Alloy negative electrodes for Li-ion batteries.

Despite the impressive photovoltaic performances with power conversion efficiency beyond 22%, perovskite solar cells are poorly stable under operation, failing by far the market requirements. Various technological approaches have been proposed to overcome the instability problem, which, while delivering appreciable incremental improvements, are still far from a market-proof solution. Here we show one-year stable perovskite devices by engineering an ultra-stable 2D/3D (HOOC(CH2)4NH3)2PbI4/CH3NH3PbI3 perovskite junction. The 2D/3D forms an exceptional gradually-organized multi-dimensional interface that yields up to 12.9% efficiency in a carbon-based architecture, and 14.6% in standard mesoporous solar cells. To demonstrate the up-scale potential of our technology, we fabricate 10 × 10 cm2 solar modules by a fully printable industrial-scale process, delivering 11.2% efficiency stable for >10,000 h with zero loss in performances measured under controlled standard conditions. This innovative stable and low-cost architecture will enable the timely commercialization of perovskite solar cells. Up-scaling represents a key challenge for photovoltaics based on metal halide perovskites. Using a composite of 2D and 3D perovskites in combination with a printable carbon black/graphite counter electrode; Granciniet al., report 11.2% efficient modules stable over 10,000 hours.

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One-Year stable perovskite solar cells by 2D/3D interface engineering

Research to develop alternative electrode materials with high energy densities in Li-ion batteries has been actively pursued to satisfy the power demands for electronic devices and hybrid electric vehicles. This critical review focuses on anode materials composed of Group IV and V elements with their composites including Ag and Mg metals as well as transition metal oxides which have been intensively investigated. This critical review is devoted mainly to their electrochemical performances and reaction mechanisms (313 references).

Li-alloy based anode materials for Li secondary batteries.

Polyoxometalates (POMs) are discrete anionic metaloxygen clusters which can be regarded as soluble oxide fragments. They exhibit a great diversity of sizes, nuclearities, and shapes. They are built from the connection of {MOx} polyhedra, M being a d-block element in high oxidation state, usually VIV,V, MoVI, or WVI.1 While these species have been known for almost two centuries, they still attract much interest partly based on their large domains of applications. They play a great role in various areas ranging from catalysis,2 medicine,3 electrochemistry,4 photochromism,5 to magnetism.6 This palette of applications is intrinsically due to the combination of their added value properties (redox properties, large sizes, high negative charges, nucleophilicity...). Parallel to this domain, the organic-inorganic hybrids area has followed a similar expansion during the last 10 years. The concept of organic-inorganic hybrid materials * To whom correspondence should be addressed. E-mail: dolbecq@ chimie.uvsq.fr. Chem. Rev. 2010, 110, 6009–6048 6009

Hybrid Organic−Inorganic Polyoxometalate Compounds: From Structural Diversity to Applications

The hybrid two-dimensional (2D) halide perovskites have recently drawn significant interest because they can serve as excellent photoabsorbers in perovskite solar cells. Here we present the large scale synthesis, crystal structure, and optical characterization of the 2D (CH3(CH2)3NH3)2(CH3NH3)n−1PbnI3n+1 (n = 1, 2, 3, 4, ∞) perovskites, a family of layered compounds with tunable semiconductor characteristics. These materials consist of well-defined inorganic perovskite layers intercalated with bulky butylammonium cations that act as spacers between these fragments, adopting the crystal structure of the Ruddlesden–Popper type. We find that the perovskite thickness (n) can be synthetically controlled by adjusting the ratio between the spacer cation and the small organic cation, thus allowing the isolation of compounds in pure form and large scale. The orthorhombic crystal structures of (CH3(CH2)3NH3)2(CH3NH3)Pb2I7 (n = 2, Cc2m; a = 8.9470(4), b = 39.347(2) A, c = 8.8589(6)), (CH3(CH2)3NH3)2(CH3NH3)2Pb3I10 (...

http://pubs.acs.org/doi/pdf/10.1021/acs.chemmater.6b00847

Ruddlesden-Popper Hybrid Lead Iodide Perovskite 2D Homologous Semiconductors

Three new organically templated polyoxomolybdates with selenite anions as capping groups have been synthesized by hydrothermal reactions and structurally characterized. The structure of {Hbipy}3{KMo4O13(SeO3)} (1; bipy = 4,4′-bipyridine) features a 1D anionic double chain of {KMo4O13(SeO3)}3− units. Four MoVIO6 octahedra in compound 1 form a planar Mo4O13 cluster unit through corner-, edge- and face-sharing. The Mo4O13 cluster unit is further capped by an SeIVO3 group in a bidentate fashion. These monocapped cluster units are further interconnected by bridging K+ cations into a 1D double chain. Both {H2bipy}2{Mo5O15(SeO3)2}·H2O (2) and {H2pip}2{Mo5O15(SeO3)2}·3H2O (3; pip = piperazine) contain a bicapped Mo5O15 cluster unit in which five MoVIO6 octahedra form a planar Mo5O15 cluster unit through edge- and corner-sharing, with the two SeIVO3 anions as tridentate capping groups on the two open sides of the cluster unit to form an {Mo5O15(SeO3)2}4− anion. The {Mo5O15(SeO3)2}4− cluster anions in compounds 2 and 3 are further inter-linked by the organic templates through hydrogen bonds to form a 2D layer. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

Three New Organically Templated Polyoxomolybdates with Capping Selenite Anions

In an attempt to grow ‘LaNaGeS 4 ’ single crystals by using NaBr as flux in a sealed evacuated carbon-coated quartz tube, transparent yellow crystals of La 4 S 3 Si 2 O 7 were isolated. La 4 S 3 Si 2 O 7 crystallizes in a tetragonal system, space group I4 1 /and (No. 141), with a =12.098(3) A, c =14.379(5) A and Z =8. The new compound belongs to the family of compounds with composition RE 4 Q 3 Si 2 O 7 (RE=rare earth; Q=S, Se). The structure of La 4 S 3 Si 2 O 7 contains two crystallographically independent La 3+ cations that are interconnected by S 2− anions and isolated [Si 2 O 7 ] 6− units. La(1) is coordinated by three O atoms and three S atoms to form a trigonal prismatic geometry, while La(2) is coordinated by six O atoms and three S atoms to form a tri-capped trigonal prismatic geometry. The Si 2 O 7 double tetrahedra are in the eclipsed configuration with nonlinear Si–O–Si bridges (angle: 131.4(6)°).

Synthesis and Crystal Structure of La4S3Si2O7.

The title new neodymium(III) selenate-selenite was obtained by hydrothermal reactions of neodymium(III) oxide, H 2 SeO 4 and 1,10-phenanthroline at 140  ° C. Its structure was established by single-crystal X-ray diffraction. The title compound crystallizes in the monoclinic space group C 2/c with cell parameters of a = 12.258(2) A, b = 7.1024(15) A, c = 13.391(3) A, β = 104.250(2)°. The structure of Nd 2 (SeO 4 )(SeO 3 ) 2 (H 2 O) 2 is isomorphous with that of Er 2 (SeO 4 )(SeO 3 ) 2 (H 2 O) 2 , which was refined in the monoclinic space group C 2 with the disordered selenate group. It features an ordered 3D network with channels along b -axis. The selenate or selenite groups alone can form a 2D layer with the Nd(III) ions. IR spectrum, TGA and luminescent studies have also been performed.

Synthesis and Crystal Structure of a New Neodymium(III) Selenate‐Selenite: Nd2(SeO4)(SeO3)2 (H2O)2.

The structures of the new title compounds (IV) (trigonal, space group P, Z = 1) and (V) (monoclinic, Cc, Z = 4) are determined by single crystal XRD.

Ba3 [Ge2B7O16(OH)2] (OH)(H2O) and Ba3Ge2B6O16: Novel Alkaline-Earth Borogermanates Based on Two Types of Polymeric Borate Units and GeO4 Tetrahedra.

Two types of new organically templated mixed-metal sulfites, namely, [H(2)pip][NaZn(2)Cu(SO(3))(4)] (1) and [H(2)pip][CdCu(4)(SO(3))(4)] (2) (pip = piperazine), have been synthesized under hydrothermal conditions and structurally characterized. Both compounds exhibit a novel 3D mixed-metal inorganic framework with organic template molecules occupying the tunnels of the inorganic skeleton. Compound 1 features a 2D Zn(2)Cu(SO(3))(4)(3-) layer parallel to the ac plane in which the 1D chains of Zn(SO(3))(2)(2-) anions along the c axis are interconnected with the Cu(+) ions via Cu-S bonds. Neighboring Zn(2)Cu(SO(3))(4)(3-) layers are further interconnected by bridging Na(+) ions via Na-O-S bonds into a 3D network, forming 1D tunnels along the a axis which are occupied by the doubly protonated piperazine cations. Compounds 2 features a novel 3D inorganic framework of CdCu(4)(SO(3))(4)(2-) with 2D layers based on Cu(4)(SO(3))(4)(4-) cubanelike clusters. The cluster layers are further interconnected by Cd(II) ions, forming 1D tunnels of eight-membered rings along the c axis in which the piperazine template cations are located. Luminescent property measurements as well as band structure calculations based on density functional theory methods were also made.

Jiang-Gao Mao

Papers

Three New Organically Templated Polyoxomolybdates with Capping Selenite Anions

Synthesis and Crystal Structure of La4S3Si2O7.

Synthesis and Crystal Structure of a New Neodymium(III) Selenate‐Selenite: Nd2(SeO4)(SeO3)2 (H2O)2.

Ba3 [Ge2B7O16(OH)2] (OH)(H2O) and Ba3Ge2B6O16: Novel Alkaline-Earth Borogermanates Based on Two Types of Polymeric Borate Units and GeO4 Tetrahedra.

New Types of 3D Organically Templated Zn2+/Cd2+—Cu+ Mixed Metal Sulfites.