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Zwitterionic materials can exhibit unique characteristics and are highly tunable by variation to the covalently bound cationic and anionic moieties. Despite the breadth of properties and potential uses reported to date, for electrolyte applications they have thus far primarily been used as additives or for making polymer gels. However, zwitterions offer intriguing promise as electrolyte matrix materials that are non-volatile and charged but non-migrating. Here we report a family of zwitterions that exhibit molecular disorder and plasticity, which allows their use as a solid-state conductive matrix. We have characterized the thermal, morphological and structural properties of these materials using techniques including differential scanning calorimetry, scanning electron microscopy, solid-state NMR and X-ray crystallography. We report the physical and transport properties of zwitterions combined with lithium salts and a lithium-functionalized polymer to form solid or high-salt-content liquid electrolytes. We demonstrate that the zwitterion-based electrolytes can allow high target ion transport and support stable lithium metal cell cycling. The ability to use disordered zwitterionic materials as electrolyte matrices for high target ion conduction, coupled with an extensive scope for varying the chemical and physical properties, has important implications for the future design of non-volatile materials that bridge the choice between traditional molecular and ionic solvent systems. The tunability of covalently bound cationic and anionic moieties of zwitterionic materials makes them attractive for potential applications. A family of zwitterions exhibiting molecular disorder and plasticity allows their use as a solid-state conductive matrix.

Lithium-O2 batteries represent one of the most appealing candidates for battery electric vehicles (BEV) due to its remarkable theoretical high energy density, similar to fossil fuels. Solid polymer electrolytes represent a plausible solution to tackle some of the challenges associated to conventional liquid-based Li-O2 batteries, including safety concerns. Herein, cross-linked robust gel polymer electrolytes (GPE) based on poly(ethylene glycol) dimethacrylate (PEGDM) and tetraethylene glycol dimethyl ether (TEGDME) as plasticizer are prepared by rapid UV-photopolymerization. Both types of robust GPEs presented high ionic conductivity at room temperature (1.6·10−4 S·cm−1 and 1.4·10−3 S·cm−1 for single ion or dual ion, respectively). Both types of GPEs, single ion and dual ion lithium conductors, have been compared for the first time on Li-O2 cells. First, their performance was investigated in symmetrical Li|Li cells. In this case, the dual-ion GPE showed an outstanding behavior where the overpotential was

Solid-state lithium batteries are considered one of the most promising battery systems due to their high volumetric energy density and safety. Poly(ethylene oxide) (PEO) is the most commonly used solid polymer electrolyte in solid-state batteries. In this article, we introduce new polyphosphoester polymer electrolytes, which show improved flame retardant properties in comparison with PEO. For this purpose, new polyphosphoester copolymers were synthesized, including phosphoester, poly(ethylene glycol) (PEG) and UV cross-linkable vinyl units. Solid polymer electrolyte films based on polyphosphoester copolymers and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) were prepared by curing under UV-light. The crystallinity present in the copolymers due to the PEG segment decreases with the amount of salt in the electrolyte, as seen by DSC. Solid polymer electrolytes based on polyphosphoester copolymers show ionic conductivity values as high as 2 × 10−4 S cm−1 at 70 °C. FTIR analysis showed that lithium cations complexed with phosphoester groups provoked an increase in the lithium transference number to 0.26 as compared to that of PEO 0.17. Pyrolysis flow combustion calorimetry (PCFC) or micro-calorimetry results demonstrated the improved flame retardancy of the polyphosphoesters in comparison to a reference PEO based polymer electrolyte. The selected polyphosphoester solid electrolyte was investigated in a solid-state lithium cell Li0/polymer electrolyte/LFP battery showing a specific capacity retention close to 80% and coulombic efficiency greater than 98% over 100 cycles at 70 °C.

Understanding the mechanisms controlling ionic conductivity is critical for the development of the next generation of batteries and supercapacitors. This paper discusses the significant role played...

RAFT polymerization of N‐vinylimidazole followed pseudo‐first‐order kinetics. Morpholine‐based chain transfer agents for rapid polymerization of vinyl acetate afforded high‐molar‐mass poly(vinyl acetate) (up to 130 kg mol−1).

In the past two decades, ionic liquids (ILs) have blossomed as versatile task-specific materials with a unique combination of properties, which can be beneficial for a plethora of different applications. The additional need of incorporating ILs into solid devices led to the development of a new class of ionic soft-solid materials, named here iongels. Nowadays, iongels cover a wide range of materials mostly composed of an IL component immobilized within different matrices such as polymers, inorganic networks, biopolymers or inorganic nanoparticles. This review aims at presenting an integrated perspective on the recent progress and advances in this emerging type of material. We provide an analysis of the main families of iongels and highlight the emerging types of these ionic soft materials offering additional properties, such as thermoresponsiveness, self-healing, mixed ionic/electronic properties, and (photo)luminescence, among others. Next, recent trends in additive manufacturing (3D printing) of iongels are presented. Finally, their new applications in the areas of energy, gas separation and (bio)electronics are detailed and discussed in terms of performance, underpinning it to the structural features and processing of iongel materials.

Composite solid electrolytes including inorganic nanoparticles or nanofibers which improve the performance of polymer electrolytes due to their superior mechanical, ionic conductivity or lithium transference number are actively being searched for applications in lithium metal batteries. However, inorganic nanoparticles present limitations such as its tedious surface functionalization and agglomeration issues and poor homogeneity at high concentrations in polymer matrices. In this work, we report on polymer nanoparticles with lithium sulfonamide surface functionality (LiPNP) for application as electrolytes in lithium metal battery. The particles are prepared by semibatch emulsion polymerization, an easily up–scalable technique. LiPNPs are used to prepare two different families of particle reinforced solid electrolytes. When mixed with polyethylene oxide and lithium bis(trifluoromethane)sulfonimide (LiTFSI/PEO), the particles provoke a significant stiffening effect (E´ > 106 Pa vs. 105 Pa at 80 ºC) while retaining high ionic conductivity (σ = 6.6 × 10–4 S cm–1). Preliminary testing in LiFePO4 full cells, showed promising performance of the PEO nanocomposite electrolytes. By mixing the particles with propylene carbonate without any additional salt, we obtain true single ion conducting gel electrolytes as the lithium sulfonamide surface functionalities are the only sources of lithium ions in the system. The gel electrolytes are mechanically robust (up to G´ =106 Pa) and show ionic conductivity up to 10–4 S cm–1. Finally, the PC nanocomposite electrolytes were tested in symmetrical lithium cells. Our findings suggest that all–polymer nanoparticles could represent a new building block material for solid–state lithium metal battery applications.

Herein, we demonstrate that the potential difference of proton reduction and hydrogen gas oxidation of protic ionic liquids is closely related to the proton exchange rate in the electrolyte. Through a careful design of anion chemistry, the proton exchange rate can be boosted by several orders of magnitude, reaching 200 kHz at 100 °C. It is found that the enhanced proton exchange rate can effectively decrease the potential loss at the electrode, most likely through alleviating the H+ concentration gradient incurred by electrochemical reactions at the electrode surfaces. This research therefore highlights the strategy of using anions of medium-strength acids, such as H2PO4-, for protic ionic liquids with enhanced proton exchange capability.

A simple method to prepare a mechanically robust ionogel film by fast (

[EN]Composite solid electrolytes including inorganic nanoparticles or nanofibers which improve the performance of polymer electrolytes due to their superior mechanical, ionic conductivity, or lithium transference number are actively being researched for applications in lithium metal batteries. However, inorganic nanoparticles present limitations such as tedious surface functionalization and agglomeration issues and poor homogeneity at high concentrations in polymer matrixes. In this work, we report on polymer nanoparticles with a lithium sulfonamide surface functionality (LiPNP) for application as electrolytes in lithium metal batteries. The particles are prepared by semibatch emulsion polymerization, an easily up-scalable technique. LiPNPs are used to prepare two different families of particle-reinforced solid electrolytes. When mixed with poly(ethylene oxide) and lithium bis(trifluoromethane)sulfonimide (LiTFSI/PEO), the particles invoke a significant stiffening effect (E' > 106 Pa vs 105 Pa at 80 °C) while the membranes retain high ionic conductivity (sigma = 6.6 * 10-4 S cm-1). Preliminary testing in LiFePO4 lithium metal cells showed promising performance of the PEO nanocomposite electrolytes. By mixing the particles with propylene carbonate without any additional salt, we obtain true single-ion conducting gel electrolytes, as the lithium sulfonamide surface functionalities are the only sources of lithium ions in the system. The gel electrolytes are mechanically robust (up to G' = 106 Pa) and show ionic conductivity up to 10-4 S cm-1. Finally, the PC nanocomposite electrolytes were tested in symmetrical lithium cells. Our findings suggest that all-polymer nanoparticles could represent a new building block material for solid-state lithium metal battery applications. L.P. has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska–Curie grant agreement no. 797295. P.S. has been funded by the SNSF (Swiss National Science Foundation) under project number P2FRP2_191846. J.R.L. and D.M. acknowledge the funding by the Basque Government (IT99-16). V.B. acknowledges support from the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory (ORNL), managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract no. DE-AC05-00OR22725. A.S. acknowledges financial support for dielectric measurements and data discussions by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division.

In this work, we develop novel single-ion polymer electrolytes by mixing poly(lithium 1-[3-(methacryloyloxy) propylsulfonyl]-1-(trifluoromethanesulfonyl) imide) (PLiMTFSI) and poly(ethylene oxide) (PEO) with different molecular weights. The impact of PLiMTFSI on the crystallization and conductivity of the blends was explored in detail. When PLiMTFSI (an amorphous polymer) is added to PEO, the crystallization ability of PEO decreases. However, blends with high-molecular weight PEO (1000 kg/mol) experience a lower reduction in crystallinity and melting points. As a result, lower conductivity values were obtained in these blends, which is why most of the study was then focused on blends incorporating a lower-molecular weight PEO (100 kg/mol). We show that the melting point, degree of crystallinity, spherulitic growth, and overall crystallization kinetics decrease in the presence of PLiMTFSI, which are all signs of miscibility. Furthermore, the blends show a single glass transition temperature over the whole composition range. Therefore, our results indicate that PEO and PLiMTFSI are miscible, as corroborated by applying the Nishi-Wang equation and obtaining negative χ12 values (i.e., the Flory-Huggins interaction parameter) for all blends. Our results show that intermediate molecular weight blends (100 kg/mol PEO and 50 kg/mol PLiMTFSI) showed the highest ionic conductivity value. Interestingly, a value of 2.1 × 10-4 S/cm was obtained at 70 °C, which is one of the highest reported so far for a free-standing film of single-ion conducting polymer electrolytes. Finally, employing dielectric spectroscopy, the contribution of ion density and ion mobility to ionic conductivity could be separated. It was found that ion mobility is the parameter that has a greater weight in the conduction process., We wish to thank the Consejo Nacional de Ciencia y Tecnología (the National Council of Science and Technology) (CONACYT), Mexico, for the grant awarded to J.L.O.-M. no. 471837. L.P. has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement no. 797295. We acknowledge funding from the Basque Government through grant IT1309-19 and IT1175-19. Authors would like to thank IONBIKE-RISE project, and this project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement no. 823989.

Unformatted postprint Lithium-ion batteries are part of modern life, being present in daily-used objects such as mobile phones, tablets, computers, watches, sport accessories, electric scooters, and cars. The next-generation batteries require the development of innovative polymers that help to improve their performance in terms of power density, cyclability, raw materials’ availability, low weight, printability, flexibility, sustainability, or security. This article highlights recent developments in the area of redox-active, electronic/ionic conducting polymers. This includes the development of innovative binders for electrodes, polymer electrolytes, and redox polymers. All these new polymer developments are leading to new battery technologies such as metal–polymer batteries, organic batteries, polymer–air, and redox–flow batteries, which are expected to complement the current lithium-ion technologies in the future. Financial support from the Basque Government, Spanish Government and the European Research Council by Starting Grant Innovative Polymers for Energy Storage (iPes) 306250 is acknowledged. L.P. has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska–Curie grant agreement No 797295.

Unformatted postprint Organic ionic plastic crystals (OIPCs) have been recognised as promising solid-state electrolyte materials for next-generation energy storage devices. Recently, the addition of polymer nanofillers to OIPCs has led to the design of OIPC-based solid-state electrolytes with enhanced mechanical stability and ion conductivity. However, the mechanisms of enhancement and the influence of different polymer surface chemistries on the ion dynamics are not yet well understood, which has hindered the further development of high-performance OIPC-based electrolytes. In this work, we selected two different polymer nanoparticles, poly(vinylidene fluoride) (PVDF) and polystyrene (PS), and investigated the effects of the polymer surfaces on the thermal behaviour and ion transport properties of the OIPC, N-ethyl N-methyl pyrrolidinium bis(fluorosulfonyl)imide ([C2mpyr][FSI]). We found significantly different thermal behaviours, as well as ion transport properties in the OIPC/nanoparticle composites. Specifically, compared with pure [C2mpyr][FSI], the addition of PVDF nanoparticles effectively enhanced the ion conductivity of the OIPC composite, with the optimum achieved near the percolation threshold of PVDF nanoparticles. In contrast, the addition of PS nanoparticles to the OIPC led to a slight enhancement at low concentrations and then a significant decrease in conductivity at higher concentrations. DSC, FTIR and EIS confirm that the interaction between the PVDF nanoparticles and the OIPC induces the formation of less ordered OIPC layers on the PVDF surfaces, leading to the conductivity enhancement. Finally, different structure models based on the results of this work are proposed, which provide principle guidelines for the design of future OIPC-based highly conductive electrolyte materials. The authors would like to thank Dr Wesley A. Henderson for his valuable discussion and the US Army Research Office (ARO) for financial support (W911NF1710560). The Australian Research Council (ARC) is acknowledged for support through the Australian Postgraduate Awards and Deakin University postgraduate research scholarships. L. P. received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska–Curie grant agreement No. 797295. Dr Ruhamah Yunis is also acknowledged for her help with plastic crystal synthesis.

A green, efficient and stable solar cell based only on water and safe and cheap elements of the periodic table is proposed in this work, finally consolidating (also from a sustainability viewpoint) the concept of “artificial photosynthesis” studied for decades by the scientific community. The concept of dye-sensitized solar cells is re-proposed here with a metal-free organic dye, an iodine-based electrolyte in a 100% aqueous environment and a new cathode (cationic PEDOT) synthesized for the first time with the aim of inhibiting the repulsion between the anions of redox couples and the PEDOT:PSS matrix commonly used as the counter-electrode. This elegant setup leads to a record efficiency of 7.02%, the highest value ever obtained for a water-based solar cell and, in general, for a photovoltaic device free of both organic solvents and expensive/heavy metals., A new cationic PEDOT derivative inhibits repulsion phenomena within iodine-based electrolytes, boosting the efficiency of aqueous solar cells.

The rational design of single-ion polymer electrolytes emerges as a primary strategy for enhancing the performance of lithium ion batteries. With the aim to increase ionic conductivity, four novel ionic liquid monomers were designed and synthesized in high purity. Such monomers differ from the previously reported systems by (1) the presence of a long and flexible spacer between the methacrylate group and chemically bonded anion or (2) by a long perfluorinated side chain. The investigation of their free radical copolymerization with poly(ethylene glycol) methyl ether methacrylate (PEGM) allowed to identify the impact of thei copolymer composition on thermal and ion conducting properties. The copolymer based on lithium 3-[4-(2-(methacryloyloxy)ethoxy)-4-oxobutanoyl)oxy) propylsulfonyl]-1-(trifluoromethylsulfonyl)imide showed the highest ionic conductivity (1.9 × 10−6 and 2 × 10−5 S cm−1 at 25 and 70 °C, respectively) at [EO]/[Li] = 61 ratio, along with a wide electrochemical stability (4.2 V vs. Li+/Li) and high lithium-ion transference number (0.91). The prepared copoly(ionic liquid)s (coPILs) were further applied for the assembly of Li/coPIL/LiFePO4 lithium-metal cells, which were capable to reversibly operate at 70 °C delivering relatively high specific capacity (up to 115 mAh g−1) at medium C/15 current rate.

Organic electrochemical transistors (OECTs) are being intensively developed for applications in electronics and biological interfacing. These devices rely on ions injected in a polymer film from an aqueous liquid electrolyte for their operation. However, the development of solid or semi-solid electrolytes are needed for future integration of OECTs into flexible, printed or conformable bioelectronic devices. Here, we present a new polyethylene glycol hydrogel with high Na+ conductivity which is particularly suitable for OECTs. This novel hydrogel was synthesized using cost-effective photopolymerization of poly(ethylene glycol)-dimethacrylate and sodium acrylate. Due to the high water content (83% w/w) and the presence of free Na+, the hydrogel showed high ionic conductivity values at room temperature (10-2 S cm-1) as characterized by electrochemical impedance spectroscopy. OECTs made using this hydrogel as a source of ions showed performance that was equivalent to that of OECTs employing a liquid electrolyte. They also showed improved stability, with only a 3% drop in current after 6 h of operation. This hydrogel paves the way for the replacement of liquid electrolytes in high performance OECTs bringing about advantages in terms of device integration and protection.

Single-ion conducting polymer electrolytes represent the ideal solution to reduce concentration polarization in lithium metal batteries (LMBs). This paper reports on the synthesis and characterization of single-ion ABA triblock copolymer electrolytes comprising PEO and poly(lithium 1-[3-(methacryloyloxy)propylsulfonyl]-1-(trifluoromethylsulfonyl)imide) blocks, poly(LiMTFSI). Block copolymers are prepared by reversible addition - fragmentation chain transfer polymerization, showing low glass transition temperature (−55 to 7 °C) and degree of crystallinity (51–0%). Comparatively high values of ionic conductivity are obtained (up to ≈ 10 −4 S cm −1 at 70 °C), combined with a lithium-ion transference number close to unity ( t L i + ≈ 0.91) and a 4 V electrochemical stability window. In addition to these promising features, solid polymer electrolytes are successfully tested in lithium metal cells at 70 °C providing long lifetime up to 300 cycles, and stable charge/discharge cycling at C/2 (≈100 mAh g −1 ).

Single-ion polymer electrolytes are expected to play an important role in the development of next-generation lithium metal batteries. In this paper, the synthesis and characterization of single-ion conducting polyurethanes (SIPUs) based on PEG and a specifically designed ionic liquid monomer (bis-MPTFSI) is presented. Exploiting the flexible chemistry of polyurethanes, it was possible to tailor the composition and chemical structure of SIPE, obtaining both segmented and crosslinked lithium ion-conductive (σ = 10 −8 −10 −4 S cm −1 ) and free-standing films with the lithium transference number close to unity. Finally, the performances of gel polymer electrolytes based on SIPUs for lithium metal batteries operating at room temperature were investigated (80 cycles at C/10 with nearly 100% efficiency). To the best of our knowledge, these SIPUs represent one of the first examples of polyurethane-based poly(ionic liquid)s for application in the field of battery science.

This paper presents the work carried out within the European project RENAISSANCE-ITN, which was dedicated to the development of innovative polyelectrolytes for energy and environmental applications. Within the project different types of innovative polyelectrolytes were synthesized such as poly(ionic liquid)s coming from renewable or natural ions, thiazolium cations, catechol functionalities or from a new generation of cheap deep eutectic monomers. Further, macromolecular architectures such as new poly(ionic liquid) block copolymers and new (semi)conducting polymer/polyelectrolyte complexes were also developed. As the final goal, the application of these innovative polymers in energy and the environment was investigated. Important advances in energy storage technologies included the development of new carbonaceous materials, new lignin/conducting polymer biopolymer electrodes, new iongels and single-ion conducting polymer electrolytes for supercapacitors and batteries and new poly(ionic liquid) binders for batteries. On the other hand, the use of innovative polyelectrolytes in sustainable environmental technologies led to the development of new liquid and dry water, new materials for water cleaning technologies such as flocculants, oil absorbers, new recyclable organocatalyst platforms and new multifunctional polymer coatings with antifouling and antimicrobial properties. All in all this paper demonstrates the potential of poly(ionic liquid)s for high-value applications in energy and enviromental areas. © 2017 Society of Chemical Industry

Mussel inspired catechol containing materials have currently drawn great attention as biomaterials, adhesives, surface coatings and in bioelectronics, among other applications. In this work, we mimicked the ability of mussels as water filtration systems to adsorb organic and inorganic contaminants. For this purpose, the synthesis of biomimetic hydrogels by co-polymerization of a new ionic monomer, dopamine methacrylic acid salt (iDA) with a series of water soluble methacrylate monomers was performed using visible light photopolymerization. The iDA ionic monomer is highly water soluble as compared to previous reported monomers containing catechol groups. This allows its incorporation into different acrylic hydrogels in concentrations up to 50 % mol of monomers containing catechol groups, leading to functional materials with variable morphology and swelling properties. The hydrogels displayed to be highly effective for the removal of heavy metals such as As(V) and Cr(VI) with very good effectiveness compared to other commonly employed natural sorbents, such as clays. Additionally, these poly(ionic liquid) hydrogels containing catechol groups were evaluated in the removal also of other pollutants such as charged organic dyes. Preliminarily results demonstrate the versatility of these materials that combine catechol and ionic chemistry for the adsorption of a wide variety of water pollutants. Fil: Gallastegui, Antonela. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; Argentina Fil: Porcarelli, Luca. Polymat University Of The Basque ; España Fil: Palacios, Rodrigo Emiliano. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; Argentina Fil: Soulé Gómez, María Lorena. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; Argentina Fil: Mecerreyes Molero, David. Polymat University Of The Basque ; España

Local drug delivery directly to the source of a given pathology using retrodialysis is a promising approach to treating otherwise untreatable diseases. As the primary material component in retrodialysis, the semipermeable membrane represents a critical point for innovation. This work presents a new ionic hydrogel based on polyethylene glycol and acrylate with dopamine counterions. The ionic hydrogel membrane is shown to be a promising material for controlled diffusive delivery of dopamine. The ionic nature of the membrane accelerates uptake of cationic species compared to a nonionic membrane of otherwise similar composition. It is demonstrated that the increased uptake of cations can be exploited to confer an accelerated transport of cationic species between reservoirs as is desired in retrodialysis applications. This effect is shown to enable nearly 10-fold increases in drug delivery rates from low concentration solutions. The processability of the membrane is found to allow for integration with microfabricated devices which will in turn accelerate adaptation into both existing and emerging device modalities. It is anticipated that a similar materials design approach may be broadly applied to a variety of cationic and anionic compounds for drug delivery applications ranging from neurological disorders to cancer. - EPSRC (EP/S009000/1) - Marie Sklodowska-Curie Grant Agreement No. 823989. - Borysiewicz Biomedical Sciences Fellowship program. - Marie SklodowskaCurie IF BIKE Project No. 742865.

The supporting information is attached. Aliphatic polycarbonates have emerged as promising polymer electrolytes due to their combination of moderate ionic conductivity and high lithium transference numbers. However, the mechanical properties of the aliphatic polycarbonates polymer electrolytes are usually weak due to the low molecular weight achieved and plasticization effect of the added lithium salt. In this article, we present a copolymer having poly(ethylene oxide) segments linked by carbonate groups with cross-linkable methacrylic pendant groups. Once the polymer and the lithium salt were mixed, the poly(ethylene oxide carbonate) was cross-linked by UV light producing a free standing solid polymer electrolyte (SPE). Different SPE formulations were designed by varying the LiTFSI concentration within the polymer matrix showing the highest ionic conductivity of 1.3·10−3 S cm−1 and a lithium transference number of 0.59 at 70 °C. 7Li solid-state NMR experiments were used to correlate the lithium cation environment and dynamics with ionic conductivity. At the same temperature the electrochemical stability window was analyzed, and a reasonable value of 4.9 V was achieved. The study was complemented by mechanical and thermal stability measurements. Finally, the optimized UV-cross-linked poly(ethylene oxide carbonate) was tested as electrolyte in lithium metal symmetric cell at 70 °C, showing low over-potential values and a stable solid electrolyte interphase layer. We are grateful to the financial support of the European Research Council by Starting Grant Innovative Polymers for Energy Storage (iPes) 306250 and the Basque Government through ETORTEK Energigune 2013 and IT 999-16. Leire Meabe thanks Spanish Ministry of Education, Culture and Sport for the predoctoral FPU fellowship received to carry out this work. The authors would like to thank the European Commission for their financial support through the project SUSPOL-EJD 642671 and the Gobierno Vasco/Eusko Jaurlaritza (IT 999-16). The authors thank for technical and human support provided by SGIker of UPV/EHU for the NMR facilities of Gipuzkoa campus.

Organic materials are being investigated as an alternative to inorganic cathodes in lithium batteries with the promise of higher sustainability as well as increased theoretical capacity. Among organic materials, redox polymers based on poly(vinyl catechol) presenting the catechol/o-benzoquinone redox pair show high energy storage potential. Our main motivation in this work was to prepare polymer nanoparticles of different sizes and study their redox properties. As linear polymers are usually soluble/mechanically unstable, we prepared cross-linked polymers to maintain the size of the nanoparticles in different electrolytes. (Mini)emulsion polymerization of two dimethoxy monomers was used to synthesize spherical polymer nanoparticles cross-linked with divinylbenzene (DVB) where the size was controlled by changing the concentration of the surfactant. Deprotection yielded poly(4-vinyl catechol) and poly(3-vinyl catechol) redox active nanoparticles (RPNs) of sizes ranging between 40 and 330 nm as characterized by scanning electron microscopy. The electrochemical properties of the RPN were tested in aqueous- and acetonitrile-based electrolytes using cyclic voltammetry. First the effect of the nanoparticle size and the cross-linker content in the electrochemical properties was investigated. Particle size did not have a crucial effect on the electrochemistry and only the biggest 330 nm RPN showed slightly diminished electrochemical properties. The cross-linker had a negative effect on the maximum reduction current (iC) but improved cycling stability. Based on these results we decided to use the smallest 40 nm nanoparticles with the lowest (1% DVB) cross-linker content for further electrochemical testing. Both RPN isomers showed reversible behavior in aqueous acidic-, neutral-, as well as in acetonitrile-based electrolyte. Poly(4-vinyl catechol)-based RPN had slightly higher reduction potential at 0.45 V versus Ag/AgCl (0.1 M HClO4) compared to another isomer with 0.40 V versus Ag/AgCl. When switching from an acidic aqueous electrolyte to neutral, the redox potential was shifted 440-475 mV to lower values. Because of their high reduction potential and theoretical capacity at 394 mA h/g these synthetic RPNs show promising properties to be used as cathodes in a variety of batteries. However, exact capacity determination, long term cycling, testing in nonaqueous electrolytes, and redox flow batteries needs to be performed in the future. This work was financially supported by the European Research Council by Starting Grant Innovative Polymers for Energy Storage (iPes) 30625 and Slovenian research agency (ARRS): research project J2-8167 and public call MS-ERC-FS/2017-002. N.B. acknowledges the financial support obtained through the Post-Doctoral fellowship Juan de la Cierva-Incorporacion (IJCI-2016-28442), from the Ministry of Economy and Competitiveness of Spain. L.P. has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement no 797295.

Unformatted postprint Electrolytes based on organic solvents used in current Li-ion batteries are not compatible with the next-generation energy storage technologies including those based on Li metal. Thus, there has been an increase in research activities investigating solid-state electrolytes, ionic liquids (ILs), polymers, and combinations of these. This Account will discuss some of the work from our teams in these areas. Similarly, other metal-based technologies including Na, Mg, Zn, and Al, for example, are being considered as alternatives to Li-based energy storage. However, the materials research required to effectively enable these alkali metal based energy storage applications is still in its relative infancy. Once again, electrolytes play a significant role in enabling these devices, and research has for the most part progressed along similar lines to that in advanced lithium technologies. Some of our recent contributions in these areas will also be discussed, along with our perspective on future directions in this field. For example, one approach has been to develop single-ion conductors, where the anion is tethered to the polymer backbone, and the dominant charge conductor is the lithium or sodium countercation. Typically, these present with low conductivity, whereas by using a copolymer approach or incorporating bulky quaternary ammonium co-cations, the effective charge separation is increased thus leading to higher conductivities and greater mobility of the alkali metal cation. This has been demonstrated both experimentally and via computer simulations. Further enhancements in ion transport may be possible in the future by designing and tethering more weakly associating anions to the polymer backbone. The second approach considers ion gels or composite polymer electrolytes where a polymerized ionic liquid is the matrix that provides both mechanical robustness and ion conducting pathways. The block copolymer approach is also demonstrated, in this case, to simultaneously provide mechanical properties and high ionic conductivity when used in combination with ionic-liquid electrolytes. The ultimate electrolyte material that will enable all high-performance solid-state batteries will have ion transport decoupled from the mechanical properties. While inorganic conductors can achieve this, their rigid, brittle nature creates difficulties. On the other hand, ionic polymers and their composites provide a rich area of chemistry to design and tune high ionic conductivity together with ideal mechanical properties. The authors are grateful to Prof. Michel Armand, Prof. Douglas MacFarlane, Prof. Patrick Howlett, Dr. John Chiefari, and Mr. Asier Fernandez De Añastro for helpful discussions and their assistance during the preparation of this manuscript. L.P. has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 797295. D.M. has received funding from the European Research Council under the F7P grant agreement No 306250. M.F. would like to acknowledge the financial supports through Australia-India Strategic Research Fund (AISRF 48515), ARC Australian Laureate Fellowship (grant agreement No FL110100013) and ARC Centre of Excellence for Electromaterials Science (grant agreement No CE140100012).

Safety issues rising from the use of conventional liquid electrolytes in lithium-based batteries are currently limiting their application to electric vehicles and large-scale energy storage from renewable sources. Polymeric electrolytes represent a solution to this problem due to their intrinsic safety. Ideally, polymer electrolytes should display both high lithium transference number (tLi+) and ionic conductivity. Practically, strategies for increasing tLi+ often result in low ionic conductivity and vice versa. Herein, networked polymer electrolytes simultaneously displaying tLi+ approaching unity and high ionic conductivity (σ ≈ 10–4 S cm–1 at 25 °C) are presented. Lithium cells operating at room temperature demonstrate the promising prospect of these materials.

In recent years, gels based on ionic liquids incorporated into polymer matrices, namely iongels, have emerged as long-term contact media for cutaneous electrophysiology. Iongels possess high ionic conductivity and negligible vapor pressure and can be designed on demand. In spite of the extensive efforts devoted to the preparation of biodegradable ionic liquids, the investigations related to the preparation of iongels based on biodegradable polymers remain scarce. In this work, biodegradable polycarbonate-based iongels are prepared by ring-opening polymerization of N-substituted eight ring membered cyclic carbonate monomers in the presence of imidazolium lactate ionic liquid. Our iongels are able to take up 10&ndash, 30 wt % of ionic liquid and become softer materials by increasing the amount of free ionic liquid. Rheological measurements showed that the cross-over point between the storage modulus G&prime, and loss modulus G&Prime, occurs at lower angular frequencies when the loading of free ionic liquid increases. These gels are able to take up to 30 wt % of the ionic liquid and the ionic conductivity of these gels increased up to 5 &times, 10&minus, 4 S&middot, cm&minus, 1 at 25 &deg, C as the amount of free ionic liquid increased. Additionally, we assess the biodegradation studies of the iongels by immersing them in water. The iongels decrease the impedance with the human skin to levels that are similar to commercial Ag/AgCl electrodes, allowing an accurate physiologic signals recording. The low toxicity and biodegradability of polycarbonate-based iongels make these materials highly attractive for cutaneous electrophysiology applications.

Proton conducting polymeric membranes are highly searched in many different technologies ranging from energy to biosensing. Protic ionic liquids and their polymeric version represent a new family of proton conducting molecules with relatively facile synthesis and excellent properties. In this work, protic poly(ionic liquids) having the most popular phosphonium counter-cations are presented for the first time. The synthesis is carried out through proton transfer reactions or through ion exchange reactions by using commercially available tertiary phosphines. Tributyl-, trioctyl-, and tricyclohexyl-phosphine are selected to form the desired cations. Polystyrene sulfonic acid, poly(2-acrylamido-2-methyl-1-propanesulfonic acid), and lithium poly[(4-styrenesulfonyl) (trifluoromethanesulfonyl)imide] polymers are used to form the polymeric anions. The chemical structure of the protic poly(ionic liquids) is confirmed by spectroscopic characterizations such as Fourier transform infrared and nuclear magnetic resonance spectroscopies. Thermal properties of the polymer are characterized by means of differential scanning calorimetry and thermogravimetric analysis. Polymers exhibit good membrane forming ability as well as high ionic conductivities in the range of 10-8 to 10-3 S cm-1 from 30 to 90 °C.

We demonstrate the fabrication of polymer thin-film transistors gated with an ion gel electrolyte made of the blend of an ionic liquid and a polymerised ionic liquid. The ion gel exhibits a high stability and ionic conductivity, combined with facile processing by simple drop-casting from solution. In order to avoid parasitic effects such as high hysteresis, high off-currents, and slow switching, a fluorinated photoresist is employed in order to enable high-resolution orthogonal patterning of the polymer semiconductor over an area that precisely defines the transistor channel. The resulting devices exhibit excellent characteristics, with an on/off ratio of 106, low hysteresis, and a very large transconductance of 3 mS. We show that this high transconductance value is mostly the result of ions penetrating the polymer film and doping the entire volume of the semiconductor, yielding an effective capacitance per unit area of about 200 μF cm−2, one order of magnitude higher than the double layer capacitance of the ion gel. This results in channel currents larger than 1 mA at an applied gate bias of only –1 V. We also investigate the dynamic performance of the devices and obtain a switching time of 20 ms, which is mostly limited by the overlap capacitance between the ion gel and the source and drain contacts.

The performance of full cells featuring high-voltage LiNi 0.4 Mn 1.6 O 4 cathode and graphite anode with carbonate-based electrolytes, ethylene carbonate (EC) -dimethyl carbonate (DMC) with conventional LiPF 6 and non-conventional Li[(C 2 F 5 ) 3 PF 3 ] (LiFAP) lithium salts with and without SEI-forming additives 1-fluoro ethylene carbonate (F 1 EC) and succinic anhydride (SA) is investigated. The results evidence the beneficial impact of EC-DMC-1M LiFAP electrolyte (LF30), with respect to EC-DMC-1M LiPF 6 electrolyte (LP30), also in presence of 1.6% F 1 EC-2% SA additives, on charge retention over cycling and on self-discharge of full cells. After the 25 cycles of the charge capability test, the charge retention reached values up to 70% with LF30 and 87% with LF30 and additives, and fully charged cells with LF30-additives delivered 53% of the stored charge after one week in OCV.

Polymer electrolytes have been proposed as replacement for conventional liquid electrolytes in lithium-ion batteries (LIBs) due to their intrinsic enhanced safety. Nevertheless, the power delivery of these materials is limited by the concentration gradient of the lithium salt. Single-ion conducting polyelectrolytes represent the ideal solution since their nature prevents polarization phenomena. Herein, the preparation of a new family of single-ion conducting block copolymer polyelectrolytes via reversible addition-fragmentation chain transfer polymerization technique is reported. These copolymers comprise poly(lithium 1-[3-(methacryloyloxy)propylsulfonyl]-1-(trifluoromethylsulfonyl)imide) and poly(ethylene glycol) methyl ether methacrylate blocks. The obtained polyelectrolytes show low Tg values in the range of -61 to 0.6 °C, comparatively high ionic conductivity (up to 2.3 × 10(-6) and 1.2 × 10(-5) S cm(-1) at 25 and 55 °C, respectively), wide electrochemical stability (up to 4.5 V versus Li(+)/Li), and a lithium-ion transference number close to unity (0.83). Owing to the combination of all mentioned properties, the prepared polymer materials were used as solid polyelectrolytes and as binders in the elaboration of lithium-metal battery prototypes with high charge/discharge efficiency and excellent specific capacity (up to 130 mAh g(-1)) at C/15 rate.

Here we demonstrate that by regulating the mobility of classic −EO− based backbones, an innovative polymer electrolyte system can be architectured. This polymer electrolyte allows the construction of all solid lithium-based polymer cells having outstanding cycling behaviour in terms of rate capability and stability over a wide range of operating temperatures. Polymer electrolytes are obtained by UV-induced (co)polymerization, which promotes an effective interlinking between the polyethylene oxide (PEO) chains plasticized by tetraglyme at various lithium salt concentrations. The polymer networks exhibit sterling mechanical robustness, high flexibility, homogeneous and highly amorphous characteristics. Ambient temperature ionic conductivity values exceeding 0.1 mS cm−1 are obtained, along with a wide electrochemical stability window (>5 V vs. Li/Li+), excellent lithium ion transference number (>0.6) as well as interfacial stability. Moreover, the efficacious resistance to lithium dendrite nucleation and growth postulates the implementation of these polymer electrolytes in next generation of all-solid Li-metal batteries working at ambient conditions.

In recent years, wide research efforts have been devoted to the development of solid polymer electrolytes (SPEs) with the goal to enhance the intrinsic safety and replace the traditional flammable liquid electrolytes employed in the lithium-ion battery technology (LIBs). Among SPEs, a new class of polyelectrolytes, namely poly(ionic liquid)s (PILs) has deserved considerable attention. Although significant progress has already been achieved with cationic PILs/Li salt composites, the power delivery of such electrolytes is hampered by the strong concentration gradients formed during battery operation. As an alternative the anionic polyelectrolytes or so called “polymeric single-ion conductors” have been recently suggested. In this work, we present two approaches for the preparation of the innovative families of single-ion polymer electrolytes. First approach consists in the synthesis of ionic block copolymers via RAFT polymerization technique. Such copolymers comprise poly(lithium 1-[3-(methacryloyloxy)propylsulfonyl]-1-(trifluoromethylsulfonyl)imide) and poly(ethylene glycol) methyl ether methacrylate blocks (Fig. 1A). This method allowed to vary the molecular weight of PILs and to gain the desired control over polymer’s T g and ionic conductivity. The “best” obtained polyelectrolyte with Mn = 2.5x104 g/mol shows the T g as low as -61 ºC, ionic conductivity as high as 2.3×10-6 and 1.2×10-5 S cm-1 at 25 and 60o C, respectively, wide electrochemical stability (4.5 V vs Li+/Li) and a lithium-ion transference number close to unity (0.83). Second utilized approach involves the free radical copolymerization of ionic liquid like monomers with poly(ethylene glycol) methyl ether methacrylate for the preparation of random ionic copolymers. Here, polymer’s ionic conductivity and T g were controlled by the nature of ionic monomer and the molar composition of statistic copolymer (Fig. 1B). The “optimal” coPIL with Mw = 4.2x105 g/mol demonstrates T g = -56 ºC, ionic conductivity equal to 1.8×10-6 and 1.5×10-5 S cm-1 at 25 and 60o C, respectively, wide electrochemical stability (4.2 V vs Li+/Li) and high lithium-ion transference number (0.91). Owing to the combination of all mentioned properties, the prepared polymer materials were used as solid polyelectrolytes as well as binders in the elaboration of truly solid Li/coPIL/LiFePO4 battery prototypes working at 60-70oC and delivering large capacities (up to 130 mAh/g), with an impressive charge/discharge efficiency and the capability to reversibly operate at relatively high rates up to C/5 (Fig. 1C). This work was supported by the Russian Foundation for Basic Research (projects no. 14-29-04039_ofi_m and 16-03-00768_a) and by European Commission (project no. 318873 «IONRUN»). J.R.N. gratefully acknowledges financial support from MARS-EV project (FP7/2007-2013, under grant agreement n° 609201). Figure 1

Hybrid solid electrolytes which combine the properties of inorganic and polymeric ion conductors are being investigated for lithium batteries which use lithium metal anodes. The number of inorganic/polymer compositions and their synergy in ion-conducting properties are limited by the hybrid fabrication method and the limited compatibility between both types of materials. Here we report a hybrid solid electrolyte formed by a poly(ethylene glycol) type single-ion polymer network and ceramic garnet-type nanoparticles of Li7−3XAlXLa3Zr2O12 (LLZO) with very high lithium conductivity. The combination of a lithium-single ion polymer matrix with LLZO inorganic particles results in flexible free-standing films by using a fast UV-photopolymerization process with facile control of its composition. This methodology showed excellent dispersion of the LLZO nanoparticles within the gel polymer network with up to 50 wt% ceramic content, as shown in the enviromental ESEM images. These hybrid electrolytes have high ionic conductivity values (1.4 × 10−4 S cm−1 at 25 °C) and high lithium transference number as compared to previous hybrid electrolytes. The effect of LLZO nanoparticle content on the lithium transport was investigated in detail using solid-state nuclear magnetic resonance spectroscopy (NMR). Finally, determination of the critical current density (CCD) before lithium dendrites are initiated has been carried out on both pristine and hybrid electrolytes, so as to assess their potential as solid electrolytes for lithium metal batteries. This work was supported by the European Commission’s funded Marie Sklodowska-Curie project POLYTE-EID (Project No. 765828). L.P. has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska–Curie grant agreement No 797295.

8 figures.-- Supporting information available on the editor's web page.-- This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Biomaterials Science & Engineering, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://dx.doi.org/10.1021/acsbiomaterials.9b01316, Three-dimensional (3D) scaffolds with tailored stiffness, porosity, and conductive properties are particularly important in tissue engineering for electroactive cell attachment, proliferation, and vascularization. Carbon nanotubes (CNTs) and poly(3,4-ethylenedioxythiophene) (PEDOT) have been extensively used separately as neural interfaces showing excellent results. Herein, we combine both the materials and manufacture 3D structures composed exclusively of PEDOT and CNTs using a methodology based on vapor phase polymerization of PEDOT onto a CNT/sucrose template. Such a strategy presents versatility to produce porous scaffolds, after leaching out the sucrose grains, with different ratios of polymer/CNTs, and controllable and tunable electrical and mechanical properties. The resulting 3D structures show Young’s modulus typical of soft materials (20–50 kPa), as well as high electrical conductivity, which may play an important role in electroactive cell growth. The conductive PEDOT/CNT porous scaffolds present high biocompatibility after 3 and 6 days of C8-D1A astrocyte incubation., The Spanish Ministry of Economy and Competitiveness MINECO (project CTQ2016-76721-R), the University of Trieste, Diputación Foral de Gipuzkoa program Red (101/16), and the European Commission (H2020-MSCA-RISE-2016, grant agreement no. 734381, acronym CARBO-IMmap) and ELKARTEK bmG2017 (Ref: Elkartek KK-2017/00008, BOPV resolution: 8 Feb 2018) are gratefully acknowledged for financial support. MP, as the recipient of the AXA Chair, is grateful to the AXA Research Fund for financial support. This work was performed under the Maria de Maeztu Units of Excellence Program from the Spanish State Research Agency—grant no. MDM-2017-0720. NA has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 753293, acronym NanoBEAT.