EurekAlert April 11, 2020 The garnet-type ceramic Li7La3Zr2O12 (LLZO) is one of the few solid-state fast-ion conductors that is stable against Li metal. However, the densification of LLZO powders usually requires high sintering temperatures which likely results in Li loss and various side reactions. Researchers in Japan have developed a process to make flexible composite Al-doped LLZO (Al-LLZO) sheet electrolyte which can be mass-produced at room temperature. The sheet electrolyte enables Li-metal batteries to operate at both 60 and 30 °C, demonstrating its potential application for developing practical Li-metal batteries…read more. TECHNICAL ARTICLE
Tag Archives: S&T Japan
Untwisting plastics for charging internet-of-things devices
Science Daily April 16, 2020 To use body heat to charge some types of micro-devices and sensors lightweight, non-toxic, wearable, and flexible thermoelectric generators are required. Japan studied the thermoelectric properties of highly conductive thiophene-based polymer, called PBTTT. They doped the polymer with a thin ion electrolyte gel, which is known to improve conductivity that infiltrates the polymer successfully when a specific electric voltage is applied. They found that, without the electrolyte gel, the PBTTT chain is highly twisted. Doping it with a critical amount of electrolyte untwists the chain and creates links between its crystalline parts, improving electron conductivity. […]
How a new quantum approach can develop faster algorithms to deduce complex networks
EurekAlert March 3, 2020 Complex networks form the basis of various applications in virtually all fields of science. To analyze and manipulate these networks, specific “search” algorithms are required. But conventional search algorithms are slow and, when dealing with large networks, require a long computational time. To develop more efficient quantum algorithms researchers in Japan performed numerical simulations on some basic fractal lattices to try to find out the relationship between the number of vertices and the optimal computational time in a quantum walk search. They confirmed that the scaling law for some fractal lattices varied according to their spectral […]
Synthesizing a superatom: Opening doors to their use as substitutes for elemental atoms
Science Daily February 25, 2020 Scientists have shown particular interest in superatomic structures, since they can be linked with atoms to produce molecules, and potentially be used to substitute certain elements in many applications. But for superatoms to be effectively utilized, they must be specially tailored to resemble the characteristics of the corresponding elements. Researchers in Japan fabricated clusters of the element gallium in solution to demonstrate the effects of changing the number of atoms in a cluster on the properties of the cluster. The team synthesized Ga clusters of 3, 12, 13 using a specialized superatom synthesizer. The 13-atom […]
A spookily good sensor
Phys.org February 19, 2020 Researchers in Japan placed a millimeter-sized sphere of yttrium iron garnet in the same resonant cavity as a superconducting Josephson junction qubit, which acted as the sensor. Because of the coupling of the sphere to resonant cavity, and, in turn, between the cavity to the qubit, the qubit could only be excited by an electromagnetic pulse if no magnetic excitations were present in the sphere. Reading the state of the qubit then reveals the state of the sphere. By using single-shot detection instead of averaging, they were able to make the device both highly sensitive and […]
A gold butterfly can make its own semiconductor skin
Science Daily February 6, 2020 Current methods for placing nano-sized semiconductors on metallic particles to utilize them in nano-lasing and nano-lithography lack precision or are too costly. Researchers in Japan have developed a method based on a hydrothermal synthesis reaction to locally and selectively synthesize zinc oxide in a plasmonic nanoantenna. They first made evident the role of localized surface plasmon resonances (LSPR) for achieving efficient heating of gold nanostructures. Then, by selectively addressing one of the LSPRs of a gold antenna, they demonstrated that localized zinc oxide formation at the targeted location of the antenna can be achieved due […]
Movement of a liquid droplet generates over 5 volts of electricity
EurekAlert February 13, 2020 Researchers in Japan have demonstrated that using molybdenum disulfide instead of graphene as the active material in the generator makes it possible to generate over 5 volts of electricity from a liquid droplet. They made a large area single -layer MoS2 film with polystyrene film as bearing material, by chemical vapor deposition using a sapphire substrate with molybdenum oxide (MoO3) and sulphur powders. The film made it easy to transfer the synthesized MoS2 film to the surface. The generator is flexible enough to be installed on the curved inner surface of plumbing and is thus expected […]
Something from nothing: Using waste heat to power electronics
EurekAlert February 12, 2020 A thermocell can convert environmental thermal energy to electric energy via thermal charging effect. However, the output voltage is low and depends on temperature. Researchers in Japan developed a thermocell containing a material that exhibited a temperature-induced phase transition of its crystal structure. Just above room temperature, the atoms in this solid material rearranged to form a different crystal structure. This phase transition resulted in an increase in output voltage from zero to around 120 mV, representing a considerable performance improvement over that of existing thermocells. They were able to finely tune the phase transition temperature […]
Slow light to speed up LiDAR sensors development
Phys.org January 14, 2020 Currently existing optical beam steering devices uses mechanics that make them large, unstable, heavy, with limited overall speed and a high cost. Optical phased arrays for steering beams requires many optical antennas. Researchers in Japan used a special waveguide “photonic crystal,” aimed through a silicon-etched medium. Light is slowed down and emitted to the free space when forced to interact with the photonic crystal. They engaged a prism lens to then direct the beam in the desired direction. The resulting method and device are small-sized, free of moving mechanics, setting the stage for a solid-state LiDAR. […]
High-performance anode for all-solid-state Li batteries is made of Si nanoparticles
EurekAlert December 23, 2019 In conventional liquid electrolytes, the use of polymeric binders is necessary to hold the active material particles in the electrode together and maintain their adhesion to the surface of metal current collectors. The repeated huge volume change of Si causes the particle isolation and thus leads to losing the active material, which results in a continuous capacity loss. Researchers in Japan have shown that in solid electrolytes, an Si anode composed only of commercial Si nanoparticles prepared by spray deposition exhibits excellent electrode performance, which has previously been observed only for film electrodes prepared by evaporation […]