Lithium metal anode is desired by high capacity and low potential toward higher energy density than commercial graphite anode. However, the low-temperature Li metal batteries suffer from dendrite formation and dead Li resulting from uneven Li behaviors of flux with huge desolvation/diffusion barriers, thus leading to short lifespan and safety concern. Herein, differing from electrolyte engineering, a strategy of delocalizing electrons with generating rich active sites to regulate Li desolvation/diffusion behaviors are demonstrated via decorating polar chemical groups on porous metal-organic frameworks (MOFs).
View Article and Find Full Text PDFChem Commun (Camb)
November 2024
Traditional ethylene carbonate (EC)-based electrolytes constrain the applications of silicon carbon (Si-C) anodes under fast-charging and low-temperature conditions due to sluggish Li migration kinetics and unstable solid electrolyte interphase (SEI). Herein, inspired by the efficient water purification and soil stabilization of aquatic plants, a stable SEI with a 3D desolvation interface is designed with gel polymer electrolyte (GPE), accelerating Li desolvation and migration at the interface and within stable SEI. As demonstrated by theoretical simulations and experiment results, the resulting poly(1,3-dioxolane) (PDOL), prepared by in situ ring-opening polymerization of 1,3-dioxolane (DOL), creates a 3D desolvation area, improving the Li desolvation at the interface and yielding an amorphous GPE with a high Li ionic conductivity (5.
View Article and Find Full Text PDFAlGaN/GaN high-electron-mobility transistors (HEMTs) are widely used in high-frequency and high-power applications owing to the high two-dimensional electron gas (2DEG) concentration. However, the microscopic origin of the 2DEG remains unclear. This hinders the development of device fabrication technologies, such as threshold voltage modulation, current collapse suppression, and 2DEG concentration enhancement technologies, as well as AlGaN/GaN sensors with very high sensitivity to polar liquids.
View Article and Find Full Text PDFLow-temperature rechargeable aqueous zinc metal batteries (AZMBs) as highly promising candidates for energy storage are largely hindered by huge desolvation energy barriers and depressive Zn migration kinetics. In this work, a superfast zincophilic ion conductor of layered zinc silicate nanosheet (LZS) is constructed on a metallic Zn surface, as an artificial layer and ion diffusion accelerator. The experimental and simulation results reveal the zincophilic ability and layer structure of LZS not only promote the desolvation kinetics of [Zn(HO)] but also accelerate the Zn transport kinetics across the anode/electrolyte interface, guiding uniform Zn deposition.
View Article and Find Full Text PDFSolid-state polymer-based electrolytes (SSPEs) exhibit great possibilities in realizing high-energy-density solid-state lithium metal batteries (SSLMBs). However, current SSPEs suffer from low ionic conductivity and unsatisfactory interfacial compatibility with metallic Li because of the high crystallinity of polymers and sluggish Li movement in SSPEs. Herein, differing from common strategies of copolymerization, a new strategy of constructing a high-entropy SSPE from multivariant polymeric ligands is proposed.
View Article and Find Full Text PDFThe structure of solvated Li has a significant influence on the electrolyte/electrode interphase (EEI) components and desolvation energy barrier, which are two key factors in determining the Li diffusion kinetics in lithium metal batteries. Herein, the "solvent activity" concept is proposed to quantitatively describe the correlation between the electrolyte elements and the structure of solvated Li. Through fitting the correlation of the electrode potential and solvent concentration, we suggest a "low-activity-solvent" electrolyte (LASE) system for deriving a stable inorganic-rich EEI.
View Article and Find Full Text PDFNaV(PO)F is recognized as a promising cathode for high energy density sodium-ion batteries due to its high average potential of ∼3.95 V (vs Na/Na). A high-voltage-resistant electrolyte is of high importance due to the long duration of 4.
View Article and Find Full Text PDFHigh-energy-density lithium metal batteries (LMBs) are limited by reaction or diffusion barriers with dissatisfactory electrochemical kinetics. Typical conversion-type lithium sulfur battery systems exemplify the kinetic challenges. Namely, before diffusing or reacting in the electrode surface/interior, the Li(solvent) dissociation at the interface to produce isolated Li, is usually a prerequisite fundamental step either for successive Li "reduction" or for Li to participate in the sulfur conversions, contributing to the related electrochemical barriers.
View Article and Find Full Text PDFLithium metal batteries (LMBs) offer significant advantages in energy density and output voltage, but they are severely limited by uncontrollable Li dendrite formation resulting from uneven Li behaviors and high reactivity with potential co-solvent plating. Herein, to uniformly enhance the Li behaviors in desolvation and diffusion, the local Li solvation shell structure is optimized by constructing an anion-braking separator, hence dynamically reducing the self-amplifying behavior of dendrites. As a prototypal, two-dimensional lithiated-montmorillonite (LiMMT) is blade-coated on the commercial separator, where abundant -OH groups as Lewis acidic sites and electron acceptors could selectively adsorb corresponding FSI anions, regulating the solvation shell structure and restricting their migration.
View Article and Find Full Text PDFSn-based anodes are promising high-capacity anode materials for low-cost lithium ion batteries. Unfortunately, their development is generally restricted by rapid capacity fading resulting from large volume expansion and the corresponding structural failure of the solid electrolyte interphase (SEI) during the lithiation/delithiation process. Herein, heterostructural core-shell SnO-layer-wrapped Sn nanoparticles embedded in a porous conductive nitrogen-doped carbon (SOWSH@PCNC) are proposed.
View Article and Find Full Text PDFHigh interconversion energy barriers, depressive reaction kinetics of sulfur species, and sluggish Li transport inhibit the wide development of high-energy-density lithium sulfur (Li-S) batteries. Herein, differing from random mixture of selected catalysts, the composite catalyst with outer delocalized isoelectronic heterostructure (DIHC) is proposed and optimized, enhancing the catalytic efficiency for decreasing related energy barriers. As a proof-of-content, the FeCoO S composites with different degrees of sulfurization are fabricated by regulating atoms ratio between O and S.
View Article and Find Full Text PDFThe lithium-metal anode is a promising candidate for realizing high-energy-density batteries owing to its high capacity and low potential. However, several rate-limiting kinetic obstacles, such as the desolvation of Li solvation structure to liberate Li , Li nucleation, and atom diffusion, cause heterogeneous spatial Li-ion distribution and fractal plating morphology with dendrite formation, leading to low Coulombic efficiency and depressive electrochemical stability. Herein, differing from pore sieving effect or electrolyte engineering, atomic iron anchors to cation vacancy-rich Co S embedded in 3D porous carbon (SAFe/CVRCS@3DPC) is proposed and demonstrated as catalytic kinetic promoters.
View Article and Find Full Text PDFTwo-dimensional covalent organic frameworks (2D COFs) are promising for gas sensing owing to the large surface area, abundant active sites, and their semiconducting nature. However, 2D COFs are usually produced in the form of insoluble micro-crystallites. Their poor contacts between grain boundaries severely suppress the conductivity, which are too low for chemresistive gas sensing.
View Article and Find Full Text PDFLithium-sulfur (Li-S) batteries exhibit unparalleled theoretical capacity and energy density than conventional lithium ion batteries, but they are hindered by the dissatisfactory "shuttle effect" and the sluggish conversion kinetics owing to the low lithium ion transport kinetics, resulting in rapid capacity fading. Herein, a catalytic two-dimensional heterostructure composite is prepared by evenly grafting mesoporous carbon on the MXene nanosheet (denoted as OMC--MXene), serving as interfacial kinetic accelerators in Li-S batteries. In this design, the grafted mesoporous carbon in the heterostructure can not only prevent the stack of MXene nanosheets with the enhanced mechanical property but also offer a facilitated pump for accelerating ion diffusion.
View Article and Find Full Text PDFPerovskite solar cells (pero-SCs) performance is essentially limited by severe non-radiative losses and ion migration. Although numerous strategies have been proposed, challenges remain in the basic understanding of their origins. Here, we report a dielectric-screening-enhancement effect for perovskite defects by using organic semiconductors with finely tuned molecular structures from the atoms level.
View Article and Find Full Text PDFLithium metal anodes are ideal for realizing high-energy-density batteries owing to their advantages, namely high capacity and low reduction potentials. However, the utilization of lithium anodes is restricted by the detrimental lithium dendrite formation, repeated formation and fracturing of the solid electrolyte interphase (SEI), and large volume expansion, resulting in severe "dead lithium" and subsequent short circuiting. Currently, the researches are principally focused on inhibition of dendrite formation toward extending and maintaining battery lifespans.
View Article and Find Full Text PDFA solid electrolyte interphase (SEI) with robust mechanical property and high ionic conductivity is imperative for high-performance lithium metal batteries since it can efficiently impede the growth of notorious lithium dendrites. However, it is difficult to form such a SEI directly from an electrolyte. In this work, a crowding dilutant modified ionic liquid electrolyte (M-ILE) has been developed for this purpose.
View Article and Find Full Text PDFLithium metal anode possesses overwhelming capacity and low potential but suffers from dendrite growth and pulverization, causing short lifespan and low utilization. Here, a fundamental novel insight of using single-atomic catalyst (SAC) activators to boost lithium atom diffusion is proposed to realize delocalized deposition. By combining electronic microscopies, time-of-flight secondary ion mass spectrometry, theoretical simulations, and electrochemical analyses, we have unambiguously depicted that the SACs serve as kinetic activators in propelling the surface spreading and lateral redistribution of the lithium atoms for achieving dendrite-free plating morphology.
View Article and Find Full Text PDFThe electrocatalytic C-N coupling for one-step urea synthesis under ambient conditions serves as the promising alternative to the traditional urea synthetic protocol. However, the hydrogenation of intermediate species hinders the efficient urea synthesis. Herein, the oxygen vacancy-enriched CeO was demonstrated as the efficient electrocatalyst with the stabilization of the crucial intermediate of *NO inserting into vacant sites, which is conducive to the subsequent C-N coupling process rather than protonation, whereas the poor selectivity of C-N coupling with protonation was observed on the vacancy-deficient catalyst.
View Article and Find Full Text PDFLithium metal is considered as the most prospective electrode for next-generation energy storage systems due to high capacity and the lowest potential. However, uncontrollable spatial growth of lithium dendrites and the crack of solid electrolyte interphase still hinder its application. Herein, Schottky defects are motivated to tune the 4f-center electronic structures of catalysts to provide active sites to accelerate Li transport kinetics.
View Article and Find Full Text PDFIn recent years, the performance research of perovskite materials is not only concentrated in the field of solar cells or optics, but the field of gas sensing has gradually entered the public view. However, the detection of nitric oxide (NO) by lead-free halide perovskites has not yet been reported. Herein, we use CsPtI to realize the first example of a halide perovskite applied to NO sensing.
View Article and Find Full Text PDFIt is of great importance and practical value to develop a facile and operable surface treatment method of materials with excellent antipollution and antiadhesion property, but still a huge challenge. In this work, a series of pseudo-zwitterions are prepared from electrostatic assembly of cationic polyethyleneimine and anionic phosphonic clusters. These pseudo-zwitterionic assemblies provide a strong hydration through electrostatic interaction with water and in turn create a barrier against oil foulants, leading to a nearly zero crude oil adhesion force.
View Article and Find Full Text PDFThree-dimensional (3D) perovskites have been demonstrated as an effective strategy to achieve efficient light-emitting diodes (LEDs) at high brightness. However, most 3D perovskite LEDs still suffer from serious efficiency roll-off. Here, using FAPbI as a model system, we find that the main reason for efficiency droop and degradation in 3D perovskite LEDs is defects and the ion migration under electrical stress.
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