Ion Conducting Polymer Electrolyte Research Articles

Soft Matter Electrolytes: Mechanism of Ionic Conduction Compared to Liquid or Solid Electrolytes

Soft matter electrolytes could solve the safety problem of widely used liquid electrolytes in Li-ion batteries which are burnable upon heating. Simultaneously, they could solve the problem of poor contact between electrodes and solid electrolytes. However, the ionic conductivity of soft matter electrolytes is relatively low when mechanical properties are relatively good. In the present review, mechanisms of ionic conduction in soft matter electrolytes are discussed in order to achieve higher ionic conductivity with sufficient mechanical properties where soft matter electrolytes are defined as polymer electrolytes and polymeric or inorganic gel electrolytes. They could also be defined by Young’s modulus from about Pa to Pa. Many soft matter electrolytes exhibit VFT (Vogel–Fulcher–Tammann) type temperature dependence of ionic conductivity. VFT behavior is explained by the free volume model or the configurational entropy model, which is discussed in detail. Mostly, the amorphous phase of polymer is a better ionic conductor compared to the crystalline phase. There are, however, some experimental and theoretical reports that the crystalline phase is a better ionic conductor. Some methods to increase the ionic conductivity of polymer electrolytes are discussed, such as cavitation under tensile deformation and the microporous structure of polymer electrolytes, which could be explained by the conduction mechanism of soft matter electrolytes.

Free Volume Mediated Decoupling of Ionic Conduction from Segmental Relaxation Leading to Enhancement in Ionic Conductivity of Polymer Electrolytes at Low Temperatures.

Coupling between segmental relaxation and ionic conduction has limited the ionic conductivity of flexible polymers like poly(ethylene oxide), PEO, based electrolytes especially at low temperatures where segmental relaxation becomes extremely slow. In the present study, we show that ionic conduction becomes decoupled from segmental relaxation in PEO-based electrolytes simply by loading succinonitrile (SN). As a result of SN interactions induced rigid chain packing of PEO, the semicrystalline morphology of PEO is completely altered along with the enhancement in number density of free volumes having smaller size and narrower size distribution. These free volumes provide additional pathways for ionic diffusion independent of segmental relaxations of PEO leading to decoupling of ionic diffusion from the segmental relaxation process. The decoupling finally leads to nearly two orders higher ionic conductivity (∼10-11 Scm-1)at glass transition temperature (Tg ∼ 210 K), than what is expected in the case of complete coupling.

Impact of functional groups on lithium salt dispersion and mobility in polymer electrolytes

AbstractSolid Polymer electrolytes are versatile, highly processible and electrochemically compatible with solid electrode materials. The versatility of these materials is a result of the existence of many possible conductive polymer‐salt, polymer‐polymer and salt‐salt combinations. Despite the wide array of available lithium salts, most polymer electrolyte materials are made using lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) due to its long history of achieving relatively high ionic conductivities in polymer electrolyte systems with the most famous being poly(ethylene oxide) (PEO). It is however possible that better ionic conductivities can be achieved with different salts and/or in polymer matrices containing different functional groups. This is because ionic conductivity in polymer electrolytes is partially based on the ability of the polymer matrix to dissolve and bond to the salt. These interactions impact local‐scale ion mobility which can be measured via NMR spectroscopy using pulsed field gradient experiments. In this work, polymer electrolytes are prepared using PEO, hydrogenated nitrile butadiene rubber and poly(propylene) carbonate. Ion mobility, lithium conductivity and salt‐polymer interactions are investigated to compare interactions between LiTFSI and lithium cyano(trifluorosulfonyl)imide in polymers with common salt‐dissociating functional groups such as ethyl, nitrile and carbonate to determine the impact of these interactions on ionic conductivity.

Binary solvent-reinforced poly (vinyl alcohol)/sodium alginate double network hydrogel as a highly ion-conducting, resilient, and self-healing gel polymer electrolyte for flexible supercapacitors

We present a reliable approach for producing high-performance ion-conducting gel polymer electrolytes (GPEs) based on the sodium chloride (NaCl)-integrated dual network hydrogel of poly (vinyl alcohol)/sodium alginate (PVA/SA) using a binary solvent system of ethylene glycol (EG) and water, providing exceptional ionic conductivity, mechanical strength, and self-healing properties. Different GPEs were produced via the freezing-thawing method using different v/v% of EG and water (named PVA/SA/EG). The best PVA/SA/EG GPE provided a maximum ionic conductivity of 25 mS cm−1, astonishing mechanical strength of 0.42 MPa, exceptional stretchability of 462 %, and remarkable self-healing properties. The binary solvent system- and water-based GPEs were utilized in the construction of symmetric supercapacitors (SSCs) using carbon cloth electrodes and their electrochemical performance were compared. At a current density of 0.5 mA cm−2, the SSC prepared using the best PVA/SA/EG GPE demonstrated a high specific capacity of 577.21 mF cm−2, maintained 94.5 % capacitance after 5000 cycles at 1 mA cm−2, and provided an energy density of 80.14 mWh cm−2 while operating at a power density of 293.3 mW cm−2. The flexible SSC prepared based on this GPE demonstrated outstanding flexibility, while no significant decline in capacitive performance and ionic conductivity was detected when it was bent.

Multi-Scale Modeling and Simulation of All-Solid-State Sodium-Ion Batteries with Polymer-Ceramic Hybrid Electrolytes

Lithium-ion batteries (LIBs) have been widely considered as the most promising power source for mobile devices. However, LIBs cannot meet the increasing global demand for electrochemical energy storage in the foreseeable future. Sodium ion-batteries (SIBs) are based on more ecofriendly and earth-abandoned materials. Commonly researched SIBs are based on liquid electrolytes. They pose leakage and thermal runaway risks. Solid polymer electrolytes solve these problems but need to operate at temperatures between 60-80°C to compensate insufficient ionic conductivity of polymer electrolytes at ambient temperatures.We present a polymer-ceramic hybrid electrolyte which overcomes the necessity to operate at high temperatures. It combines the advantages of high ion-conducting solid ceramic particles and flexible polymers. Sodium metal serves as the anode and PEO with inorganic fillers is used as cathode electrolyte. Due to their sustainability and high efficiency —comparable to LIBs— sodium-ion batteries are a promising candidate for small scale stationary energy storage applications or mobile energy storage applications with less constrains regarding energy density (e.g. trains, ships, submarines etc.). This contribution highlights a modeling approach for simulations of a single battery cell to develop an optimal cell design of the aforementioned battery system. A newly developed multiscale modeling method for hybrid polymer-ceramic sodium ion batteries reflects the different length scales of the active particle level and the electrode level. We precisely describe the spatially resolved mass and charge transport as well as electrochemical reactions in the active particle and the surrounding electrolyte employing a finite volume method [1]. Both domains are resolved in 3D and the model framework was validated against experimental data. The model output is incorporated in the connected pseudo-two-dimensional battery model for fast simulations of the overall battery cell considering mass and charge transport. The results support the importance of particle (active particle and ceramic filler particle) properties and configurations as well as electrolyte composition. Based on this, we exploit an evolutionary algorithm to suggest optimized battery designs for different use cases. In Addition, we present the evaluation of electrolyte properties with solid-state NMR spectroscopy and their model implementation [2]. μCT imaging experimentally investigates the cathode half-cell morphology. The derived virtual reconstructions enable realistic microstructure simulations of the battery cells. In this presentation, we will suggest two cell designs: The high-energy cell optimizes material efficiency and energy density. The high-power cell opts for high power densities (fast charging).In summary, we present a novel all-solid-state polymer-ceramic hybrid sodium-ion battery type for small stationary or large mobile energy storage units. Our contribution outlines a simulation approach that sheds light on macroscopic and microscopic processes inside the battery-cell using a multiscale modeling method. As a result, a high-energy and a high-power design is derived. Gerbig, M. Holzapfel and H. Nirschl, J. Electrochem. Soc., 170(4), 40517 (2023).Moradipour, A. Markert, T. Rudszuck, N. Röttgen, G. Dück, M. Finsterbusch, F. Gerbig, H. Nirschl and G. Guthausen, J Energ Power Technol, 05(04), 1–21 (2023).

Conducting Carbon Black Nano‐Filler Doped Polymer Electrolyte for Electrochemical Application

AbstractThis study provides a development of polymer electrolytes with an emphasis on their use in electrochemical devices. In present study we develop a new conducting carbon black (CB) powder dispersed into polyethylene oxide (PEO) polymer electrolyte using solution cast method. Various characterization techniques such as Impedance spectroscopy technique (EIS), Fourier transform infrared spectroscopy (FTIR), and Window stability (LSV) Linear sweep voltammetry has been studied in detail. The maximum ionic conductivity polymer electrolyte was at 0.05 wt%. of CB with σ value 1.20×10−5 S/cm. Finally the prepared CB dispersed polymer electrolyte using maximum conductivity sample is sandwiched between electrodes to fabricate an Electric double layer capacitor and Dye‐sensitized solar cell which show highest electrical capacity value of 68.5 F/gm at 5 mV/s respectively and 2.97 % efficiency shown by solar cell at 1 sun condition.

Stretchable interconnected modular electrochromic devices enabled by self-healing, self-adhesive, and ion-conducting polymer electrolyte

Here, we propose a versatile terpolymer electrolyte material, UPy-PEGMA-VBMI, comprised of three monomers: ureidopyrimidinone methacrylate (UPyMA), poly(ethylene glycol) methacrylate (PEGMA), and vinyl benzyl-methylimidazolium (VBMI). The UPy-PEGMA-VBMI, supported by a combination of soft ethylene glycol chains, an ion-conducting imidazole unit, and self-complementary quadruple hydrogen bonds of UPy, exhibits exceptional properties such as high stretchability, rapid self-repair, solution processability, self-adhesion, and ion conduction. The UPy-PEGMA-VBMI was then applied to make ion gel composite films, demonstrating a notable ionic conductivity of 3.84 × 10−3 S cm−1 while maintaining robust stretching and adhesive characteristics. The electrochromic devices (ECDs) fabricated by this ion gel demonstrate outstanding performance, with fast switching times, long-term kinetic stability, and extraordinarily high coloration efficiency of 443.83 cm2 C−1. The stretchable ECDs are fabricated by utilizing the stretchable nature of UPy-PEGMA-VBMI, exhibiting a transmittance contrast of 42.7 % at an extension of 53 % and operational stability during stretching cycles. Moreover, self-healing and self-adhesive features enable the fabrication of interconnected modular ECDs, implementing area-scalable devices. These modular ECDs, each powered independently, provide arbitrary positioning and shifting of individual device patches, overcoming the performance limitations of conventional large-area devices. The unprecedented material and resulting devices open new possibilities for electrochromic applications, particularly in stretchable ECDs, pattern-switching devices, and scalable flexible ECDs.

Identifying ultrathin dielectric nanosheets induced interface polarization for high-performance solid-state lithium metal batteries

Solid-state lithium metal batteries (SSLMBs) with polymer electrolytes are promising due to enhanced safety and high energy density, but the low ionic conductivity of polymer electrolytes and the unstable interface of lithium metal anode hinder the development of SSLMBs. Herein, we propose a unique strategy to address these challenges by coupling ultrathin high-dielectricity Ca2Nb3O10 (CNO) nanosheets with PEO-based electrolyte. The interfacial polarization originating from the distortion of NbO6 octahedra along the vertical direction of CNO nanosheets is maximized and so the interaction between CNO and LiTFSI, which greatly supports the dissociation of LiTFSI and improves the ionic conductivity (2.0 × 10−4 S cm−1) of the composite polymer electrolyte, compared to that without CNO. The optimized interfacial polarization effect is thoroughly demonstrated by theoretical calculation and experimental results. Moreover, due to a homogeneous, robust and LiF-rich solid electrolyte interphase film with promoted Li ion transport being formed at the lithium metal interface, the superior cycling stability (90 % capacity retention after 440 cycles at 0.5 C) and rate capability for LFP||Li full batteries are achieved. This design of composite polymer electrolyte with ultrathin dielectric nanosheet fillers demonstrates a new approach to the development of high-performance polymer electrolytes for SSLMBs.

Application of triblock copolymers in lithium-ion batteries based on solid electrolyte

In the future, all-solid Li-ion batteries are expected to gain widespread acceptance in larger markets due to their high safety and excellent electrochemical performance. However, it is important to acknowledge their drawbacks, including the inadequate compatibility between the electrode and electrolyte interface and the low ionic conductivity at room temperature. This paper reviews the specific methods and the latest research progress of triblock copolymers to solve the above problems. Block copolymerization is an effective way to enhance the efficiency and performance of electrolyte. Its advantage is that two or more monomers with different properties can be polymerized into the same structure, which is conducive to the ionic conductivity of polymer electrolyte. In the latest research results, straight-chain block copolymers have been synthesized, which have better physical and chemical properties compared to traditional comb block copolymers. However, the electrochemical properties of the straight-chain block copolymer electrolyte and the stability of the interface between the electrode and the solid electrolyte are rarely reported. Therefore, it is particularly important to systematically study the electrochemical properties and interface properties of block copolymer electrolytes. In the future, more attention should be drawn to not only improving the properties of SPEs but also building a stable interface with low interface resistance.

Chitosan as a suitable host for sustainable plasticized nanocomposite sodium ion conducting polymer electrolyte in EDLC applications: Structural, ion transport and electrochemical studies

The challenge in front of EDLC device is their low energy density compared to their battery counter parts. In the current study, a green plasticized nanocomposite sodium ion conducting polymer blend electrolytes (PNSPBE) was developed by incorporating plasticized Chitosan (CS) blended with polyvinyl alcohol (PVA), doped with NaBr salt with various concentration of CaTiO3 nanoparticles. The most optimized PNSPBE film was subsequently utilized in an EDLC device to evaluate its effectiveness both as an electrolyte and a separator. Structural and morphological changes were assessed using XRD and SEM techniques. The PNSPBE film demonstrated a peak ionic conductivity of 9.76×10−5 S/cm, as determined through EIS analysis. The dielectric and AC studies provided further confirmation of structural modifications within the sample. Both TNM and LSV analyses affirmed the suitability of the prepared electrolyte for energy device applications, evidenced by its adequate ion transference number and an electrochemical potential window of 2.86 V. Electrochemical properties were assessed via CV and GCD techniques, confirming non-Faradaic ion storage, indicated by the rectangular CV pattern at low scan rates. The parameters associated with the designed EDLC device including specific capacitance, ESR, power density (1950 W/kg) and energy density (12.3 Wh/kg) were determined over 1000 cycles.

Proton ion-conducting polymer electrolytes added with SiO2 nanoparticles: conductivity, dielectric, relaxation, and physical studies

Proton ion-conducting polymer electrolytes added with SiO2 nanoparticles: conductivity, dielectric, relaxation, and physical studies

Amorphous Magnesium-Doped Chitosan films as solid polymer electrolytes for energy storage device applications

Magnesium ion-conducting biodegradable solid polymer electrolyte (SPE) films of magnesium perchlorate [Mg(ClO4)2] doped Chitosan [CS] were prepared using the solution casting technique at room temperature. XRD study shows that amorphous nature of the polymer matrix increases upon doping. FTIR deconvolution confirm the complexation generated between the salt and the polymer. The current–voltage measurement exhibited electrochemical stability window for all samples above 2.14 V. The ionic transference number for the highest conducting sample was 0.99. The impedance analysis was done for each SPE film, and the sample with the highest concentration (40 wt%) exhibited the highest conductivity, 5.7 × 10-4 Scm−1. The prepared primary magnesium battery using the highest conducting SPE showed open circuit potential of 2.112 V. Due to its exceptional qualities, this prepared electrolyte may be a strong contender for energy storage systems.

Improving the ionic conductivity of polymer electrolytes induced by ceramic nanowire fillers with abundant lithium vacancies.

The addition of ceramic fillers is regarded as an effective strategy for enhancing the ionic conductivity of polymer electrolytes. However, particulate fillers typically fail to provide continuous conductive pathways and effective reinforcement. Herein, we report a ceramic nanowire filler with long-range interfacial conductivity and abundant lithium vacancies for a poly(ethylene oxide) (PEO)-based all-solid-state polymer electrolyte. LLZO nanowires (LLZO NWs) with a high aspect ratio are synthesized by combining sol-gel electrospinning and the multi-step process involving pre-oxidation, pre-sintering, and secondary sintering, resulting in a high tensile strength of the composite electrolyte (6.87 MPa). Notably, tantalum-aluminum co-substituted LLZO NWs (TALLZO NWs) release abundant lithium vacancies, further enhancing the Lewis acid-base properties, leading to a rapid ion migration speed (Li+ transfer number = 0.79) and significantly high ionic conductivity (3.80 × 10-4 S cm-1). Due to the synergistic effect of nanostructure modification and heteroatom co-doping, the assembled all-solid-state lithium-sulfur battery exhibits a high initial discharge capacity (776 mA h g-1 at 25 °C), remarkable rate capability, and excellent cycling performance (81% capacity retention after 200 cycles at 0.1C).

Investigation on the properties of PVDF matrix composite porous gel polymer electrolyte doped with lithium silicon gel

Gel polymer electrolytes are safer because they do not contain liquid phase components. On this basis, the introduction of inorganic fillers effectively overcame the problem of low ionic conductivity of polymer electrolyte at room temperature, and the constructed composite polymer electrolyte (CPEs) combined the advantages of inorganic fillers and polymer segments. In this paper, lithium silicon gel SiO2(Li+) was prepared by in-situ polymerization and sol-gel method, and doped in PVDF composite porous gel polymer electrolyte film prepared by immersion precipitation method. The electrochemical properties and surface topography of lithium iron phosphate were investigated by mounting a bonded lithium iron phosphate quasisolid lithium-ion battery. The experimental results show that the solid electrolyte film modified by SiO2(Li+) has good electrochemical and a certain reference value.

Comb-like poly(β-amino ester)-integrated PEO-based self-healing solid electrolytes for fast ion conduction in lithium-sulfur batteries.

All-solid-state lithium-sulfur batteries (ASSLSBs) using poly(ethylene oxide) (PEO) electrolytes offer significant advantages in energy density and safety. However, their development is hampered by the slow Li+ conduction in solid polymer electrolytes and sluggish electrochemical conversion at the cathode-electrolyte interface. Herein, we fabricate a self-healing poly(β-amino ester) with a comb-like topological structure and multiple functional groups, synthesized through a Michael addition strategy. This material modifies the PEO-based solid-state electrolyte, creating fast Li+ transport channels and improving polysulfides conversion kinetics at the electrode surface. Consequently, both modified all-solid-state lithium symmetric cells and lithium-sulfur batteries exhibit improved electrochemical performance. This work demonstrates an expanded interpenetrating macromolecular engineering approach to develop highly ion-conductive solid polymer electrolytes for ASSLSBs.

Development and Characterization of a New Solid Polymer Electrolyte for Supercapacitor Device

In this study, solid polymer electrolytes (SPEs) are based on methylcellulose (MC) used as a polymer host and sodium iodide (NaI) as a dopant. The SPE films are developed using different contents of ethyl carbonate (EC) as a plasticizer to enhance their properties via a solution casting method. The surface morphology of SPE films is shown using polarized optical microscopy (POM), which indicates the existence of amorphous patches due to the plasticizing effect of EC. The creation of a complex between MC, NaI, and EC was confirmed by Fourier transform infrared (FTIR) spectra. A tiny amount of EC applied to the MC-NaI polymer salt matrix increases the number of charge carriers and improves ionic conductivity. The ionic conductivity of the generated polymer electrolytes is examined using electrochemical impedance spectroscopy (EIS). The high-ion conducting PE of 5.06 × 10−3 S·cm−1 was found with the mixture MC + 50 wt% NaI + 10 wt% EC (room temperature). The linear speed voltammetry (LSV) test shows that the optimized polymer electrolyte can withstand decomposition up to 2.5 V. The optimized sample transmission numbers were calculated using a TNM (transference number measurement) approach, and the results show that 99% of the ions contribute to the conductivity, compared to only 1% of the electrons. A solid-state electrical double-layer capacitor (EDLC) was fabricated using the highest ion-conductive polymer electrolyte and graphene oxide (GO)-based electrodes. The galvanostatic charge-discharge (GCD) technique was performed, and the GCD graph shows the behavior of an ideal capacitor with a less Faradic process and a low ESR value. The GO-based cell’s columbic efficiency is 100%, and the system delivers the charge for a long duration. The EDLC cell demonstrates outstanding cyclability. The specific capacitance of the EDLC cell incorporated with MC + 50 wt. % NaI + 10 wt. % EC was found to be 154.66 F/g.

The impact of lithiated active binder on Li-ion battery charge–discharge and rate capability, Part II: Mesoscale modeling of LCO based Half-cell

Even though thick electrodes are essential to increasing the energy density of LIBs, high current rates cause them to lose power density due to high polarization and ion depletion in the pore spaces. Mixed active binders with lithiated bound charges can improve the battery capacity and voltage at high C-rates, even compared to similar high concentrated electrolyte. The lithiated binders also provide a more uniform spatial distribution of intercalation reaction current, electric potential, and open circuit potential. The LIB half cell is modeled at mesoscale by taking into account the diffusion–reaction physics of the bound charge mixed electrolyte in active carbon-binder-domain (CBD), that accounts the dissociation of anionic ligands. Electrolyte in separator and active CBD are coupled by Donnan theory at the interface, and the reaction interfaces are modeled by the standard Butler–Volmer equation. By means of a thermodynamically consistent model and its implementation in a FEM code, we investigate the impact of particle distribution, electrode thickness, and separator thickness for both standard binder and active binder mixed cathodes in terms of ion depletion, current density, and electric potential. This mathematical model can also be extended to the modeling of ion conducting polymer electrolytes, gel polymers, and other conductive materials for battery applications.

Durability and Performance of Poly(norbornene) Membranes and Ionomers in Alkaline Electrolyzers

Ion conducting polymer electrolytes provide an enabling technology for low-temperature alkaline electrolyzers. The critical parameters of solid polymer electrolytes include ionic conductivity, ion selectivity, chemical resistance and dimensional stability in the presence of excess water. High pH operation using anion conductive polymer electrolytes has several potential advantages over acid-based polymer devices including low-cost catalysts, hydrocarbon (non-perfluorinated) polymer, and low cost cell components.In this study, a family of hydroxide conducting, poly(norbornene) solid polymer electrolytes were synthesized and used in high-performance, durable membrane electrode assemblies for fuel cells and electrolyzers. In addition to membranes, covalently bonded, self-adherent, hydroxide conducting ionomers were used to form high-performance, durable membrane electrode assembly for water electrolysis. The self-adhesive ionomers and membranes are based on hydroxide conducting poly(norbornene) polymers. The effect of porous transport layer material and porosity was examined. High performance electrolysis with very low degradation rates was achieved using stainless steel and nickel porous transport layers and flow-channels

Ion Transport in Polymer/Inorganic Composite Electrolytes – a Comparison between Broadband Dielectric Spectroscopy and Impedance Spectroscopy

Significant efforts have been made to develop composite electrolytes combining polymer matrix with Li-ion conducting inorganic solids for feasible construction of solid-state batteries. However, the Li-ion transfer kinetics at the interface between polymer/inorganic electrolyte is unfavorable for Li-ion conduction in the composite electrolyte because of the interfacial resistance and the activation energy barrier for interfacial Li-ion transfer. The activation energy barrier for the Li-ion transfer reaction at the interface is correlated with the interaction between Li-ion and polymer matrix in the polymer electrolyte, interaction between Li-ion and anions in inorganic electrolytes and the interaction between polymer and inorganic electrolytes, therefore, the electrolyte composition significantly affects the interfacial charge transfer kinetics in composites.In this work, Li-ion transport properties in the composite electrolytes are investigated by using broadband dielectric spectroscopy (BDS) and impedance spectroscopy (IS). We particularly focus on Li-ion charge transfer at the polymer/inorganic interface from the dual ion conducting polymer to the single ion conducting polymer electrolytes with different Li-ion conducting salts such as LiN(SO2CF3)2 (LiTFSI) and (LiMTFSI) in vinyl ethylene carbonate (VEC) or polymerized vinyl ethylene carbonate (PVEC). The interfacial resistances of inorganic electrolytes Li0.34La0.56TiO3 (LLTO) in polymer electrolytes are elucidated. To further evaluate the polymer/inorganic electrolyte interfaces, various types of cell are assembled in a glove box filled with argon gas and characterized by a series of techniques such as BDS and IS. The Li-ion transfer kinetics at the interface significantly affects the Li-ion flux through the composite electrolytes and will be presented. In addition, we will present a systematic comparison between BDS and IS results in order to build connections between the two communities. Acknowledgements This work was supported as part of the Fast and Cooperative Ion Transport in Polymer-Based Materials (FaCT), an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences at Oak Ridge National Laboratory under contract DE-AC05-00OR22725.

Interfacial polymer architecture can control nanoparticle dispersion and rheological behavior of nanocomposites

Polymer nanocomposites (PNCs) have become essential components in many advanced materials applications, from solid state battery electrolytes to high-performance structural components. In PNCs, the large fraction of interfacial polymers determines their outstanding rheological performance; yet, strategies to control the structure and dynamics of the interfacial polymer has been very limited. Here, using poly(ethylene oxide)-silica model nanocomposite system, we propose a facile approach based on varying macromolecular architecture of interfacial polymers. We show that by changing the topology of the bound polymer from linear to star and hyperbranched, polymer-NP interaction as well as chain interpenetration in the interphases can be effectively altered without changing type or molecular weight of the polymer, or NP surface chemistry in attractive PNCs. Our results show that both dispersion and rheological behavior of PNCs depend highly on functionality and arm length of the polymers used at the interfaces. These results can be used to design ion-conductive molten polymer electrolytes with significantly improved mechanical properties suitable for solid-state battery applications.