Film cognition explores the influence of cinematic elements, such as editing and film color, on viewers' perception. The Kuleshov effect, a famous example of how editing influences viewers' emotional perception, was initially proposed to support montage theory through the Kuleshov experiment. This effect, which has since been recognized as a manifestation of point-of-view (POV) editing practices, posits that the emotional interpretation of neutral facial expressions is influenced by the accompanying emotional scene in a face-scene-face sequence.
View Article and Find Full Text PDFIncreasing sulfur mass loading and minimizing electrolyte amount remains a major challenge for the development of high-energy-density Li-S batteries, which needs to be tackled with combined efforts of materials development and mechanistic analysis. This work, following the same team's most recent identification of the potential-limiting step of Li-S batteries under lean electrolyte conditions, seeks to advance the understanding by extending it to a new catalyst and into the high-sulfur-mass-loading region. CeO nanostructures are integrated into cotton-derived carbon to develop a multifunctional 3D network that can host a large amount of active material, facilitate electron transport, and catalyze the sulfur lithiation reaction.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
July 2023
Photothermal CO reduction is one of the most promising routes to efficiently utilize solar energy for fuel production at high rates. However, this reaction is currently limited by underdeveloped catalysts with low photothermal conversion efficiency, insufficient exposure of active sites, low active material loading, and high material cost. Herein, we report a potassium-modified carbon-supported cobalt (K -Co-C) catalyst mimicking the structure of a lotus pod that addresses these challenges.
View Article and Find Full Text PDFThe Li-S chemistry is thermodynamically promising for high-density energy storage but kinetically challenging. Over the past few years, many catalyst materials have been developed to improve the performance of Li-S batteries and their catalytic role has been increasingly accepted. However, the classic catalytic behavior, i.
View Article and Find Full Text PDFAlthough studies of transition metal sulfides (TMS) as anode materials for sodium-ion batteries are extensively reported, the short cycle life is still a thorny problem that impedes their practical application. In this work, a new capacity fading mechanism of the TMS electrodes is demonstrated; that is, the parasitic reaction between electrolyte anions (i.e.
View Article and Find Full Text PDFNa metal anode receives increasing attention as a low-cost alternative to Li metal anode for the application in high energy batteries. Despite extensive research efforts to improve the reversibility and cycle life of Na metal electrodes, their rate performance, i.e.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
August 2020
The energetic chemical reaction between Zn(NO ) and Li is used to create a solid-state interface between Li metal and Li La Zr Ta O (LLZTO) electrolyte. This interlayer, composed of Zn, ZnLi alloy, Li N, Li O, and other species, possesses strong affinities with both Li metal and LLZTO and affords highly efficient conductive pathways for Li transport through the interface. The unique structure and properties of the interlayer lead to Li metal anodes with longer cycle life, higher efficiency, and better safety compared to the current best Li metal electrodes operating in liquid electrolytes while retaining comparable capacity, rate, and overpotential.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
May 2020
Developing electrolytes compatible with efficient and reversible cycling of electrodes is critical to the success of rechargeable Li metal batteries (LMBs). The Coulombic efficiencies and cycle lives of LMBs with ethylene carbonate (EC), dimethyl carbonate, ethylene sulfite (ES), and their combinations as electrolyte solvents show that in a binary-solvent electrolyte the extent of electrolyte decomposition on the electrode surface is dependent on the solvent component that dominates the solvation sheath of Li . This knowledge led to the development of an EC-ES electrolyte exhibiting high performance for Li||LiFePO batteries.
View Article and Find Full Text PDFThe electrochemical reduction of CO to give CO in the presence of O would allow the direct valorization of flue gases from fossil fuel combustion and of CO captured from air. However, it is a challenging task because O reduction is thermodynamically favored over that of CO. 5% O in CO near catalyst surface is sufficient to completely inhibit the CO reduction reaction.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
November 2018
The presence of electrocatalysis in lithium-sulfur batteries has been proposed but not yet sufficiently verified. In this study, molybdenum phosphide (MoP) nanoparticles are shown to play a definitive electrocatalytic role for the sulfur cathode working under lean electrolyte conditions featuring a low electrolyte/active material ratio: the overpotentials for the charging and discharging reactions are greatly decreased. As a result, sulfur electrodes containing MoP nanoparticles show faster kinetics and more reversible conversion of sulfur species, leading to improvements in charging/discharging voltage profiles, capacity, rate performance, and cycling stability.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
May 2018
Discovering new chemistry and materials to enable rechargeable batteries with higher capacity and energy density is of paramount importance. While Li metal is the ultimate choice of a battery anode, its low efficiency is still yet to be overcome. Many strategies have been developed to improve the reversibility and cycle life of Li metal electrodes.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
July 2018
Developing Na metal anodes that can be deeply cycled with high efficiency for a long time is a prerequisite for rechargeable Na metal batteries to be practically useful despite their notable advantages in theoretical energy density and potential low cost. Their high chemical reactivity with the electrolyte and tendency for dendrite formation are two major issues limiting the reversibility of Na metal electrodes. In this work, we introduce for the first time potassium bis(trifluoromethylsulfonyl)imide (KTFSI) as a bifunctional electrolyte additive to stabilize Na metal electrodes, in which the TFSI anions decompose into lithium nitride and oxynitrides to render a desirable solid electrolyte interphase layer while the K cations preferentially adsorb onto Na protrusions and provide electrostatic shielding to suppress dendritic deposition.
View Article and Find Full Text PDFJ Am Chem Soc
January 2018
Chemistry at the cathode/electrolyte interface plays an important role for lithium-sulfur batteries in which stable cycling of the sulfur cathode requires confinement of the lithium polysulfide intermediates and their fast electrochemical conversion on the electrode surface. While many materials have been found to be effective for confining polysulfides, the underlying chemical interactions remain poorly understood. We report a new and general lithium polysulfide-binding mechanism enabled by surface oxidation layers of transition-metal phosphide and chalcogenide materials.
View Article and Find Full Text PDFTransition-metal-based molecular complexes are a class of catalyst materials for electrochemical CO reduction to CO that can be rationally designed to deliver high catalytic performance. One common mechanistic feature of these electrocatalysts developed thus far is an electrogenerated reduced metal center associated with catalytic CO reduction. Here we report a heterogenized zinc-porphyrin complex (zinc(II) 5,10,15,20-tetramesitylporphyrin) as an electrocatalyst that delivers a turnover frequency as high as 14.
View Article and Find Full Text PDFACS Appl Mater Interfaces
August 2017
One major challenge to the electrochemical conversion of CO to useful fuels and chemical products is the lack of efficient catalysts that can selectively direct the reaction to one desirable product and avoid the other possible side products. Making use of strong metal/oxide interactions has recently been demonstrated to be effective in enhancing electrocatalysis in the liquid phase. Here, we report one of the first systematic studies on composition-dependent influences of metal/oxide interactions on electrocatalytic CO reduction, utilizing Cu/SnO heterostructured nanoparticles supported on carbon nanotubes (CNTs) as a model catalyst system.
View Article and Find Full Text PDFDendrite growth and low coulombic efficiency are two major factors that limit the utilization of Li metal electrodes in future generations of high-energy-density rechargeable batteries. This article reports the first study on metal-organic framework (MOF) materials for boosting the electrochemical performance of Li metal electrodes and demonstrates the power of molecular-structure functionalization for realizing desirable ion transport and Li metal nucleation and growth. We show that dendrite-free dense Li deposition and stable Li plating/stripping cycling with high coulombic efficiency are enabled by modifying a commercial polypropylene separator with a titanium-based MOF (NH-MIL-125(Ti)) material.
View Article and Find Full Text PDFLithium-sulfur batteries (Li-S batteries) have attracted intense interest because of their high specific capacity and low cost, although they are still hindered by severe capacity loss upon cycling caused by the soluble lithium polysulfide intermediates. Although many structure innovations at the material and device levels have been explored for the ultimate goal of realizing long cycle life of Li-S batteries, it remains a major challenge to achieve stable cycling while avoiding energy and power density compromises caused by the introduction of significant dead weight/volume and increased electrochemical resistance. Here we introduce an ultrathin composite film consisting of naphthalimide-functionalized poly(amidoamine) dendrimers and graphene oxide nanosheets as a cycling stabilizer.
View Article and Find Full Text PDFRational design of multicomponent material structures with strong interfacial interactions enabling enhanced electrocatalysis represents an attractive but underdeveloped paradigm for creating better catalysts for important electrochemical energy conversion reactions. In this work, we report metal-phosphide core-shell nanostructures as a new model electrocatalyst material system where the surface electronic states of the shell phosphide and its interactions with reaction intermediates can be effectively influenced by the core metal to achieve higher catalytic activity. The strategy is demonstrated by the design and synthesis of iron-iron phosphide (Fe@FeP) core-shell nanoparticles on carbon nanotubes (CNTs) where we find that the electronic interactions between the metal and the phosphide components increase the binding strength of hydrogen adatoms toward the optimum.
View Article and Find Full Text PDFConfining lithium polysulfide intermediates is one of the most effective ways to alleviate the capacity fade of sulfur-cathode materials in lithium-sulfur (Li-S) batteries. To develop long-cycle Li-S batteries, there is an urgent need for material structures with effective polysulfide binding capability and well-defined surface sites; thereby improving cycling stability and allowing study of molecular-level interactions. This challenge was addressed by introducing an organometallic molecular compound, ferrocene, as a new polysulfide-confining agent.
View Article and Find Full Text PDFACS Appl Mater Interfaces
June 2015
Co2(OH)2CO3 nanosheets were prepared and initially tested as anode materials for Li ion batteries. Benefiting from hydroxide and carbonate, the as-prepared sample delivered a high reversible capacity of 800 mAh g(-1) after 200 cycles at 200 mA g(-1) and long-cycling capability of 400 mAh g(-1) even at 1 A g(-1). Annealed in Ar, monoclinic Co2(OH)2CO3 nanosheets were transformed into cubic CoO nanonets with rich pores.
View Article and Find Full Text PDFMnCO3 particles uniformly distributed on large-area graphene form 2D composites whose large-area character enables them to self-assemble face-to-face into orderly packed electrodes. Such regular structures form continuous and efficient transport networks, leading to outstanding lithium storage with high capacity, ultralong cycle life, and excellent rate capability--all characteristics that are required for high-power lithium-ion batteries.
View Article and Find Full Text PDFAntimony nanoparticle decorated N-rich porous carbon nanosheets were prepared through a sol-gel route. The composite displayed high reversible capacity, superior rate performance and long cycling stability as an anode material for room temperature Na-ion batteries. Even at an ultrahigh charge-discharge rate of 2 A g(-1), a large specific capacity of 220 mA h g(-1) was still achieved after 180 cycles.
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