Keywords: Li-ion batteries, intercalation cathodes, disordered rock salt, Li 2 VO 2 F Advanced cathode materials with superior energy storage capability are highly demanded for mobile and stationary applications. The inherent structural feature of Li + hosts is critical for the battery performance. High-capacity conversion cathode materials often encounter large voltage hysteresis (low energy efficiency) accompanied with the structural reconstruction.[1]The current commercial cathode materials are still dominated by intercalation materials with intrinsic structural integrity for accommodating Li + .[2] However, the known intercalation materials have limited theoretical capacity (< 300 mAh g -1 ). [3] In addition, structural transition/degradation have often been observed for the common intercalation hosts with ordered Li + / transition metal (TM) lattice sites. Antisite disorder (Li + sites/layers occupied by TM ions) in olivines can block the one-dimensional Li + diffusion path.[4] The activation barrier for Li + diffusion in layered oxides is sensitive to the Li-content, the spacing of the

The current report describes the installation and the preliminary commissioning of the Material Science Powder Diffraction (MSPD) beamline at the Spanish synchrotron ALBA-CELLS. The beamline is fully dedicated to powder diffraction techniques and consists of two experimental stations positioned in series: a High Pressure/Microdiffraction station and a High Resolution/High Throughput powder diffraction station.

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In recent years, the stability field of a monoclinic phase at the morphotropic phase boundary in lead zirconate titanate, Pb͓Zr 1−x Ti x ͔O 3 , has been under discussion. In the present study, we investigated samples in the compositional range between 0.40ഛ x ഛ 0.475 and x = 0.55 using high-resolution synchrotron x-ray diffraction in combination with transmission electron microscopy and electron paramagnetic resonance to correlate average structure and microstructural information. It is shown that the microstructure plays a crucial role in the analysis of diffraction data. The appearance of intensity in diffraction patterns formerly linked to a monoclinic phase ͓B. Noheda et al., Phys. Rev. B 61, 8687 ͑2000͔͒ can directly be correlated to a miniaturization of the average domain structure of the material visible in the presence of nanodomains. The internal symmetry of the nanodomains is not necessarily monoclinic due to coherence effects in diffraction and is discussed with respect to martensitic theory.

One major challenge in the field of lithium-ion batteries is to understand the degradation mechanism of high-energy lithium- and manganese-rich layered cathode materials. Although they can deliver 30 % excess capacity compared with today’s commercially- used cathodes, the so-called voltage decay has been restricting their practical application. In order to unravel the nature of this phenomenon, we have investigated systematically the structural and compositional dependence of manganese-rich lithium insertion compounds on the lithium content provided during synthesis. Structural, electronic and electrochemical characterizations of LixNi0.2Mn0.6Oy with a wide range of lithium contents (0.00 ≤ x ≤ 1.52, 1.07 ≤ y < 2.4) and an analysis of the complexity in the synthesis pathways of monoclinic-layered Li[Li0.2Ni0.2Mn0.6]O2 oxide provide insight into the underlying processes that cause voltage fading in these cathode materials, i.e. transformation of the lithium-rich layered phase to a lithium-poor spinel phase via an intermediate lithium-containing rock-salt phase with release of lithium/oxygen.

The origin of the electric field-induced strain in the polycrystalline ceramic 0.92Bi 1/2 Na 1/2 TiO 3 -0.06BaTiO 3 -0.02K 1/2 Na 1/2 NbO 3 was investigated using in situ high-resolution X-ray and neutron diffraction techniques. The initially existing tetragonal phase with pseudocubic lattice undergoes a reversible phase transition to a significantly distorted rhombohedral phase under electric field, accompanied by a change in the oxygen octahedral tilting from a 0 a 0 c + to a À a À a À and in the tilting angle. The polarization values for the tetragonal and rhombohedral phases were calculated based on the structural information from Rietveld refinements. The large recoverable electric field-induced strain is a consequence of a reversible electric field-induced phase transition from an almost nonpolar tetragonal phase to a ferroelectrically active rhombohedral phase.

An in situ structural description of the origin of the ferroelectric properties as a function of the applied electric field E was obtained by synchrotron x-ray diffraction. A setup was used to average the effects of the preferred orientation induced by the strong piezoelectric strain and solve in situ the crystal structure as a function of the applied electric field. Hence, we were able to describe the microscopic origin of the macroscopic ferro- and piezoelectric properties of the most widely used ferroelectric material, lead zirconate titanate.

Conventional lithium-ion batteries embrace graphite anodes which operate at potential as low as metallic lithium, subjected to poor rate capability and safety issues. Among possible alternatives, oxides based on titanium redox couple, such as spinel Li 4 Ti 5 O 12 , have received renewed attention. Here we further expand the horizon to include a perovskite structured titanate La 0.5 Li 0.5 TiO 3 into this promising family of anode materials. With average potential of around 1.0 V vs. Li + /Li, this anode exhibits high specific capacity of 225 mA h g −1 and sustains 3000 cycles involving a reversible phase transition. Without decrease the particle size from micro to nano scale, its rate performance has exceeded the nanostructured Li 4 Ti 5 O 12. Further characterizations and calculations reveal that pseudocapacitance dictates the lithium storage process and the favorable ion and electronic transport is responsible for the rate enhancement. Our findings provide fresh impetus to the identification and development of titanium-based anode materials with desired electrochemical properties.