There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Solid-state electrolytes are attracting increasing interest for electrochemical energy storage technologies. In this Review, we provide a background overview and discuss the state of the art, ion-transport mechanisms and fundamental properties of solid-state electrolyte materials of interest for energy storage applications. We focus on recent advances in various classes of battery chemistries and systems that are enabled by solid electrolytes, including all-solid-state lithium-ion batteries and emerging solid-electrolyte lithium batteries that feature cathodes with liquid or gaseous active materials (for example, lithium–air, lithium–sulfur and lithium–bromine systems). A low-cost, safe, aqueous electrochemical energy storage concept with a ‘mediator-ion’ solid electrolyte is also discussed. Advanced battery systems based on solid electrolytes would revitalize the rechargeable battery field because of their safety, excellent stability, long cycle lives and low cost. However, great effort will be needed to implement solid-electrolyte batteries as viable energy storage systems. In this context, we discuss the main issues that must be addressed, such as achieving acceptable ionic conductivity, electrochemical stability and mechanical properties of the solid electrolytes, as well as a compatible electrolyte/electrode interface. This Review details recent advances in battery chemistries and systems enabled by solid electrolytes, including all-solid-state lithium-ion, lithium–air, lithium–sulfur and lithium–bromine batteries, as well as an aqueous battery concept with a mediator-ion solid electrolyte.

Lithium battery chemistries enabled by solid-state electrolytes

The science and technology of ultracapacitors are reviewed for a number of electrode materials, including carbon, mixed metal oxides, and conducting polymers. More work has been done using microporous carbons than with the other materials and most of the commercially available devices use carbon electrodes and an organic electrolytes. The energy density of these devices is 3¯5 Wh/kg with a power density of 300¯500 W/kg for high efficiency (90¯95%) charge/discharges. Projections of future developments using carbon indicate that energy densities of 10 Wh/kg or higher are likely with power densities of 1¯2 kW/kg. A key problem in the fabrication of these advanced devices is the bonding of the thin electrodes to a current collector such the contact resistance is less than 0.1 cm2. Special attention is given in the paper to comparing the power density characteristics of ultracapacitors and batteries. The comparisons should be made at the same charge/discharge efficiency.

Ultracapacitors: Why, How, and Where is the Technology

羟氨苄青霉素引起大疱性类天疱疮样疹

Note: Times Cited: 875 Reference EPFL-ARTICLE-206025doi:10.1021/cr0501846View record in Web of Science URL: ://WOS:000249839900009 Record created on 2015-03-03, modified on 2017-05-12

Complex Hydrides for Hydrogen Storage

In this paper, a high-performance multi-channel heterostructure based on lattice-matched AlInN/GaN has been reported. The stacking of five heterostructures yields a high two-dimensional electron gas density of 3.67 × 1013 cm−2 and a small sheet resistance (RSH) of 74.5 Ω/sq. Compared with the AlGaN/GaN sample with the same number of heterojunctions, the AlInN/GaN sample reduces the RSH by 51.2%. Since the AlInN barrier and GaN channel are lattice-matched, the strain defects caused by piezoelectric strain can be alleviated. The high-resolution x-ray diffraction results show that the total dislocation density in AlInN/GaN multi-channels is reduced by 18.9%. The calculation models of multiple-channel heterostructures are obtained to investigate the electron population and energy band diagram, and the calculated results are roughly consistent with the experimental results. With a gate–drain spacing of 11.5 μm, the on-resistance (RON) of the AlInN/GaN multi-channel HEMT was only 2.26 Ω mm, indicating that the lattice-matched multi-channel AlInN/GaN heterostructure can substantially enhance the current drive efficiency and improve the output performance of the devices.

Lattice-matched AlInN/GaN multi-channel heterostructure and HEMTs with low on-resistance

Effects of sintering temperatures on the infrared emissivity of La0.7Sr0.3MnO3

This paper concentrates on the impact of SiN passivation layer deposited by plasma-enhanced chemical vapor deposition (PECVD) on the Schottky characteristics in GaN high electron mobility transistors (HEMTs) Three types of SiN layers with different deposition conditions were deposited on GaN HEMTs Atomic force microscope (AFM), capacitance–voltage (C–V), and Fourier transform infrared (FTIR) measurement were used to analyze the surface morphology, the electrical characterization, and the chemical bonding of SiN thin films, respectively The better surface morphology was achieved from the device with lower gate leakage current The fixed positive charge Q f was extracted from C–V curves of Al/SiN/Si structures and quite different density of trap states (in the order of magnitude of 1011–1012 cm−2) was observed It was found that the least trap states were in accordance with the lowest gate leakage current Furthermore, the chemical bonds and the %H in Si–H and N–H were figured from FTIR measurement, demonstrating an increase in the density of Q f with the increasing %H in N–H It reveals that the effect of SiN passivation can be improved in GaN-based HEMTs by modulating %H in Si–H and N–H, thus achieving a better Schottky characteristics

https://iopscience.iop.org/article/10.1088/1674-1056/27/9/097309/pdf

Effect of SiN:H x passivation layer on the reverse gate leakage current in GaN HEMTs

The behaviors of the gate induced drain leakage (GIDL) stress during the single and alternating stresses were investigated. A combination of threshold voltage Vth and GIDL current Igidl has been applied to investigate n-channel metal-oxide-semiconductor field-effect transistors with different gate oxide thicknesses. The recovery and enhancement of Vth depending on the gate oxide thickness, are found to result from the GIDL stress in the two processes. This study reveals that different behaviors of GIDL stress for different gate oxide thicknesses are attributed to the rivalship between the hole-induced carrier mobility increase and the interface states-induced increase in lightly doped drain resistance.

Behaviors of gate induced drain leakage stress in lightly doped drain n-channel metal-oxide-semiconductor field-effect transistors

Herein, physically transient Schottky diode with a structure of W/ZnO/MgO/W was proposed. By insert of 5 nm MgO layer between ZnO and W, Schottky barrier diode with rectification ratio of $7.8\times 10^{3}$ at ±1.5 V and a current density of 1780 mA/cm2 is obtained. In addition, the AC rectification frequency exceeds 1 MHz is observed. Meanwhile, stable resistive switching (RS) memory with remarkable performance and typical synapse functions have also been observed by applying a larger forming voltage. Additionally, the dissolution tests of ZnO, MgO and W films in deionized water (DI) demonstrate physically transient nature of the devices. The proposed transient W/ZnO/MgO/W Schottky diode provides the feasibility to control the functional for target use which have great potential for security computing systems, environmental friendly electronics, and biological integrated interfaces application.

Xiaohua Ma

Papers

Lattice-matched AlInN/GaN multi-channel heterostructure and HEMTs with low on-resistance

Effects of sintering temperatures on the infrared emissivity of La0.7Sr0.3MnO3

Effect of SiN:H x passivation layer on the reverse gate leakage current in GaN HEMTs

Behaviors of gate induced drain leakage stress in lightly doped drain n-channel metal-oxide-semiconductor field-effect transistors

Physically Transient W/ZnO/MgO/W Schottky Diode for Rectifying and Artificial Synapse