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Over the past 20 years, silicon (Si) has been an investigated anode material for lithium-ion batteries due to its high capability. However, the large strain evolution during lithiation/delithiation that leads to pulverization and delamination has hindered its industrial realization. Effectively suppressing the stress evolution that arises in Li–Si alloy reactions has been an endless debate. Recently, multiscale pattern technologies have been demonstrated on activated materials and current collectors to achieve better performance, especially in terms of lifetime. Our pattern strategy is inspired by the structure of "waterbeds", where individual Si islands were surrounded by buffer walls to accomplish stress relaxation. We developed an advanced pattern technique based on lithiated polyacrylate acid (LiPAA) for its bi-functionalization of adhesion and viscoelasticity with Si to better accommodate the mechanical stress, especially at high-rates. Ultimately, we demonstrate longevity performance with almost "zero-loss" over 200 cycles at 1C and an excellent rate retention of 26.7% at 20C. We systematically analyze the diffusivity of Li-ions in various patterned Si anodes to explain the fast-charging and the long-term cycling properties. This facile fabrication of a unique pattern structure can provide new strategies for the rational design of various thin-film materials that suffer from the volume change issue during battery operation. [ABSTRACT FROM AUTHOR]

We have synthesized novel metal organic hybrid mixed compounds of bis (acetylacetonato κ-O, O′) [zinc(ii)/copper(ii)]. Taking C10H14O4Zn0.7Cu0.3 (Z0.7C0.3AA) as an example, the crystals are composed of Z0.7C0.3AA units and uncoordinated water molecules. Single-crystal X-ray diffraction results show that the complex Z0.7C0.3AA crystallizes in the monoclinic system, space group P21/n. The unit cell dimensions are a = 10.329(4) Å, b = 4.6947(18) Å, and c = 11.369(4) Å; the angles are α = 90°, β = 91.881(6)°, and γ = 90°, the volume is 551.0(4) Å3, and Z = 2. In this process, the M(ii) ions of Zn and Cu mix and occupy the centers of symmetrical structural units, which are coordinated to two ligands. The measured bond lengths and angles of O–M–O vary with the ratio of metal species over the entire series of the complexes synthesized. The chemistry of the as-synthesized compounds has been characterized using infrared spectroscopy, mass spectroscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy analysis, and the morphology of the products has been characterized using scanning electron microscopy. The thermal decomposition of the Z0.7C0.3AA composites measured by thermogravimetric analysis suggests that these complexes are volatile. The thermal characteristics of these complexes make them attractive precursors for metal organic chemical vapor deposition. [ABSTRACT FROM AUTHOR]

We demonstrate the synergistic effects of Ga doping and Mg alloying into ZnO on the large enhancement of the piezopotential and stress sensing performance of piezotronic pressure sensors made of Ga-doped MgZnO films. Piezopotential-induced pressure sensitivity was enhanced through the modulation of the Schottky barrier height. Doping with Ga (0.62 Å) of larger ionic radius and alloying with Mg (0.57 Å) of smaller ionic radius than Zn ions can synergistically affect the overall structural, optical and piezoelectric properties of the resulting thin films. The crystal quality of Ga-doped MgZnO films either improved ( X Ga ≦ 0.041) or deteriorated ( X Ga ≧ 0.041) depending on the Ga doping concentration. The band gap increased from 3.90 eV for pristine MgZnO to 3.93 eV at X Ga = 0.076, and the piezoelectric coefficient ( d 33 ) improved from ∼23.25 pm V -1 to ∼33.17 pm V -1 at an optimum Ga concentration ( X Ga = 0.027) by ∼2.65 times. The change in the Schottky barrier height Δ Φ b increased from -4.41 meV (MgZnO) to -4.81 meV ( X Ga = 0.027) and decreased to -3.99 meV at a high Ga doping concentration ( X Ga = 0.041). The stress sensitivity (0.2 kgf) enhanced from 28.50 MPa -1 for the pristine MgZnO to 31.36 MPa -1 ( X Ga = 0.027) and decreased to 25.56 MPa -1 at higher Ga doping concentrations, indicating the synergistic effects of Ga doping and Mg alloying over the pressure sensing performance of Ga-doped MgZnO films., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

We have synthesized novel metal organic hybrid mixed compounds of bis (acetylacetonato κ-O, O') [zinc(ii)/copper(ii)]. Taking C10H14O4Zn0.7Cu0.3 (Z0.7C0.3AA) as an example, the crystals are composed of Z0.7C0.3AA units and uncoordinated water molecules. Single-crystal X-ray diffraction results show that the complex Z0.7C0.3AA crystallizes in the monoclinic system, space group P21/n. The unit cell dimensions are a = 10.329(4) Å, b = 4.6947(18) Å, and c = 11.369(4) Å; the angles are α = 90°, β = 91.881(6)°, and γ = 90°, the volume is 551.0(4) Å(3), and Z = 2. In this process, the M(ii) ions of Zn and Cu mix and occupy the centers of symmetrical structural units, which are coordinated to two ligands. The measured bond lengths and angles of O-M-O vary with the ratio of metal species over the entire series of the complexes synthesized. The chemistry of the as-synthesized compounds has been characterized using infrared spectroscopy, mass spectroscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy analysis, and the morphology of the products has been characterized using scanning electron microscopy. The thermal decomposition of the Z0.7C0.3AA composites measured by thermogravimetric analysis suggests that these complexes are volatile. The thermal characteristics of these complexes make them attractive precursors for metal organic chemical vapor deposition.