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The "community cat program (CCP)" is a non-lethal control measure in which stray cats are owned and cared for as community cats at high welfare standards, while the Trap-Neuter-Return (TNR) or Trap-Test-Vaccinate-Alter-Return-Monitor (TTVARM) event is performed. The program is recommended by the Ministry of the Environment in Japan. Here, we evaluated the health status of community cats inhabiting a tourist area in Onomichi City. A medical check was conducted on 30 community cats as a part of the TTVARM event. The following health problems were identified: alopecia, gingivitis, incisor teeth loss, anemia, and urine glucose. An ELISA (the enzyme linked immunosorbent assay) showed that 16.7% of the cats were FIV-positive. The cats were also carriers of zoonoses (Capnocytophaga genus (100%) and Bartonella henselae (ITS, nested; 38.0%)), which pose a risk to tourists and residents. Our findings suggest that most cats require medical treatment. We recommend that friendly cats should be adopted rather than maintained as community cats and that a comprehensive review of the CCP is required.

The surface freezing transition of a mixed adsorbed film containing cetyltrimethylammonium chloride (CTAC) and n-hexadecanol (C16OH) was utilized at the dodecane-water interface to control the stability of oil-in-water (O/W) emulsions. The corresponding surface frozen and surface liquid mixed adsorbed films were characterized using interfacial tensiometry and X-ray reflectometry. The emulsion samples prepared in the temperature range of the surface frozen and surface liquid phases showed a clear difference in their stability: the emulsion volume decreased continuously right after the emulsification in the surface liquid region, while it remained constant or decreased at a much slower rate in the surface frozen region. Compared to the previously examined CTAC-tetradecane mixed adsorbed film, the surface freezing temperature increased from 9.5 to 25.0 °C due to the better chain matching between CTAC and C16OH and higher surface activity of C16OH. This then renders such systems much more attractive for practical applications.

A condensed film formation of surfactants with a charged head group at the oil/water interface was achieved by mixing surfactants of different geometric shapes to control molecular packing at the interface. The adsorbed films of mixed tetradecyltrimethylammonium bromide (C14TAB)-cholesterol (Chol) and tetradecylphosphocholine (C14PC)-Chol systems at the hexane/water interface were examined by interfacial tension and X-ray reflectivity measurements. The interfacial tension versus Chol concentration curves have break points because of the expanded-condensed phase transition of the adsorbed film. A two dimensional (2D) phase diagram, phase diagram of adsorption, indicated that 1:1 mixing in the condensed film is energetically favorable because of stronger mutual interaction between different molecules than between the same ones. The electron density profile normal to the interface manifested that the packing of C14TAB (or C14PC) and Chol molecules is like a 2D solid in the condensed state. As C14TAB and C14PC molecules take a corn shape with a large head group (critical packing parameter: CPP ≈ 1/3) and Chol takes an inverted corn shape with a bulky sterol ring (CPP1), the mixing of corn shape and inverted corn shape molecules produces well-ordered packing to promote solid-like molecular packing at the interface by energy gain because of vdW interaction between hydrophobic chains in addition to attractive ion-dipole interaction between head groups. Furthermore, the heterogeneous feature in the adsorbed film of the C14TAB-Chol system is explained by an interplay between contact energy and dipole interaction, which contribute to line tension at the domain boundary.

The correlation between the Pt–Pt interatomic distance of a Pt/C catalyst and the specific activity of the oxygen reduction reaction is discussed. Total X-ray scattering measurement coupled with pa...

The development of non-precious metal oxygen reduction catalysts is vital for enabling the commercialization of proton exchange membrane fuel cells, and Fe/N/C catalysts prepared by the pyrolysis of Fe, N, and C-containing precursors have been widely studied for this purpose. The role of atomically dispersed Fe centers in the reaction mechanisms of Fe/N/C catalysts has been widely studied. This paper demonstrates a facile magnetic purification approach for obtaining atomically dispersed Fe centers for conducting superior Fe/N/C catalysis. Upon treatment of a Fe/N/C catalyst prepared by pyrolyzing Fe-containing polyimide nanoparticles with a magnet, the clustered Fe species (metallic Fe and Fe3C) observed before the purification were successfully eliminated, and atomically dispersed Fe species were clearly observed by microscopy. Comparison of the oxygen reduction activities of the Fe/N/C catalysts before and after the magnetic purification in half-cell and fuel cell testing revealed the retention of the high catalytic performances of the Fe/N/C catalysts. Furthermore, no loss in catalytic performance or durability was observed after the magnetic purification.

The community cat program (CCP) was recommended by the Ministry of the Environment to reduce cats in local animal shelters and improve stray cat welfare in Japan. It is a non-lethal control measure with stray cats cared for as free-roaming cats for their lifetime in the community, while Trap-Neuter-Return (TNR) or Trap-Test-Vaccinate-Alter-Return-Monitor (TTVARM) activities are carried out. In the CCP, community cat colonies are hypothesized to be closed and static populations. However, it remains unknown whether the cats stay in the colonies, without migration of non-neutered cats following TNR/TTVARM events. We examined the population dynamics of cats before and after a TTVARM event using route censuses (107 days), fixed-point observations, and GPS-tracking in a tourist area in Onomichi. Eleven out of the 30 cats remained in the CCP areas, whereas 13 non-neutered cats immigrated into the CCP areas, within a year, suggesting the CCP program has limited efficacy. Besides, the program cannot support the lifetime management of the cats due rapid turnover of cats. Our results reject the CCP hypothesis, so that the program neither restricts cat breeding nor enhances cat welfare.

Competitive binding of binary mixed counterions to the headgroups of adsorbed surfactant films has been investigated at solution surfaces by total reflection X-ray absorption fine structure (XAFS) spectroscopy. The obtained extended XAFS χ spectra for bromide counterions are linear combinations of the spectra of fully hydrated bromide ions (free Br) and partially dehydrated bromide ions bound to the headgroups of the surfactant ions (bound Br). From the fraction of bound Br in counterion mixed systems, two series of the relative strengths of counterion binding are proposed for the trimethylammonium (TA+) and 3-methylimidazolium (MIM+) headgroups: (a) TA–SO4 < TA–Cl < TA–Br < TA–BF4 and (b) MIM–Br < TA–Br < TA–BF4 < MIM–BF4. For the TA headgroup, matching the hydration of the headgroups and counterions gives series (a) according to Collins’ law, which states that the tendency of contact ion pair formation becomes larger when the absolute values of the hydration enthalpies of the ions match. For the MIM hea...

Li-rich type manganese oxides are one of the most promising cathodes for lithium-ion batteries in recent years; thanks to their high energy density. In these cathodes, partial substitution of manga...

The surface freezing (SF) of liquid 6-perfluorohexyl hexanol (F6H6OH)–1-dodecanol (C12OH) mixture was studied by surface tension, external reflection absorption FTIR (ERA-FTIR), and X-ray reflectivity (XR) measurements. The surface tension vs. temperature curve of pure C12OH liquid shows a sharp break point at the surface liquid (SL)–SF phase transition temperature Ts. The surface tension of pure F6H6OH, on the other hand, decreases monotonically with increasing temperature. The entropy of surface formation in the SF state of C12OH is large negative due to a well-ordered structure at the surface. The electron density profile determined by XR showed that the C12OH molecules form bilayer stabilized by the hydrogen bonding between hydroxyl groups facing each other through water molecule intercalated in between them. In the F6H6OH–C12OH system, the estimation of surface composition indicated that the SL state is enriched in F6H6OH compared to bulk liquid. The negative excess entropy in the SL layer suggests that F6H6OH molecules form domains at the surface. Furthermore, the surface composition and electron density profile in the SF state indicated that a small amount of F6H6OH mix with C12OH in the SF bilayer in which F6H6OH molecules preferentially exist in the upper layer of the bilayer.

Here, we report remarkable oxygen evolution reaction (OER) catalytic activity of brownmillerite (BM)-type Ca2 FeCoO5 . The OER activity of this oxide is comparable to or beyond those of the state-of-the-art perovskite (PV)-catalyst Ba0.5 Sr0.5 Co0.8 Fe0.2 O3-δ (BSCF) and a precious-metal catalyst RuO2 , emphasizing the importance of the characteristic BM structure with multiple coordination environments of transition metal (TM) species. Also, Ca2 FeCoO5 is clearly advantageous in terms of expense/laboriousness of the material synthesis. These facts make this oxide a promising OER catalyst used in many energy conversion technologies such as metal-air secondary batteries and hydrogen production from electrochemical/photocatalytic water splitting.

In situ X-ray absorption spectroscopy has afforded detailed structural and electronic characterization of a newly developed stabilized Pt-skin/PtCo alloy nanoparticle catalyst for CO-tolerant H2 oxidation. The X-ray absorption near-edge structure (XANES) results show the significant effects of H and CO adsorption on white lines for pure Pt nanoparticles, which are correlated with the depletion of the density of states (DOS) just below the Fermi level (FL) calculated with density-functional theory (DFT). In contrast, for the Pt-skin/PtCo surface, there is little effect on the XANES for either H or CO adsorption. The lack of effect is consistent with the lack of variation of the DOS near the FL. The extended X-ray absorption fine structure (EXAFS) results for pure Pt nanoparticles have exhibited significant changes caused by H and CO adsorption. Such changes are suggested to be associated with the selected surface expansion of Pt atoms, as revealed from DFT-calculated radial distribution functions (RDFs). In contrast, for the Pt-skin/PtCo surface, there were negligible changes in the EXAFS, either with H or CO adsorption, which is consistent with the lack of changes in the DFT-calculated RDF. Notably, the rigidity of the Pt skin and the lower degree of overlap between Pt and CO orbitals, due to the narrowing of the d-band, are thought to be responsible for the weak adsorption.

The effect of oil on condensed film formation in the adsorbed film of hexadecyltrimethylammonium bromide (C16TAB) at the tetradecane (C14)/water (W) interface was examined by interfacial tension and X-ray reflectivity measurements. The interfacial tension vs temperature curves have break point due to the expanded?condensed phase transition of the adsorbed film. The partial molar entropy of C16TAB at the interface changes discontinuously, whereas the interfacial density changes almost continuously at the phase transition point. The electron density profile normal to the interface manifested that the condensed film is regarded as a two-dimensional (2D) solid rotator phase in which C16TAB and C14 molecules are densely packed with perpendicular orientation. Combining the interfacial tension and X-ray reflectivity data, the mixing ratio of C16TAB to C14 in the solid film was determined to be 2:3 and thus the film is enriched in oil molecules than surfactant ones. Furthermore, the partial molar entropy change of C14 associated with solid film formation was found to be largely negative and very close to that of surface freezing of liquid alkane, manifesting that C14 molecules are well ordered to form a 2D solid film by mixing with C16TAB molecules at the interface. The solid film formation of the present system is driven by effective vdW interactions between adsorbed C16TAB and intercalated C14 molecules. The morphology of the condensed domain observed during phase transition suggested that the contact energy is more predominant than the dipole repulsion at the domain boundary, which promotes coalescence of small domains into large ones during phase transition.

Clarification of the interaction between the electrode and the electrolyte is crucial for further improvement of the performance of lithium-ion batteries. We have investigated the structural change at the interface between the surface of a 104- oriented epitaxial thin film of LiCoO2 (LiCoO2(104)), which is one of the stable surfaces of LiCoO2, and an electrolyte prepared using a carbonate solvent (1 M LiClO4 in ethylene carbonate and dimethyl carbonate) by in situ neutron reflectivity measurements. Owing to the decomposition of the organic solvent, a new interface layer was formed after contact of LiCoO2(104) with the electrolyte. The composition and thickness of the interface layer changed during Li+ extraction/insertion. During Li+ extraction, the thickness of the interface layer increased and the addition of an inorganic species is suggested. The thickness of the interface layer decreased during Li+ insertion. We discuss the relationship between battery performance and the dynamic behavior at the interface.

The oxidation/reduction behaviours of lattice oxygen and transition metals in a Li-rich manganese-based layered oxide Li[Li0.25Ni0.20Mn0.55]O1.93 are investigated by using hard X-ray photoelectron spectroscopy (HAX-PES). By making use of its deeper probing depth rather than in-house XPS analyses, we clearly confirm the formation of O- ions as bulk oxygen species in the active material. They are formed on the 1st charging process as a charge compensation mechanism for delithiation and decrease on discharging. In particular, the cation-anion dual charge compensation involving Ni and O ions is suggested during the voltage slope region of the charging process. The Ni ions in the material are considered to increase the capacity delivered by a reversible anion redox reaction with the suppression of O2 gas release. On the other hand, we found structural deterioration in the cycled material. The O- species are still observed but are electrochemically inactive during the 5th charge-discharge cycle. Also, the oxidation state of Ni ions is divalent and inactive, although that of Mn ions changes reversibly. We believe that this is associated with the structural rearrangement occurring after the activation process during the 1st charging, leading to the formation of spinel- or rocksalt-like domains over the sub-surface region of the particles.

The structure at air interface and water (W) interface of a hydrophobic ionic liquid (IL), trioctylmethylammonium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate ([TOMA+][TFPB−]), has been studied using x-ray reflectometry. Multilayering of ions has been found at the IL/air interface, with the topmost ionic layer having lower density than the IL bulk. For the IL/W interface, x-ray reflectivity data depends on the phase-boundary potential across the IL/W interface. When the phase-boundary potential of W with respect to IL, ΔILWϕ, is + 0.20 V, TFPB− ions are accumulated at the topmost ionic layer on the IL side of the IL/W interface. On the other hand, when ΔILWϕ = - 0.27 V, the accumulation of TOMA+ ions occurs with bilayer thickness, which is probably due to local interaction between TOMA+ ions at the topmost layer and at the second layer through interdigitation of their alkyl chains. To quantitatively analyze the x-ray reflectivity data, we construct a model of the electrical double layer (EDL) at the IL/W interface, by combining the Gouy–Chapman–Stern model on the W side and the Oldham model on the IL side. The constructed model predicts that the EDL on the IL side is within the topmost layer for the phase-boundary potentials in the present study, suggesting that the TOMA+ bilayer found at the negative potential results from the local interaction beyond the framework of the present mean-field theory. Even at the positive potential the surface charge density predicted by the EDL theory is significantly smaller than that estimated from x-ray reflectivity data, which implies that densification of the topmost ionic layer leads us to overestimate the surface charge density.

Feces littered on the ground by free-roaming cats contain bacteria, viruses, and parasites and pose a significant health risk to humans. The purpose of this study was to examine the effect of communal litter box provision on the defecation behavior of a free-roaming cat population. The study was conducted at H temple and its graveyard in the uptown area of old-town Onomichi, Japan. Cat feces were collected and weighed once a week for 4 weeks, at five popular defecation sites in the temple precincts and graveyard, to assess the quantity of feces left by the cats. A commercial cat repellent was then applied to the ground at 11 sites, including the five popular defecation sites, and six communal litter boxes, created by filling repurposed plastic planters with cat litter, were provided at different sites. The feces in the six litter boxes and on the ground at the five defecation sites were collected and weighed once a week for 14 weeks. The behavior of the cats around the litter boxes and defecation sites was captured using trail cameras. The total weight of the feces collected from the ground before the application of the litter boxes and cat repellent was 939 g. Three adult cats were mainly responsible for the feces on the ground. The amount of feces found on the ground around the temple decreased gradually and significantly after the provision application of the litter boxes and repellent, and reached 0 g in the final week of the study. In contrast, the average weight of the feces in the six litter boxes increased gradually and significantly, and reached 65.7 g/litter box/week in the 14th week. The results showed that the provision of litter boxes and the use of repellent is effective in changing the defecation behavior of ownerless free-roaming cats. We recommend promoting the provision of litter boxes to free-roaming cats to reduce fecal pollution in Onomichi and engaging with local cat feeders to participate in the management of the litter boxes, such as cleaning and changing the litter.

We have succeeded in observing Fe-ion-beam induced nanostructural change of MA956 oxide dispersion-strengthened (ODS) steel using anomalous small-angle X-ray scattering (ASAXS) diffractometry. The ASAXS curve shows a power-law scattering that follows the Porod’s law and an overlapped shoulder peak at the magnitude of scattering vector, Q, around 0.6 nm−1. As the X-ray energy approaches the absorption K-edge of Cr (5.990 keV), the intensity of the power-law scattering slightly decreases, but that of the shoulder peak remarkably increases. From these results, the power-law scattering is attributed to Cr-poor scatterers with a radius much larger than 5 nm, and the shoulder peak is attributed to Cr-rich α′ precipitates with a mean radius of 2.8 nm. After the ion-beam irradiation, intensity of the power-law scattering is nearly doubled, but the shoulder peak remains unchanged within an error of 2%. The latter result indicates that the irradiation-induced changes of radius and inter-precipitation distance of the α′ precipitates are smaller than 10%, and the change of their interface thickness is less than 0.5 nm. In this way, our ASAXS results guarantee an absence of irradiation-induced nanostructure change of specific kinds of precipitates together with statistical errors, while observing changes of other precipitates.

The adsorbed film of n-tetradecylphosphocholine (C14PC) at the tetradecane (C14)/aqueous solution (W) interface was studied by interfacial tensiometry and X-ray reflection (XR). The interfacial tension γ was measured as a function of molality m C 14 PC and temperature T under atmospheric pressure. The interfacial density of C14PC Γ C 14 PC H increases with increasing m C 14 PC and converges into 3 μmol m−2 (first saturation) at m C 14 PC ≈ 0.08 mmol kg − 1 and into 4.2 μmol m−2 (second saturation) at the critical micelle concentration (CMC). The electron density profile determined by XR indicated that C14PC molecules form monolayer with relatively loose packing at the first saturation. In the second saturation, on the other hand, the molecules form bilayer in which charge separated phosphocholine groups take upside-down arrangement to interact attractively between neighbors. The positive entropy changes associated with adsorption both from monomeric and from micellar states result from that the contribution of dehydration around C14PC molecules, especially around PC groups, by the adsorption from aqueous solution overcomes that of a comparatively ordered molecular orientation at the interface. By comparing the results at the C14/W interface with those at the Air (A)/W one, it was shown that in the monolayer and bilayer states, hydrophobic chains of C14PC molecules are more ordered at the C14/W than at the A/W interface because of attractive interaction between C14PC and C14 molecules. This leads to smaller value of the partial molar entropy and energy changes associated with the adsorption at the C14/W than at the A/W interface. Furthermore the entropy of micelle formation changes from positive to negative with increasing T, suggesting that the entropy gain due to the dehydration exceeds the entropy loss by the aggregation at low temperatures, while the gain is less than the loss at high temperature.

Lifetimes of lithium-ion batteries are often affected by deterioration of positive electrodes. It is well-known that the deterioration of the positive electrodes can be reduced by using electrolyte additives; however, the mechanism underlying this cyclability improvement needs to be clarified. In this study, we investigate electronic structure at the electrode/electrolyte interface using in situ total-reflection fluorescence X-ray absorption spectroscopy to elucidate the mechanism underlying the cyclability improvement of a LiCoO2 electrode upon addition of vinylene carbonate (VC) to the electrolyte. The results indicate that the reduction of cobalt ions at the surface of the LiCoO2 electrode, which occurs upon soaking in the electrolyte in the absence of VC, is suppressed by the presence of the VC additive. The VC additive also suppresses irreversible change in the electronic structure of the cobalt ions at the LiCoO2 surface during successive charge/discharge processes. The effects of the VC additive ca...

The free-roaming cat population in Japan is increasing, and these cats are regarded as a tourism resource in some areas; however, their welfare status is unknown. Thus, this study assessed the welfare status of free-roaming cats in the old town of Onomichi City, Hiroshima, Japan. Route censuses were conducted 8 times per month for 3 years to estimate cat populations in the uptown and downtown areas of Onomichi. In the 1st year, we found 124 cats and 80 cats in the uptown and downtown areas, respectively. Approximately half the cats in each area were in poor physical condition. By the 3rd year, 99 of the 124 uptown cats and 66 of the 80 downtown cats had disappeared; moreover, uptown cats in poor physical condition disappeared in significantly greater numbers than those in good condition. It was presumed most missing cats died from illness or injury as opposed to having migrated elsewhere. This study suggests the welfare status of free-roaming cats in Onomichi is poor, and organized management of these cats is a matter of great urgency to improve their status.

Here, we report remarkable oxygen evolution reaction (OER) catalytic activity of brownmillerite (BM)-type Ca

The effect of molecular orientation on the miscibility and structure of the adsorbed film of the 1H,1H,10H,10H-perfluorodecane-1,10-diol (FC10diol)-1H,1H,2H,2H-perfluorodecanol (FC10OH) mixture at the hexane/water interface were examined by interfacial tension and X-ray reflectivity measurements. The interfacial tension and X-ray reflectivity at the hexane solution/water interface were measured as a function of total molality m and composition of FC10OH in the mixture X2 under atmospheric pressure at 298.15 K. The interfacial pressure vs mean area per molecule curves showed that two kinds of condensed monolayers (C1 and C2) and multilayer (M) states appeared depending on m and X2. In the pure component systems, it was found that FC10OH forms condensed monolayer in which the molecules orient almost normally to the interface, and FC10diol orients parallel and is densely packed in the condensed monolayer and then piles spontaneously to form multilayer. In the mixed system, the phase diagram of adsorption indicated that FC10OH molecules are richer in C2 than in C1 state. The X-ray reflectivity measurements manifest that the condensed monolayer below X2 = 0.985 is heterogeneous in which the normal- and parallel-oriented domains coexist at the interface (C1 state), and that above X2 = 0.985 seems to be homogeneous with normal molecular orientation (C2 state). The structure of M state depends on those of condensed monolayers, on which the molecules pile spontaneously. The heterogeneous structure in C1 state is compared to that previously observed in the mixed system of FC10diol-FC12OH (1H,1H,2H,2H-perfluorododecanol), where FC12OH has longer fluorocarbon chain length than FC10OH and is discussed in terms of domain line tension.

Degradation mechanism of surface coating effects at the cathode/electrolyte interface is investigated using thin-film model electrodes combined with operando X-ray absorption spectroscopy (XAS). MgO-coated LiCoO[2] thin-film electrodes prepared via pulsed laser deposition at room temperature and high temperature are used as model systems. The MgO coating improves the durability of the cathode during high-potential cycling. Operando total reflection fluorescence XAS reveals that initial deterioration due to reduction of Co ions at the surface of the uncoated-LiCoO[2] thin film upon electrolyte immersion is inhibited by the MgO coating. Operando depth-resolved XAS reveals that the MgO coating suppresses drastic distortions of local structure at the LiCoO[2] surface as observed in the uncoated-LiCoO[2] during charging process. The electronic and local structure changes at the electrode/electrolyte interface for two types of surface coating morphologies are discussed.

Reaction distribution in the composite electrode of LiCoO 2 , an acetylene black and an organic binder was evaluated by two-dimensional X-ray absorption spectroscopy (XAS). The valence change of Co ion in LiCoO 2 due to the Li de-intercalation during charging was evaluated as the change of the absorption energy of Co K -edge. To demonstrate the reaction distribution due to ionic transportation in the composite cathode, a composite electrode laminated by an aluminum foil and a polyimide film was fabricated in this study. After charging, clear shifts of the absorption energy was observed. The reaction distribution was evaluated by evaluating the peak top energy of Co K -edge as a function of the distance from the edge of the laminated cathode. Two-dimensional mapping of the reaction distribution revealed that the electrochemically active area expands about 700 μm from the edge of the electrode under the charging condition of 0.2 C. This is consistent with a result of electrochemical charging test showing only 42% of the theoretical capacity with the current rate of 0.2 C.

For the further development of lithium-ion batteries, improvement of their cyclic performance is crucial. However, the mechanism underlying the deterioration of the battery cyclic performance is not fully understood. We investigated the effects of the electronic structure at the electrode/electrolyte interface on the cyclic performance of the cathode materials via in situ total-reflection fluorescence X-ray absorption spectroscopy. In a LiCoO2 thin-film electrode that exhibits gradual deterioration upon subsequent Li ion extractions and insertions (cycling), the reduction of Co ions at the electrode/electrolyte interface was observed upon immersion in an organic electrolyte, with subsequent irreversible changes after cycling. In contrast, in a LiFePO4 thin-film electrode, the electronic structure at the electrode/electrolyte interface was stable and reversible upon electrolyte immersion with subsequent cycling. The increased stability of the electronic structure at the LiFePO4/electrolyte interface affect...

Phenomena at electrode/electrolyte interface of LiNi 0.5 Mn 1.5 O 4 are studied by in situ total-reflection fluorescence X-ray absorption spectroscopy (TRF-XAS), ex situ X-ray photoelectron spectroscopy (XPS), and electrochemical tests. Flat and well-defined thin films of LiNi 0.5 Mn 1.5 O 4 prepared by pulsed laser deposition (PLD) are used as model electrodes to facilitate the observation of the interface. The thin-film LiNi 0.5 Mn 1.5 O 4 electrode showed good cycling characteristics at around 4.7 V vs. Li/Li + . The TRF-XAS measurements reveal that nickel and manganese species at the surface have almost the same chemical states and local environments as those in the bulk when in contact with organic electrolyte solutions (1 mol dm −3 LiClO 4 in a 1:1 volumetric mixture of ethylene carbonate and diethyl carbonate). This is in sharp contrast to the behavior of a LiCoO 2 electrode, in which the surface cobalt species is irreversibly reduced by soaking to the organic electrolyte solutions, leading to gradual material deterioration during the delithiation/lithiation cycling (D. Takamatsu et al., Angew. Chem. Int. Edit., 51 (2012) 11597). It is suggested that the electrolyte decomposition products detected by XPS form a protective layer to restrict the reduction of the surface species of LiNi 0.5 Mn 1.5 O 4 , leading to good cycling characteristics of LiNi 0.5 Mn 1.5 O 4 in spite of its high operating potential.

X-ray reflectivity measurements were applied to hexadecane wetting film on aqueous solutions of hexadecyltrimethylammonium bromide (CTAB) and tetradecyltrimethylammonium bromide (TTAB). In both cas...

The phase transition between LiFePO4 and FePO4 during nonequilibrium battery operation was tracked in real time using time-resolved X-ray diffraction. In conjunction with increasing current density, a metastable crystal phase appears in addition to the thermodynamically stable LiFePO4 and FePO4 phases. The metastable phase gradually diminishes under open-circuit conditions following electrochemical cycling. We propose a phase transition path that passes through the metastable phase and posit the new phase's role in decreasing the nucleation energy, accounting for the excellent rate capability of LiFePO4. This study is the first to report the measurement of a metastable crystal phase during the electrochemical phase transition of LixFePO4.

The redox reaction of Li1.16Ni0.15Co0.19Mn0.50O2 positive electrode material during the charging and discharging processes was investigated by using spectroscopic methods, i.e. in situ hard X-ray absorption near edge structure (XANES) at transition metal K-edges and ex situ soft XANES at oxygen K- and transition metal L-edges. The spectral changes of constituent elements during the initial charging to 4.5 V vs. Li/Li+ are quite similar to those of conventional layer-structured positive materials, such as LiNi1/3Mn1/3Co1/3O2. Ni2+ and Co3+ ions are fully oxidized to Ni4+ and Co4+, while Mn4+ remains unchanged. Ligand oxygen ions also take part in charge compensation. In the process of charging to 4.8 V via the plateau voltage region, no significant spectral change appears except partial reduction of Ni and Co ions in spite of lithium extraction. By discharging to 2.0 V the spectra of each element return to those of the pristine material.

In-situ time-resolved X-ray absorption spectroscopy (XAS) and X-ray diffraction (XRD) are applied to investigate the phase transition mechanism between LiFePO4 and FePO4. Phase formation kinetics is discussed by using the phase fractions of LiFePO4 and FePO4 directly obtained from the XRD measurement and the amount of the passed current synchronized by the XRD measurement with Kolmogorov-Johnson-Mehl-Avrami (KJMA) analysis. For both of the lithium extraction and insertion process, the KJMA analysis from the XRD and amount of the passed current data indicate that the phase formation of LiFePO4 and FePO4 proceeds via one-dimensional phase boundary movement. For the lithium extraction process, the two phase coexistence of LiFePO4 and FePO4 is observed under the potential step conditions, and the KJMA plot based on the passed current data is relatively in good agreement with the one based on the XRD data. On the other hand, for the lithium insertion process, considerable peak boarding which implies intermediate state formation during the phase transition occurs, and the LiFePO4 phase formation is delayed compared with the amount of the passed current, especially in the case of small particle size. These results indicate that the phase transition behavior during lithium insertion is different from that of the typical two phase reaction.

The total reflection X-ray absorption fine structure (TR-XAFS) technique was applied to adsorbed films at the surface of aqueous solutions of surfactant mixtures composed of dodecyltrimethylammonium bromide (DTAB) and dodecyltrimethylammonium tetrafluoroborate (DTABF4). The obtained XAFS spectra were expressed as linear combinations of two specific spectra corresponding to fully hydrated bromide ions (free-Br) and partially dehydrated bromide ions adsorbed to the hydrophilic groups of surfactant ions (bound-Br) at the surface. The ratio of free- and bound-Br ions was determined as a function of surface tension and surface composition of the surfactants. Taking also the results in our previous studies on the DTAB – dodecyltrimethylammonium chloride (DTAC) and 1-hexyl-3-methylimidazolium bromide (HMIMBr) – 1-hexyl-3-methylimidazolium tetrafluoroborate (HMIMBF4) mixed systems into consideration, the relation between counterion distribution and miscibility of counterions at the solution surface was deduced for the surfactant mixtures having common surfactant ions but different counterions.

We report a novel low-temperature crystallization path for perovskite lead zirconate titanate (PZT) from solution. The modification of a PZT solution by monoethanolamine (MEA) resulted in a change in the crystallization behavior. MEA was strongly coordinated to the metal ions, resulting in destroy of multinuclear metal organic complexes. This led to a remarkably increased pyrolysis temperature, and Pb2+ was reduced into Pb0 because of a reducing environment at 200–300 °C. Nanoscopic separations of Pb0 was later transformed into uniformly distributed α-PbO nanocrystals and clusters in the amorphous Zr/Ti–O matrix, and finally the sample crystallized into perovskite at 400–500 °C. On the other hand, pyrochlore phase was observed in the conventional crystallization process. The avoidance of pyrochlore formation is the key for the low-temperature crystallization of perovskite. X-ray absorption fine structure (XAFS) analysis was performed to reveal the structures in solutions and amorphous phases.

Solid electrolyte interface (SEI) films formed on Li1−xCoO2 electrodes were observed with hard X-ray photoelectron spectroscopy (HX-PES). This paper particularly focuses on film thickness estimation using HX-PES with theoretical calculation. The validity of the calculation was proven by experiments using model SEI films. The native film formed on a LiCoO2 composite electrode was estimated to be LiF with its thickness of 5 nm. Formation of Co (II) species on top of LiCoO2 was also indicated. Storage of the electrode at 60 °C brought about considerable film growth (30–40 nm) with carbonate compounds formation. SEI film changes during charging of the LiCoO2 electrode were also examined. The main component in the film was deduced to be LiF or a kind of fluorite, with its thickness decreased during charging. The SEI formation mechanisms are also elucidated.