Composite Gel Research Articles

The intermolecular interaction enables ordered ion transport in quasi-solid-state electrolyte for ultra-long life lithium-metal battery

Composite gel polymer electrolytes (CGPEs) have received wide attention due to their great potential to improve the safety and cycling stability of lithium (Li) metal batteries. However, the poor interface compatibility between the filler and polymer in CGPEs severely hinders lithium-ion (Li+) pathways and limits cell performance. Herein, we propose an Al(EtO)3 nanowires framework that can trigger poly (ethylene glycol) diglycidyl ether (PEGDE) to undergo ring opening polymerization, thus inducing polymer tight combination on the surface of Al(EtO)3 nanowires framework and dividing the polymer matrix into mesh units, contributing to ordered Li+ transport and dendrite-free deposition on the metallic anode. Such a CGPE with highly conductive and interface compatibility facilitates a high-performance quasi-solid-state Li||Li cell with an excellent long-term cycling stability for over 3000 h without a short circuit and registers a high capacity of 146.9 mAh g−1 after 46 cycles at a mass loading of 6 mg cm−2. Solid-state nuclear magnetic technology clearly clarifies the transport path of lithium ions in Al(EtO)3-based gel polymer electrolyte (AGPE). The results open up a new way to improve the electrochemical performances of composite electrolyte and promote its commercial application process.

Dual enhancement effects of different yeast extract on gel properties and saltiness perception of low-salt surimi gel from silver carp

This study investigated the dual enhancement effect of five yeast extracts (YE) on gel properties and saltiness perception of low-salt (1% NaCl) surimi gels. The addition of YE not only pronouncedly enhanced the gel strength, texture properties (hardness, cohesiveness and chewiness) and elasticity of low-salt surimi gel (P < 0.05), but also increased the gelation rate of surimi during kamaboko stage. When YE was added, the water holding capacity of surimi gels increased, accompanied by decreased water fluidity, and composite gels exhibited a relatively dense and ordered microstructure. Electronic tongue analysis indicated that YE addition enhanced umami and saltiness, and decreased the sour and bitterness characteristic values (P < 0.05). Besides, sensory evaluation showed that YE increased the texture, saltiness, umami and smell score of low-salt surimi gel (P < 0.05), and the saltiness perception of low-salt surimi gel added with YE1 and YE2 was similar to normal-salt surimi gel (2% NaCl), which was consistent with the result of electronic tongue. The correlation analysis result revealed that the enhancement of gel properties of surimi may be attributed to the charged amino acids (Arg, Lys, His, Glu and Asp) in YE, and the umami substances (Glu, Asp, IMP and GMP) in YE could not only improve the umami taste, but also enhance the saltiness perception of low-salt surimi gel. Overall, YE had the dual effect of remarkably improving the gel properties and enhancing saltiness perception of low-salt surimi gel, providing a salt reduction effect, with YE2 being the best.

IMMOBILIZATION AND STUDY OF TRYPSIN ON MAGNETITE-Fe3O4 NANOPARTICLE-BASED NATURAL AND SYNTHETIC POLYMER HYDROGELS

The presented article designs hydrogel structures with magnetite nanoparticles in the composition, involving various synthetic and natural polymers. The synthesis of magnetite nanoparticles in the hydrogel composition was accomplished through the co-precipitation method, and the immobilization of protein using trypsin as a model drug was investigated. The incorporated of micro-quantities of magnetite Fe3O4 nanoparticles into the gel matrix enhances the affinity for the enzyme, resulting in a significant improvement in specific activity and stability compared to gels without magnetite Fe3O4 nanoparticles. In other words, increasing the degree of immobilization of magnetite Fe3O4 nanoparticles enhances both the immobilization degree and the biological activity of the enzyme. This phenomenon manifests as a continuous interaction between the gel composition and the magnetite nanoparticles of the enzyme

Controlling the Potential of Affordable Quasi‐Solid Composite Gel Polymer Electrolytes for High‐Voltage Lithium‐Ion Batteries

AbstractThis study focuses on the development of a composite gel polymer electrolyte membrane (CGPEM) as a solution to address safety concerns arising from the reactivity of lithium metal and the formation of dendrites. The CGPEM integrates a solid polymer matrix, solid‐electrolyte LSiPS (Li10SiP2S12), with a plasticizer that countering the performance decline caused by sulfide solid electrolyte (SSE) interactions with the cathode. Poly ethylene oxide (PEO) emerges as a promising polymer matrix due to its flexibility, cost‐effectiveness, eco‐friendliness, solvability for Li‐salt, mechanical processing adaptability, adhesive strength, and ionic conductivity. Conductivity and processability of CGPEM were optimized through meticulous adjustment of liquid plasticizer concentration. The CGPEM′s chemical and electrochemical stability were systematically investigated using in‐situ electrochemical impedance spectroscopy (EIS) and distribution of relaxation times (DRTs). A lithium metal battery is constructed against a high voltage cathode and newly developed CGPEM. Impressively, the cell exhibited outstanding performance, maintaining a discharge capacity of around 146.22 mAh/g after 200 cycles, retaining 86.38 % of its initial capacity. The formation of a LiF‐rich interface layer near the lithium surface, a vital element in curbing CGPE degradation and dendritic growth, resulted in enhanced overall cell performance.

Preparation and properties of fiber-reinforced polybenzoxazine composite aerogels based on freeze drying and ambient pressure drying methods

Polybenzoxazine aerogels have gained much attention as a new type of polymeric aerogels in the field of flame resistant materials. Herein, a unique method for the preparation of fiber-reinforced PBa composite aerogels has been reported using polyvinyl alcohol (PVA) and carboxymethyl cellulose (CMC) as dispersion carriers through freeze-drying for surface modified basalt fibers (Z@BF). Bisphenol-A type benzoxazine (Ba) monomer was used as the matrix, which infiltrated into the carrier for dispersed fibers to obtain a PBa composite gel by sol-gel method. Solvent exchange and ambient drying techniques were used to obtain the final composite aerogel samples. Z@BF formed a double-network structure with the aerogel matrix, which resulted in 55.43% increase in compressive strength, a low volumetric shrinkage (27.46%), and density (0.19–0.21 g cm3) of the prepared aerogel. The addition of Z@BF increased the residual carbon content (59.6% at 800 °C) in the aerogel, while reducing the total heat release rate by 36.9% and the peak heat release rate by 60.61%. Besides, the aerogels possessed excellent self-extinguishing property, and the self-extinguishing time was only 1.31 s after flame burning at 1200 ℃ for 10 s. The composite aerogels obtained by this combination of atmospheric pressure drying and freeze-drying techniques not only possessed high mechanical strength and excellent flame retardant properties, but also provided a new idea for the preparation of fiber-reinforced PBa aerogels. This would further expand the potential use of PBa aerogels in flame retardant materials.

Fully Printable and Reconfigurable Hufu-type Electroluminescent Devices for Visualized Encryption.

Hufu, serving as evidence of imperial authorization in ancient China, comprises two parts in the form of tiger-shaped tallies that only become effective when matched. Drawing inspiration from the concept of Hufu, a reconfigurable electroluminescent (EL) device is designed by separating conventional integral devices into two parts that contain the EL layer (part A) and the transparent electrode (part B), respectively. The key to realizing such strategy is employing an adhesive and stretchable polymer gel composite as the transparent electrodes for the EL devices. The polymer gel composite facilitates robust yet reversible contact between the EL layer and transparent electrode, enabling high-performance and stretchable EL devices that can be readily disassembled and reassembled: the EL devices can maintain ≈81% of their initial luminance after 1000 times of repeated disassembly and reassembly. Moreover, the precursor ink of the polymer gel composite is compatible with a wide variety of coating and printing technologies, such as spin-coating, inkjet printing, dispensing, and brush painting. Importantly, the reconfigurable feature of the devices opens up a new path to encryption display systems, and as a proof-of-concept, EL encrypted password, and content-changeable digital clock are demonstrated.

Role of pectin in the delivery of β-carotene embedded in interpenetrating emulsion-filled gels made with soy protein isolate

This study investigated the effects of different matrices on gel properties, lipid digestibility, β-carotene bioaccessibility, released free amino acids and gel network degradation. Microstructure studies have proven that sugar beet pectin/soy protein isolate-based emulsion-filled gel (SBP/SPI-E) with interpenetrating networks was formed. SBP/SPI-E exhibited higher hardness (2.67 N, p < 0.05) and released lesser free amino acids (269.48-μmol/g SPI) than soy protein isolate-based emulsion-filled gel (SPI-E) in simulated intestinal fluid (SIF); however, both had similar free amino acids contents in simulated colonic fluid. SBP has the potential to delay gel network degradation in SIF, as evidenced by the sugar stain strips of SDS-PAGE and microstructure observation. Furthermore, SBP/SPI-E and SPI-E exhibited similar β-carotene bioaccessibility in SIF, suggesting that SBP from composite gel could not affect the aforementioned bioaccessibility. The study provides useful information for the design of functional gels in the application of fat-soluble nutrient delivery.

A composite gel polymer electrolyte by incorporating modified POSS endowing inorganic-rich SEI formation and stable cycle life for lithium metal batteries

Low density and high theoretical capacity lithium metal anode is an ideal material to replace graphite anode. However, key issues such as the instability of the solid electrolyte intermediate phase (SEI), the degradation of the liquid electrolyte, and the growth of dendrites still hinder its practical application. Here, a composite gel polymer electrolyte with a well Li+ solvated structure was prepared by incorporating PEG-modified POSS. The introduction of modified POSS not only enhanced the structural strength of GPE, but also induced the formation of Li+ solvated sheath structures that dominated by SSIPs/CIPs and AGGs. The well solvated structure of Li+ is beneficial for the generation of stable LiF-rich SEIs to resist the lithium dendrites, improving the anti-oxidation ability of GPE and the cycling performance of the LMBs. Benefiting from the uniform and stable SEIs, the capacity retention rate of the composite GPE-based LiFePO4 full cell can be high up to 95.7 % after 300 cycles at 0.2C and 87.9 % after 400 cycles at 0.5C. This work provides valuable ideas for the study of organic–inorganic composite gel electrolytes.

Eutectogels as a Semisolid Electrolyte for Organic Electrochemical Transistors.

Organic electrochemical transistors (OECTs) are signal transducers offering high amplification, which makes them particularly advantageous for detecting weak biological signals. While OECTs typically operate with aqueous electrolytes, those employing solid-like gels as the dielectric layer can be excellent candidates for constructing wearable electrophysiology probes. Despite their potential, the impact of the gel electrolyte type and composition on the operation of the OECT and the associated device design considerations for optimal performance with a chosen electrolyte have remained ambiguous. In this work, we investigate the influence of three types of gel electrolytes-hydrogels, eutectogels, and iongels, each with varying compositions on the performance of OECTs. Our findings highlight the superiority of the eutectogel electrolyte, which comprises poly(glycerol 1,3-diglycerolate diacrylate) as the polymer matrix and choline chloride in combination with 1,3-propanediol deep eutectic solvent as the ionic component. This eutectogel electrolyte outperforms hydrogel and iongel counterparts of equivalent dimensions, yielding the most favorable transient and steady-state performance for both p-type depletion and p-type/n-type enhancement mode transistors gated with silver/silver chloride (Ag/AgCl). Furthermore, the eutectogel-integrated enhancement mode OECTs exhibit exceptional operational stability, reflected in the absence of signal-to-noise ratio (SNR) variation in the simulated electrocardiogram (ECG) recordings conducted continuously over a period of 5 h, as well as daily measurements spanning 30 days. Eutectogel-based OECTs also exhibit higher ECG signal amplitudes and SNR than their counterparts, utilizing the commercially available hydrogel, which is the most common electrolyte for cutaneous electrodes. These findings underscore the potential of eutectogels as a semisolid electrolyte for OECTs, particularly in applications demanding robust and prolonged physiological signal monitoring.

PVDF-HFP/BP nanosheets composite gel electrolyte with high ionic conductivity for lithium batteries

In this work, polyvinylidene fluoride-co-hexafluropropylene (PVDF-HFP) /phosphorene (BP) nanosheets composite gel electrolytes with high ionic conductivity are prepared by macrophase separation method to address the problems of low ionic conductivity of pure PVDF electrolyte. The ionic conductivity of the gel electrolyte reaches 1.34 × 10−3 S/cm at room temperature when the BP content is 0.3 wt%, and the electrochemical window was stable up to 6.0 V. The discharge capacity of the anode at 0.1 C for the first cycle of Li//PVDF-HFP/BP//LiFePO4 battery raises to 142 mA h/g, reaching 83.5% of the theoretical capacity, and retains 94.9% of capacity and 97.8% of charge/discharge efficiency after 100 cycles at 0.2 C. The microscopic morphology shows that the lithium deposition is transformed from dendrites to spheres, which greatly improves the stability of the SEI film. And the DFT calculations indicate that the binding energy of Li+ to the BP surface is − 0.811 eV, and the diffusion potential barrier is only 0.380 eV when Li+ migrates along the (100) crystal plane of BP nanosheets.

Functionally responsive hydrogels with salt-alkali sensitivity effectively target soil amelioration

The long-standing crisis of soil salinization and alkalization poses a significant challenge to global agricultural development. High soil salinity-alkalinity, water dispersion, and nutrient loss present major hurdles to soil improvement. Novel environmentally friendly gels have demonstrated excellent water retention and slow-release capabilities in agricultural enhancement. However, their application for improving saline-alkali soil is both scarce and competitive. This study proposes a new strategy for regulating saline-alkali soil using gel-coated controlled-release soil modifiers (CWR-SRMs), where radical-polymerized gels are embedded on the surface of composite gel beads through spray coating. Characterization and performance analysis reveal that the three-dimensional spatial network structure rich in hydrophilic groups exhibits good thermal stability (first-stage weight loss temperature of 257.7 °C in thermogravimetric analysis) and encapsulation efficiency for fulvic acid‑potassium (FA-K), which can enhance soil quality in saline-alkali environments. The molecular chain relaxation under saline-alkali conditions promotes a synergistic effect of swelling and slow release, endowing it with qualifications as a water reservoir, Ca2+ source unit, and slow-release body. The results of a 6 weeks incubation experiment on 0–20 cm saline-alkaline soil with different application gradients showed that the gradient content had a significant effect on the soil improvement effect. Specifically, the T2 (the dosage accounted for 1 % of soil mass) treatment significantly increases water retention (30 % ~ 90 %), and nutrient levels (30 % ~ 50 %), while significantly decreasing soil sodium colloid content (30 % ~ 60 %) and soil pH (10 % ~ 15 %). Furthermore, PCA analysis indicates that the addition of 1 % CWR-SRMs as amendments can significantly adjust the negative aspects of soil salinity and alkalinity. This highlights the excellent applicability of CWR-SRMs in improving saline-alkali agricultural ecosystems, demonstrating the potential value of novel environmentally friendly gels as an alternative solution for soil challenges persistently affected by adverse salinity and alkalinity.

Structure and Stability of Composite Gels Based on Collagen and Carboxymethylcellulose

Structure and Stability of Composite Gels Based on Collagen and Carboxymethylcellulose

Quality, Thermo-Rheology, and Microstructure Characteristics of Cubic Fat Substituted Pork Patties with Composite Emulsion Gel Composed of Konjac Glucomannan and Soy Protein Isolate.

Composite emulsion gel can effectively mimic animal adipose tissue. In this study, composite emulsion gels composed of soy protein isolates and konjac glucomannan (KGM) were prepared as plant-based cubic fat substitutes (CFS). The effects of CFS on the quality and structure of pork patties were investigated in terms of the proximate composition, lipid oxidation stability, technological characteristics, color, sensory attributes, texture, thermo-rheological behavior, and microstructure. CFS samples composed of various ratios of KGM were added to lean meat patties to ascertain the optimal CFS composition for its potential replacement of pork back fat in patties. The addition of CFS containing 7.0% KGM was found to decrease the hardness of the lean meat patties by 71.98% while simultaneously improving their sensory quality. The replacement of pork back fat with CFS also reduced the fat content of the patties to as little as 3.65%. Furthermore, the addition of CFS enhanced the technological characteristics, lipid oxidation stability, and surface color of the fat-replaced patties, with no significant impact on their overall acceptability. The gel network of the patties was shown to be fine and remained compact as the fat replacement ratio increased to 75%, while the texture parameters, storage modulus, and fractal dimension all increased. Quality and structure improvements may allow the composite emulsion gels to replace fat in pork patties to support a healthy diet. This study may be beneficial for the application and development of plant-based cubic fat substitutes.

Light-responsive MXenegel via interfacial host-guest supramolecular bridging

Living in the global-changing era, intelligent and eco-friendly electronic components that can sense the environment and recycle or reprogram when needed are essential for sustainable development. Compared with solid-state electronics, composite hydrogels with multi-functionalities are promising candidates. By bridging the self-assembly of azobenzene-containing supramolecular complexes and MXene nanosheets, we fabricate a MXene-based composite gel, namely MXenegel, with reversible photo-modulated phase behavior. The MXenegel can undergo reversible liquefication and solidification under UV and visible light irradiations, respectively, while maintaining its conductive nature unchanged, which can be integrated into traditional solid-state circuits. The strategy presented in this work provides an example of light-responsive conducting material via supramolecular bridging and demonstrates an exciting platform for functional soft electronics.

Repair of hydrogel wearable devices through topological adhesion and cross-shaped sectional enhancement strategy

Hydrogels, recognized for their biocompatibility, are extensively employed in the realm of wearable devices. Nevertheless, their application is often constrained by their low mechanical robustness, rendering them susceptible to damage during operation. The restoration of their load-bearing and sensory functionalities post-damage represents a captivating yet underexplored domain. Conventional repair techniques, reliant on hydrogen bonding or van der Waals forces, falter in the face of hydrogels’ high water content. In this study, a novel composite adhesive gel (SGG), integrating sodium alginate, guar gum, and graphene oxide, was engineered to mend impaired hydrogels. Furthermore, an optimized repair approach, utilizing a cross-shaped sectional (CSS) enhancement strategy, was devised to reinstate the hydrogels' load and sensory capabilities. Investigations revealed that the SGG adhesive infiltrated the hydrogel, establishing an intermediary gel stratum, subsequently solidifying to mend the material through topological adhesion. This process reestablished the continuity of the polymer network and the aqueous phase within the hydrogel. Following the application of the CSS augmentation method, the peak tensile strain of the remediated hydrogel exceeded 200 %, with the uppermost observable adhesive energy touching 2526 J/m2. In addition, the ability to respond to strain was significantly rejuvenated, suggesting an effective methodology for the rehabilitation of wearable technology.

Effect of polysaccharide concentration on heat-induced Tremella fuciformis polysaccharide-soy protein isolation gels: Gel properties and interactions

The formation of a single soybean protein isolate (SPI) gel is limited by the processing conditions, and has the disadvantages of poor gel property, and it is usually necessary to add other biomacromolecules to improve its property. In this study, we investigated the effects of polysaccharide concentration on gel properties and interaction mechanisms of Tremella fuciformis polysaccharide (TFP)-SPI complexes. It was found that (1) the rheological properties, texture properties, water-holding properties, and thermal stability of TFP-SPI composite gels were improved with the addition of TFP (0.25–2.0 %, w/v) in a concentration-dependent manner; (2) hydrogen bond, the electrostatic interaction, hydrophobic interaction, and disulfide bond in the gel system increased with the increase of TFP concentration; (3) the electrostatic and hydrophobic interactions played an important role in the formation of the TFP-SPI composite gel while hydrogen bond formation was the least contributor to the binary composite gel network. Overall, TFP is not only a critical health food but also a promising structural component for improving the gel properties of SPI.

Fluorescent MOF and Its Gel Composite for the Fluorescence Recovery "Turn-On" Detection of Al3+ Ions and "Turn-Off" Detection of Oxo-Anions.

The exploration of smart sensors is of great significance for the selectivity, sensitivity, and ability to show the low detection limit for the target analyte. Here, we have used the linker H2L (5-((anthracen-9-ylmethyl)amino)isophthalic acid) for the construction of {[Cd(L)(DMF)(H2O)2]·H2O}n (1) which is in order with the chromophore anthracene moiety and the free -NH functionality as a guest interaction site. This framework showed the luminescence recovery "turn-on" detection of the Al3+ ion in an aqueous solution. An exhaustive mechanism study disclosed that the Lewis acid-base-type interaction between the Al3+ ion and the -NH functionality of the linker in the framework revealed that the absorbance caused an enhancement for the "turn-on" sensing event. Besides the "turn-on" sensing event, the "turn-off" sensing phenomenon of 1 is also noticed when it detects the hazardous oxo-anions (MnO4- and CrO42-) with limit of detection values of 17.08 and 19.91 ppb, respectively. The detection of these diverse analytes are very fast (10 s) and they can also be recognized through a colorimetric response. The sensing mechanisms for these analytes are established by photoinduced electron transfer, Forster resonance energy transfer, and inert filter effect along with theoretical investigation. Furthermore, to show the sensing application of 1 in a versatile podium, a MOF gel composite, 1@AA (AA = Agar-Agar), was developed from 1 with AA. Interestingly, 1@AA showed the colorimetric detection of these analytes under UV light. Therefore, sensor 1 behaves as a smart sensory material for the recognition of the above analytes through a simultaneous "turn-on" and "turn-off" effect.

Polysaccharide from Clitocybe squamulosa: Gel-forming properties and its compound effect with food thickener

To study the gel-forming properties of polysaccharide from the fruiting body of Clitocybe squamulosa (CSFP) and its degradation product (UH-CSFP), the changes in steady-state and dynamic rheological properties of CSFP and UH-CSFP under different conditions (polysaccharide mass fraction, temperature, pH, and salt ion concentration) were studied. Polysaccharides with good gel-forming properties were selected and mixed with common edible thickeners (gelatin, guar gum, and locust bean gum), after which the properties of the composite gel were assessed. The steady-state rheological results showed that CSFP and UH-CSFP were pseudoplastic fluids, their apparent viscosity decreased with increasing temperature, the viscosity was greatest when the pH was 7. The addition of Na+ and Ca2+ could increase the viscosity, and the viscosity of UH-CSFP was lower than that of CSFP at the same mass fraction. The results of dynamic rheology indicated that G´ and G´´ of CSFP and UH-CSFP increased with increasing mass fraction, pH, and ion concentration (0.01 M to 1 M), and G´´ was always smaller than G´ indicating weak gel behavior. The thixotropy-related experimental results showed that the thixotropy ring area of CSFP and UH-CSFP increased with increasing mass fraction, the ring area of CSFP was larger than that of UH-CSFP, and the gel strength of CSFP was greater than that of UH-CSFP. The results of CSFP and three types of edible gels showed that the composite gels were pseudoplastic fluids, and their apparent viscosity was ranked (in descending order) as follows: guar bean gum, locust bean gum, and gelatin. The addition of CSFP improved the gel-forming properties of guar gum but did not significantly improve the gel properties of locust bean gum and gelatin. This study provides a theoretical basis for the selection of processing methods and the application of polysaccharides.

The effect of agar on rheological properties and thermal stability of rennet-induced casein micelle gel

Effects of agar on the rheological property and heat stability of casein micelle gels induced by rennet were investigated. The interactions between casein micelle and agar were investigated. Electrostatic interactions between casein micelle and agar were not observed. The movement of agar characteristic bonds indicated the hydrogen bond interaction existed in the casein micelle/agar mixture. The addition of agar promoted the casein micelles aggregation and decreased the rennet coagulation time (RCT) and the storage modulus (G'). The strip-like network microstructure changed into a sheet-like network after the addition of agar. The composite gels were present as a bicontinuous phase structure. The agar and protein were both present as continuous phases. The addition of 0.5% agar increased the water holding capacity (WHC) from 63.30% to 92.44% and decreased the gel hardness from 73.41 g to 60.57 g. The protein digestion rate of gels increased after agar addition during gastric digestion. The WHC increased from 35.20% to 83.56% and the microstructure of gels improved by the addition of 0.5% agar after heating at 80 °C for 30 min. In conclusion, the WHC and thermal stability of the gels improved after the addition of agar.

A preliminary attempt at capacitive deionization with PVA/PSS gel coating as an alternative to ion exchange membrane

ABSTRACT PVA/PSS composite gel membrane electrode for membrane capacitive deionization (MCDI) was fabricated and characterised in the present study. The composite electrode with ion exchange surface is prepared by coating glutaraldehyde cross-linked polyvinyl alcohol (PVA) composite hydrogel, with Poly (Sodium 4-Styrenesulfonate) (PSS) added into the network, on the surface of activated carbon (AC) electrode. The feasibility of the gel membrane is analyzed by rheological, swelling rates and ion exchange capacity tests. Then electrochemical test and desalination test are used to study the performance of the MCDI electrode. The results show that coating of composite hydrogel layer improved the hydrophilicity, specific capacitance and lower interfacial electron transfer resistance of the electrode. Finally, we assemble the asymmetrical CDI cell with PVA/PSS composite gel electrode and AC electrode. Compared with the AC electrode, the salt adsorption capacity of PVA6-PSS15 can reach 18.9 mg g−1 and stable charge efficiency at 73.0% at operating voltage of 1.2 V. The decrease in specific capacitance of PVA6-PSS15 after 50 cycles is 1.33%, indicating that the electrode has a good cycling life. The gel membrane coated electrode prepared by PSS provides a new idea for the development of MCDI.