We analyze the competition between strong correlations and dissipation in quantum impurity systems from the Kondo regime to the valence fluctuation regime by developing a slave-boson theory for a non-Hermitian Anderso...
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We analyze the competition between strong correlations and dissipation in quantum impurity systems from the Kondo regime to the valence fluctuation regime by developing a slave-boson theory for a non-Hermitian Anderson impurity model with one-body loss. Notably, in the non-Hermitian Kondo regime, strong correlations qualitatively change the nature of dissipation through renormalization effects, where the effective one-body loss is suppressed and emergent many-body dissipation characterized by the complex-valued hybridization is generated. We unveil the mechanism of a dissipative quantum phase transition of the Kondo state on the basis of this renormalization effect, which counterintuitively enhances the lifetime of the impurity against loss. We also find a crossover from the non-Hermitian Kondo regime to the valence fluctuation regime dominated by one-body dissipation. Our results can be tested in a wide variety of setups such as quantum dots coupled to electronic leads and quantum point contacts in ultracold Fermi gases.
The extensive commercialization of practical solid-state batteries (SSBs) necessitates the development of high-loading solid-state cathodes with fast charging capability. However, electrochemical kinetics are severely...
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The extensive commercialization of practical solid-state batteries (SSBs) necessitates the development of high-loading solid-state cathodes with fast charging capability. However, electrochemical kinetics are severely delayed in thick cathodes due to tortuous ion transport pathways and slow solid-solid ion diffusion, which limit the achievable capacity of SSBs at high current densities. In this work, we propose a conductivity gradient cathode with low-tortuosity to enable facile ion transport and counterbalance ion concentration gradient, thereby overcoming the kinetic limitations and achieving fast charging capabilities in thick cathodes. The LiNi 0.8 Co 0.1 Mn 0.1 O 2 cathodes deliver a room-temperature (RT) capacities of 147 and 110 mAh g −1 at 5 C and 10 C, respectively, and meanwhile achieve a RT areal capacity of 3.3 mAh cm −2 at 3 C, enabling SSBs simultaneously high energy and power densities. The universality of this strategy is demonstrated in LiFePO 4 cathodes, providing a novel solution for fast charging and large-scale application of high-loading SSBs.
The influence of SiC particulate size on the age-hardening response of 2009 aluminium has been monitored utilizing hardness, electrical conductivity and differential scanning calorimetry. Ageing involved either two or...
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The influence of SiC particulate size on the age-hardening response of 2009 aluminium has been monitored utilizing hardness, electrical conductivity and differential scanning calorimetry. Ageing involved either two or three stages depending on the reinforcement size. For 2009 Al reinforced with 29 mu m SiCp, initial ageing consisted of GPB (Guinier Preston Baqaryatsky) I zone formation. Decreasing the particulate size to 4 mu m eliminated GPB I formation. This suppression of GPB I formation during ageing suggests that decreasing SiC size decreases the vacancy supersaturation following quenching by providing additional vacancy sinks at SiC/matrix interfaces. Subsequent ageing involved, at the larger reinforcement sizes, a transition with increasing time from GPB I zones to GPB Il-dislocation complexes. At smaller (4 mu m) reinforcement sizes, the formation of GPB Il-dislocation complexes occurs directly. Finally, the last stages of age hardening in all SiCp-reinforced composites examined consisted of heterogeneous nucleation of S'/S and GPB II --> S'/S transformation.
Martensitic phase transformations in the solution-treated and water-quenched binary Ti-Nb alloys in the range of 16-26 at % Nb, were examined. An ordered, base-centred orthorhombic martensite was observed for alloys c...
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Martensitic phase transformations in the solution-treated and water-quenched binary Ti-Nb alloys in the range of 16-26 at % Nb, were examined. An ordered, base-centred orthorhombic martensite was observed for alloys containing up to 23.4 at % Nb. The substructure of this martensite was generally composed of twins and stacking faults, the presence of antiphase boundaries observed in the plates indicating that the martensite underwent ordering during quenching. Both order-disorder and NJ,temperatures were. observed to be affected by total interstitial content, higher contents increasing both temperatures. Increasing the niobium content to above 23.4% resulted in retention of the beta phase, this phase containing either athermal omega or ''diffuse'' omega depending upon niobium and total interstitial concentration. Finally, the microhardness of the Ti-Nb alloys examined was observed to decrease with increase in niobium and decrease in total interstitial content.
Three natural alkaloids: caffeine, theobromine and theophylline are reported for their application as dielectric layers in organic field effect transistors (OFETs) utilizing both gold and aluminum gate electrodes. Aft...
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Wetting, indicating the ability of a liquid to spread out over solid surfaces,is of vital importance in addressing the scientific issues related to energy and environment technologies. The study of wetting encompasses...
Wetting, indicating the ability of a liquid to spread out over solid surfaces,is of vital importance in addressing the scientific issues related to energy and environment technologies. The study of wetting encompasses the academic disciplines of surface chemistry, nanotechnology, materialsscience and energy *** past several decades have witnessed significant progress in achieving desirable wetting performance with water,
This study concerns alkaline fluorides such as CaF2 and BaF2 contained in gadolinium phosphate glass doped with CeF3, which were synthesized using a melt-quenching technique. Ce3+ was activated in both glasses and a c...
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Sodium-ion batteries (SIBs) are emerging as a viable alternative for sustainable and cost-effective energy storage, yet their energy density is curtailed by relatively low voltage outputs (< 4 V) due to the la...
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Sodium-ion batteries (SIBs) are emerging as a viable alternative for sustainable and cost-effective energy storage, yet their energy density is curtailed by relatively low voltage outputs (< 4 V) due to the lack of high-voltage electrolytes. Here, for the first time, we describe a high-voltage Na + electrolyte featuring a macromolecule-enriched solvation architecture. The vulnerable small molecules in the Na + solvation shell are replaced by macro polyamide (PA) molecules with high thermodynamic resilience, ensuring a wide electrochemical stability window for the electrolytes with suppressed oxidative/reductive decomposition. Concomitantly, the anions engage in H-bonding with the amido groups of PA, which not only stabilizes the anions against hydrolysis, but also delivers a high Na + transference number of 0.93. Importantly, the nitrogen-rich composition of the macromolecule-enriched electrolyte (MEE) fosters the formation of robust nitride interphases that impart enduring stability to both the cathode and anode. As a result, the hard carbon (HC) || NaNi 1/3 Fe 1/3 Mn 1/3 O 2 (NFM) full cells demonstrate significant rechargeability even with an ultrahigh cutoff voltage of 4.4 V. Our approach distinctively avoids the use of fluorinated molecules typically found in (localized-) high-concentration electrolytes, presenting a novel principle that could revolutionize high-voltage electrolyte design.
Organosulfur materials are a sustainable alternative to the present-day layered oxide cathodes in lithium-based *** such organosulfur material that was intensely explored from the 1990s to early 2010s is 2,5-dimercapt...
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Organosulfur materials are a sustainable alternative to the present-day layered oxide cathodes in lithium-based *** such organosulfur material that was intensely explored from the 1990s to early 2010s is 2,5-dimercapto-1,3,4-thiadiazole(DMCT).However,research interest declined as the electrode reactions with DMCT were assumed to be too sluggish to be *** with the advances in metal-sulfur batteries,we revisit DMCT-based materials in the form of poly[tetrathio-2,5-(1,3,4-thiadiazole)],referred to as *** an appropriate choice of electrode design and electrolyte,pDMCT-S cathode paired with a Li-metal anode shows a capacity of 715 mA h g^(-1)and a Coulombic efficiency of 97.7%at a C/10 rate,thus quelling the concerns of sluggish ***,pDMCT-S shows significantly improved long-term cyclability compared to a sulfur *** into the origin of the stability reveals that the discharge product Li-DMCT in its mesomeric form can strongly bind to polysulfides,preventing their dissolution into the electrolyte and *** unique mechanism solves a critical problem faced by sulfur ***,this mechanism results in a stable performance of pDMCT-S with Na-metal cells as *** study opens the potential for exploring other organic materials that have inherent polysulfide sequestering capabilities,enabling long-life metal-sulfur batteries.
Room-temperature sodium–sulfur (RT Na–S) batteries are garnering attention for large-scale energy storage. However, their practical application is hindered by challenges, such as the shuttle effect of sodium polysul...
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Room-temperature sodium–sulfur (RT Na–S) batteries are garnering attention for large-scale energy storage. However, their practical application is hindered by challenges, such as the shuttle effect of sodium polysulfides (NaPS) and dendrite growth. The high solubility of NaPS in the electrolyte is particularly problematic. It disrupts electron transfer and obstructs mass transport in the electrical double layer (EDL) region. The EDL plays a pivotal role in governing the interfacial chemistry between the electrode and electrolyte, significantly impacting the overall electrochemical performance. Through simulations and experimental screening of various solvents, including 1,2-dimethoxyethane (DME), tetrahydrofuran (THF), and tetrahydropyran (THP), along with ethyl 1,1,2,2-tetrafluoroethyl ether (ETFE) as a diluent, the relationship between NaPS solvation structure and EDL chemistry has been elucidated. Our findings reveal that THP-based localized high-concentration electrolyte (LHCE) not only reduces the solubility of NaPS by altering its solvation structure but also promotes the formation of a stable inorganic solid-electrolyte interphase (SEI) and improves compatibility with sodium metal. Consequently, Na–S batteries with LHCE-THP/ETFE exhibit long-term stability over 500 cycles at 1C rate with a capacity decay rate of only 0.07% per cycle. This study provides a methodology for designing electrolytes based on molecular structure, polysulfide solvation properties, and EDL interfacial chemistry.
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