Organic Inorganic Hybrid Electrolyte Research Articles

Optimizing Aqueous Zinc-Sulfur Battery Performance via Regulating Acetonitrile Co-Solvents and Carbon Nanotube Carriers.

Rechargeable aqueous zinc-sulfur batteries (AZSBs) are gaining attention due to their high energy density, ultra-stable discharge platform, and safety. However, poor liquid/solid reaction processes at the anode and cathode reduce reaction kinetics, and the severe dissolution of polysulfides causes shuttle effects during discharge/charge cycles, hindering practical applications. Improving performance requires optimizing both the cathode and electrolyte. Herein, we design an organic-inorganic hybrid electrolyte (zinc trifluoromethanesulfonate and trace iodine monomer dissolved in an acetonitrile/water co-solvent (AN-X)) and a partially exfoliated multi-walled carbon nanotube (PECNT) hosted sulfur (S@PECNTs) cathode for AZSBs. The sulfur is highly dispersed along the PECNTs with appropriate wettability at the electrode/electrolyte interface using AN-3 as the electrolyte. Meanwhile, this electrolyte inhibits hydrogen evolution at negative potentials and promotes uniform Zn ion stripping/plating. Expressively, the AN-3-based AZSB exhibits a high discharge capacity of 1370 mAh g-1 with excellent Coulombic efficiency (79.9%), outstanding rate capability, and cycling performance. These improvements are attributed to the synergistic effect between the S@PECNTs and the AN-3 electrolyte, which reduces Rct to enhance reaction kinetics and blocks the dissolution and shuttle effect of polysulfides, ensuring a reversible reaction between zinc and sulfur.

POSS based poly (zwitterionic liquids) electrolytes with 3D crosslinked networks for lithium metal batteries

Polymer electrolyte is a potential candidate for the next-generation lithium metal batteries. However, its low room temperature ionic conductivity limited its practical application. Here, a novel POSS-based poly (zwitterionic liquids) organic–inorganic hybrid electrolyte with 3D crosslinked networks was proposed for enabling lithium-ion fast transport by photoinitiated radical polymerization of vinyl zwitterionic monomers and acrylate monomers containing rich EO units and POSS. The synergistic effect of unique structures of 3D organic–inorganic hybrids gel electrolytes such as zwitterionic, rich EO segments and POSS cages facilitate Li+ conduction, resulting in high room temperature ionic conductivity (1.03 × 10-3 S cm-1) and a satisfactory Li+ transference number (0.45). The lithium-symmetric batteries assembled with the novel POSS-based poly (zwitterionic liquids) gel hybrid electrolytes can operate continuously at 0.1 mA cm-2 for 2300 h without any obvious short circuit, indicating good interfacial compatibility between the electrolytes and lithium electrodes. The Li/LiFePO4 batteries assembled with the novel POSS-based poly (zwitterionic liquids) gel hybrid electrolytes exhibit long-term stability.

Ultrathin All-Solid-State MoS2-Based Electrolyte Gated Synaptic Transistor with Tunable Organic-Inorganic Hybrid Film.

Electrolyte-gated synaptic transistors (EGSTs) have attracted considerable attention as synaptic devices owing to their adjustable conductance, low power consumption, and multi-state storage capabilities. To demonstrate high-density EGST arrays, 2D materials are recommended owing to their excellent electrical properties and ultrathin profile. However, widespread implementation of 2D-based EGSTs has challenges in achieving large-area channel growth and finding compatible nanoscale solid electrolytes. This study demonstrates large-scale process-compatible, all-solid-state EGSTs utilizing molybdenum disulfide (MoS2) channels grown through chemical vapor deposition (CVD) and sub-30nm organic-inorganic hybrid electrolyte polymers synthesized via initiated chemical vapor deposition (iCVD). The iCVD technique enables precise modulation of the hydroxyl group density in the hybrid matrix, allowing the modulation of proton conduction, resulting in adjustable synaptic performance. By leveraging the tunable iCVD-based hybrid electrolyte, the fabricated EGSTs achieve remarkable attributes: a wide on/off ratio of 109, state retention exceeding 103, and linear conductance updates. Additionally, the device exhibits endurance surpassing 5 × 104 cycles, while maintaining a low energy consumption of 200 fJ/spike. To evaluate the practicality of these EGSTs, a subset of devices is employed in system-level simulations of MNIST handwritten digit recognition, yielding a recognition rate of 93.2%.

Lithium-Ion Transport and Exchange between Phases in a Concentrated Liquid Electrolyte Containing Lithium-Ion-Conducting Inorganic Particles.

Understanding Li+ transport in organic-inorganic hybrid electrolytes, where Li+ has to lose its organic solvation shell to enter and transport through the inorganic phase, is crucial to the design of high-performance batteries. As a model system, we investigate a range of Li+-conducting particles suspended in a concentrated electrolyte. We show that large Li1.3Al0.3Ti1.7P3O12 and Li6PS5Cl particles can enhance the overall conductivity of the electrolyte. When studying impedance using a cell with a large cell constant, the Nyquist plot shows two semicircles: a high-frequency semicircle related to ion transport in the bulk of both phases and a medium-frequency semicircle attributed to Li+ transporting through the particle/liquid interfaces. Contrary to the high-frequency resistance, the medium-frequency resistance increases with particle content and shows a higher activation energy. Furthermore, we show that small particles, requiring Li+ to overcome particle/liquid interfaces more frequently, are less effective in facilitating Li+ transport. Overall, this study provides a straightforward approach to study the Li+ transport behavior in hybrid electrolytes.

Synergistic effect of organic-inorganic hybrid electrolyte for ultra-long Zn–I2 batteries

Hydrogel electrolytes are widely used in wearable aqueous zinc-ion batteries (ZIBs) which are considered as the most promising candidate for future energy storage systems. However, traditional organic hydrogel ions have the disadvantages of low ionic conductivity and poor mechanical properties. To conquer this, an organic-inorganic hybrid hydrogel electrolyte (PVA/CNC–C/sepiolite) is developed to improve ionic conductivity and reduce side reactions in ZIBs simultaneously. In this system, hydrogen bonds are formed between sulfonic acid groups in the polymer and the hydroxyl groups in sepiolite. The existence of these hydrogen bonds enhances the binding force between the organic and inorganic components, thus improving the ionic conductivity and mechanical properties of the electrolyte. Also, sulfonic acid groups in this hydrogel electrolyte can induce homogeneous deposition of Zn2+. The pores between the multilayer structures in sepiolite further optimize the ion transport channel and improve the transfer kinetics of Zn2+. Due to the synergistic effect of organic-inorganic compositions in this electrolyte, the Zn/Zn cell operates for more than 2000 h and Zn/I2 cell full exhibits an ultra-stable lifespan for 10,000 cycles. This work opens up a new avenue for the design of hydrogel electrolytes in ZIBs.

Inorganic–Organic Hybrid Electrolytes Based on Al-Doped Li7La3Zr2O12 and Ionic Liquids

Organic–inorganic hybrid electrolytes based on Al-doped Li7La3Zr2O12 (LLZO) and two different ionic liquids (ILs), namely N-ethoxyethyl-N-methylpiperidinium bis(fluorosulfonyl)imide (FSI IL) and N-ethoxyethyl-N-methylpiperidinium difluoro(oxalato)borate (DFOB IL), were prepared with the aim of improvement of inherent flexibilities of inorganic solid electrolytes. The composites were evaluated in terms of thermal, spectroscopical, and electrochemical properties. In the impedance spectra of LLZO composites with 15 wt% ILs, a semi-circle due to grain boundary resistances was not observed. With the sample merely pressed with 1 ton, without any high-temperature sintering process, the ionic conductivity of 10−3 S cm−1 was achieved at room temperature. Employing a ternary composite of LLZO, FSI IL, and LiFSI as an electrolyte, all-solid-state lithium metal batteries having LiFePO4 as a cathode were assembled. The cell exhibited a capacity above 100 mAh g−1 throughout the course of charge–discharge cycle at C/20. This confirms that FSI IL is an effective additive for inorganic solid electrolytes, which can guarantee the ion conduction.

High-performance polymer electrolyte membrane modified with isocyanate-grafted Ti3+ doped TiO2 nanowires for lithium batteries

The Ti3+ doped TiO2 nanowires were grafted by tolylene-2,4- diisocyanate (TDI) and applied as a modifier for the preparation of organic–inorganic hybrid electrolyte in high performing lithium batteries. The PEO-based polymer electrolyte was optimized at different organic–inorganic ratios and exhibited excellent lithium-ion conductivity of 1 × 10−4 S·cm−1 at 30 °C when adding 8% TDI-TiO2 nanowires, outstanding electrochemical stability with a wide electrochemical window up to 5.5 V at 60 °C and a high lithium-ion transport number of 0.36. The LiFePO4|PTTNW8%|Li cells deliver excellent rate capability and cycling performance, with a high initial discharge capacity up to 151 mAh·g−1 at 60 °C at 0.1 C rate and excellent capacity retention of 91% after 100th cycle. NCM811|PTTNW8%|Li high-voltage lithium batteries were also demonstrated at a 50 °C, which displayed a superior cycling performance. Therefore, the prepared PEO-TDI-TiO2 electrolyte is a promising polymer electrolyte for solid- state lithium batteries.

An Organic-Inorganic Hybrid Electrolyte as a Cathode Interlayer for Efficient Organic Solar Cells.

An organic-inorganic hybrid electrolyte based on a cyclic Ti-oxo cluster as the inorganic core and naphthalene-based organic ammonium bromide salts as the electrolyte was developed with easy synthesis and low cost. The new hybrid electrolyte exhibits excellent solubility in methanol, aligned work function, good conductivity, and amorphous state in thin film, enabling its successful application as a cathode interlayer in organic solar cells with a high power conversion efficiency of 17.19 %. This work demonstrates that the hybrid electrolytes are a new kind of semiconductor, exhibiting promising applications in organic electronics.

An Organic–Inorganic Hybrid Electrolyte as a Cathode Interlayer for Efficient Organic Solar Cells

AbstractAn organic–inorganic hybrid electrolyte based on a cyclic Ti‐oxo cluster as the inorganic core and naphthalene‐based organic ammonium bromide salts as the electrolyte was developed with easy synthesis and low cost. The new hybrid electrolyte exhibits excellent solubility in methanol, aligned work function, good conductivity, and amorphous state in thin film, enabling its successful application as a cathode interlayer in organic solar cells with a high power conversion efficiency of 17.19 %. This work demonstrates that the hybrid electrolytes are a new kind of semiconductor, exhibiting promising applications in organic electronics.

Interfacial barrier free organic-inorganic hybrid electrolytes for solid state batteries

Organic-inorganic hybrid solid electrolytes (HSEs) are expected to overcome the inherent limitations of rigid fragile inorganic electrolytes for solid state batteries. Li-ion conductive filler such as garnet Li7La3Zr2O12 (LLZO) is proposed for the high performance of HSEs, unfortunately, which suffers from native surface layer resistance to Li-ion transport. Here we present highly conductive polyvinylidene fluoride (PVDF)-based HSEs incorporating LLZO fillers, whose resistive barriers are eliminated by dry etching. Our optimal composition of etched LLZO fillers (30 wt%) leads to ionic conductivity of 4.05 × 10-4 S cm-1, about two-fold improvement from non-etched counterpart. Li symmetric cells with etched fillers exhibit low interfacial resistance of 110 Ω cm2 and minimal overpotential of 90 mV. Moreover, high capacity of 79 mA h g-1 is highlighted at 4C, comparable or superior to liquid electrolyte or sulfide-based electrolyte devices. Interfacial environment in HSEs ideally modified for Li-ion transport is identified by 7Li NMR measurements.

Enhanced transport and favorable distribution of Li-ion in a poly(ionic liquid) based electrolyte facilitated by Li1.3Al0.3Ti1.7(PO4)3 nanoparticles for highly-safe lithium metal batteries

Solid-state batteries, which exhibit characteristics including uniform Li deposition, non-flammability and low interfacial resistance, are desirable for novel energy storage devices. Herein, a self-standing, fireproof and electrochemically stable organic-inorganic composite ionogel electrolyte was carefully designed and prepared by using polymerized ionic liquid (PIL), ionic liquid (IL), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and lithium aluminum titanium phosphate (LATP) nanoparticles. The incorporation of LATP nanoparticles into polymer backbone was found to facilitate ionic transport due to the homogenous Li+ distribution, which would further boost the ionic conductivity and mechanical properties. In addition, the introduction of IL favored the reduction of interface resistance. Benefiting from the nonflammability, the thermal shrinkage performance of as-prepared electrolyte could stand over a broad operating temperature range. A Li/Li symmetric cell containing optimized PIL-14 wt% LATP could be cycled steadily for over 2000 h at 50 °C. A lithium metal battery containing composite ionogel electrolyte exhibited an outstanding specific capacity of 145 mAh g−1 and 95% capacity retention at 50 °C even after 100 cycles. This study indicates that the co-employment of IL and inorganic nanoparticle is an effective strategy for the construction of organic-inorganic hybrid electrolytes for high-safety solid-state lithium metal batteries (LMBs).

Effect of nanoparticles in cathode materials for flexible Li-ion batteries

In this article, we report the effect of using nanoparticles for LiMn2O4 cathode materials in flexible batteries with organic–inorganic hybrid electrolytes. LiMn2O4 nanoparticles for the cathode are prepared by pyro-synthesis. Electrochemical measurement indicated the discharge capacities were 118.41 and 138.12mAhg−1 and the coulombic efficiencies were 91.50% and 97.28% for the micro- and nano-LMO materials, respectively. This is attributed to the nano-LiMn2O4 material having particle sizes in the nanoscale dimension, and shorter diffusion paths combined with a large contact area at the electrode/electrolyte interface. Furthermore, the pouch-type cells demonstrated similar properties, with initial discharge capacities of 85.63 and 99.96mAhg−1 and coulomb efficiencies of 79.27% and 90.27% for the micro- and nano-LMO cells, respectively. Nanoparticles allow Li+ ions to de-intercalate and intercalate very easily because of the very short lithium diffusion distance.

Flame-retardant properties of in situ sol-gel synthesized inorganic borosilicate/silicate polymer scaffold matrix comprising ionic liquid

This paper focuses on the superiority of organic-inorganic hybrid ion-gel electrolytes for lithium-ion batteries (LiBs) over commercial electrolytes, such as 1 M LiPF6 in 1:1 ethylene carbonate (EC): dimethyl carbonate (DMC) {1 M LiPF6-EC: DMC}, in terms of their flame susceptibility. These ion-gel electrolytes possess ionic liquid monomers, which are confined within the borosilicate or silicate matrices that are ideal for nonflammability. Naked flame tests confirm that the organic-inorganic hybrid electrolytes are less susceptible to flames, and these electrolytes do not suffer from a major loss in terms of weight. In addition, the hybrids are self-extinguishable. Therefore, these hybrids are only oxidized when subjected to a flame unlike other commercial electrolytes used in lithium-ion batteries. Supplementary analyses using differential scanning calorimetric studies reveal that the hybrids are glassy until the temperature reaches more than 100°C. The current results are consistent with previously published data on the organic-inorganic hybrids.

Ionic liquid‐based organic–inorganic hybrid electrolytes: Impact of in situ obtained and dispersed silica

ABSTRACTOrganic–inorganic hybrid electrolytes based on PEO‐NaTFSI‐ionic liquid (HMIMTFSI)‐silica (in situ production via sol gel process) are being reported in this article. The variation in conductivity with ionic liquid (IL) addition has been explained on the basis of number of free TFSI anions evaluated using ATR‐IR data. The deconvolution of the IR spectra of these hybrid electrolytes has given evidence of ion‐pair formation which has been compared vis‐á‐vis the conductivity variation. The hybrid electrolyte with maximum conductivity comprises the highest number of free imide ions and has lowest glass transition temperature. FESEM has displayed a porous and layered surface morphology with dispersed silica nanoparticles. In addition, the optimized hybrid electrolyte has been compared with 5 wt% (limit of mechanical stability) ex situ silica added composite where the temperature cycling of conductivity has shown that the ex situ dispersed hybrid electrolytes do not retrace their conductivity path contrary to the in situ prepared hybrid electrolytes. This behavior has been explained to be due to the hindrance offered by the ex situ added silica in the recrystallization kinetics of PEO. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018, 56, 207–218

Organic-inorganic hybrid electrolytes by in-situ dispersion of silica nanospheres in polymer matrix

In the present study, an organic-inorganic hybrid electrolyte based on a polymer (PEO) and silica (SiO2) matrix containing different amounts of lithium salt (LiTf) is being reported. The synthesized hybrid electrolytes are freestanding flexible films with good mechanical stability. The interaction/complexation of the cation (Li+) with the polymeric chain has been confirmed by the ATR-IR spectroscopic measurements. TEM images of these hybrid electrolytes clearly show the appearance of in-situ formed silica nanospheres within the PEO matrix while the FESEM analysis confirms the layered morphology of such systems. DSC results show that the melting temperature (Tm) of the hybrid electrolytes decreases with the increase in the concentration of lithium salt which, in turn, is responsible for the increase in the ionic conductivity due to the enhancement in the flexibility of the polymer backbone. It is evident from the TGA that these hybrid electrolytes are thermally stable upto 200°C. The ionic conductivity obtained by complex impedance spectroscopy technique has been found to increase with increasing concentrations of LiTf and reaches a value of 1.24×10−6S/cm at 30°C and 1.15×10−4S/cm at 100°C for the loading of 20wt% of LiTf in the matrix. Temperature dependence of ionic conductivity has been found to be typical of thermally activated process as well as phase transition behavior of PEO both at T>Tm and T<Tm. These results indicate that the prepared organic-inorganic hybrid electrolyte films could be a promising alternative as an electrolyte for all solid state rechargeable lithium-ion batteries.

Hybrid electrolytes based on ionic liquids and amorphous porous silicon nanoparticles: Organization and electrochemical properties

Ionic liquids (ILs) and ionic liquid-nanoparticle (IL-NP) hybrid electrolytes have garnered a lot of interest due to their unique properties that stimulate their use in various applications. Herein, we investigate the electrochemical and photo-physical properties of organic-inorganic hybrid electrolytes based on three imidazolium-based ionic liquids, i.e., 1-buthyl-3-methylimidazolium thiocyanate ([bmim] [SCN]), 1-ethyl-3-methylimidazolium tetrafluoroborate ([emim] [BF4]) and 1-buthyl-3-methylimidazolium acetate ([bmim] [Ac]) that are covalently tethered to amorphous porous silicon nanoparticles (ap-Si NPs). We found that the addition of ap-Si NPs confer to the ILs a pronounced boost in the electrocatalytic activity, and in mixtures of ap-Si NPs and [bmim] [SCN], the room-temperature current transport is enhanced by more than 5 times compared to bare [bmim] [SCN]. A detailed structural investigation by transmission electron microscope (TEM) showed that the ap-Si NPs were well dispersed, stabilized and highly aggregated in [bmim] [SCN], [emim] [BF4] and [bmim] [Ac] ILs, respectively. These observations correlate well with the enhanced current transport observed in ap-Si NPs/[bmim] [SCN] evidenced by electrochemical measurements. We interpreted these observations by the use of UV–vis absorbance, photoluminescence (PL), FTIR and solid-state NMR spectroscopy. We found that the ap-Si NPs/[bmim] [SCN] hybrid stands out due to its stability and optical transparency. This behavior is attributed to the iron(III) thiocyanate complexion as per the experimental findings. Furthermore, we found that the addition of NPs to [emim] [BF4] alters the equilibrium of the IL, which consequently improved the stability of the NPs through intermolecular interactions with the two ionic layers (anionic and cationic layers) of the IL. While in the case of [bmim] [Ac], the dispersion of ap-Si NPs was restrained because of the high viscosity of this IL.

Solid polymer electrolytes based on coupling of polyetheramine and organosilane for applications in electrochromic devices

In this work, cyanuric chloride is employed as the core element to react with polyetheramine in various ratios, and then chemical crosslinking with an organosilane, i.e., (3-isocyanatopropyl)triethoxysilane (ICPTES) to form a new organic-inorganic hybrid electrolyte with a core branched structure. The solid state of the hybrid electrolyte is fabricated via the doping of LiClO4 salt, and possessed the maximum ionic conductivity value of 1.1×10−4Scm−1 at 30°C and electrochemical stability window of around 5.0V for the sample with the [O]/[Li] ratio of 32. The structure of the organic-inorganic hybrid is confirmed by FTIR and solid-state NMR measurements. The lithium ion mobility in the hybrid electrolyte is investigated by monitoring the lithium linewidths from static 7Li solid-state NMR. An optical density change value of 0.56 and an exceptionally high coloration efficiency value of 675cm2C−1 with good cycle life are obtained when the present hybrid electrolyte is employed to fabricate the prototype electrochromic device. These electrochromic performances are the best as compared to the previously reported electrochromic devices made of hybrid electrolytes. The present organic-inorganic hybrid electrolyte holds great potentials to be used in different applications of electrochromic devices.

Novel Organic-Inorganic Hybrid Electrolyte to Enable LiFePO4 Quasi-Solid-State Li-Ion Batteries Performed Highly around Room Temperature.

A novel type of organic-inorganic hybrid polymer electrolytes with high electrochemical performances around room temperature is formed by hybrid of nanofillers, Y-type oligomer, polyoxyethylene and Li-salt (PBA-Li), of which the Tg and Tm are significantly lowered by blended heterogeneous polyethers and embedded nanofillers with benefit of the dipole modification to achieve the high Li-ion migration due to more free-volume space. The quasi-solid-state Li-ion batteries based on the LiFePO4/15PBA-Li/Li-metal cells present remarkable reversible capacities (133 and 165 mAh g-1 @0.2 C at 30 and 45 °C, respectively), good rate ability and stable cycle performance (141.9 mAh g-1 @0.2 C at 30 °C after 150 cycles).

Optimisation of Potential Boundaries with Dynamic Electrochemical Impedance Spectroscopy for an Anodic Half‐Cell Based on Organic–Inorganic Hybrid Electrolytes

AbstractAdvances in lithium‐ion battery electrolyte materials have created a niche for the evolution of various electrochemical techniques. Appropriate diagnostic techniques to evaluate new electrolytes are of paramount importance, as the conventional techniques lead to prejudiced conclusions. Organic–inorganic hybrid ion gels, employed as electrolytes for the carbon anodic half‐cell, showing discrepancies in its charge discharge profile, were probed for their abnormal charge–discharge behaviour. Dynamic electrochemical impedance spectroscopy (DEIS) was used as a diagnostic tool; inferences were drawn from charge‐transfer resistance values and used as indicators to delimit the potential boundaries for optimum performance of the cells. Identifying the cut‐off potentials through DEIS and subsequent charge–discharge provided clean profiles.

Effect of Al2O3 nanowires on the electrochemical properties of di-ureasil-based organic–inorganic hybrid electrolytes

Organic–inorganic hybrid electrolytes based on the reaction of triblock copolymer poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol) bis(2-aminopropyl ether) and 3-(triethoxysilyl)propyl isocyanate doped with lithium trifluoromethanesulfonate and Al2O3 nanowires were synthesized by a sol–gel process. The structural and electrochemical properties of the materials thus obtained were systematically investigated by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry, thermogravimetric analysis, powder X-ray diffraction, 29Si CPMAS (cross-polarization magic angle spinning) NMR, alternate current impedance, and linear sweep voltammetry measurements. FTIR spectra showed the occurrence of complexation and interaction among the components. The maximum ionic conductivity values of 9.8 × 10−5 S cm−1 and 6.8 × 10−4 S cm−1 were obtained at 30 and 75 °C, respectively, for the solid hybrid electrolyte with a [O]/[Li] ratio of 16 and 1 wt% of Al2O3 nanowires. A Vogel–Tamman–Fulcher-like temperature dependence of ionic conductivity was observed for the hybrid electrolytes doped with fillers. The electrochemical stability window of ~4.0 V makes the organic–inorganic hybrid electrolyte promising for lithium-ion battery application at low voltages.