Electrolyte Matrix Research Articles

Si3N4-Assisted Densification Sintering of Na3Zr2Si2PO12 Ceramic Electrolyte toward Solid-State Sodium Metal Batteries

The solid-state metal battery with solid-state electrolytes has been considered the next generation of energy storage technology owing to its superior safety and high energy density. But, unfavorable ionic conductivity and interfacial problems make it difficult to widely use in practice. In this work, Si3N4 was rationally introduced into the NASICON matrix as a sintering aid, and the influence of Si3N4 on the crystal phase, microstructure, electrochemical and electrical performance of Na3Zr2Si2PO12 (NZSP) ceramic was systematically studied. The results demonstrate that the introduction of Si3N4 can effectively lower the densification sintering temperature of Na3Zr2Si2PO12 electrolyte and enhance the room temperature ionic conductivity of the NZSP to 3.82 × 10−4 S cm−1. In addition, since Si3N4 has a high thermal conductivity and can inhibit the transmission of electrons between the grains of the electrolyte matrix, it will effectively hinder the generation of sodium metal dendrites and relieve the concentration of the heat source. Moreover, owing to the desirable interface compatibility of the Na and NZSP-Si3N4 electrolyte, the Na/NZSP-1150-1%Si3N4/Na symmetric battery exhibits excellent stability, and the electrode/electrolyte interface still maintains good integrity even after long-term cycling. The assembled Na/NZSP-1150-1%Si3N4/Na3.5V0.5Mn0.5Fe0.5Ti0.5(PO4)3 cell manifests an initial specific capacity of 152.5 mA h g−1, together with an initial Coulombic efficiency of 99.8%. Furthermore, after 200 cycles, the battery displays a capacity retention rate of 82%.

Competitive adsorption of oxytetracycline and sulfamethoxazole by nanosized activated carbon in aquatic environments: Experimental analysis and DFT calculations

Nanosized activated carbon (NAC) is an emerging carbonaceous nanomaterial for water treatment, while oxytetracycline (OTC) and sulfamethoxazole (SMX) coexisting in aquatic environments may undergo competitive adsorption to influence its removal efficiency. This study investigated the competitive adsorption of OTC and SMX onto NAC under different interaction sequence, pH, electrolyte, and water matrix conditions, using experimental analysis and density function theory (DFT) calculations. Adsorption kinetics show that increasing concentration of one antibiotic inhibited the adsorption of another. Faster equilibrium was attained in binary systems than single systems due to competitive adsorption, with pseudo-second-order model providing the best fit in both systems. Adsorption isotherms suggest that NAC exhibited stronger affinity towards OTC (395.26 mg/g) than SMX (232.02 mg/g), with Langmuir model showing satisfactory fitting in both single and binary systems. Sequential adsorption of [NAC + OTC] + SMX was more favored than binary adsorption, aligning with the optimum configuration of SMX--[NAC-OTC±] with binding energy of −57.25 kcal/mol from DFT calculations. Competitive adsorption was preferred within pH 3.2–5.6, where electrostatic attraction existed between NAC and cationic antibiotics. Salting-out, charge screening, and complexation effects from Na+ and Ca2+ influenced competitive adsorption. Optimal removal of OTC and SMX by NAC was achieved in wastewater effluent among four water matrices in both single and binary systems. Hydrogen bonding, π − π electron donor–acceptor interactions, electrostatic interactions, and hydrophobic interactions contributed to adsorption. Sequential change in functional groups of NAC followed − OH → C − H → C − O → C = C and C = C → C − O → C − H → − OH in single and binary systems, respectively. The findings provide valuable insights into the competitive adsorption mechanisms of antibiotics on NAC, highlighting its potential for remediating mixtures of antibiotics in complex aquatic environments.

Characterization and properties of solid-state nanocomposite Acacia gum electrolytes with emphasis on diverse applications

A novel, natural, eco-friendly, solid-state Acacia gum nanocomposite electrolyte has been prepared with different weight ratios of nanoparticle ZrO2 introduced to the standard composition of 70% Acacia gum and 30% ZnSO4·7H2O. Sequential examinations, encompassing XRD, and FTIR, were conducted to evaluate the amorphous characteristics, complexation nature, and interaction of dopant nanoparticles within the acacia-salt electrolyte matrix network. The optimum ionic conductivity of nanocomposite electrolytes was found using electrochemical impedance analysis. The remarkable ionic conductivity was achieved for the electrolyte sample consisting of 10% nanoparticle ZrO2 introduced to the standard composition of 70% of Acacia gum and 30% of ZnSO4·7H2O(AZR4) at 100 °C, 6.1×10−3S/cm, at room temperature (RT) the electrolyte sample exhibited conductivity value of 1.13×10−3 S/cm. Additionally, an examination of the dielectric characteristics dependent on frequency demonstrated the existence of space charge polarization in the electrolyte and a notable tail in the low-frequency area. Through the parameters of the dielectric modulus, the research also investigated the hopping mechanism and relaxation time. Furthermore, nano-composite electrolytes were employed in the construction of solar cell devices. The outstanding results were obtained for electrolyte upon (10 wt%) nanoparticle-introduced, overall power conversion efficiency (ƞ) reached 5.38%, short-circuit photocurrent density (Jsc) 10.92 mA/cm2, open-circuit voltage (Voc) at 735 mV, and fill factor (FF) at 0.63.

Ionic liquid supported chitosan-g-SPA as a biopolymer-based single ion conducting solid polymer electrolyte for energy storage devices

This article discusses the preparation of different grades of single-ion conducting quasi-solid polymer electrolytes (q-SPE) material (Chit-g-SPA-IL) based on biopolymer (chitosan), polyacrylic acid and DBU-acetate (DBUH+ AcO−) ionic liquid. Chit-SPA-60 %-IL exhibited the highest conductivity within the range of 10−4 S/cm. TGA analysis demonstrated the stability of electrolytes up to a temperature of 120 °C. SEM-EDS analysis unveiled the porous nature of the electrolyte and even distribution of ions throughout the matrix. It exhibited an electrochemical stability window (EWS) of 2.53 V with significant current density and an ionic transference number (ITN) of ~99.9 %. The temperature-dependent conductivity established an Arrhenius-type conduction mechanism with an activation energy of 0.149 eV for ion movement within the electrolyte matrix. The AC conductivity analysis emphasized the time-temperature independence of the ionic conduction mechanism. Dielectric analysis highlighted the capacitive nature of the electrolyte, underlining its substantial capacitance, while modulus studies indicated minimal influence from the electrode-electrolyte interface. Chit-SPA-60 %-IL at 30 °C included a self-diffusion coefficient of 4.57 × 10−5 m2/s, ionic mobility of 1.75 × 10−3 m2/Vs, and drift ionic velocity of 0.44 m/s. These findings makes SPE as a promising candidate for sodium-ion-based energy storage devices.

Soy protein isolate–based gel polymer electrolyte for flexible solid-state supercapacitor

At present, the polymer matrices of most polymer electrolytes are derived from petroleum-based synthetic polymers. Herein, sustainable and renewable soy protein isolate (SPI) was grafted with methacrylic acid (MAA) and then cross-linked by ring-opening reaction with polyethylene glycol diglycidyl ether as cross-linking agent to obtain a biomass-based polymer electrolyte. Results show that when the added amount of MAA is twice the quality of SPI, gel polymer electrolyte displays the best comprehensive properties and presents the highest ionic conductivity of 5.24 × 10−3 S/cm. The flexible supercapacitor was fabricated by using SPI-based gel polymer electrolyte with activated carbon electrodes, which exhibited excellent specific capacitance (128.63 F/g) and energy density (9.52 Wh/kg) at 0.5 A/g with a decent capacitance retention of 93% after 5000 charge–discharge cycles. It can be ascribed that grafting modification of SPI improves the interface performance of electrode–polymer electrolyte. Furthermore, potassium iodide is introduced to form a redox polymer electrolyte to achieve a high-energy-density supercapacitor, which provides outstanding energy density of 24.40 Wh/kg at 1.0 A/g. This work demonstrates that sustainable and renewable biomass can be converted into matrix of polymer electrolyte for high performance supercapacitor based on aqueous polymer electrolyte.

Porous Wood Composite as a Green Approach for Enhancing Electrochemical Performance of Gel Polymer Electrolytes for Supercapacitors.

Delignified wood (DW) is a kind of environment-friendly porous material, and its unique hierarchical orous structure and excellent wettability are conducive to the rapid transfer and storage of ions, which can be used as electrolyte matrix of supercapacitors. In order to solve the deficiency of mechanical properties of DW as electrolyte materials, a novel cross-linked polyurethane (CPU) with high water absorption is designed as a reinforced matrix to improve the mechanical properties of electrolytes while maintaining high ionic conductivity. First, DW is immersed in CPU precursor solution, and the DW/CPU composite (W-CPC) is obtained by thermal crosslinking. Finally, W-CPC is soaked in 1 M LiClO4 aqueous electrolyte to obtain the composite gel polymer electrolyte (W-CPC-GPE). Benefiting from the good hydrophilicity of W-CPC, the anisotropic vertical channels inside the DW, and the synergism of hydrogen bond and covalent bond. The highest ionic conductivity and mechanical strength of W-CPC-GPE are 3.5×10-2 S cm-1 and 0.67 MPa, respectively. The W-CPC-5-G based supercapacitor exhibits a high specific capacitance of 146.52 F g-1 and favorable capacitance retention rate of 90.7 % after 5000 cycles. The results show that compounding with DW is an efficient and green way to develop high-performance gel polymer electrolytes for supercapacitors.

Urea-lactic acid as efficient lignin solvent and its practical utility in sustainable electrospinning

The development of lignin-based materials presents a promising avenue for advancing green chemistry and mitigating environmental impact. However, the key challenge lies in the processability of lignin, which significantly affects its practical applications. Addressing the issues related to lignin's complex structure, variability, and reactivity is crucial for optimizing its incorporation into high-performance materials. Therefore, in this study we explore the efficacy of a urea-lactic acid-based deep eutectic solvent (ULA) for the dissolution of kraft lignin, aiming to enhance its practical utility in sustainable electrospinning processes, for the first time. Results of elemental analysis, IR and 2D NMR spectroscopy, provide crucial insights into the structural properties of the regenerated material post-DES treatment. The findings confirm a high lignin recovery rate, reaching up to 96.6 % for samples dissolved at 100°C. Additionally, 2D NMR analysis indicates that the process leads to partial esterification of lignin with lactate ions. The ability of the studied DES to effectively solubilize lignin underscores its potential as an efficient lignin solvent and facilitates the fabrication of lignin-based nanofibers via electrospinning. The incorporation of this DES in electrospinning processes promises significant advancements in the development of sustainable, lignin-derived materials and offers a green alternative for production of high-performance nanofibers. Preliminary results of electrochemical impedance spectroscopy and galvanostatic charge/discharge measurements confirm that the EDLC with prepared hydrogel electrolyte demonstrates attractive electrochemical properties (specific capacitance, CSP = 95 F g–1; series resistance RS = 2.2 Ω; charge transfer resistance, RCT = 1.6 Ω), which are comparable with the reference cell based on a commercial glass fibre separator. Hence, the DES-assisted-electrospinned lignin membrane can be viewed as a potential gel electrolyte matrix for practical use in construction of sustainable energy storage devices.

Comparative Study of Quasi-Solid-State Dye-Sensitized Solar Cells Using Z907, N719, Photoactive Phenothiazine Dyes and PVDF-HFP Gel Polymer Electrolytes with Different Molecular Weights

The present study investigates the influence of photosensitizer selection and the polymer electrolyte composition on the performance of quasi-solid-state dye-sensitized solar cells (QsDSSCs). Two benchmark ruthenium dyes, N719 and Z907, alongside a novel photoactive phenothiazine dye were used. Each dye was incorporated into a QsDSSC architecture employing poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) as the gel electrolyte matrix, with varying molecular weights, to investigate their impacts on the overall device performance and long-term stability. Our results demonstrated that the N719 dye exhibited the highest power conversion efficiency (PCE), attributed to its strong absorption in the visible spectrum and efficient electron injection into the TiO2 photoanode. Z907, on the other hand, showed moderate PCE due to its broader absorption profile but slower electron injection kinetics. The phenothiazine dye revealed promising PCE, with tunable absorption properties and efficient charge transfer. Furthermore, the impact of PVDF-HFP polymer gel electrolytes with varying molecular weights on cell stability was explored. The QsDSSC incorporating the PVH80 polymer with the phenothiazine dye exhibited reduced dye desorption, due to the effective dye molecules’ immobilization by the gel matrix, and consequently enhanced long-term stability over 600 h. This comparative study sheds light on the interplay between dye selection, the polymer gel’s properties, and QsDSSCs’ performance. These insights are crucial in designing robust and efficient QsDSSCs for practical applications.

Multifunctional composite electrolytes for mechanically-robust and high energy density carbon fiber structural batteries

Mechanically robust electrolytes with high ionic conductivity play an essential role in carbon fiber (CF) structural batteries that simultaneously store energy and bear mechanical loads. However, multifunctional composite electrolytes are rarely developed, especially for air-stable and safe structural Zn-ion batteries. Herein, a composite electrolyte GF-SPE is designed and fabricated by integrating ionic conductive poly(ethylene glycol) diacrylate (PEGDA)-based solid-state polymer electrolyte (SPE) matrix and glass fiber fabric (GF) reinforcement, which simultaneously exhibits mechanical robustness and high ionic conductivity, facilitating homogeneous Zn electrodeposition without obvious side reaction, such as dendrite growth, corrosion et al. Therefore, the symmetric cells Zn//GF-SPE//Zn cell can cycle stably for more than 800 h at 1 mA cm−2. The carbon fiber structural battery fabricated with composite structural electrolyte GF-SPE delivers a high energy density of 19.35 Wh kg−1 based on the total mass of the whole device and cycling stability over 1,000 cycles in extreme environments. Furthermore, the high capacity of structural Zn-ions batteries can be maintained when they withstand flexural stress of over 120 MPa. The in-situ mechanical-electrochemical testing further confirms the priority of structural Zn-ion batteries.

Towards Safer Li-Ion Batteries: A Study on Electrolyte Solvation and Dynamics with the Incorporation of Low Volatility Co-Solvents

Molecular dynamics (MD) simulations were employed to investigate how the content and type of co-solvents influence the solvation structure and transport properties of lithium ions (Li+) in electrolytes. Our focus was on lithium hexafluorophosphate (LiPF6) at a concentration of 1.0 M in a carbonate-based solvent composed of ethylene carbonate (EC) and dimethyl carbonate (DMC) with a 1:1 mixing ratio. Low-volatility co-solvents, including tetramethylene sulfone (TMS), dimethyl sulfoxide (DMSO), fluoroethylene carbonate (FEC), and succinonitrile (SN), were introduced into the electrolytic matrix at concentrations of 0, 10, 25, 50, 75, and 100 wt.%. Li+ dynamics were notably influenced by these factors. The highest Li+ transference number was observed at a 25 wt.% concentration for each co-solvent, particularly with 25 wt.% DMSO, resulting in the highest ionic conductivity (14.13 mS/cm) and Li+ transference number (0.47). In this system, the PF6 - anion refrains from joining the initial solvation shell of Li+. This is attributed to the higher donor number of DMSO compared to TMS, FEC, and SN, leading to a weakening of electrostatic interactions. These findings advance our comprehension of electrochemical principles in bulk electrolytes, providing insights for designing safer and more efficient lithium-ion batteries.

Microstructure-Aware Mesoscale Modeling of Chemomechanical Stress Evolution during Cycling in Solid Electrolyte-Cathode Composite

The volume change of cathode active materials during charge-discharge cycling is responsible for the capacity fading of all-solid-state Li batteries due to mechanical degradation in the cathode such as delamination and crack formation. Many strategies to alleviate the chemomechanical stress buildup have been proposed in experiments but rationale of the stress release mechanisms at the mesoscale remain elusive. In this presentation, we present a microstructure-aware mesoscale model to quantitatively predict the stress distribution during cycling in a secondary particle agglomerate of the cathode active material embedded within a solid electrolyte matrix, taking the LiCoO2-Li7La3Zr2O12 (LCO-LLZO) as a model system. We find that the mechanical stress hotspots develop at different stages within the grain boundaries of the LCO agglomerate and the LCO-LLZO interfaces. We investigate the influences of microstructural morphology (columnar versus equiaxial), grain orientations (textured versus random), mechanical properties at the grain boundaries and heterogeneous interfaces, and anisotropy of chemical expansion on the stress hotspot evolution and provide optimal mitigation strategies. The theoretical results can help gain mechanistic understanding on cathode degradation and inform guidelines for experimental design of mechanically optimized cathode materials for long-life solid-state batteries.This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 and 22-ERD-043.

Unveiling the Reactivity and the Li‐Ion Exchange at the PEO‐Li6PS5Cl Interphase: Insights from Solid‐State NMR

Li6PS5Cl (LPSCl) argyrodites offer high room temperature ionic conductivity (>1 mS cm−1) and are among the most promising solid electrolytes. However, their chemical instability against Li metal compromises the long‐term cyclability. Using PEO‐LiTFSI as an interlayer or as a matrix for composite electrolytes is a promising strategy to address this issue. Nevertheless, the interphase of PEO‐LiTFSI and LPSCl requires further detailed investigations. This work explores the interfacial reactions between these phases using solid‐state nuclear magnetic resonance. Results show that PEO facilitates the formation of a complex with LiCl and Li3PS4 from LPSCl, resulting in an interphase material with limited local mobility, thus impeding ion transport. Although the addition of Br as a dopant can improve the ionic conductivity of LPSCl by inducing disorder and generating the Li vacancies, it makes the LPSCl more susceptible to PEO and increases the extent of the interfacial reaction. 6Li–6Li EXSY experiments demonstrate spontaneous Li‐ion exchange between the PEO and the LPSCl, yet this exchange is significantly hindered by reaction products within the PEO‐LPSCl interphase, attributable to their sluggish local dynamics. This study sheds light on the complex interfacial interaction between PEO‐LiTFSI and sulfide argyrodite, providing insights into designing solid electrolytes for the new generation of electrochemical devices.

High-Stability Composite Solid Polymer Electrolyte Composed of PAEPU/PP Nonwoven Fabric for Lithium-Ion Batteries.

Solid polymer electrolytes have attracted considerable attention, owing to their flexibility and safety. At present, poly(ethylene oxide) is the most widely studied polymer electrolyte matrix. It exhibits higher safety than the polyolefin diaphragm used in traditional lithium-ion batteries. However, it readily crystallizes at room temperature, resulting in low ionic conductivity, and the preparation process involves organic solvents. In this study, from the perspective of molecular design, solvent-free polyaspartate polyurea (PAEPU) and the cheap and easily available polypropylene (PP) nonwoven fabric were used as support materials for the PAEPU/PP composite solid polymer electrolyte (PAEPU/PP m -CPE). This CPE has good thermal stability, dimensional stability, flexibility, and mechanical properties. Among the different CPEs that were analyzed, PAEPU/PP10-CPE@20 had the highest ionic conductivity, which was reinforced with 10 g/m2 PP nonwoven fabric and the content of lithium salt was 20 wt %. Furthermore, PAEPU/PP10-CPE@20 exhibited the highest electrochemical stability with an electrochemical window value of 5.53 V. Moreover, the capacity retention rate of the Li//PAEPU/PP10-CPE@20//LiFePO4 half-cell was 96.82% after 150 cycles at 0.05 C and 60 °C, and the capacity recovery rate in the rate test reached 98.81%.

Quasi-Solid-State Na-O2 Battery with Composite Polymer Electrolyte.

Na-O2 batteries have emerged as promising candidates due to their high theoretical energy density (1,601 Wh kg-1), the potential for high energy storage efficiency, and the abundance of sodium in the earth's crust. Considering the safety issue, quasi-solid-state composite polymer electrolytes are among the promising solid-state electrolyte candidates. Their higher mechanical toughness provides superior resistance to dendritic penetration compared with traditional liquid electrolytes. The flexibility of the composite polymer electrolyte matrix allows it to conform to various battery configurations and considerably reduces safety concerns related to the combustion risks associated with conventional liquid electrolytes. In this study, we employed poly(ethylene oxide) (PEO) and sodium bis(trifluoromethanesulfonyl)imide (NaTFSI) as the polymer matrix and sodium ion-conducting agent, respectively. We incorporated nanosized NZSP (25 wt %) to create the composite polymer electrolyte membrane. This CPE design facilitates ion conduction pathways through both sodium salt and NZSP. By utilizing a liquid electrolyte infiltration method, we successfully enhanced its ionic conductivity, achieving an ionic conductivity of 10-4 S cm-1 at room temperature.

Effect of Fluorine Segments in Fluoropolymer matrix on the Properties of Gel Polymer Electrolytes

Polymer quasi‐solid electrolytes have been paid widely attention in account of their outstanding advantages in safety, flexibility, viscoelasticity and film formation. Fluoropolymer is used as matrix of gel electrolytes not only has high electrochemical stability, but also facilitates the dissociation of lithium salts owning to the strong electron‐absorbing C‐F groups, which makes it a very promising choice for the further development of gel electrolytes. Due to the different sites of C‐F bonds, their activity is also diverse, which results in the difference of the mobility of lithium ions and the LiF composition of SEI film on the surface of lithium metal anode. As a result, distinct fluorine‐containing gel polymer electrolytes are prepared by in‐situ polymerization of two different monomers, HFMA and TFMA. Compared with ‐CF3 on terminal group in TFMA, the gel electrolyte polymerized with HFMA whose C‐F group with stronger electronegativity is at the intermediate carbon site, as polymer matrix has better performance. The ionic conductivity achieves 7.02×10−3 S cm−1 at room temperature, and the assembled batteries have a capacity retention rate of 91% after 200 cycles of 1 C. Our research has laid a solid theoretical foundation for the further development of quasi‐solid electrolyte.

Boosting lithium-ion conductivity of polymer electrolyte by selective introduction of covalent organic frameworks for safe lithium metal batteries

The demand for high-energy-density batteries has prompted exploration into advanced materials for enhancing the safety and performance of lithium metal batteries (LMBs). This study introduces a novel approach, incorporating two-dimensional (2D) pyrazine and imine-linked covalent organic frameworks (COFs) into a polyethylene oxide (PEO)-based solid electrolyte matrix. The synthesized COFs act as multifunctional additives, improving mechanical strength, ionic conductivity (reaching 1.86 ×10−3 S/cm at room temperature), electrochemical window (oxidation resistance up to 5 V vs. Li/Li+), and thermal stability (up to 400 °C). The unique electron-rich and polar functionalities of pyrazine and imine linkages facilitate strong interactions with lithium ions (Li+), resulting in a flexible composite solid electrolyte that mitigates dendrite formation and interface instability. Electrochemical performance of LMBs with LiNi0.8Mn0.1Co0.1O2 (NMC811) cathode further confirm the enhanced Li+ conductivity, prolonged cycling stability, and a stable solid electrolyte interface, showcasing the potential of COFs in improving LMB performance. Overall, this study highlights the promising role of pyrazine and imine-linked COFs as effective additives for polymer-based solid electrolytes and their potential for developing safer and more efficient LMBs in the future.

Vitrified Metal-Organic Framework Composite Electrolyte Enabling Dendrite-Free and Long-Lifespan Solid-State Lithium Metal Batteries.

Solid-state lithium metal batteries (LMBs) are still plagued with low ionic conductivity and inferior interfacial contact, which hinder their practical implementation. Herein, a quasi-solid-state composite electrolyte, poly(1,3-dioxolane) (PDOL)/glassy ZIF-62 (PGZ) with fast ion transport and intimate interface contact, is fabricated via in situ polymerization. The in situ polymerization of DOL in an electrolyte matrix not only improves the exterior interface between electrolyte/electrode but also optimizes the inner interfaces among glassy particles, rendering PGZ as an uninterrupted ionic conductor. Moreover, PGZ inherits the superior ionic conductivity and the robust dendrite prohibition of glassy MOFs originating from their grain-boundary-free nature, isotropy, and abundant groups containing N species. As expected, our proposed PGZ exhibits a prominent ionic conductivity of 6.3 × 10-4 S cm-1 at 20 °C. Li|PGZ|LiFePO4 delivers an outstanding rate performance (103 mAh g-1 at 4C) and a stable cycling capacity (118 mAh g-1 at 1C over 1000 cycles). PGZ also presents excellent low-temperature cycling performance with 75 mAh g-1 for 480 cycles at -20 °C and excellent flame retardance. Even at a high loading of 12.1 mg cm-2, it can still discharge at 140 mAh g-1 for 100 cycles. Hence, PGZ prepared via in situ polymerization holds enormous prospects as a solid-state electrolyte for high-performance and safe LMBs.

Entanglement Added to Cross-Linked Chains Enables Tough Gelatin-Based Hydrogel for Zn Metal Batteries.

Currently, it is still challenging to develop a hydrogel electrolyte matrix that can successfully achieve a harmonious combination of mechanical strength, ionic conductivity, and interfacial adaptability. Herein, a multi-networked hydrogel electrolyte with a high entanglement effect based on gelatin/oxidized dextran/methacrylic anhydride, denoted as ODGelMA is constructed. Attribute to the Schiff base network formulation of ─RC═N─, oxidized dextran integrated gelatin chains induce a dense hydrophilic conformation group. Furthermore, addition of methacrylic anhydride through a grafting process, the entangled hydrogel achieves impressive mechanical features (6.8MPa tensile strength) and high ionic conductivity (3.68mScm-1 at 20°C). The ODGelMA electrolyte regulates the zinc electrode by circumventing dendrite growth, and showcases an adaptable framework reservoir to accelerate the Zn2+ desolvation process. Benefiting from the entanglement effect, the Zn anode achieves an outstanding average Coulombic efficiency (CE) of 99.8% over 500 cycles and cycling stability of 900h at 5mAcm-2 and 2.5mAhcm-2. The Zn||I2 full cell yields an ultra-long cycling stability of 10000 cycles with a capacity retention of 92.4% at 5C. Furthermore, a 60mAh single-layer pouch cell maintains a stable work of 350 cycles.

A-LLTO Nanoparticles Embedded Composite Solid Polymer Electrolyte for Room Temperature Operational Li-metal Batteries.

Solid-state batteries (SSBs) have the potential to revolutionize the current energy storage sector. A significant portion of the current development of electric vehicles and the electrification of various appliances relies on Lithium (Li)-ion batteries. However, future energy demands will require the development of stronger and more reliable batteries. This report presents a novel solid state electrolyte (SSE) composed of a self-healing composite solid polymer electrolyte (CSPE) matrix and aluminum-doped (Li0.33La0.56)1.005Ti0.99Al0.01O3 (A-LLTO) nanofillers. The CSPE contains Jeffamine ED-2003 monomer, Benzene-1,3,5-tricarbaldehyde (BTC)crosslinker dissolved in a 1:1 ratio of Dimethylformamide (DMF) to LiPF6, and a certain amount (x) of A-LLTO nanofillers (x=5, 7.5, 10, 12.5%). A CSPE containing x-amount of A-LLTO fillers (referred to as CAL-x%) demonstrates excellent ion-conducting properties and stable battery performance. The CAL-10% demonstrates 1.1×10-3Scm-1 of ionic conductivity at room temperature (RT). A-LLTO nanofillers dispersed uniformly within the polymer matrix form a percolation network, which is believed to improve ionic conductivity and the diffusion of Li+ ions. The CR-2032 cell, consisting of LiFePO4 (LFP)║CAL-10%║Li, at RT offers an initial discharge capacity of ≈165mAhg-1 at 0.1C rate for 120 cycles with 98.85% coulombic efficiency (C.E.).

Dynamic Covalent Amphiphilic Polymer Conetworks Based on End-Linked Pluronic F108: Preparation, Characterization, and Evaluation as Matrices for Gel Polymer Electrolytes.

We present the development of a platform of well-defined, dynamic covalent amphiphilic polymer conetworks (APCN) based on an α,ω-dibenzaldehyde end-functionalized linear amphiphilic poly(ethylene glycol)-b-poly(propylene glycol)-b-poly(ethylene glycol) (PEG-b-PPG-b-PEG, Pluronic) copolymer end-linked with a triacylhydrazide oligo(ethylene glycol) triarmed star cross-linker. The developed APCNs were characterized in terms of their rheological (increase in the storage modulus by a factor of 2 with increase in temperature from 10 to 50 °C), self-healing, self-assembling, and mechanical properties and evaluated as a matrix for gel polymer electrolytes (GPEs) in both the stretched and unstretched states. Our results show that water-loaded APCNs almost completely self-mend, self-organize at room temperature into a body-centered cubic structure with long-range order exhibiting an aggregation number of around 80, and display an exceptional room temperature stretchability of ∼2400%. Furthermore, ionic liquid-loaded APCNs could serve as gel polymer electrolytes (GPEs), displaying a substantial ion conductivity in the unstretched state, which was gradually reduced upon elongation up to a strain of 4, above which it gradually increased. Finally, it was found that recycled (dissolved and re-formed) ionic liquid-loaded APCNs could be reused as GPEs preserving 50-70% of their original ion conductivity.