The exploration of aqueous flexible metal–air batteries with high energy density and durability has attracted many research efforts with the demand for portable and wearable electronic devices. ...Aqueous flexible metal–air batteries feature Earth‐abundant materials, environmental friendliness, and operational safety. Each part of one metal–air battery can significantly affect the overall performance. This review starts with the fundamental working principles and the basic battery configurations and then highlights on the common issues and the recent advances in designing high‐performance metal electrodes, solid‐state electrolytes, and air electrodes. Bifunctional oxygen electrocatalysts with high activity and long‐term stability for constructing efficient air electrodes in flexible metal–air batteries are summarized including metal‐free carbon‐based materials and nonprecious Co/Fe‐based materials (alloys, metal oxides, metal sulfites, metal phosphates, metal nitrates, single‐site metal–nitrogen–carbon materials, and composites). Finally, a perspective is provided on the existing challenges and possible future research directions in optimizing the performance and lifetime of the flexible aqueous solid‐state metal–air batteries.
A high‐performance aqueous flexible metal–air battery requires the proper matching between the used system and materials including the metal electrodes, solid‐state electrolytes, air electrodes, and oxygen electrocatalysts within a durable battery configuration. The recent progress, accompanied challenges, and future perspectives are presented in this review aiming to explore novel and powerful aqueous flexible metal–air batteries.
Full text
Available for:
FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Superradiance and subradiance concerning enhanced and inhibited collective radiation of an ensemble of atoms have been a central topic in quantum optics. However, precise generation and control of ...these states remain challenging. Here we deterministically generate up to 10-qubit superradiant and 8-qubit subradiant states, each containing a single excitation, in a superconducting quantum circuit with multiple qubits interconnected by a cavity resonator. The sqrtN-scaling enhancement of the coupling strength between the superradiant states and the cavity is validated. By applying an appropriate phase gate on each qubit, we are able to switch the single collective excitation between superradiant and subradiant states. While the subradiant states containing a single excitation are forbidden from emitting photons, we demonstrate that they can still absorb photons from the resonator. However, for an even number of qubits, a singlet state with half of the qubits being excited can neither emit nor absorb photons, which is verified with 4 qubits. This study is a step forward in coherent control of collective radiation and has promising applications in quantum information processing.
Full text
Available for:
CMK, CTK, FMFMET, IJS, NUK, PNG, UL, UM
Electrocatalysts can optimize the sulfur/sulfide reaction kinetics in Li–S batteries to compete with the loss of lithium polysulfides (LiPSs) caused by the shuttling effect. However, the design ...rationale of electrocatalysts to drive roundtrip sulfur/sulfide conversion is lacking. Here, pairing Lewis acidic and Lewis basic active sites to reach collective adsorption of LiPSs and simultaneous activation of electrophiles and nucleophiles in LiPSs is proposed. This concept is validated by doping polyaniline with protonated metatungstate anions, which enables reduced activation energies for both sulfur reduction reaction and sulfide oxidation reaction and results in significantly improved kinetics. Such electrocatalysts enable a Li–S battery to reach a low capacity‐decay rate of 0.029% per cycle for 1000 cycles. This work would offer insights into battery technologies where sulfur electrocatalysis will play pivotal roles.
A design rationale for a Lewis acid–Lewis base hybridized electrocatalyst of Li–S batteries is proposed. Doping polyaniline with protonated metatungstate anions enables the synthesis of the roundtrip electrocatalyst, which promotes kinetics of both sulfur reduction and sulfide oxidation. Consequently, a stable cycling for 1000 cycles with a capacity decay rate of 0.029 % per cycle is achieved.
Full text
Available for:
FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Novel scheelite‐type Ca0.55(Nd1‐xBix)0.3MoO4 (0.2 ≤ x ≤ 0.95) ceramics were prepared using the solid‐state reaction method. According to the X‐ray diffraction data, a solid solution was formed in ...0.2 ≤ x ≤ 0.95 and all the samples belong to pure scheelite phase with the tetragonal structure. As revealed by Raman spectroscopy, the number of vibrational modes decreased with the increase in x value, which further indicated that Bi3+ ions occupied A‐site of scheelite structure. As the x value increased, the sintering temperature decreased from 740°C to 660°C; the permittivity increased from 12.6 to 20.3; the Qf value first decreased slightly and gradually remained stable. Based on the infrared reflectivity spectrum analysis, the calculated permittivity derived from the fitted data shared the same trend with the measured value. The Ca0.55(Nd0.05Bi0.95)0.3MoO4 ceramic sintered at 660 °C attained a near‐zero value temperature coefficient ~τf (−7.1 ppm/°C) and showed excellent microwave dielectric properties with a ɛr ~ 20.3 and a Qf ~ 33 860 GHz, making this system a promising candidate in the ultralow temperature cofired ceramic (ULTCC) technology.
Full text
Available for:
BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
Phosphorene is a promising candidate for gas sensing materials. This letter describes our study of the adsorption of SF 6 and SF 6 decomposition gases (SO 2 and H 2 S) on phosphorene. We used first ...principles calculations to explore phosphorene's potential applications as gas sensor to diagnose the state of online gas insulated switchgear (GIS). The calculation results showed that only the adsorption of SO 2 induced a moderate adsorption energy and apparent charge transfer. We further investigated the current-voltage (I-V) relationships before and after gas absorption through the non-equilibrium Green's function method. It was found that only SO 2 induced a dramatic change in the I-V relationships. Therefore, phosphorene appears to be a promising candidate for highly sensitive and selective SF 6 decomposition gas sensors for online GIS diagnosis.
Topological photonics provides a powerful platform to explore topological physics beyond traditional electronic materials and shows promising applications in light transport and lasers. Classical ...degrees of freedom are routinely used to construct topological light modes in real or synthetic dimensions. Beyond the classical topology, the inherent quantum nature of light provides a wealth of fundamentally distinct topological states. Here we implement experiments on topological states of quantized light in a superconducting circuit, with which one- and two-dimensional Fock-state lattices are constructed. We realize rich topological physics including topological zero-energy states of the Su-Schrieffer-Heeger model, strain-induced pseudo-Landau levels, valley Hall effect, and Haldane chiral edge currents. Our study extends the topological states of light to the quantum regime, bridging topological phases of condensed-matter physics with circuit quantum electrodynamics, and offers a freedom in controlling the quantum states of multiple resonators.
Topological quantum photonics
Exploiting the topological properties of materials is expected to provide a route to developing robust platforms for transport and communication systems that are immune to defects. In optics, the demonstration of topological behavior has been confined mainly to classical light. Deng
et al
. introduce a superconducting chip–based platform consisting of a single qubit coupled to a number of resonators. By controlling the photon population in each resonator and the coupling strength, the authors were able to realize several important models in topological physics. The approach bridges the gap between topological states of classical and quantum origin. —ISO
A superconducting-based circuit allows the coherent control of topological states of quantized light.
Asymmetric supercapacitor is constructed using hierarchical porous electrode materials of nickel oxide and carbon with the aim to facilitate ion transport. Hierarchical porous nickel oxide and carbon ...are prepared by template-directed synthesis. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charging–discharging are used to test the asymmetric supercapacitor and investigate the electrode processes at different supercapacitor voltages. The capacitance, energy density and power density of the asymmetric supercapacitor can be improved by elevating the supercapacitor voltage, and its cycling stability decays at high voltage, but the columbic efficiency stays close to 100%.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
This work shows an ultrahigh sensitivity microwave sensor for microfluidic applications. The proposed sensor is made of a microstrip line loaded with a complementary splitring resonator (CSRR). The ...meander slot is adopted in the CSRR to achieve high field confinement and is therefore covered with a polydimethylsiloxane (PDMS) microfluidic channel to enable strong interaction between the field and the liquid sample. The complex permittivity of the liquid sample can be retrieved by the variations in the resonant frequency and peak attenuation. The proposed design requires a very small liquid volume of ~0.5 μL while offering a high sensitivity. A prototype is fabricated and tested, with a good agreement achieved between the extracted values and the reference data.
Microwave microfluidic sensors have been employed for dielectric characterization of different liquids. Intuitively, the microfluidic channel plays a vital role in determining the sensor performance. ...In this article, for the first time, numerical optimization design of microfluidic channel route is carried out with the aim of improving the sensor sensitivity. Two swarm intelligence algorithms, i.e., particle-ant colony optimization algorithm and wolf colony algorithm, are implemented for the route optimization. Through the developed optimization procedure, the sensor sensitivity of the original design can be increased significantly. Several prototypes of optimized sensors are fabricated and tested, and they exhibit good capability in retrieving the liquid properties. In comparison with original complementary split-ring resonator-based sensor with a sensitivity of 0.308% for water measurement, the optimized sensor achieves a high sensitivity value of 0.55%, i.e., the sensor sensitivity is increased by 78.6% after optimization. The developed methodology can also be used in other designs, such as series LC -based sensor, whose sensitivity can be improved by about 50%. It is demonstrated that the developed methodology possesses good automatic optimization ability and universality for the optimal design of microwave microfluidic sensors.
PDF
