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Showing papers on "Ionic conductivity published in 2019"


Journal ArticleDOI
TL;DR: A nanoporous polyimide film filled with a solid polymer electrolyte has high ionic conductivity and high mechanical strength, and an all-solid-state lithium-ion batteries fabricated with PI/PEO/LiTFSI solid electrolyte show good cycling performance and withstand abuse tests such as bending, cutting and nail penetration.
Abstract: The urgent need for safer batteries is leading research to all-solid-state lithium-based cells. To achieve energy density comparable to liquid electrolyte-based cells, ultrathin and lightweight solid electrolytes with high ionic conductivity are desired. However, solid electrolytes with comparable thicknesses to commercial polymer electrolyte separators (~10 μm) used in liquid electrolytes remain challenging to make because of the increased risk of short-circuiting the battery. Here, we report on a polymer–polymer solid-state electrolyte design, demonstrated with an 8.6-μm-thick nanoporous polyimide (PI) film filled with polyethylene oxide/lithium bis(trifluoromethanesulfonyl)imide (PEO/LiTFSI) that can be used as a safe solid polymer electrolyte. The PI film is nonflammable and mechanically strong, preventing batteries from short-circuiting even after more than 1,000 h of cycling, and the vertical channels enhance the ionic conductivity (2.3 × 10−4 S cm−1 at 30 °C) of the infused polymer electrolyte. All-solid-state lithium-ion batteries fabricated with PI/PEO/LiTFSI solid electrolyte show good cycling performance (200 cycles at C/2 rate) at 60 °C and withstand abuse tests such as bending, cutting and nail penetration. A nanoporous polyimide film filled with a solid polymer electrolyte has high ionic conductivity and high mechanical strength. An all-solid-state battery made with an approximately 10-μm-thick film shows good cyclability at 60 °C and no dendrite formation.

661 citations


Journal ArticleDOI
Qing Zhao1, Xiaotun Liu1, Sanjuna Stalin1, Kasim Khan1, Lynden A. Archer1 
TL;DR: In this paper, a ring-opening polymerization of molecular ethers inside an electrochemical cell was proposed to produce solid-state polymer electrolytes (SPEs), which retain conformal interfacial contact with all cell components.
Abstract: Solid-state electrolytes with high room-temperature ionic conductivity and fast interfacial charge transport are a requirement for practical solid-state batteries. Here, we report that cationic aluminium species initiate ring-opening polymerization of molecular ethers inside an electrochemical cell to produce solid-state polymer electrolytes (SPEs), which retain conformal interfacial contact with all cell components. SPEs exhibit high ionic conductivity at room temperature (>1 mS cm−1), low interfacial resistances, uniform lithium deposition and high Li plating/striping efficiencies (>98% after 300 charge–discharge cycles). Applications of SPEs in Li–S, Li–LiFePO4 and Li–LiNi0.6Mn0.2Co0.2O2 batteries further demonstrate that high Coulombic efficiency (>99%) and long life (>700 cycles) can be achieved with an in situ SPE design. Our study therefore provides a promising direction for creating solid electrolytes that meet both the bulk and interfacial conductivity requirements for practical solid polymer batteries. High-performance polymer electrolytes are highly sought after in the development of solid-state batteries. Lynden Archer and co-workers report an in situ polymerization of liquid electrolytes in a lithium battery for creating promising polymer electrolytes with high ionic conductivity and low interfacial resistance.

551 citations


Journal ArticleDOI
Qing Zhang1, Daxian Cao1, Yi Ma1, Avi Natan1, Peter Aurora1, Hongli Zhu1 
TL;DR: A comprehensive update on the properties (structural and chemical), synthesis of sulfide solid-state electrolytes, and the development of sulfides in all-solid-state batteries is provided, including electrochemical and chemical stability, interface stabilization, and their applications in high performance and safe energy storage.
Abstract: Due to their high ionic conductivity and adeciduate mechanical features for lamination, sulfide composites have received increasing attention as solid electrolyte in all-solid-state batteries. Their smaller electronegativity and binding energy to Li ions and bigger atomic radius provide high ionic conductivity and make them attractive for practical applications. In recent years, noticeable efforts have been made to develop high-performance sulfide solid-state electrolytes. However, sulfide solid-state electrolytes still face numerous challenges including: 1) the need for a higher stability voltage window, 2) a better electrode-electrolyte interface and air stability, and 3) a cost-effective approach for large-scale manufacturing. Herein, a comprehensive update on the properties (structural and chemical), synthesis of sulfide solid-state electrolytes, and the development of sulfide-based all-solid-state batteries is provided, including electrochemical and chemical stability, interface stabilization, and their applications in high performance and safe energy storage.

307 citations


Journal ArticleDOI
TL;DR: New halide-rich solid solution phases in the argyrodite Li6 PS5 Cl family are reported, and weakened interactions between the mobile Li-ions and surrounding framework anions incurred by substitution of divalent S2- for monovalent Cl- play a major role in enhancing Li+ -ion diffusivity.
Abstract: Developing high-performance all-solid-state batteries is contingent on finding solid electrolyte materials with high ionic conductivity and ductility. Here we report new halide-rich solid solution phases in the argyrodite Li6 PS5 Cl family, Li6-x PS5-x Cl1+x , and combine electrochemical impedance spectroscopy, neutron diffraction, and 7 Li NMR MAS and PFG spectroscopy to show that increasing the Cl- /S2- ratio has a systematic, and remarkable impact on Li-ion diffusivity in the lattice. The phase at the limit of the solid solution regime, Li5.5 PS4.5 Cl1.5 , exhibits a cold-pressed conductivity of 9.4±0.1 mS cm-1 at 298 K (and 12.0±0.2 mS cm-1 on sintering)-almost four-fold greater than Li6 PS5 Cl under identical processing conditions and comparable to metastable superionic Li7 P3 S11 . Weakened interactions between the mobile Li-ions and surrounding framework anions incurred by substitution of divalent S2- for monovalent Cl- play a major role in enhancing Li+ -ion diffusivity, along with increased site disorder and a higher lithium vacancy population.

255 citations


Journal ArticleDOI
TL;DR: This study used first principles computation to investigate the Li-ion diffusion, electrochemical stability, and interface stability of chloride and bromide materials and elucidated the origin of their high ionic conductivities and good electrochemical stabilities.
Abstract: Enabling all-solid-state Li-ion batteries requires solid electrolytes with high Li ionic conductivity and good electrochemical stability. Following recent experimental reports of Li3 YCl6 and Li3 YBr6 as promising new solid electrolytes, we used first principles computation to investigate the Li-ion diffusion, electrochemical stability, and interface stability of chloride and bromide materials and elucidated the origin of their high ionic conductivities and good electrochemical stabilities. Chloride and bromide chemistries intrinsically exhibit low migration energy barriers, wide electrochemical windows, and are not constrained to previous design principles for sulfide and oxide Li-ion conductors, allowing for much greater freedom in structure, chemistry, composition, and Li sublattice for developing fast Li-ion conductors. Our study highlights chloride and bromide chemistries as a promising new research direction for solid electrolytes with high ionic conductivity and good stability.

246 citations


Journal ArticleDOI
TL;DR: A lithium sulfonated covalent organic framework (denoted as TpPa-SO3Li) is demonstrated as a new class of solvent-free, single lithium-ion conductors, allowing reversible and stable lithium plating/stripping on lithiumMetal electrodes, demonstrating its potential use for lithium metal electrodes.
Abstract: Porous crystalline materials such as covalent organic frameworks and metal-organic frameworks have garnered considerable attention as promising ion conducting media. However, most of them additionally incorporate lithium salts and/or solvents inside the pores of frameworks, thus failing to realize solid-state single lithium-ion conduction behavior. Herein, we demonstrate a lithium sulfonated covalent organic framework (denoted as TpPa-SO3Li) as a new class of solvent-free, single lithium-ion conductors. Benefiting from well-designed directional ion channels, a high number density of lithium-ions, and covalently tethered anion groups, TpPa-SO3Li exhibits an ionic conductivity of 2.7 × 10-5 S cm-1 with a lithium-ion transference number of 0.9 at room temperature and an activation energy of 0.18 eV without additionally incorporating lithium salts and organic solvents. Such unusual ion transport phenomena of TpPa-SO3Li allow reversible and stable lithium plating/stripping on lithium metal electrodes, demonstrating its potential use for lithium metal electrodes.

240 citations


Journal ArticleDOI
TL;DR: A complex hydride lithium superionic conductor with excellent stability against lithium metal and a high conductivity is reported, enabling all-solid-state lithium-sulfur batteries with high energy density at a high current density.
Abstract: All-solid-state batteries incorporating lithium metal anode have the potential to address the energy density issues of conventional lithium-ion batteries that use flammable organic liquid electrolytes and low-capacity carbonaceous anodes. However, they suffer from high lithium ion transfer resistance, mainly due to the instability of the solid electrolytes against lithium metal, limiting their use in practical cells. Here, we report a complex hydride lithium superionic conductor, 0.7Li(CB9H10)–0.3Li(CB11H12), with excellent stability against lithium metal and a high conductivity of 6.7 × 10−3 S cm−1 at 25 °C. This complex hydride exhibits stable lithium plating/stripping reaction with negligible interfacial resistance ( 2500 Wh kg−1) at a high current density of 5016 mA g−1. The present study opens up an unexplored research area in the field of solid electrolyte materials, contributing to the development of high-energy-density batteries. All-solid-state batteries could deliver high energy densities without using organic liquid electrolytes. Here the authors report a complex hydride Li-ion conductor 0.7Li(CB9H10)–0.3Li(CB11H12) that exhibits impressive ionic conductivity and other electrochemical characteristics in an all-solid-state cell.

236 citations


Journal ArticleDOI
TL;DR: Li et al. as mentioned in this paper used a vertically aligned ceramic/polymer composite electrolyte composed of high ionic conductivity Li 1.5Al0.5Ge1.5(PO4)3 and polyethylene oxide (PEO) polymer.

236 citations


Journal ArticleDOI
TL;DR: This work provides a simple and effective strategy to develop low-T AABs by using dimethyl sulfoxide (DMSO) as an additive with the molar fraction of 0.3 and reveals that the hydrogen bonds are stably formed between DMSO and water molecules and this is taking the role for the electrolyte working at an ultra-low-T.
Abstract: Insufficient ionic conductivity and freezing of the electrolyte are considered the main problems for electrochemical energy storage at low temperatures (low T). Here, an electrolyte with a freezing point lower than -130 °C is developed by using dimethyl sulfoxide (DMSO) as an additive with molar fraction of 0.3 to an aqueous solution of 2 m NaClO4 (2M-0.3 electrolyte). The 2M-0.3 electrolyte exhibits sufficient ionic conductivity of 0.11 mS cm-1 at -50 °C. The combination of spectroscopic investigations and molecular dynamics (MD) simulations reveal that hydrogen bonds are stably formed between DMSO and water molecules, facilitating the operation of the electrolyte at ultra-low T. Using DMSO as the electrolyte additive, the aqueous rechargeable alkali-ion batteries (AABs) can work well even at -50 °C. This work provides a simple and effective strategy to develop low T AABs.

226 citations


Journal ArticleDOI
TL;DR: Sulfide-based solid electrolytes are promising candidates for all solid-state batteries (ASSBs) due to their high ionic conductivity and ease of processability, however, their narrow electrochemica...
Abstract: Sulfide-based solid electrolytes are promising candidates for all solid-state batteries (ASSBs) due to their high ionic conductivity and ease of processability. However, their narrow electrochemica...

224 citations


Journal ArticleDOI
01 May 2019-Nature
TL;DR: The atomic structure of H2O is documented at several million atmospheres of pressure and temperatures of several thousand degrees, revealing shockwave-induced ultrafast crystallization and a novel water ice phase, ice XVIII, with exotic superionic properties.
Abstract: Since Bridgman’s discovery of five solid water (H2O) ice phases1 in 1912, studies on the extraordinary polymorphism of H2O have documented more than seventeen crystalline and several amorphous ice structures2,3, as well as rich metastability and kinetic effects4,5. This unique behaviour is due in part to the geometrical frustration of the weak intermolecular hydrogen bonds and the sizeable quantum motion of the light hydrogen ions (protons). Particularly intriguing is the prediction that H2O becomes superionic6–12—with liquid-like protons diffusing through the solid lattice of oxygen—when subjected to extreme pressures exceeding 100 gigapascals and high temperatures above 2,000 kelvin. Numerical simulations suggest that the characteristic diffusion of the protons through the empty sites of the oxygen solid lattice (1) gives rise to a surprisingly high ionic conductivity above 100 Siemens per centimetre, that is, almost as high as typical metallic (electronic) conductivity, (2) greatly increases the ice melting temperature7–13 to several thousand kelvin, and (3) favours new ice structures with a close-packed oxygen lattice13–15. Because confining such hot and dense H2O in the laboratory is extremely challenging, experimental data are scarce. Recent optical measurements along the Hugoniot curve (locus of shock states) of water ice VII showed evidence of superionic conduction and thermodynamic signatures for melting16, but did not confirm the microscopic structure of superionic ice. Here we use laser-driven shockwaves to simultaneously compress and heat liquid water samples to 100–400 gigapascals and 2,000–3,000 kelvin. In situ X-ray diffraction measurements show that under these conditions, water solidifies within a few nanoseconds into nanometre-sized ice grains that exhibit unambiguous evidence for the crystalline oxygen lattice of superionic water ice. The X-ray diffraction data also allow us to document the compressibility of ice at these extreme conditions and a temperature- and pressure-induced phase transformation from a body-centred-cubic ice phase (probably ice X) to a novel face-centred-cubic, superionic ice phase, which we name ice XVIII2,17. The atomic structure of H2O is documented at several million atmospheres of pressure and temperatures of several thousand degrees, revealing shockwave-induced ultrafast crystallization and a novel water ice phase, ice XVIII, with exotic superionic properties.

Journal ArticleDOI
TL;DR: The method reported here of decoupling ionic conductivity from mechanical properties opens a promising route to create high-toughness ion transport materials for energy storage applications.
Abstract: The emergence of wearable electronics puts batteries closer to the human skin, exacerbating the need for battery materials that are robust, highly ionically conductive, and stretchable. Herein, we introduce a supramolecular design as an effective strategy to overcome the canonical tradeoff between mechanical robustness and ionic conductivity in polymer electrolytes. The supramolecular lithium ion conductor utilizes orthogonally functional H-bonding domains and ion-conducting domains to create a polymer electrolyte with unprecedented toughness (29.3 MJ m−3) and high ionic conductivity (1.2 × 10−4 S cm−1 at 25 °C). Implementation of the supramolecular ion conductor as a binder material allows for the creation of stretchable lithium-ion battery electrodes with strain capability of over 900% via a conventional slurry process. The supramolecular nature of these battery components enables intimate bonding at the electrode-electrolyte interface. Combination of these stretchable components leads to a stretchable battery with a capacity of 1.1 mAh cm−2 that functions even when stretched to 70% strain. The method reported here of decoupling ionic conductivity from mechanical properties opens a promising route to create high-toughness ion transport materials for energy storage applications. Typically, ion conducting polymers exhibit a trade-off between mechanical robustness and ionic conducting performance. Here, the authors utilize supramolecular chemistry obtaining extremely tough electrolytes with high ionic conductivity and enabling stretchable lithium-ion batteries.

Journal ArticleDOI
TL;DR: Using the random resistor model, the lithium-ion transport in the composite polymer electrolyte is simulated by the Monte Carlo simulation, demonstrating that the enhanced ionic conductivity can be ascribed to the ionic conduction in the space Charge regions and the percolation of the space charge regions.
Abstract: By dispersing Li6.25Ga0.25La3Zr2O12 (Ga-LLZO) nanoparticles in poly(ethylene oxide) (PEO) matrix, PEO:Ga-LLZO composite polymer electrolytes are synthesized. The PEO: Ga-LLZO composite with 16 vol % Ga-LLZO nanoparticles shows a conductivity of 7.2 × 10–5 S cm–1 at 30 °C, about 4 orders of magnitude higher than the conductivity of PEO. The enhancement of the ionic conductivity is closely related to the space charge region (∼3 nm) formed at the interface between the PEO matrix and the Ga-LLZO nanoparticles. The space charge region is observed by transmission electron microscope (TEM) and corroborated by the phase-field simulation. Using the random resistor model, the lithium-ion transport in the composite polymer electrolyte is simulated by the Monte Carlo simulation, demonstrating that the enhanced ionic conductivity can be ascribed to the ionic conduction in the space charge regions and the percolation of the space charge regions.

Journal ArticleDOI
TL;DR: The authors incorporate a mixed ion-electron semiconductor into another semiconductor to form a p-n junction to suppress electron conduction and enhance ion conduction, leading to a low-temperature electrolyte.
Abstract: Interest in low-temperature operation of solid oxide fuel cells is growing. Recent advances in perovskite phases have resulted in an efficient H+/O2-/e- triple-conducting electrode BaCo0.4Fe0.4Zr0.1Y0.1O3-δ for low-temperature fuel cells. Here, we further develop BaCo0.4Fe0.4Zr0.1Y0.1O3-δ for electrolyte applications by taking advantage of its high ionic conduction while suppressing its electronic conduction through constructing a BaCo0.4Fe0.4Zr0.1Y0.1O3-δ-ZnO p-n heterostructure. With this approach, it has been demonstrated that BaCo0.4Fe0.4Zr0.1Y0.1O3-δ can be applied in a fuel cell with good electrolyte functionality, achieving attractive ionic conductivity and cell performance. Further investigation confirms the hybrid H+/O2- conducting capability of BaCo0.4Fe0.4Zr0.1Y0.1O3-δ-ZnO. An energy band alignment mechanism based on a p-n heterojunction is proposed to explain the suppression of electronic conductivity and promotion of ionic conductivity in the heterostructure. Our findings demonstrate that BaCo0.4Fe0.4Zr0.1Y0.1O3-δ is not only a good electrode but also a highly promising electrolyte. The approach reveals insight for developing advanced low-temperature solid oxide fuel cell electrolytes.

Journal ArticleDOI
TL;DR: Li et al. as mentioned in this paper synthesized a halide Li+ superionic conductor, Li3 InCl6, that can be synthesized in water and showed a high ionic conductivity of 2.04×10-3 ǫS cm-1 at 25°C.
Abstract: To promote the development of solid-state batteries, polymer-, oxide-, and sulfide-based solid-state electrolytes (SSEs) have been extensively investigated. However, the disadvantages of these SSEs, such as high-temperature sintering of oxides, air instability of sulfides, and narrow electrochemical windows of polymers electrolytes, significantly hinder their practical application. Therefore, developing SSEs that have a high ionic conductivity (>10-3 S cm-1 ), good air stability, wide electrochemical window, excellent electrode interface stability, low-cost mass production is required. Herein we report a halide Li+ superionic conductor, Li3 InCl6 , that can be synthesized in water. Most importantly, the as-synthesized Li3 InCl6 shows a high ionic conductivity of 2.04×10-3 S cm-1 at 25 °C. Furthermore, the ionic conductivity can be recovered after dissolution in water. Combined with a LiNi0.8 Co0.1 Mn0.1 O2 cathode, the solid-state Li battery shows good cycling stability.

Journal ArticleDOI
TL;DR: In this article, a solution-engineered, scalable approach to these materials, including the new argyrodite solid solution phase Li6−yPS5−yCl1+y (y = 0−0.5), was reported.
Abstract: Argyrodites, Li6PS5X (X = Cl, Br), are considered to be one of the most promising solid-state electrolytes for solid-state batteries. However, while traditional ball-mill approaches to prepare these materials do not promote scale-up, solution-based preparative methods have resulted in poor ionic conductivity. Herein, we report a solution-engineered, scalable approach to these materials, including the new argyrodite solid solution phase Li6–yPS5–yCl1+y (y = 0–0.5), that shows very high ionic conductivities (up to 3.9 mS·cm–1) and negligible electronic conductivities. These properties are almost the same as their analogues prepared by solid-state methods, owing to a lack of amorphous contributions and low impurity contents ranging from 3 to 10%. Electrochemical performance is demonstrated for Li6PS5Cl in a prototype solid-state battery and compared to that of the same solid electrolyte derived from classic ball-milling processing.

Journal ArticleDOI
TL;DR: A new three-dimensional metal-organic framework was synthesized by linking ditopic amino functionalized polyoxometalate with 4-connected tetrahedral tetrakis(4-formylphenyl)methane building units through imine condensation and found to be triply interpenetrated diamond-based dia topology.
Abstract: A new three-dimensional metal-organic framework (MOF) was synthesized by linking ditopic amino functionalized polyoxometalate [N(C4H9)4]3[MnMo6O18{(OCH2)3CNH2}2] with 4-connected tetrahedral tetrakis(4-formylphenyl)methane building units through imine condensation. The structure of this MOF, termed MOF-688, was solved by single crystal X-ray diffraction and found to be triply interpenetrated diamond-based dia topology. Tetrabutylammonium cations fill the pores and balance the charge of the anionic framework. They can be exchanged with lithium ions to give high ionic conductivity (3.4 × 10-4 S cm-1 at 20 °C), a high lithium ion transference number (tLi+ = 0.87), and low interfacial resistance (353 Ω) against metallic lithium-properties that make it ideally suited as a solid-state electrolyte. Indeed, a prototype lithium metal battery constructed using MOF-688 as the solid electrolyte can be cycled at room temperature with a practical current density of ∼0.2 C.

Journal ArticleDOI
TL;DR: A sulfide sodium-ion conductor, Na2.88Sb0.88W0.12S4, is reported, with conductivity superior to that of the benchmark electrolyte, Li10GeP2S12, with record high ionic conductivity of 32 mS/cm at room temperature.
Abstract: Solid electrolytes are key materials to enable solid-state rechargeable batteries, a promising technology that could address the safety and energy density issues. Here, we report a sulfide sodium-ion conductor, Na2.88Sb0.88W0.12S4, with conductivity superior to that of the benchmark electrolyte, Li10GeP2S12. Partial substitution of antimony in Na3SbS4 with tungsten introduces sodium vacancies and tetragonal to cubic phase transition, giving rise to the highest room-temperature conductivity of 32 mS cm−1 for a sintered body, Na2.88Sb0.88W0.12S4. Moreover, this sulfide possesses additional advantages including stability against humid atmosphere and densification at much lower sintering temperatures than those (>1000 °C) of typical oxide sodium-ion conductors. The discovery of the fast sodium-ion conductors boosts the ongoing research for solid-state rechargeable battery technology with high safety, cost-effectiveness, large energy and power densities. Solid-state rechargeable batteries using solid electrolytes instead of liquid ones could address the safety and energy density issues. Here the authors report a Na-ion solid electrolyte Na2.88Sb0.88W0.12S4 which exhibits record high ionic conductivity of 32 mS/cm at room temperature.

Journal ArticleDOI
01 Jul 2019-Vacuum
TL;DR: A facile hydrothermal method has been used to synthesis of cubic CuCo2O4 nanoparticles by using two types of precipitate agents like oxalic acid and NaOH as mentioned in this paper.

Journal ArticleDOI
TL;DR: In this article, the tetrakis(hexafluoroisopropyloxy)borate Ca[B(hfip)4]2 based electrolytes exhibiting reversible Ca deposition at room temperature, a high oxidative stability up to 4.5 V and high ionic conductivity >8 mS cm−1.
Abstract: Rechargeable calcium (Ca) batteries have the prospect of high-energy and low-cost. However, the development of Ca batteries is hindered due to the lack of efficient electrolytes. Herein, we report novel calcium tetrakis(hexafluoroisopropyloxy)borate Ca[B(hfip)4]2 based electrolytes exhibiting reversible Ca deposition at room temperature, a high oxidative stability up to 4.5 V and high ionic conductivity >8 mS cm−1. This finding opens a new approach towards room-temperature rechargeable calcium batteries.

Journal ArticleDOI
TL;DR: A stable quasi-solid-state Li metal battery by employing a hierarchical multifunctional polymer electrolyte (HMPE) that efficiently prevents the migration of negatively charged iodine (I) species, which provides the as-developed Li-I batteries with high capacity and long cycling stability.
Abstract: The low Coulombic efficiency and serious safety issues resulting from uncontrollable dendrite growth have severely impeded the practical applications of lithium (Li) metal anodes. Herein we report a stable quasi-solid-state Li metal battery by employing a hierarchical multifunctional polymer electrolyte (HMPE). This hybrid electrolyte was fabricated via in situ copolymerizing lithium 1-[3-(methacryloyloxy)propylsulfonyl]-1-(trifluoromethanesulfonyl)imide (LiMTFSI) and pentaerythritol tetraacrylate (PETEA) monomers in traditional liquid electrolyte, which is absorbed in a poly(3,3-dimethylacrylic acid lithium) (PDAALi)-coated glass fiber membrane. The well-designed HMPE simultaneously exhibits high ionic conductivity (2.24×10-3 S cm-1 at 25 °C), near-single ion conducting behavior (Li ion transference number of 0.75), good mechanical strength and remarkable suppression for Li dendrite growth. More intriguingly, the cation permselective HMPE efficiently prevents the migration of negatively charged iodine (I) species, which provides the as-developed Li-I batteries with high capacity and long cycling stability.

Journal ArticleDOI
TL;DR: In this article, g-C3N4 nanosheets are used as a filler for PEO-based electrolytes to improve the electrical properties and thermal stability of the composite electrolyte.
Abstract: Solid polymer electrolytes (SPEs) are expected to improve the safety and performance of lithium ion batteries (LIB). However, the low ionic conductivity limit the further application of PEO based electrolytes. Herein, g-C3N4 nanosheets is proposed as a novel filler for PEO based electrolytes. The addition of g-C3N4 improves the electrical properties (ionic conductivity, lithium ion transference number and electrochemical window), mechanical properties and thermal stability of the composite electrolyte. The two-dimensional g-C3N4 forms an effective ion transport network in the composite electrolyte. In addition, the surface atoms of the g-C3N4 interact with groups in the lithium salt, promoting further dissociation of the lithium salt. Furthermore, the all solid state batteries assembled by the g-C3N4 composite electrolyte exhibited good cycle performance at 60 °C (remained at 155 mA h g−1 after 100 cycles). Owing to the simple synthesis and environmental friendliness, g-C3N4 nanosheets has a certain practical prospect as a filler for solid polymer electrolytes.


Journal ArticleDOI
TL;DR: The concept of photoswitchable ionic conductivity of a hydrogel mediated by competitive molecular recognition is potentially promising toward the fabrication of optoelectronic devices and applications in bioelectronic technology.
Abstract: A novel ion-conducting supramolecular hydrogel with reversible photoconductive properties in which the azobenzene motif, α-cyclodextrin (α-CD), and ionic liquid are grafted onto the gel matrix is reported. Host-guest interactions with different association constants between α-CD and azobenzene or the anionic part of the ionic liquid can be readily tuned by photoinduced trans-cis isomerization of the azobenzene unit. When irradiated by 365 nm light, α-CD prefers to form a complex with the anionic part of the ionic liquid, resulting in decreased ionic mobility and thus high resistance of the hydrogel. However, under 420 nm light irradiation, a more stable complex is again formed between α-CD and trans-azobenzene, thereby releasing the bound anions to regenerate the low-resistive hydrogel. As such, remote control of the ionic conductivity of the hydrogel is realized by simple host-guest chemistry. With the incorporation of a logic gate, this hydrogel is able to reversibly switch an electric circuit on and off by light irradiation with certain wavelengths. The concept of photoswitchable ionic conductivity of a hydrogel mediated by competitive molecular recognition is potentially promising toward the fabrication of optoelectronic devices and applications in bioelectronic technology.

Journal ArticleDOI
TL;DR: Li et al. as mentioned in this paper fabricate Li6PS5Cl/poly(ethylene oxide) composite solid electrolytes with enhanced mechanical property and stable lithium/electrolyte interface.

Journal ArticleDOI
TL;DR: Wang et al. as mentioned in this paper proposed a logical design of non-stoichiometric CeO2-δ based on non-doped ceria with a focus on the surface properties of the particles.
Abstract: Producing electrolytes with high ionic conductivity has been a critical challenge in the progressive development of solid oxide fuel cells (SOFCs) for practical applications. The conventional methodology uses the ion doping method to develop electrolyte materials, e.g., samarium-doped ceria (SDC) and yttrium-stabilized zirconia (YSZ), but challenges remain. In the present work, we introduce a logical design of non-stoichiometric CeO2-δ based on non-doped ceria with a focus on the surface properties of the particles. The CeO2−δ reached an ionic conductivity of 0.1 S/cm and was used as the electrolyte in a fuel cell, resulting in a remarkable power output of 660 mW/cm2 at 550 °C. Scanning transmission electron microscopy (STEM) combined with electron energy-loss spectroscopy (EELS) clearly clarified that a surface buried layer on the order of a few nanometers was composed of Ce3+ on ceria particles to form a CeO2−δ@CeO2 core–shell heterostructure. The oxygen deficient layer on the surface provided ionic transport pathways. Simultaneously, band energy alignment is proposed to address the short circuiting issue. This work provides a simple and feasible methodology beyond common structural (bulk) doping to produce sufficient ionic conductivity. This work also demonstrates a new approach to progress from material fundamentals to an advanced low-temperature SOFC technology. The performance of non-doping ceria used in solid oxide fuel cells for generating electricity has been improved by modifying its surface. A logical design of non-stoichiometric CeO2-δ was in-situ formed by fuel cell to make ions, e.g., the oxygen ion conducted through the pathway built in ceria surface for the electrolyte to realize the fuel cell reactions, enabling an electrical current to flow. Optimizing the properties of the electrolyte is vital for maximizing the efficiency of the fuel cell. Baoyuan Wang and Bin Zhu from Hubei University, Wuhan, China and coworkers from China, Germany and Sweden set out to improve the electrical conductivity of the surface on non-doping ceria, an oxide of the rare earth metal cerium succeeded in excellent electrolyte functions. The modified surface states created new electrical pathways useful for fuel cell applications. This study highlights a new methodology to develop electrical property of CeO2 without doping based on characteristic surface defects. The CeO2 surface approach presented in this work addresses the electrolyte material challenge faced by solid state oxide fuel cells (SOFCs) over 100 years. In our approach, we take advantage of the energy band structure and surface defect to develop new functional electrolyte material based on non-doped ceria. The oxygen vacancies and defects in surface state of the CeO2 result in new electrical and band properties, thus giving rise in superionic conduction for successful SOFCs application.

Journal ArticleDOI
TL;DR: Rupp et al. as discussed by the authors used Li3N multilayers as a lithium reservoir for the formation of lithium-garnet films, significantly reducing the operating temperature while maintaining the ionic conductivity.
Abstract: A critical parameter for the large-scale integration of solid-state batteries is to establish processing strategies to assemble battery materials at the lowest processing temperature possible while keeping lithium conduction up. Despite extensive research efforts, integrating ceramic film electrolytes while keeping a high lithium concentration and conduction at a low processing temperature remains challenging. Here, we report an alternative ceramic processing strategy through the evolution of multilayers establishing lithium reservoirs directly in lithium–garnet films that allow for lithiated and fast-conducting cubic solid-state battery electrolytes at unusually low processing temperatures. A lithium–garnet film processed via the multilayer processing approach exhibited the fastest ionic conductivity of 2.9 ± 0.05 × 10−5 S cm−1 (at room temperature) and the desired cubic phase, but was stabilized at a processing temperature lowered by 400 °C. This method enables future solid-state battery architectures with more room for cathode volumes by design, and reduces the processing temperature. Manufacturing high-performing solid electrolytes at low processing temperature requires improved techniques. Here Jennifer Rupp and colleagues report a ceramic processing strategy, using Li3N multilayers as a lithium reservoir for the formation of lithium–garnet films, significantly reducing the operating temperature while maintaining the ionic conductivity.

Journal ArticleDOI
TL;DR: In this paper, novel nanoporous fillers, i.e., UIO/Li-IL, are developed for polymer electrolytes, which can suppress the crystallinity and improve the stability of polyethylene oxide (PEO) against the lithium electrode.
Abstract: Polymer electrolytes usually suffer from low ionic conductivity and poor stability against the lithium electrode. Taking advantage of nanostructured metal–organic frameworks (MOFs), novel nanoporous fillers, i.e., UIO/Li-IL, are developed for polymer electrolytes; in UIO/Li-IL, a Li-containing ionic liquid (Li-IL) is absorbed in UIO-66 MOFs. These fillers are multifunctional: high ionic conductivity and capability to suppress the crystallinity and to improve the stability of polyethylene oxide (PEO) against the lithium electrode. PEO-n-UIO composite polymer electrolytes are formed by dispersing the multifunctional fillers in PEO; the conductivity of the PEO-n-UIO solid electrolytes is increased by a factor of ∼37 to 1.3 × 10−4 S cm−1 at 30 °C with 40% UIO/Li-IL, and the current density for stable Li plating/stripping in PEO-n-UIO solid electrolytes is enhanced to 500 μA cm−2 at 60 °C. Solid-state lithium batteries based on the PEO-n-UIO solid electrolyte show an initial discharge capacity of ∼151 mA h g−1 with a capacity retention of 95% after 100 cycles at 0.5C and 60 °C. Our work pioneers novel multifunctional fillers to boost the performances of composite polymer electrolytes for high energy density, safe and long lifetime energy storage systems.

Journal ArticleDOI
TL;DR: In this paper, the authors have fabricated elastic solid electrolytes by filling ionic-conductive polymers into well-aligned Li6.4La3Zr2Al0.2O12 (LLZO) nanofiber films.

Journal ArticleDOI
05 Aug 2019
TL;DR: In this paper, the authors provide an overview of the different approaches to achieve such decoupling, including a brief recapitulation of the segmental-relaxation dependent ion conduction mechanism, exemplarily focusing on the archetype of polymer electrolytes.
Abstract: The use of polymer electrolytes instead of liquid organic systems is considered key for enhancing the safety of lithium batteries and may, in addition, enable the transition to high-energy lithium metal anodes. An intrinsic limitation, however, is their rather low ionic conductivity at ambient temperature. Nonetheless, it has been suggested that this might be overcome by decoupling the ion transport and the segmental relaxation of the coordinating polymer. Here, we provide an overview of the different approaches to achieve such decoupling, including a brief recapitulation of the segmental-relaxation dependent ion conduction mechanism, exemplarily focusing on the archetype of polymer electrolytes – polyethylene oxide (PEO). In fact, while the understanding of the underlying mechanisms has greatly improved within recent years, it remains rather challenging to outperform PEO-based electrolyte systems. Nonetheless, it is not impossible, as highlighted by several examples mentioned herein, especially in consideration of the extremely rich polymer chemistry and with respect to the substantial progress already achieved in designing tailored molecules with well-defined nanostructures.