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Two key problems inhibiting the commercialization of direct methanol fuel cells (DMFCs) are the cost of the precious metals employed and the sluggish kinetics and catalyst poisoning by CO or CHO species. Research to solve the first drawback [1][2][3][4] focuses on the reduction of precious metal loading, which is achieved by increasing the catalysts specific surface area and its accessibility. For the second problem, advanced electrocatalyst design relies on the "bifunctional approach", [5][6][7][8][9][10] in which a second compound such as ruthenium or RuO 2 ·x H 2 O assists the oxidation of CO or CHO species by adsorption of oxygen-containing species close to the poisoned Pt sites. In contrast to previous work on PtRu alloy catalysts, [11][12][13] Rolison and co-workers [14,15] emphasized the importance of hydrous ruthenium oxides because the RuO 2 ·x H 2 O speciation of Ru in nanoscale PtRu blacks shows both high electron and proton conductivity, which results in a much more active catalyst for methanol oxidation. However, direct evidence of the catalytic function of hydrous oxides is very scarce.Mixed proton-electron conducting materials should be ideal catalyst supports for DMFCs since they allow for low ohmic resistance in both the proton and electron conduction at the same time. As hydrous ruthenium(IV) oxide has been reported to contain liquid or liquid-like regions of water to

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A brief review of in situ powder diffraction methods for battery materials is given. Furthermore, it is demonstrated that the new beamline P02.1 at the synchrotron source PETRA III (DESY, Hamburg), equipped with a new electrochemical test cell design and a fast two‐dimensional area detector, enables outstanding conditions for in situ diffraction studies on battery materials with complex crystal structures. For instance, the time necessary to measure a pattern can be reduced to the region of milliseconds accompanied by an excellent pattern quality. It is shown that even at medium detector distances the instrumental resolution is suitable for crystallite size refinements. Additional crucial issues like contributions to the background and available q range are determined.

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In-situ and operando neutron powder diffraction is well established method for studying structural changes in Li-ion electrode materials in real time during battery operation. Quality of diffraction data obtained in operando experiments depends on characteristics of diffractometer (brightness, space resolution) and design and assembly of electrochemical cell. Operando neutron diffraction experiments can be successfully performed with real batteries; however using special designed electrochemical cell allows us to exclude some undesirable reflexes of battery components from diffraction pattern, use Li-metal as counter electrode, decrease background from incoherent scattering elements, be almost independent from commercial machines for battery preparation and considerably reduce a mass of investigated materials. In this report we present special designed electrochemical cells developed for operando study of Li-ion electrode materials at time-of-flight neutron diffractometers at the IBR-2 neutron source (Dubna, Frank Laboratory of Neutron Physics). The cells are easily assembled in a glove box and demonstrate the excellent parameters of cyclabilities (with graphite electrodes, more than 700 cycles) and absence of leakage current. In dependence of scattering properties of studied materials the measured diffraction patterns can be analyzed by Rietveld method or Peak's profile data analysis. Several successful operando experiments on Li-ion electrode materials using these cells have been performed. In particular, investigation of LiNi0.8Co0.15Al0.05O2 (NCA) cathode material in the electrochemical cell allowed us to reveal the microstructural reasons of phase separation that occurs in cycled NCA during the first charge. The work is supported by Russian Science Foundation (project №14-12-00896). [1] A.

X-ray photoelectron spectroscopy (XPS) is a key method for studying (electro-)chemical changes in metal-ion battery electrode materials. In a recent publication, we pointed out a conflict in binding energy (BE) scale referencing at alkali metal samples, which is manifested in systematic deviations of the BEs up to several eV due to a specific interaction between the highly reactive alkali metal in contact with non-conducting surrounding species. The consequences of this phenomenon for XPS data interpretation are discussed in the present manuscript. Investigations of phenomena at surface-electrolyte interphase regions for a wide range of materials for both lithium and sodium-based applications are explained, ranging from oxide-based cathode materials via alloys and carbon-based anodes including appropriate reference chemicals. Depending on material class and alkaline content, specific solutions are proposed for choosing the correct reference BE to accurately define the BE scale. In conclusion, the different approaches for the use of reference elements, such as aliphatic carbon, implanted noble gas or surface metals, partially lack practicability and can lead to misinterpretation for application in battery materials. Thus, this manuscript provides exemplary alternative solutions.