Showing papers on "Conductivity published in 2019"
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
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
TL;DR: A double-layer polymer electrolyte is investigated, in which one polymer provides dendrite-free plating of a Li-metal anode and the other allows a Li+ extraction from an oxide host cathode without oxidation of the electrolyte in a 4 V cell over a stable charge/discharge cycling at 65 °C.
Abstract: No single polymer or liquid electrolyte has a large enough energy gap between the empty and occupied electronic states for both dendrite-free plating of a lithium-metal anode and a Li+ extraction from an oxide host cathode without electrolyte oxidation in a high-voltage cell during the charge process. Therefore, a double-layer polymer electrolyte is investigated, in which one polymer provides dendrite-free plating of a Li-metal anode and the other allows a Li+ extraction from an oxide host cathode without oxidation of the electrolyte in a 4 V cell over a stable charge/discharge cycling at 65 °C; a poly(ethylene oxide) polymer contacts the lithium-metal anode and a poly(N-methyl-malonic amide) contacts the cathode. All interfaces of the flexible, plastic electrolyte remain stable with no visible reduction of the Li+ conductivity on crossing the polymer/polymer interface.
321 citations
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
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
TL;DR: This study reports the first example of a series of crystalline imidazolate-containing ICOFs as single-ion conducting COF solid electrolyte materials, where lithium cations freely travel through the intrinsic channels with outstanding ion conductivity and impressively low activation energy.
Abstract: Ionic covalent organic frameworks (ICOFs) have recently emerged as promising candidates for solid-state electrolytes. Herein, we report the first example of a series of crystalline imidazolate-containing ICOFs as single-ion conducting COF solid electrolyte materials, where lithium cations freely travel through the intrinsic channels with outstanding ion conductivity (up to 7.2 × 10-3 S cm-1) and impressively low activation energy (as low as 0.10 eV). These properties are attributed to the weak Li ion-imidazolate binding interactions and well-defined porous 2D framework structures of such ICOFs. We also investigated the structure-property relationship by varying the electronic properties of substituents (electron donating/withdrawing) that covalently attached to the imidazolate groups. We found electron-withdrawing substituents significantly improve the ion-conducting ability of imidazolate-ICOF by weakening ion-pair interactions. Our study provides a convenient bottom-up approach toward a novel class of highly efficient single-ion conducting ICOFs which could be used in all solid-state electrolytic devices.
209 citations
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.
203 citations
TL;DR: It is reported that use of a perovskite Li+ electrolyte in place of the garnet ceramic provides an adequate Li+ conductivity at 25 °C without dendrite formation and a binding of the TFSI− anion of a LiTFSI [lithium bis(trifluoromethanesulfonyl)imide] salt to the polymer increases both the Li-ion conductivity and the Li+ transport number.
Abstract: Flexible and low-cost poly(ethylene oxide) (PEO)-based electrolytes are promising for all-solid-state Li-metal batteries because of their compatibility with a metallic lithium anode. However, the low room-temperature Li-ion conductivity of PEO solid electrolytes and severe lithium-dendrite growth limit their application in high-energy Li-metal batteries. Here we prepared a PEO/perovskite Li3/8Sr7/16Ta3/4Zr1/4O3 composite electrolyte with a Li-ion conductivity of 5.4 × 10−5 and 3.5 × 10−4 S cm−1 at 25 and 45 °C, respectively; the strong interaction between the F− of TFSI− (bis-trifluoromethanesulfonimide) and the surface Ta5+ of the perovskite improves the Li-ion transport at the PEO/perovskite interface. A symmetric Li/composite electrolyte/Li cell shows an excellent cyclability at a high current density up to 0.6 mA cm−2. A solid electrolyte interphase layer formed in situ between the metallic lithium anode and the composite electrolyte suppresses lithium-dendrite formation and growth. All-solid-state Li|LiFePO4 and high-voltage Li|LiNi0.8Mn0.1Co0.1O2 batteries with the composite electrolyte have an impressive performance with high Coulombic efficiencies, small overpotentials, and good cycling stability.
185 citations
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.
169 citations
01 Jan 2019
TL;DR: Experimental discovery of high thermal conductivity at room temperature in cubic boron arsenide (BAs) grown through a modified chemical vapor transport technique shows that BAs represents a class of ultrahigh–thermal conductivity materials predicted by a recent theory, and that it may constitute a useful thermal management material for high–power density electronic devices.
Abstract: The high density of heat generated in power electronics and optoelectronic devices is a critical bottleneck in their application. New materials with high thermal conductivity are needed to effectively dissipate heat and thereby enable enhanced performance of power controls, solid-state lighting, communication, and security systems. We report the experimental discovery of high thermal conductivity at room temperature in cubic boron arsenide (BAs) grown through a modified chemical vapor transport technique. The thermal conductivity of BAs, 1000 ± 90 watts per meter per kelvin meter-kelvin, is higher than that of silicon carbide by a factor of 3 and is surpassed only by diamond and the basal-plane value of graphite. This work shows that BAs represents a class of ultrahigh-thermal conductivity materials predicted by a recent theory, and that it may constitute a useful thermal management material for high-power density electronic devices.
142 citations
TL;DR: Results indicate that the organic potassium salt-containing electrolyte helps to form thin and robust solid electrolyte interphase layers, which reduce the formation of byproducts during the potassiation-depotassiation process and enhance the mechanical stability of electrodes.
Abstract: Metal-organic framework-derived NiCo2.5 S4 microrods wrapped in reduced graphene oxide (NCS@RGO) were synthesized for potassium-ion storage. Upon coordination with organic potassium salts, NCS@RGO exhibits an ultrahigh initial reversible specific capacity (602 mAh g-1 at 50 mA g-1 ) and ultralong cycle life (a reversible specific capacity of 495 mAh g-1 at 200 mA g-1 after 1 900 cycles over 314 days). Furthermore, the battery demonstrates a high initial Coulombic efficiency of 78 %, outperforming most sulfides reported previously. Advanced ex situ characterization techniques, including atomic force microscopy, were used for evaluation and the results indicate that the organic potassium salt-containing electrolyte helps to form thin and robust solid electrolyte interphase layers, which reduce the formation of byproducts during the potassiation-depotassiation process and enhance the mechanical stability of electrodes. The excellent conductivity of the RGO in the composites, and the robust interface between the electrodes and electrolytes, imbue the electrode with useful properties; including, ultrafast potassium-ion storage with a reversible specific capacity of 402 mAh g-1 even at 2 A g-1 .
TL;DR: In this article, a garnet-type solid-state electrolyte Li6.4La3Zr1.4Ta0.6O12 (LLZTO) was modified using dopamine to improve the wettability of LLZTO with PEO.
Abstract: A garnet-type solid-state electrolyte Li6.4La3Zr1.4Ta0.6O12 (LLZTO) was modified using dopamine to improve the wettability of LLZTO with PEO, allowing 80 wt% LLZTO to be uniformly dispersed in 20 wt% PEO/LiTFSI polymer electrolyte. Transmission electron microscopy and Fourier transform infrared spectroscopy confirmed a 4–5 nm thick polydopamine (PDA) layer coating on LLZTO nanoparticles. The composite LLZTO@PDA/PEO electrolyte was synthesized using a solvent casting method. The composite electrolyte has good compatibility and adhesion with both positive and negative electrodes of Li-ion batteries owing to the superior wetting capability of dopamine. This property allows for improved interfacial contact at the electrode/solid electrolyte interface which can decrease the overall resistance of the battery. With dopamine modification, the conductivity of the composite electrolyte at 30 °C increased from 6.3 × 10−5 S cm−1 to 1.1 × 10−4 S cm−1, and the interfacial resistance between the composite electrolyte and a metallic lithium anode decreased from 308 Ω cm2 to 65 Ω cm2 at 50 °C. The composite electrolyte also demonstrated improved thermal stability.
TL;DR: In this article, a confined proton transportation in the CeO2/CeO2−δ core-shell structure was reported, leading to a super proton conductivity of 0.16 S cm−1 for the electrolyte and advance proton shuttles.
Abstract: We report a confined proton transportation in the CeO2/CeO2−δ core–shell structure to build up proton shuttles, leading to a super proton conductivity of 0.16 S cm–1 for the electrolyte and advance...
TL;DR: In this paper, the existence of a previously unreported Na5 site in monoclinic Na3Zr2Si2PO12 is revealed, as suggested by a much lower energy barrier compared to the single-ion migration barrier.
Abstract: In the last few decades, rechargeable batteries have garnered considerable attention for large-scale energy storage applications, for example, power grids and electric vehicles.[1] In the pursuit of safer and higher-energy-density batteries, increasingly rigorous requirements are being imposed on the electrolyte, with the organic liquid electrolytes used in conventional batteries being plagued by safety concerns and their limited electrochemical windows. The substitution of liquid electrolytes with solid electrolytes can potentially address these safety concerns while also enabling the use of high-voltage cathode materials and Li/Na metal anodes to generate high-energy-density batteries.[2] Although many advances and breakthroughs have been achieved in Li-ion solid electrolytes[3,4] and intensive studies have been conducted on the electrolyte/electrode interface,[5–8] only a few Na super ion conductor (NaSICON), Na1+nZr2SinP3–nO12 is considered one of the most promising solid electrolytes; however, the underlying mechanism governing ion transport is still not fully understood. Here, the existence of a previously unreported Na5 site in monoclinic Na3Zr2Si2PO12 is unveiled. It is revealed that Na+-ions tend to migrate in a correlated mechanism, as suggested by a much lower energy barrier compared to the single-ion migration barrier. Furthermore, computational work uncovers the origin of the improved conductivity in the NaSICON structure, that is, the enhanced correlated migration induced by increasing the Na+-ion concentration. Systematic impedance studies on doped NaSICON materials bolster this finding. Significant improvements in both the bulk and total ion conductivity (e.g., σbulk = 4.0 mS cm−1, σtotal = 2.4 mS cm−1 at 25 °C) are achieved by increasing the Na content from 3.0 to 3.30–3.55 mol formula unit−1. These improvements stem from the enhanced correlated migration invoked by the increased Coulombic repulsions when more Na+-ions populate the structure rather than solely from the increased mobile ion carrier concentration. The studies also verify a strategy to enhance ion conductivity, namely, pushing the cations into high energy sites to therefore lower the energy barrier for cation migration.
TL;DR: In this paper, a spray-assisted self-assembly method was developed to prepare spherical boron nitride, which improved the thermal conductivity of polydimethylsiloxane.
TL;DR: This Review presents the latest advances related to Na2/3Ni1/3Mn 2/3O2, with a main focus on strategies to stabilize the structural framework and improve the electrochemical properties.
Abstract: P2-type Na2/3Ni1/3Mn2/3O2 is a promising cathode material for practical applications in Na-ion batteries, due to its high energy density, high volumetric capacity, excellent Na ion conductivity, ea...
TL;DR: A 3D structured composite was designed to improve the conductivity and to ease the volume problems of Si anode during cycling for lithium-ions batteries and is expected to exhibit benign electrochemical performances with a commendable capacity and high rate performance.
Abstract: A 3D structured composite was designed to improve the conductivity and to ease the volume problems of Si anode during cycling for lithium-ions batteries. An in situ method via a controllable gelation process was explored to fabricate the 3D composite of a multilayer carbon matrix toughened by cross-linked carbon nanotubes (CNTs) and decorated with conductive Cu agents. Structurally, a bifunctional carbon shell was formed on the surface of Si to improve the conductivity but alleviate side reactions. Cu particles as conducting agents decorated in the carbon matrix are also used to further improve the conductivity. The volume issue of Si particles can be effectively released via toughening the carbon matrix through the multilayered structure and cross-linked CNTs. Moreover, the carbon matrix might prevent silicon particles from agglomeration. Consequently, the Si@C@Cu composite is expected to exhibit benign electrochemical performances with a commendable capacity of 1500 mAh g–1 (900 cycles, 1 A g–1) and a h...
TL;DR: Li6PS5Br superionic conductors were synthesized from a homogeneous solution by a liquid-phase technique as discussed by the authors, which is suitable for application in all-solid-state cells.
Abstract: Sulfide-based solid electrolytes with halide elements are essential components of advanced all-solid-state batteries. Argyrodite crystals are viable candidates as solid electrolytes for realizing all-solid-state batteries. However, a simple and effective route for the synthesis of these solid electrolytes is required. Herein, argyrodite Li6PS5Br superionic conductors were synthesized from a homogeneous solution by a liquid-phase technique. The Li6PS5Br solid electrolyte was prepared in a shorter synthesis time of one day using tetrahydrofuran and ethanol as compared with the solid-phase method. More importantly, of all the sulfide-based solid electrolytes prepared by liquid-phase techniques, Li6PS5Br showed the highest ionic conductivity of 3.1 mS cm−1 at 25 °C. The obtained particle size of 1 μm is suitable for application in all-solid-state cells. Moreover, coating electrode active materials with the solid electrolyte using the precursor solution led to a large contact area between the electrode and electrolyte and improved the cell performance. In addition, infiltrating a porous electrode with the precursor solution of the solid electrolyte is suitable for forming homogeneous composite electrodes to improve the cell performance. The all-solid-state cell using the Li6PS5Br fine powder with a high conductivity of 1 mS cm−1 or more exhibited a reversible capacity of 150 mA h g−1. This technique is effective for the industrial production of solid electrolytes and is applicable to all-solid-state batteries.
TL;DR: It is concluded that 60 min ultrasonication is the optimum time in which the thermal conductivity and stability of MWCNT-water nanofluid reached their highest point.
TL;DR: In this article, a composite solid polymer electrolyte containing 15 wt % garnet nanosheets exhibits a practically useful conductivity of 3.6 × 10−4 S cm−1 at room temperature.
Abstract: Solid electrolytes potentially provide safety, Li dendrites blocking, and electrochemical stability in Li-metal batteries. Large efforts have been devoted to disperse ceramic nanoparticles in a poly(ethylene oxide) (PEO) matrix to improve the ions transport. However, it is challengeable to create efficient framework for ions transport with nanoparticles. Here we report for the first time garnet nanosheets to provide interconnected Li-ions transport pathway in a PEO matrix. The garnet nanosheet fillers would not only facilitate ions transport but also enhance ionic conductivity in comparison with their nanoparticle counterparts. A composite solid polymer electrolyte containing 15 wt % garnet nanosheets exhibits a practically useful conductivity of 3.6 × 10–4 S cm–1 at room temperature. Besides, the composite electrolyte can robustly isolate Li dendrites in a symmetric lithium metal-composite electrolyte battery during reversible Li dissolution/deposition at a relatively low temperature of 40 °C. The symmet...
TL;DR: In this paper, in situ catalytic growth graphene on the surface of nano-Si (Si@Graphene) composite is successfully developed through a novel electroless deposition approach with Ni as the catalyst.
TL;DR: This approach provides an ideal roadmap for producing highly conductive MOFs with great potential for applications in batteries, thermoelectric, supercapacitors and related areas.
Abstract: Designing highly conducting metal–organic frameworks (MOFs) is currently a subject of great interest for their potential applications in diverse areas encompassing energy storage and generation. Herein, a strategic design in which a metal–sulfur plane is integrated within a MOF to achieve high electrical conductivity, is successfully demonstrated. The MOF {[Cu2(6-Hmna)(6-mn)]·NH4}n (1, 6-Hmna = 6-mercaptonicotinic acid, 6-mn = 6-mercaptonicotinate), consisting of a two dimensional (–Cu–S–)n plane, is synthesized from the reaction of Cu(NO3)2, and 6,6′-dithiodinicotinic acid via the in situ cleavage of an S–S bond under hydrothermal conditions. A single crystal of the MOF is found to have a low activation energy (6 meV), small bandgap (1.34 eV) and a highest electrical conductivity (10.96 S cm−1) among MOFs for single crystal measurements. This approach provides an ideal roadmap for producing highly conductive MOFs with great potential for applications in batteries, thermoelectric, supercapacitors and related areas. Metal–organic frameworks that contain metal–sulfur chains have been demonstrated to exhibit good electrical conductivity. Here, the authors integrate a 2D metal–sulfur plane into a metal–organic framework, reporting a single crystal with a high conductivity of 10.96 S/cm.
TL;DR: This MOF is one of the first in a promising class of frameworks that introduces the opportunity to control the identity, geometry, and distribution of the cation hopping sites, offering a versatile template for application-directed design of solid electrolytes.
Abstract: A Cu-azolate metal–organic framework (MOF) uptakes stoichiometric loadings of Groups 1 and 2 metal halides, demonstrating efficient reversible release and reincorporation of immobilized anions within the framework. Ion-pairing interactions lead to anion-dependent Li+ and Mg2+ transport in Cu4(ttpm)2·0.6CuCl2, whose high surface area affords a high density of uniformly distributed mobile metal cations and halide binding sites. The ability to systematically tune the ionic conductivity yields a solid electrolyte with a Mg2+ ion conductivity rivaling the best materials reported to date. This MOF is one of the first in a promising class of frameworks that introduces the opportunity to control the identity, geometry, and distribution of the cation hopping sites, offering a versatile template for application-directed design of solid electrolytes.
TL;DR: In this article, a triple-conducting double perovskite oxide (SSNCF) was proposed as a novel cathode for dual-ion solid oxide fuel cells (SOFCs).
Abstract: As a new electrolyte category, dual-ion electrolytes show the advantages of both oxygen ion conducting electrolytes and proton-conducting electrolytes to provide favorably low ohmic resistance at 450–650 °C without external gas humidification, while the insufficient activity of conventional cathodes has become the main concern for practical applications. Here, we report a triple-conducting double perovskite oxide Sr2Sc0.1Nb0.1Co1.5Fe0.3O6−δ (SSNCF) as a novel cathode for dual-ion solid oxide fuel cells (SOFCs). We further report a method based on an oxygen ion blocking technique in combination with a hydrogen permeability test for determining the proton conductivity in SSNCF. The results indicate the triple-conducting (H+|O2−|e−) capability of the perovskite with a Grotthuss mechanism for the proton diffusion. A cell with a thin-film BZCYYb electrolyte and an SSNCF cathode delivered peak power densities (PPDs) of 840 and 732 mW cm−2, respectively, at 650 and 600 °C, superior to most other similar cells with different cathodes. Compared with Ba0.5Sr0.5Co0.8Fe0.2O3−δ (BSCF), the non-conflicting oxygen ion and proton diffusion channels in the SSNCF cathode significantly improved the performance of dual-ion SOFCs, where oxygen ions and protons diffuse through oxygen vacancies (vehicle mechanism) and lattice oxygen (Grotthuss mechanism), respectively. This finding highlights the potential to attain further performance enhancements for reduced-temperature SOFCs through the adoption of dual-ion electrolyte and triple-conducting cathode.
TL;DR: In this article, a series of tetrablock copolymers containing an all-hydrocarbon backbone were synthesized, and they were cast into membranes with an ion-exchange capacity between 1.55 and 2.60 milliequivalents per gram (meq/g).
TL;DR: The performance of low-to-intermediate temperature (400-800°C) solid-oxide fuel cells (SOFCs) depends on the properties of electrolyte used as mentioned in this paper.
TL;DR: InspInspired by the carbon nanotubes (CNTs) with high elasticity, the authors designed a flexible conductive Si/CNT composite where the CNTs are in situ grown in the porous Si particles with mesoscale porosity to solve the problems facing high capacity Si-based anodes.
TL;DR: 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.
Abstract: 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.
TL;DR: In this paper, a solution-assisted solid-state reaction for preparation of Na3+xZr2Si2+xP1−xO12 was used to achieve 5 × 10−3 S cm−1 at room temperature for Na3.4Zr 2Si2.4P0.6O12 at 25 °C, higher than the values previously reported for polycrystalline Naion conductors.
Abstract: The lack of suitable candidate electrolyte materials for practical application limits the development of all-solid-state Na-ion batteries. Na3+xZr2Si2+xP1−xO12 was the very first series of NASICONs discovered some 40 years ago; however, separation of bulk conductivity from total conductivity at room temperature is still problematic. It has been suggested that the effective Na-ion conductivity is ∼10−4 S cm−1 at room temperature for Na3+xZr2Si2+xP1−xO12 ceramics; however using a solution-assisted solid-state reaction for preparation of Na3+xZr2Si2+xP1−xO12, a total conductivity of 5 × 10−3 S cm−1 was achieved for Na3.4Zr2Si2.4P0.6O12 at 25 °C, higher than the values previously reported for polycrystalline Na-ion conductors. A bulk conductivity of 1.5 × 10−2 S cm−1 was revealed by high frequency impedance spectroscopy (up to 3 GHz) and verified by low temperature impedance spectroscopy (down to −100 °C) for Na3.4Zr2Si2.4P0.6O12 at 25 °C, indicating further the potential of increasing the related total conductivity. A Na/Na3.4Zr2Si2.4P0.6O12/Na symmetric cell showed low interface resistance and high cycling stability at room temperature. A full-ceramic cell was fabricated and tested at 28 °C with good cycling performance.
TL;DR: The results indicate that the molecular weight of S-PEDOT is the critical parameter for increasing the number of nanocrystals, corresponding to the S- PEDOT crystallites evaluated by x-ray diffraction and conductive atomic force microscopic analyses as having high electrical conductivity.
Abstract: Wet-processable and highly conductive polymers are promising candidates for key materials in organic electronics. Poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) is commercially available as a water dispersion of colloidal particles but has some technical issues with PSS. Here, we developed a novel fully soluble self-doped PEDOT (S-PEDOT) with an electrical conductivity as high as 1089 S cm-1 without additives (solvent effect). Our results indicate that the molecular weight of S-PEDOT is the critical parameter for increasing the number of nanocrystals, corresponding to the S-PEDOT crystallites evaluated by x-ray diffraction and conductive atomic force microscopic analyses as having high electrical conductivity, which reduced both the average distance between adjacent nanocrystals and the activation energy for the hopping of charge carriers, leading to the highest bulk conductivity.