrast soft tissue images during irradiation allows for compensation of intrafraction motion and deformation by gating or tracking the target volume. The implementation of MRI-guided tracking radiotherapy is not without risks as any lag or organ deformation may not be accounted for. Polymer gel dosimetry has the potential to measure the integral dose delivered to deforming and moving targets as the gels are flexible and provide a high-resolution 3D dose profile. Spherical silicone casts filled with polymer gel and silica beads were compressed to measure the deformation of gel phantoms. The effect of compression on the dose response was studied by irradiating and scanning the spherical phantoms in various states of compression. End-to-end gel dosimetry experiments with MRI-guided tracking radiotherapy were conducted on a prototype MRI-linac (Australian MRI-Linac) using a moving, non-deformable, rectangular-shaped gel dosimeter phantom and an MRI-safe, pneumatically actuated, anthropomorphic, breathing phantom containing a liver-shaped gel dosimeter. Radiochromic film dosimeters within the phantoms were used as secondary validations of the dose profile. The tracking performance of the MRI-linac was assessed by comparing measured dose distributions in the phantoms in static and actuated experiments. There was no significant impact of compression on the dose response in the irradiated spheres. The gel-measured dose profiles in the phantoms matched closely with the film dosimeters for tracked and non-tracked scenarios. The end-to-end gel dosimeter experiments illustrate the improvement in dose conformality with MRI-guided tracking. Deformable 3D gel dosimeters in an anthropomorphic body phantom can be used for assessing 3D geometric accuracy of tracked treatments on MRI-linacs, but care should be taken to account for the oxygen inhibition at the edges of the dosimeter.

The development of polymer electrolytes with high ionic conductivity, robust mechanical strength, and excellent interfacial stability remains a critical challenge for high-performance sodium metal batteries (SMBs). Herein, a "chemical-structural dual regulation" strategy introduces complementary soft and hard segments into a gel polymer electrolyte (GPE), enabling concurrent optimization of solvation structure and mechanical properties. Soft segments with strong electron-withdrawing -CF3 groups form solvent-rich domains that weaken Na+-solvent interactions, while amide N-H groups create polymer-rich domains that enhance mechanical strength and anchor anions via hydrogen bonding, promoting sodium salt dissociation. Benefiting from this rational molecular design, GPE-9 delivers an outstanding ionic conductivity of 1.11 mS cm-1 and a high Na+ transference number of 0.74 at room temperature, and supports long-term cycling of Na||Na symmetric cell at 0.2 mA cm-2 for 7000 h. The Na|GPE-9|Na3V2(PO4)3 (NVP) cell demonstrates excellent rate durability, sustaining 12000 and 20000 cycles at 5C and 10C, respectively, with nearly 100% Coulombic efficiency. Furthermore, a 29-layer pouch cell with NVP cathode and hard carbon (HC) anode delivers a high capacity approaching 1.0 Ah. This study demonstrates that designing polymer segments capable of regulating solvation structure and directing interfacial fluorination offers a promising strategy for high-performance GPEs for Na batteries.

Gel dosimeters are an important tool for radiotherapy dose verification due to their tissue equivalence, but their widespread use has been constrained by complex readout processes, limited spatial resolution, and instability of postirradiation. Herein, we use radiation-induced expansion, yielding a dose-dependent and continuous redshift in its structural color. This double network dosimeter can detect X-rays with a maximum sensitivity of 35.8 nm/Gy and spatial resolution exceeding 50 μm in the range of 0-10 Gy. Moreover, it exhibits excellent stability against environmental factors, including UV irradiation, and its dosimetric information (spectral reflection peak position) remains unchanged after 10 drying-wetting cycles. In addition, it is feasible for three-dimensional (3D) printing of complex shapes, a capability that is inaccessible to existing gel dosimeters. Therefore, the present study provides spatially precise gel dosimeters for advanced radiotherapy verification.

In the present investigation, we report the synthesis of composite gel polymer electrolytes (CGPEs) based on a poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP)/poly(methyl methacrylate) (PMMA) blend incorporated with 2D layered vanadium disulfide (VS2). The incorporation of VS2 significantly enhances the ionic conductivity (3.6 × 10-3 S cm-1) compared with that of the pristine GPE (2.5 × 10-3 S cm-1). The optimized CGPE achieves a high ionic conductivity of 3.6 × 10-3 S cm-1, a good sodium-ion transference number of 0.44, a wide electrochemical stability window (ESW) of ∼4.1 V vs. Na+/Na, and excellent thermal stability up to ∼125 °C. Structural analyses confirmed uniform polymer-filler interactions, contributing to efficient ion transport. The fabricated sodium-ion battery using the CGPE as the electrolyte delivered a high reversible capacity of 195 mA h g-1 after 30 cycles at 50 mA g-1, with stable cycling performance up to 100 cycles. The enhanced electrochemical performance of the CGPE demonstrates the potential of VS2-incorporated systems as promising electrolytes for flexible, high-energy sodium-ion batteries (SIBs) and highlights the suitability of 2D materials as effective fillers in GPEs.

Gel polymer electrolytes (GPEs) are key components in electrochemical energy-storage devices, as they simultaneously serve as ion-conducting media and separators. However, their performance is often limited by the trade-off between mechanical robustness and ionic conductivity, which becomes particularly problematic in highly concentrated aqueous electrolytes due to electrolyte-induced dimensional instability. Here, we report a composite GPE based on a rigid aramid nanofiber (ANF) network coated with a hydrophilic poly(vinyl alcohol) (PVA) layer, designed for compatibility with water-in-salt electrolyte systems. The ANF scaffold provides a high-modulus framework for dimensional stability, while hydrogen-bonding interactions at the ANF-PVA interface enable effective stress redistribution without significantly impeding ion transport. The ANF-PVA composite hydrogel was impregnated with a lithium chloride-based water-in-salt electrolyte to form a GPE and subsequently coated onto activated-carbon-decorated carbon-fiber electrodes to fabricate supercapacitors. The resulting devices exhibit stable electric double-layer capacitive behavior, reliable rate capability, and excellent cycling stability over a wide temperature range from -20 to 50 °C, together with scalable electrochemical performance upon increasing device length. These results highlight the effectiveness of composite polymer-network engineering for mechanically robust and ionically efficient aqueous GPEs suitable for low-temperature energy-storage applications.

Gel polymer electrolytes (GPEs) are promising electrolyte candidates for lithium metal batteries (LMBs) due to their favorable interfacial contact and enhanced safety. However, GPE electrolytes suffer from severe interfacial instability against lithium metal anodes (LMAs) and limited lithium‑ion transference number (tLi+), which significantly restricts the fast‑charging performance of LMBs. Herein, we propose a fast‑charging gel polymer electrolyte (GPE‑FN) using fluoroacetonitrile (FAN) as the solvent, with fluoroethylene carbonate (FEC) and LiNO3 as reduction additives. The GPE‑FN electrolyte addresses the interfacial incompatibility issues of FAN in LMBs by forming a stable solid electrolyte interphase (SEI) layer through the reduction of FEC and LiNO3 on LMA, which effectively prevents the continuous consumption of FAN. Furthermore, this SEI layer also effectively enhances the interfacial Li+ transport. The results show that the GPE‑FN electrolyte demonstrates a high ionic conductivity (σ) of 1.66 mS cm-1 and a high tLi+ of 0.848 at 25°C. Both LiFePO4 (LFP)||Li and LiNi0.8Co0.1Mn0.1O2 (NCM811)||Li cells based on the GPE‑FN electrolyte achieve 4100 cycles with 80.3% capacity retention and 800 cycles with 79.5% capacity retention at 5C, respectively, exhibiting excellent fast‑charging performance. Furthermore, full cells incorporating high‑loading cathodes demonstrate stable cycling, highlighting the promising potential of the GPE‑FN electrolyte.

Sorption-based atmospheric water harvesting (SAWH) is a promising strategy for freshwater production. While salt-based composites are widely employed as SAWH sorbents, they are often constrained by limited water yield from low sorption capacity and slow sorption/desorption kinetics due to diffusion barriers. Here, a new strategy is proposed to enhance moisture transport and storage space by fabricating oriented interconnected macroporous polymer gels via salt-templated crystallization-induced confined polymerization. Benefiting from this optimized interconnected hierarchical structure and the synergistic effect between PAMPS and LiCl, the salt-templated crystallization gel (STC/TiN-gel@LiCl) exhibits a record-breaking moisture uptake of 7.19gg- 1, ultrafast sorption kinetics of 1.96gg- 1h- 1, and rapid desorption rate of 96.8% per hour under 1.0 sun illumination. After 20 cycles under high-humidity conditions (25°C, 90% RH), the gel retains over 90.4% of its initial water uptake capacity without leakage, confirming its long-term durability. Moreover, it delivers an outstanding water production rate of 3.29kgkg- 1day- 1 even under low-temperature and moderate humidity conditions (14.5°C, 55.6% RH). This work pioneers an oriented interconnected macroporous architecture engineering strategy to concurrently unlock rapid transport and high-capacity storage in hygroscopic gels, establishing a new paradigm for atmospheric water harvesting.

Additive manufacturing offers new opportunities for fabricating next-generation battery components with unprecedented control over three-dimensional architecture and spatial complexity. This study presents the development and electrochemical characterization of 3D printable gel polymer electrolytes (GPEs) based on a UV-curable PEGDA resin and a liquid electrolyte composed of 1 M LiClO4 in EC:DEC or EC:PC (1:1 v/v). The impact of resin-to-electrolyte ratios on ionic conductivity and processability is systematically evaluated, with 1:4 v/v identified as the optimal formulation. GPEs fabricated via vat photopolymerization exhibit high ionic conductivities of up to 3.4 × 10-3 S.cm-1 (DEC-based) and 3.1 × 10-3 S.cm-1 (PC-based), closely matching their tape-cast counterparts. Electrochemical stability is maintained up to ~4.5 V vs. Li0/Li+, with symmetric cell testing confirming effective Li0 plating/stripping over 100 cycles. The 3D printed GPEs retain their electrochemical performance despite performing the printing process in ambient air, demonstrating robustness and compatibility with scalable manufacturing. In addition, the GPEs can be printed into complex geometries, further underscoring their suitability for advanced device architectures. This work highlights the critical role of solvent selection and printing parameters in designing printable GPEs and paves the way toward shape-conformable, solid-state battery systems.

Molecular recognition plays a central role in supramolecular chemistry. The concept of molecular recognition initially emerged from discrete molecular systems and has now been expanded to solid-state soft materials; however, there remains a lack of knowledge to elucidate the relationship between molecular recognition events and the modulation of macroscale properties. Here, we present a new type of polymer gel that discriminates structurally similar guests by utilizing coordination interactions. Our approach uses Rh(II)-based metal-organic polyhedra (MOPs) as both coordinative recognition sites and cross-linking nodes. By connecting MOPs with flexible, deformable poly(ethylene glycol)s, covalently linked MOP polymer gels are formed while preserving accessible coordination sites. The resulting MOP polymer gels exhibit macroscale shrinkage and swelling behavior in response to solvent exchange and guest molecule recognition. Specifically, ditopic coordinative guests induce significant gel shrinkage, whereas a structurally similar noncoordinative guest results in negligible volumetric changes. This difference highlights the capability of the MOP polymer gel to distinguish subtle structural differences of the guests at the coordinative recognition sites and to propagate the recognition events into macroscale shrinkage. Correspondingly, the storage modulus of the gel increases upon guest-induced shrinkage, which indicates that coordinative guest recognition reinforces the polymer network within the gel. These results establish a correlation between coordinative guest recognition and macroscale changes in the volumetric deformation and mechanical properties of the gels. This covalently linked MOP polymer gel system paves the way for designing stimuli-responsive, functional soft materials.

The rapid transition toward electric vehicles and large-scale energy storage systems has intensified the demand for lithium-ion batteries (LIBs) capable of reliable operation under harsh temperature conditions. However, conventional liquid electrolytes suffer from severe degradation at elevated temperatures. Herein, we report a multifunctional gel polymer electrolyte (GPE) employing a siloxy-functionalized cross-linker, siloxy-pentaerythritol triacrylate (SiO-PETA), to enhance the high-temperature cycling stability and safety of LIBs. The trimethylsilane groups in SiO-PETA effectively scavenge corrosive HF, thereby mitigating cell degradation associated with transition metal dissolution. In addition, the chemically cross-linked polymer matrix encapsulates the liquid components in the GPE, suppressing parasitic side reactions and reducing electrolyte vaporization at elevated temperatures. A graphite/LiNi0.6Co0.2Mn0.2O2 pouch-type cell employing the GPE exhibits superior capacity retention at 70 °C, markedly outperforming a conventional liquid-electrolyte cell. Furthermore, the GPE provides enhanced safety, as evidenced by stable open-circuit voltage at 150 °C and reduced flammability. These results demonstrate that the SiO-PETA-based GPE effectively suppresses electrolyte and electrode degradation, enabling stable LIB operation at high temperatures.