NGK

About: NGK is a company organization based out in Nagoya, Japan. It is known for research contribution in the topics: Spark plug & Ceramic. The organization has 2387 authors who have published 2741 publications receiving 25761 citations. The organization is also known as: NGK Spark Plug Co.,Ltd. & Nippon Tokushu Tōgyō Kabushiki-gaisha.

Solid-State Li–Metal Batteries: Challenges and Horizons of Oxide and Sulfide Solid Electrolytes and Their Interfaces

Abstract: DOI: 10.1002/aenm.202002689 lightweight, and compact and allow for versatile device geometries. They must also be scalable and offer high energy density to provide improved packing efficiency and longer device operation. Although both Ni–MH batteries and LIBs have been commercialized since the 1990s,[1] LIBs possess twice the gravimetric/volumetric energy density (250 Wh kg−1/700 Wh L−1 vs 170 Wh kg−1/350 Wh L−1),[2] higher battery voltage (3.7 V vs 1.2 V), and longer cycle life with lower self-discharge,[3] contributing tremendously to the proliferation of portable electronic devices (e.g., mobile phones, laptops, cameras, tablets) as well as emerging new technologies such as wearable electronic devices (e.g., smart watches and sport-related tracking devices). Their high gravimetric/ volumetric energy density,[2] excellent cycle life (thousands of cycles), and lack of the memory effect have positioned LIBs as state-of-the-art power sources and one of the greatest successes of modern electrochemistry, revolutionizing the way we acquire, process, transmit, and share information globally. Nevertheless, advances in battery energy density, safety, costs, and flexibility in shape and size are still needed to keep up with the rapidly growing demand for devices with even longer runtime as well as real-time data collection and transmission capabilities in addition to increasingly energy-demanding applications such as electric vehicles (EVs) and electricity grid storage. Even though LIBs were first commercialized in all electric vehicles (EVs) in 2010 and also emerged for grid application in the same time frame, the low energy density (≈250 Wh kg−1) and high average cost (≈$156 kWh−1 in 2019) of conventional LIBs do not meet the requirements for advanced EVs and grid-scale energy storage.[4–6] Specifically, the driving range per charge (miles), which is related to the energy density of each cell, and the cost are important parameters for EVs. For example, one 85 kWh battery pack in a Tesla Model S requires 7104 LIB cells, with an energy density of 265 Wh kg−1, providing an average range of 250 miles, which is ahead of the range of other EVs but still behind the target of 375 miles.[4] In grid-scale applications, LIBs can be used for various tasks: frequency regulation, peak shaving, load leveling, and large-scale integration of renewable energies, with specific properties generally required for each task. For frequency regulation, LIBs need to provide a fast response, high rate performance, and high-power capability, The introduction of new, safe, and reliable solid-electrolyte chemistries and technologies can potentially overcome the challenges facing their liquid counterparts while widening the breadth of possible applications. Through tech-historic evolution and rationally analyzing the transition from liquidbased Li-ion batteries (LIBs) to all-solid-state Li-metal batteries (ASSLBs), a roadmap for the development of a successful oxide and sulfide-based ASSLB focusing on interfacial challenges is introduced, while accounting for five parameters: energy density, power density, longterm stability, processing, and safety. First taking a strategic approach, this review dismantles the ASSLB into its three major components and discusses the most promising solid electrolytes and their most advantageous pairing options with oxide cathode materials and the Li metal anode. A thorough analysis of the chemical, electrochemical, and mechanical properties of the two most promising and investigated classes of inorganic solid electrolytes, namely oxides and sulfides, is presented. Next, the overriding challenges associated with the pairing of the solid electrolyte with oxide-based cathodes and a Li-metal anode, leading to limited performance for solid-state batteries are extensively addressed and possible strategies to mitigate these issues are presented. Finally, future perspectives, guidelines, and selective interface engineering strategies toward the resolution of these challenges are analyzed and discussed.

Crystal growth and low coercive field 180° domain switching characteristics of stoichiometric LiTaO3

Abstract: We grew LiTaO3 single crystals with a composition close to stoichiometry by using a double crucible Czochralski method. The switching field required for 180° ferroelectric domain reversal and the internal fields originating from nonstoichiometric point defects were compared for the stoichiometric and conventional commercially available crystals. The switching fields for the domain reversal in the stoichiometric crystal with a Curie temperature of 685 °C was 1.7 kV/mm. This is about one thirteenth of the switching field required for the conventional LiTaO3 crystals with a Curie temperature near 600 °C. The internal field in the stoichiometric crystal drastically decreased to 0.1 kV/mm.

Dye-sensitized solar cell

Abstract: A dye-sensitized solar cell that includes a semiconductor layer, to which a photosensitive dye generating electrons is adhered; a photo electrode disposed on a side of the semiconductor layer so as to transfer electrons; and an auxiliary electrode disposed on the other side of the semiconductor layer so as to transfer the electrons, and at least one semiconductor layer and at least one auxiliary electrode are stacked alternatively. Thus, an amount of molecules of the photosensitive dye may be increased without increasing the moving distance of electrons, and the efficiency of the solar cell may be increased.

Air/fuel ratio sensor

Abstract: An air/fuel ratio sensor having an unambiguous output with respect to both the fuel-rich and the fuel-lean regions and which does not require the introduction of atmospheric air. The sensor is composed of first and second elements, each having porous electrodes formed on opposite sides of an oxygen-ion-conductive electrolyte plate. The two elements are arranged to define between them a gas compartment communicating with the atmosphere to be detected via one or more diffusion limiting portions. One of the elements serves as an oxygen concentration differential electrochemical cell and the other one as an oxygen pump. An internal reference oxygen source is formed on the side of one of the elements opposite the gas compartment, and a small current is caused to flow the first element so as to transfer oxygens from the gas compartment to the oxygen source. The second element pumps oxygen into or out of the gas compartment in such a manner that the air/fuel ratio of the gas in the gas compartment is held at a predetermined value.