Oxygen defect-rich iron oxide (ODFO) nanoparticle catalyst on nanocarbon is in situ synthesized with the assistance of multi-ion modulation in one pot. The nanoparticle catalyst is employed to propel electrochemical kinetics in lithium/sulfur batteries. Electrochemical analysis and theoretical simulation evidently verify the critical role of defect sites on catalyzing conversion reactions of sulfur species and reducing energy barriers. As a consequence, the ODFO-enhanced sulfur cathode exhibits a high specific capacity of 1489 mA h g −1 at 0.1 C, an excellent rate performance of 644 mA h g −1 at 10 C, and a superior cycling stability with an average capacity fading rate of as low as 0.055% per cycle under an ultrahigh rate of 10 C. More importantly, even with a high sulfur loading of 11.02 mg cm −2 , the Li/S cell can still deliver an areal capacity of 8.7 mA h cm −2 at 0.5 C (9.23 mA cm −2 ). Such performance is the highest among reported metal oxide-catalyzed sulfur cathodes. This work opens a new route to boosting conversion reaction kinetics by introduction of active oxygen defect sites in electrodes of various emerging ultrafast batteries.
Spatially random lithium nucleation and sluggish lithium diffusion across the electrode/electrolyte interface lead to uncontrollable lithium deposition and the growth of lithium dendrite on metallic lithium surface, causing severe safety problems. Herein, a functional rapid-ion-diffusion alloy layer on the metallic lithium surface (RIDAL-Li) is designed through a simple chemical reduction reaction. Such a layer efficiently reduces energy barriers for lithium transport and thus significantly homogenizes the lithium atom flux for lateral deposition, which are confirmed by electrochemical tests, theoretical simulations, and spectroscopic analysis. Furthermore, the as-prepared RIDAL layer also displays a much higher corrosion resistance to moisture and oxygen. As a result, in ether-based and carbonate-based electrolytes, the pretreated RIDAL-Li anode can achieve a long stripping/plating lifespan of 900 h and a high Coulombic efficiency of 99% without dendrite growth. Even after being exposed to the ambient environment with relative humidity of 51% for 60 min, the RIDAL-Li can survive for stripping/plating 400 h and exhibit a low overpotential of 18 mV, displaying the superiority for ambient atmosphere battery assembly. Matched with LiFePO 4 or sulfur cathode, the full cells exhibit remarkably improved stability and capacity retention, showing its suitability for applications in lithium metal batteries.
The volumetric energy density of the lithium-sulfur (Li-S) batteries shows particular importance to accommodate the ever-shrinking space of practical devices. A feasible path for improving volumetric energy density of the...
In the extended chiral constituent quark model, the intrinsic cc content of the nucleon is investigated. The probabilities of the quark-antiquark components in the nucleon wave functions are calculated by taking the nucleon to be admixtures of three-and five-quark components, with the relevant transitions handled via the 3 P 0 mechanism. Predictions for the probability of the cc in the nucleon wave function and the charmness-nucleon sigma term are presented. Our numerical results turn out to be consistent with the predictions from various other approaches reported in the literature.
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