Multi-adaptability supercapacitor electrolyte based on Na-MMT/PDADMAC and application in wide temperature range

n+InAs(Si) epitaxial thin films heavily doped by silicon and Hall effect magnetic field sensors based on this structures have been fabricated and studied. We have demonstrated the successful formation of highly doped InAs thin films (∼100 nm) with the different intermediate layer arrangement and appropriate electron mobility values. Hall sensors performance parameters have been measured in wide temperature range. Obtained sensitivity varied from 1 to 40 Ω/T, while the best linearity and lower temperature coefficient have been found in the higher doped samples with lower electron mobility. We attribute this to the electron system degeneracy and decreased phonon contribution to electron mobility and resistance.

Radiation induced degradation of widely used bipolar voltage comparators was investigated in wide temperature range from high to liquid nitrogen temperatures. It was obtained, that the parametric degradation is significantly greater at low temperature measurements.

The mostly widely used lithium (Li) batteries, including lithium-ion (Li-ion) batteries, are activated via organic solvent based electrolytes that are highly flammable. The flammable electrolyte can potentially impose impediments to large-format battery device implementation because, under abuse conditions (e.g., internal short circuit, overcharge, crush, etc.), Li batteries can be hazardous due to heat generation which can potentially lead to toxic/flammable material release, fire and over-pressurization/explosion [1]. These hazards represent major concerns for power source platforms populated by personnel, sensitive equipment and/or vital structures. Recent high-profile incidents involving energy dense batteries (e.g., the Boeing 787 Dreamliner battery fire incident [2]) have increased public awareness of battery safety and resulted in intensified scrutiny for the processes used to develop, manufacture, certify and transport Li batteries. Here we present ADA efforts in the development of a Li battery technology comprised from a nonflammable, high performance, room temperature ionic liquid (RTIL)-based or hydrofluoroether (HFE)-based electrolytes and a nano-engineered, atomic layer deposition (ALD) functional material coated, high voltage, high energy density cathode (i.e., high voltage LiCoO2 or HV-LCO). We demonstrate that such combinations can afford a Li battery technology with an unprecedented high energy density (over state-of-the-art Li-ion or Li batteries), high rate capability, a wide operation temperature range, long cycle life at room temperature (RT) and temperature extremes and safety. Figure 1 shows electrolyte flammability test results. A lighter was used to ignite the electrolyte in a watch glass dish in open air. An organic solvent based, Li-ion battery baseline (conventional) electrolyte was ignited and self-burning when the ignitor was moved away. Each of the RTIL- and HFE-based electrolytes did not ignite and, no self-combustion was observed. Figure 2 shows discharge voltage profiles of Li/HV-LCO cells with RTIL- and HFE-based nonflammable electrolytes as a function of temperature. The cells were cycled between 3-4.6V. At RT, the cells delivered a high specific capacity/energy (> 200 mAh/g and > 800 Wh/kg, cathode active weight). At 50°C, the cells delivered a slightly higher (1-3%) specific capacity than RT. At -20°C, the cells were cycled at C/10 rate and delivered ~75% of the capacity at RT (~155 mAh/g). At -40°C, the cells were cycled at C/20 rate. The HFE-based electrolyte cell delivered a much higher specific capacity (66.5 mAh/g) than the RTIL-based (negligible). Figure 3 shows excellent rate capability of the RTIL-based electrolyte with 85% capacity retention at 10C rate. Figure 4(a) shows high voltage cycle life between 3-4.6V at RT for pristine LCO and HV-LCO based Li cells using the RTIL-based electrolyte. The pristine LCO cells experienced a rapid capacity fade while the HV-LCO cells demonstrated excellent cycle life stability with > 92% capacity retention after 100 cycles. We attribute the excellent HV-LCO high voltage cycle performance to the ALD functional material coating on LCO; this coating effectively suppresses the degradation root cause, i.e., the Co4+ dissolution and hexagonal to monoclinic phase transition [3]. We also evaluated cycle life at an extreme high temperature of 75°C. Figure 4(b) shows high voltage cycle life test data for pristine LCO and HV-LCO based lithium cells using RTIL-based electrolyte with additives. The cells were cycled between 3-4.5V. The pristine LCO based cell still faded much more quickly than the HV-LCO based cell; the latter exhibited an extraordinary high voltage high temperature cycle resiliency (97% capacity retention after 30 cycles, vs. 75% of the pristine LCO) even at the extreme high temperature of 75°C. We attribute the outstanding cycle stability at 75°C to the synergistic benefits of nano-engineered cathode and passivation protection from the electrolyte additives. Our study highlights the importance of combining high performance, safe electrolyte with nano-engineered cathode (e.g., ALD nano-engineered LCO) to render the resultant lithium battery with unprecedented energy density (gained from the high voltage operation), high rate capability, safety (nonflammability) and robust cycle life over a wide temperature range particularly at the extreme high temperatures (e.g., 75°C). We demonstrate that our Li battery technology is ideally suited for many high energy density and safety demanding applications, such as, electric drive vehicles, consumer electronics, medical, space and military applications. References Peter Roth and Christopher J. Orendorff, Electrochem. Soc. Interface, Summer 2012, page 44.“FAA Grounds Boeing 787 Dreamliner for Battery Problems”, Aviation International News, January 2013Akira Yano, Masahiro Shikano, Atsushi Ueda, Hikari Sakaebe, and Zempachi Ogumi, Electrochem. Soc., 164, A6116 (2017). Figure 1

The anode materials for sodium‐ion batteries (SIBs) such as soft carbon, hard carbon, or alloys suffer from low specific capacity, poor rate capability, and high cost. Various transition metal oxides materials possess high specific capacity and suitable working potential, however, huge volume change and unstable electrode/electrolyte interfaces limit their practical applications. Herein, an ultrathin carbon‐coated iron‐based borate, (Fe3BO5), as an anode material for SIBs is reported. The carbon coated Fe3BO5 composite as an anode material possesses a reversible specific capacity of 548 mAh g−1 with a high initial coulombic efficiency of 72.6% at a current density of 50 mA g−1, and maintains a capacity retention ratio of 99% after 1000 cycles at 2000 mA g−1. Moreover, this anode can work well over a wide temperature range (‐40–60 °C). Furthermore, a sodium‐ion full cell using this anode coupling with iron‐based cathode (Na3Fe2(PO4)2(P2O7)@rGO) cathode is fabricated, which exhibits a wide operating temperature range from −40 to 60 °C with a maximum energy density of 175 Wh Kg−1 and a maximum power density of 1680 W Kg−1. Most importantly, this full‐cell configuration is low‐cost due to its inexpensive iron based raw material for both anode and cathode.

Electrolyte is an important component in redox flow batteries (RFBs) that determines the current capability, potential window, and safety, but both aqueous and nonaqueous electrolytes have their intrinsic limits. Here, we develop the proof‐of‐concept hybrid electrolyte chemistry to enable the design of safe and wide‐temperature RFBs. In addition to the non‐flammable characteristics, the hybrid electrolyte also inherits the high electrochemical stability and wide operational temperature range. It can show a potential window of 2.5 V and maintain high ion conductivities at low temperatures. It also enables LiI to achieve high Coulombic efficiencies of >99.9 %, showing long cycling stability over 800 cycles. Moreover, it enables the successful operation of Zn/LiI RFBs at −20 °C for 150 cycles with nearly no capacity loss. This study highlights the great potential of hybrid electrolyte chemistry for the approach of safe and high‐performance large‐scale energy storage systems in wide temperature ranges.

All‐solid‐state thin film lithium‐ion microbatteries (TFBs) are regarded as the ideal on‐board power sources for microelectronic devices. However, the indispensable high preparation temperature (≥500 °C) required for commonly used cathodes, coupled with the Li anode's low melting point and high chemical reactivity, restricts TFBs’ on‐chip integration and high‐temperature operational capabilities. In this work, a Li x MnO 2 /LiPON/Nb 2 O 5‐x configuration (LMN‐TFB), featuring a low preparation temperature (180 °C) and exceptional chemical and thermal stability, is proposed to simultaneously enable a wide operational temperature range and on‐chip multilayer integration. The LMN‐TFB exhibits a reversible capacity of 26.5 µAh cm −2 and a long cycle life (83.5% capacity retention after 1500 cycles) at room temperature, as well as adequate working ability in a wide temperature range between ‐20 and 210 °C. Moreover, the integration of multilayer stacked LMN‐TFBs on a chip allows for increased capacity (37.5 µAh cm −2 ) or higher working voltage (6.5 V) than the individual LMN‐TFB, resulting in increased areal energy densities within the limited footprint area without significantly increasing the volume or weight. This work presents a promising approach for constructing integratable and wide‐temperature TFBs, offering significant potential for on‐board microelectronic devices.

Localized data conversions for sensors placed under harsh environmental conditions often require Analog to Digital Converters (ADC) capable of working under wide operating temperature range. Even though the fastest analog to digital converter, flash ADC is omitted from the high temperature regime due to the requirements of reference voltage source, reference voltage divider and a comparator array capable of providing stable operation under wide operating temperatures. A CMOS Schmitt inverter-based internal reference comparator array for flash ADC which is efficient in terms of area and power consumption, capable of working under wide temperature range is presented in this paper. The proposed idea replaces the reference voltage source, resistive reference voltage divider and differential comparator array of a conventional flash ADC by an array of suitably sized Schmitt inverters. The circuit was simulated for static and dynamic characteristics with gpdk 180 nm library using cadence virtuoso simulation suite. The voltage transfer characteristic curve (VTC) of the proposed comparator array was found invariable when a temperature sweep in the range of −40 to 170 degree Celsius was performed. Each of the comparator in the proposed array consumes a silicon area of 40.68 and the average dynamic power consumption per cycle is estimated as 103.1 uW.

Developing solid-state lithium metal batteries with wide operating temperature range is important in future. Polyethylene oxide (PEO)-based solid-state electrolytes are extensively studied for merits including superior flexibility and low glass transition temperature. However, ideal usage temperatures for conventional PEO-based solid-state electrolytes are between 60 and 65°C, and unequable temperature degrades their electrochemical performances at low and high temperatures (≤25°C and ≥80°C). Herein, modification methods of PEO electrolytes for low, high especially wide-temperature applications are reviewed based on detailed analyses of mechanisms involved in its modification at different temperatures. First, shortcomings of PEO solid electrolytes due to influence of temperature are pointed out. Second, existing modification strategies are summarized in detail from three aspects of high, low especially wide temperatures, including application of PEO derivatives or chain segment modification treatment of PEO, addition of fillers, and other modification methods such as reasonable regulation of lithium salts, introduction of functional layers and addition of metal-organic frameworks (MOFs) or covalent organic frameworks (COFs). Finally, a summary and description of PEO-based solid electrolyte research and development trends for wide-temperature applications are provided. The review aims to offer some guidance for the creation of PEO solid batteries with wider working temperature ranges.

This paper presents a high-precision, low temperature coefficient (TC) CMOS bandgap reference for high-performance multi-channel ADC working under wide temperature range. A piecewise curvature compensation technique is proposed to extend its operating temperature range and keep its low temperature coefficient. A s-compensation technique is used to cancel the PTAT and non-PTAT spread of the output due to variation of β in the BJTs. Moreover, the trimming resistors are implemented to calibrate the 1st-order temperature coefficient and absolute value of the output voltage. The bandgap reference designed in 0.18μm CMOS process has a super low temperature coefficient of 2.1ppm/°C over a wide temperature of −55 ° C to 140 ° C, making it appropriate to provide reference voltage for a high-precision ADC.

Effect of Ag content on friction and wear properties of Ag and V co-doped CrN coatings at 25–700 °C

Ab initio calculations of the total dielectronic recombination (DR) rate coefficient of Ni-like barium ( ) and tungsten ( ) in the ground state have been performed using the HULLAC atomic code package. Resonant and nonresonant stabilizing radiative transitions are included. Collisional transitions following electron capture are neglected. The present level-by-level calculations include the DR contributions of all of the levels (over 17000) in the Cu-like inner-shell excited configurations 3d 9 4ln'l' ( ), 3p 5 3d 10 4ln'l' ( ), and 3s3p 6 3d 10 4ln'l' ( ). For both ions, the configuration complexes with a hole in the 3p inner shell contribute almost 10% to the total DR rate coefficient, while the complexes with a hole in the 3s inner shell contribute about 1%. The converging contributions of the 3d 9 4ln'l' (n' > 9) configurations are evaluated by applying the complex-by-complex extrapolation method and are found to comprise up to about 20% of the total DR rate coefficients throughout a wide electron temperature range. The total DR rate coefficients are fitted to an easy-to-use analytic expression which reproduces the original data with an accuracy of about 2% or better in a very wide temperature range.

Structural relaxation and its influence on the elastic properties and notch toughness of Mg–Zn–Ca bulk metallic glass

In the present work we apply the cBΩ thermodynamic model to study the diffusion of Si in stishovite crystal at high pressure and in a wide temperature range. According to this model, the point defect activation Gibbs free energy is expressed as a function of the bulk properties of the material, i.e., gact = cBΩ, where B is the isothermal bulk modulus, Ω is the mean atomic volume, and c is a dimensionless constant. In this way, other important point defect parameters, such as the activation volume vact, the activation entropy sact, and the activation enthalpy hact may be estimated if the thermoelastic properties of the material are known over a wide temperature and pressure range. Our calculations are based on previously reported self-diffusion coefficients in stishovite single crystals measured at 14 GPa and at temperatures from 1400 to 1800 °C, in the [110] and [001] directions, by Shatskiy et al. (Am. Mineral. 2010, 95, 135–43). Furthermore, the EOS of stishovite, proposed by Wang et al. (J. Geophys. Res. 2012, 117, B06209) has been used for the accurate implementation of the cBΩ model. Our results suggest that the aforementioned point defect parameters exhibit considerable temperature dependence over the studied temperature range (1000–2000 °C). The estimated activation volumes (4.4–5.3 cm3/mol, in the range of 1400–1800 °C) are in agreement with reported experimental results. Our study confirms the potential of the cBΩ model for the theoretical investigation of diffusion processes in minerals, in order to overcome the experimental difficulties and the lack of experimental diffusion data in mantle conditions.

The reaction between H and benzene is a prototype for reactions of radicals with aromatic hydrocarbons. Here we report calculations of the reaction rate constants and the branching ratios of the two channels of the reaction (H addition and H abstraction) over a wide temperature and pressure range. Our calculations, obtained with an accurate potential energy surface, are based on variational transition-state theory for the high-pressure limit of the addition reaction and for the abstraction reaction and on system-specific quantum Rice-Ramsperger-Kassel theory calibrated by variational transition-state theory for pressure effects on the addition reaction. The latter is a very convenient way to include variational effects, corner-cutting tunneling, and anharmonicity in falloff calculations. Our results are in very good agreement with the limited experimental data and show the importance of including pressure effects in the temperature interval where the mechanism changes from addition to abstraction. We found a negative temperature effect of the total reaction rate constants at 1 atm pressure in the temperature region where experimental data are missing and accurate theoretical data were previously missing as well. We also calculated the H + C6H6/C6D6 and D + C6H6/C6D6 kinetic isotope effects, and we compared our H + C6H6 results to previous theoretical data for H + toluene. We report a very novel nonmonotonic dependence of the kinetic isotope effect on temperature. A particularly striking effect is the prediction of a negative temperature dependence of the total rate constant over 300-500 K wide temperature ranges, depending on the pressure but generally in the range from 600 to 1700 K, which includes the temperature range of ignition in gasoline engines, which is important because aromatics are important components of common fuels.

Prediction of thermal expansion properties of carbon nanotubes using molecular dynamics simulations