Lithium-ion-conducting solid electrolytes hold promise for enabling high-energy battery chemistries and circumventing safety issues of conventional lithium batteries. Achieving the combination of high ionic conductivity and a broad electrochemical window in solid electrolytes is a grand challenge for the synthesis of battery materials. Herein we show an enhancement of the room-temperature lithium-ion conductivity by 3 orders of magnitude through the creation of nanostructured Li(3)PS(4). This material has a wide electrochemical window (5 V) and superior chemical stability against lithium metal. The nanoporous structure of Li(3)PS(4) reconciles two vital effects that enhance the ionic conductivity: (1) the reduction of the dimensions to a nanometer-sized framework stabilizes the high-conduction β phase that occurs at elevated temperatures, and (2) the high surface-to-bulk ratio of nanoporous β-Li(3)PS(4) promotes surface conduction. Manipulating the ionic conductivity of solid electrolytes has far-reaching implications for materials design and synthesis in a broad range of applications, including batteries, fuel cells, sensors, photovoltaic systems, and so forth.

Elemental carbon materials exhibit unique electronic, mechanical, and chemical properties that make them attractive, for example, for nanoelectronic devices, [1] strengthenhancing materials, [2] separation media, [3][4][5][6] catalyst supports, [7] energy storage/conversion systems, [8] proximal probes, [9] optical components. [10] Well-defined nanoporous carbon materials are essential for a number of these applications. Ordered porous carbon materials have previously been replicated by using colloidal crystals [10] and presynthesized mesoporous silicas as scaffolds.[7] These methodologies are extremely difficult to adapt to the fabrication of large-scale ordered nanoporous films with controlled pore orientations. Although numerous methods (e.g., chemical vapor deposition, [11] ultrasonic deposition, [3a] silica template synthesis, [3b, 7] hydrothermal decomposition of carbide compounds, [12] and polymer coating and pyrolysis [13] ) have been developed for the fabrication of carbon films, no ordered nanoporous carbon films have been obtained with such methods. Accordingly, the large-scale alignment of the carbon nanostructural films is still a big challenge. Herein, we demonstrate a stepwise self-assembly approach to the preparation of large-scale, highly ordered nanoporous carbon films. The carbon precursor molecules are spatially arranged into well-defined nanostructures by the self-assembly of block copolymers (BCPs). A hexagonally packed carbon-channel array whose orientation is normal to the carbon film surface has been successfully synthesized. Large-scale crack-free carbon films of up to 6 cm 2 can be readily fabricated on common substrates such as silica, copper, silicon, and carbon.The self-assembly of BCPs has proven to be a versatile approach to the selective organization and nanoscale regulation of the concentration distribution of target molecular species for the fabrication of nanoporous materials. [14][15][16] The mechanism for such organization involves hydrogen-bonding, [17] ion-pairing, [18] and/or dative interactions [19] between supramolecular assemblies of BCPs and target molecular species. The resulting composites can give rise to various nanostructures according to the structural and phase behaviors of the BCPs. The target molecular species are spatially concentrated in selected microdomains and can eventually serve as nanostructured catalysts, [20] spacers, [21] or precursors [22] for the further fabrication of ordered nanostructures. Highly ordered nanoporous materials, such as polymer, [22] silica, [23,24] and organic-inorganic hybrid materials, [25,26] have been created through polymerization in the presence of the self-assembled BCPs.Although BCPs contain high atomic carbon concentrations, ordered nanoporous carbon films have not been successfully fabricated through the direct pyrolysis of selfassembled BCPs.[27] This inability is attributed to the fact that linearly structured BCP compounds have very poor carbon yields in carbonization reactions. Furthermore, the survival of the nan...

PTB7 semiconducting copolymer comprising thieno[3,4-b]thiophene and benzodithiophene alternating repeat units set a historic record of solar energy conversion efficiency (7.4%) in polymer/fullerene bulk heterojunction solar cells. To further improve solar cell performance, a thorough understanding of structure-property relationships associated with PTB7/fullerene and related organic photovoltaic (OPV) devices is crucial. Traditionally, OPV active layers are viewed as an interpenetrating network of pure polymers and fullerenes with discrete interfaces. Here we show that the active layer of PTB7/fullerene OPV devices in fact involves hierarchical nanomorphologies ranging from several nanometers of crystallites to tens of nanometers of nanocrystallite aggregates in PTB7-rich and fullerene-rich domains, themselves hundreds of nanometers in size. These hierarchical nanomorphologies are coupled to significantly enhanced exciton dissociation, which consequently contribute to photocurrent, indicating that the nanostructural characteristics at multiple length scales is one of the key factors determining the performance of PTB7 copolymer, and likely most polymer/fullerene systems, in OPV devices.

A rational strategy has been used to immobilize open metal sites in ultramicroporosity for stronger binding of multiple H 2 molecules per unsaturated metal site for H 2 storage applications. The synthesis and structure of a mixed zinc/copper metal-organic framework material Zn 3(BDC) 3[Cu(Pyen)] .(DMF) 5(H 2O) 5 (H 2BDC = 1,4 benzenedicarboxylic acid and PyenH 2 = 5-methyl-4-oxo-1,4-dihydro-pyridine-3-carbaldehyde) is reported. Desolvation provides a bimodal porous structure Zn 3(BDC) 3[Cu(Pyen)] (M'MOF 1) with narrow porosity (<0.56 nm) and an array of pores in the bc crystallographic plane where the adsorbate-adsorbent interactions are maximized by both the presence of open copper centers and overlap of the potential energy fields from pore walls. The H 2 and D 2 adsorption isotherms for M'MOF 1 at 77.3 and 87.3 K were reversible with virtually no hysteresis. Methods for determination of the isosteric enthalpies of H 2 and D 2 adsorption were compared. A virial model gave the best agreement (average deviation <1 standard deviation) with the isotherm data. This was used in conjunction with the van't Hoff isochore giving isosteric enthalpies at zero surface coverage of 12.29 +/- 0.53 and 12.44 +/- 0.50 kJ mol (-1) for H 2 and D 2 adsorption, respectively. This is the highest value so far observed for hydrogen adsorption on a porous material. The enthalpy of adsorption, decreases with increasing amount adsorbed to 9.5 kJ mol (-1) at approximately 1.9 mmol g (-1) (2 H 2 or D 2 molecules per Cu corresponding to adsorption on both sides of planar Cu open centers) and is virtually unchanged in the range 1.9-3.6 mmol g (-1). Virial analysis of isotherms at 87.3 K is also consistent with two H 2 or D 2 molecules being bound to each open Cu center. The adsorption kinetics follow a double exponential model, corresponding to diffusion along two types of pores, a slow component with high activation energy (13.35 +/- 0.59 kJ mol (-1)) for the narrow pores and a faster component with low activation energy (8.56 +/- 0.41 kJ mol (-1)). The D 2 adsorption kinetic constants for both components were significantly faster than the corresponding H 2 kinetics for specific pressure increments and had slightly lower activation energies than the corresponding values for H 2 adsorption. The kD 2/ kH 2 ratio for the slow component was 1.62 +/- 0.07, while the fast component was 1.38 +/- 0.04 at 77.3 K, and the corresponding ratios were smaller at 87.3 K. These observations of kinetic isotope quantum molecular sieving in porous materials are due to the larger zero-point energy for the lighter H 2, resulting in slower adsorption kinetics compared with the heavier D 2. The results show that a combination of open metal centers and confinement in ultramicroporosity leads to a high enthalpy for H 2 adsorption over a wide range of surface coverage and quantum effects influence diffusion of H 2 and D 2 in pores in M'MOF 1.