A universal graphitic interlayered centroid intercalation theory for intercalation chemistry

Neither of the two widely used staging models in the long history of intercalation chemistry, namely the classical Rüdorff-Hofmann model proposed in 1938 and the pleated-layer domain-modified one in 1969, can explain the intercalation reaction phenomena and mechanism logically. Taking the landmark potassium-intercalation reaction of graphite as a model case and two advanced monolithic graphitic/graphenic carbon foams as model electrodes, here we have revealed that the electrochemical storage of potassium in graphitic/graphenic carbon (as that of lithium) obeys a simple interlayered centroid intercalation (ICIC) rule to achieve the staged potassium intercalation into each graphitic interlayer: C → KC72 → KC24 → KC8. Moreover, judging from the typical potassium-storage behaviors and crystal texture of graphitic electrodes, nitrogen doping and pre-embedded K atoms would enable incoming K+ ions to perform fast pseudocapacitive diffusion in graphitic gallery. This study not only makes clear the basic K-storage mechanism and phenomena in graphitic carbon, but also establishes a more reasonable ICIC model for intercalation chemistry, and thus may help open a new research era for this field as well as graphite-based metal-ion batteries.

Effects of JGB Additives on the Microstructures and Electrical Properties of Electroplated Copper Foil

Extremely thin film high quality copper foil is required to ensure high performance in electronics and slimness in secondary batteries. During the electroplating of copper foil, Janus Green B(JGB) and Collagen were introduced as additives to the electrolytes to study their effects. The structural and electrical properties of the electroplated copper foil were evaluated. When each additive was added individually, the potential was increased. Specifically, the potential of the group with 30 ppm added collagen was about 27% higher rather than the non-additive group. When Cl- ions and MPSA(3-mercapto-1-propane sulfonic acid) were added to the electrolytes without collagen and JGB, the surface roughness(Rz) increased by about 136% to 2.24 μm compared to the non-additive group. This was the highest value among all groups. However, a uniform layer with a surface roughness value below 0.3 μm was formed when less than 30 ppm and 10 ppm collagen and JGB were added, respectively, to the electrolyte. The direction of crystal growth with the JGB additives tended to go forward to the (220) direction, and the crystal size was reduced by 10~27% compared to the non-additive group. The addition of Collagen is necessary to reduce the difference in resistivity of the shiny layer and right matte layer. JGB additives were required to reduce the deviation in grain size. The results confirmed that the accelerators, inhibitors and leveler need to be properly added to form a copper plating layer with low surface roughness and to reduce differences in crystal texture of the shiny layer and right matte layer. Copper foil can be safely and uniformly deposited from electrolytes with JGB below 10 ppm and collagen below 30 ppm.

Tuning photoluminescence spectra of MoS2 with liquid crystals

The liquid crystal texture on molybdenum disulfide (MoS2). And the photoluminescence and Raman spectra of MoS2 are shifted with liquid crystals.

Resolving uncertainties in the application of zircon Th / U and CL gauges to interpret U-Pb ages: a case study of eclogites in polymetamorphic terranes of NW Iberia

Zircon crystal texture and Th / U ratio have been used as a watertight argument when interpreting U-Pb ages. The wide, and sometimes indiscriminate, use of those gauges could result into misinterpretation of the geological meaning of U-Pb data. A case study is presented here where zircons from a controversial polymetamorphic eclogite unit were analyzed with SHRIMP. Both U-Pb and trace element (TE) data were collected for each point. The combination of TE and structural arguments indicates that zircon was part of the eclogite facies mineral assemblage at 390 Ma. However, using Th / U ratio and CL textures lead to a different interpretation. Our results suggest that in complex orogenic scenarios and extreme environments well-known techniques (CL) and geochemical relationships (Th / U) must be used in combination with TE data and structural relationships as provenance/process gauges. While geochronology provides accurate isotope relationships, their temporal dimension must rely on structural and petrological evidence.