An ionic‐liquid‐based Zn salt electrolyte is demonstrated to be an effective route to solve both the side‐reaction of the hydrogen evolution reaction (HER) and Zn‐dendrite growth in Zn‐ion batteries. ...The developed electrolyte enables hydrogen‐free, dendrite‐free Zn plating/stripping over 1500 h cycle (3000 cycles) at 2 mA cm–2 with nearly 100% coulombic efficiency. Meanwhile, the oxygen‐induced corrosion and passivation are also effectively suppressed. These features bring Zn‐ion batteries an unprecedented long lifespan over 40 000 cycles at 4 A g–1 and high voltage of 2.05 V with a cobalt hexacyanoferrate cathode. Furthermore, a 28.6 µm thick solid polymer electrolyte of a poly(vinylidene fluoride‐hexafluoropropylene) film filled with poly(ethylene oxide)/ionic‐liquid‐based Zn salt is constructed to build an all‐solid‐state Zn‐ion battery. The all‐solid‐state Zn‐ion batteries show excellent cycling performance of 30 000 cycles at 2 A g–1 at room temperature and withstand high temperature up to 70 °C, low temperature to –20 °C, as well as abuse test of bending deformation up to 150° for 100 cycles and eight times cutting. This is the first demonstration of an all‐solid‐state Zn‐ion battery based on a newly developed electrolyte, which meanwhile solves the deep‐seated hydrogen evolution and dendrite growth problem in traditional Zn‐ion batteries.
Zn anodes persistently suffer from deep‐seated issues of the parasitic hydrogen evolution reaction (HER) and dendrite growth. Meanwhile, hydrogel‐based Zn batteries suffer from poor mechanical properties and dehydration. An ionic‐liquid‐based Zn salt electrolyte to solve both the side‐reaction of the HER and Zn‐dendrite growth is developed. Furthermore, a solid polymer electrolyte is constructed to build an all‐solid‐state Zn‐ion battery.
Composite solid electrolyte (CSE) membranes for lithium metal batteries attract great attention with excellent safety and suitable flexibility. Herein, we construct a polyethylene oxide-based ...ultrathin CSE membrane that is enhanced by a 3D fiber network composed of Poly (vinylidene fluoride-co-hexafluoropropylene) fibers and Li7La3Zr2O12 particles directly fabricated on the cathode. The 3D fiber network facilitates the rapid transport and uniform deposition of Li+, and enhances the mechanical strength of the electrolyte membrane, thereby effectively inhibiting the growth of lithium dendrites. Moreover, the unique preparation method reduces the interfacial impedance, and it can also greatly reduce the electrolyte thickness, which is beneficial to increasing the energy density of the battery. The lithium symmetric battery shows stable cycling over 1500 h under 0.2 mA cm−2. Li/LiFePO4 battery with the CSE membrane exhibits a high reversible capacity of 155.8 mAh·g−1 at 0.2 C for 100 cycles and the capacity retention rate is 98.0%. Furthermore, the obtained CSE membrane has a broadened electrochemical window of 4.83 V, and the reversible capacity of the Li/LiNi0.8Co0.1Mn0.1O2 battery is 160.6 mAh·g−1 at 0.2 C for 100 cycles. These findings showed that the structure proposed here is a viable electrolyte strategy for advanced solid-state lithium metal batteries.
Display omitted
•An ultrathin composite solid electrolyte membrane supported by a 3D fiber network structure was successfully prepared.•Unique integrated process greatly improves interfacial contact between electrolyte and electrode material.•The CSE membrane presents improved mechanical strength, ionic conductivity, Li+ migration number, and electrochemical window.•The CSE membrane can be matched with the LFP and NCM811 to achieve good cycling stability.
Polyethylene oxide‐poly(3,4‐ethylenedioxythiophene) (PEO‐PEDOT) nanocomposite films ‐ incorporated with NiZnFeO4 nanoparticles (NPs) were deposited using a dip‐coating technique. X‐ray diffraction ...(XRD) analysis revealed peaks at 35.4, 43.2, 54.5, and 56.3° diffraction angles, corresponding to NiZnFeO4NPs diffraction planes of 311, 400, 422, and 511, respectively. The PEO‐PEDOT film exhibited a smooth amorphous nature with a sheet nanostructure behavior. The incorporation of NiZnFeO4NPs NPs into the PEO‐PEDOT nanocomposite films led to an increase in surface roughness and thermal stability. The nanocomposite films also exhibited sheet nanostructure behavior as observed by SEM micrographs. The bandgap energies of the films, as deduced from the Tauc plot, exhibited a monotonic decrease from 3.91 to 3.60 eV as the NiZnFeO4NPs concentration increased from 0 to 8 wt%. A mathematical model was formulated to predict the bandgap energies versus NiZnFeO4NPs concentration. Additionally, the electrical conductivity of the nanocomposite films increased monotonically from 0.46 to 1.30 mS cm−1 as the NiZnFeO4NPs concentration increased from 0 to 8 wt%, as determined by 4‐point probe. The observed correlation between the optical and electrical properties of the nanocomposite films indicates promising prospects for utilizing these materials in optoelectronic devices.
Characterizations of PEO‐PEDOT/NiZnFeO4 NPs nanocomposite films.
Polyethylene oxide (PEO) complexed with molecular iodine (
I
2
) forming PEO/
I
2
complex composites stand‐free films were investigated using dielectric relaxation, X-ray photoelectron spectroscopy ...(XPS), UV–Vis spectrophotometry, structural and morphological techniques. Scanning electron microscopy was used to monitor the variation in the surface morphology and the related roughness. 2D Energy-dispersive X-ray spectroscopy (EDX) measurements enabled to observe the distribution of iodine on the film surface. High resolution XPS measurements were used to define the iodine anion types and the metallic iodine existence, as well as the relevant concentrations based on the binding energies. The dielectric relaxation measurements were carried out over the frequency range from 0.1 to 10
7
Hz and temperature range from 155 to 330 K. Dielectric loss (ε′′) curves were fitted to the Havriliak–Negami (HN) model for one and/or two relaxation peaks (α and β), with and without the electrical conductivity contribution term, in order to deduce the relaxation time (τ) and the dielectric strengths (Δ
ε
), in addition to the electrical conductivities (
σ
). The temperature-dependent data of β- and σ- relaxations follow the law of Arrhenius thermal activation indicating the presence of typical glass-forming polymers. Δ
ε
of α-relaxation obeys the curvature pattern of Vogel-Tammann-Fulcher (VTF) thermal activation law. The electrical conductivity of the system increases 6000 folds by doping PEO with 5 wt% of iodine at the same temperature (293 K).
Composite polymer electrolyte membranes are fabricated by the incorporation of Li10SnP2S12 into the poly(ethylene oxide) (PEO) matrix using a solution-casting method. The incorporation of ...Li10SnP2S12 plays a positive role on Li-ionic conductivity, mechanical property, and interfacial stability of the composite electrolyte and thus significantly enhances the electrochemical performance of the solid-state Li–S battery. The optimal PEO–1%Li10SnP2S12 electrolyte presents a maximum ionic conductivity of 1.69 × 10–4 S cm–1 at 50 °C and the highest mechanical strength. The possible mechanism for the enhanced electrochemical performance and mechanical property is analyzed. The uniform distribution of Li10SnP2S12 in the PEO matrix inhibits crystallization and weakens the interactions among the PEO chains. The PEO–1%Li10SnP2S12 electrolyte exhibits lower interfacial resistance and higher interfacial stability with the lithium anode than the pure PEO/LiTFSI electrolyte. The Li–S cell comprising the PEO–1%Li10SnP2S12 electrolyte exhibits outstanding electrochemical performance with a high discharge capacity (ca. 1000 mA h g–1), high Coulombic efficiency, and good cycling stability at 60 °C. Most importantly, the PEO–1%Li10SnP2S12-based cell possesses attractive performance with a high specific capacity (ca. 800 mA h g–1) and good cycling stability even at 50 °C, whereas the PEO/LiTFSI-based cell cannot be successfully discharged because of the low ionic conductivity and high interfacial resistance of the PEO/LiTFSI electrolyte.
Weakly hydrated anions help to solubilize hydrophobic macromolecules in aqueous solutions, but small molecules comprising the same chemical constituents precipitate out when exposed to these ions. ...Here, this apparent contradiction is resolved by systematically investigating the interactions of NaSCN with polyethylene oxide oligomers and polymers of varying molecular weight. A combination of spectroscopic and computational results reveals that SCN
accumulates near the surface of polymers, but is excluded from monomers. This occurs because SCN
preferentially binds to the centre of macromolecular chains, where the local water hydrogen-bonding network is disrupted. These findings suggest a link between ion-specific effects and theories addressing how hydrophobic hydration is modulated by the size and shape of a hydrophobic entity.
The development of commercial solid-state batteries has to date been hindered by the individual limitations of inorganic and organic solid electrolytes, motivating hybrid concepts. However, the ...room-temperature conductivity of hybrid solid electrolytes is still insufficient to support the required battery performance. A key challenge is to assess the Li-ion transport over the inorganic and organic interfaces and relate this to surface chemistry. Here we study the interphase structure and the Li-ion transport across the interface of hybrid solid electrolytes using solid-state nuclear magnetic resonance spectroscopy. In a hybrid solid polyethylene oxide polymer–inorganic electrolyte, we introduce two representative types of ionic liquid that have different miscibilities with the polymer. The poorly miscible ionic liquid wets the polymer–inorganic interface and increases the local polarizability. This lowers the diffusional barrier, resulting in an overall room-temperature conductivity of 2.47 × 10−4 S cm−1. A critical current density of 0.25 mA cm−2 versus a Li-metal anode shows improved stability, allowing cycling of a LiFePO4–Li-metal solid-state cell at room temperature with a Coulombic efficiency of 99.9%. Tailoring the local interface environment between the inorganic and organic solid electrolyte components in hybrid solid electrolytes seems to be a viable route towards designing highly conducting hybrid solid electrolytes.NMR measurements show that the interface between the inorganic and organic components can be tailored to design a highly conducting hybrid solid electrolyte.
The effects of polyethylene oxide (PEO) dosage and solution pH on the flocculation, rheological and surface/interfacial properties of the slurry were investigated by sedimentation, rheology, ...adsorption and surface force experiments. The results demonstrate that the initial settling rate (ISR) of the tailings is at its lowest in strongly acidic solutions. The ISR reaches its peak in strongly alkaline solutions. The PEO dosage exhibits a modest impact on the yield stress of the concentrate in strong acid solutions, while it wields a notable influence on the yield stress in neutral and strongly alkaline solutions. Quartz crystal microbalance with dissipation (QCM-D) measurements reveal that strong alkaline solutions enhance the adsorption of PEO chains on silica surfaces. Strongly acidic solutions partially inhibit the adsorption of PEO chains. Surface force measurement results indicate that PEO chains can bridge the tailings particles in concentrated suspensions through hydrogen bonding, and consequently elevating the suspension's yield stress.
Display omitted
•Flocculation, rheology and surface/interface properties of ultrafine tailings with PEO were studied.•The repulsive forces between particles significantly affect PEO adsorption.•Bridging effect is essential for the rheological properties of tailings slurries.•pH affects flocculant adsorption and inter-particle interactions.
PDF
