Composite sulfur electrodes are prepared by prolonged mechanical milling (≥300 min) for use in all-solid-state lithium-sulfur batteries, and their structure and electrochemical properties are investigated. These batteries exhibit a high initial discharge capacity (>1500 mAh g−1). Sulfur, acetylene black, and the solid electrolyte Li3.25Ge0.25P0.75S4 are mixed by planetary ball milling to form composites that contain amorphous phases of the starting materials, as well as a byproduct with a novel structural unit arising from the reaction between sulfur and the solid electrolyte. Batteries with a composite electrode/Li3.25Ge0.25P0.75S4/Li–In anode configuration exhibit a high initial discharge capacity (>1100 mAh g−1). However, the capacity fades during cycling (∼500 mAh g−1 at the 30th cycle), possibly because of the increased resistance of the composite. Structural and compositional changes of the byproduct and the solid electrolyte itself during the battery reaction could contribute to the increase in resistance that cause the deterioration of cyclability.
A right triangle chip was prepared by cutting a rectangular polystyrene plate (0.3 mmt) that was produced by the ejection of melted polystyrene into a metal mold. The chip was attached on the inside bottom of a culture dish. In light microscopy, the x-y coordinates of several HeLa single-cells were registered by referring to the x-y axes that were defined as the 2 lines forming the right angle. After fixation of these cells and resin embedding, the epoxy block containing cell specimen was peeled off from the culture dish by heating at 145°C for 5 min. Then the right triangle chip was separated by heating again at 145°C for 3 min. The engraved right triangle was used as an x-y coordinate system in electron microscopy. The target HeLa cells registered initially in light microscopy could be found shortly in electron microscopy. The right triangle chip and its engraved shape could be used as an x-y coordinate system transferrable from light microscopy to electron microscopy.
In our previous paper (Electrochemistry, 85(4), 186 (2017)), we have reported that the porous current collector could be produced with a pico-second pulse laser system and that graphite electrodes prepared with porous Cu current collectors improved the rate of Li+-pre-doping reaction in the laminated graphite electrodes. In this study, in order to speed up the rate of the pre-doping reaction more, the porous graphite electrodes were prepared by directly opening the holes on the surface of graphite electrodes with a pico-second laser. In the cell composed of laminated graphite electrodes and a lithium metal, the Li+-doping reaction proceeded much faster than in the cells of the graphite electrodes prepared with porous current collectors and a Li metal. In addition, the results of electrochemical impedance spectroscopy suggested that the transfer of Li+ ions though the holes on the graphite electrodes was a rate determining step of the doping reaction of Li+ to laminated graphite electrodes and that the decrease in the hole diameter at the constant of opening rate of holes on the graphite electrodes cased the reduction of resistance for Li+ ions, resulting in shortening the time for completing the doping reaction of Li+ ions.