查看更多>>摘要：High nickel content worsens the thermal stability of layered cathodes for lithium-ion batteries,raising safety concerns for their applications.Thoroughly understanding the thermal failure process can offer valuable guidance for material optimization on thermal stability and new opportunities in monitoring battery thermal runaway(TR).Herein,this work comprehensively investigates the thermal failure pro-cess of a single-crystal nickel-rich layered cathode and finds that the latent thermal failure starts at～120 ℃ far below the TR temperature(225 ℃).During this stage of heat accumulation,sequential structure transition is revealed by atomic resolution electron microscopy,which follows the layered → cation mixing layered → LiMn2O4-type spinel → disordered spinel → rock salt.This progres-sion occurs as a result of the continuous migration and densification of transition metal cations.Phase transition generates gaseous oxygen,initially confined within the isolated closed pores,thereby not showing any thermal failure phenomena at the macro-level.Increasing temperature leads to pore growth and coalescence,and eventually to the formation of open pores,causing oxygen gas release and weight loss,which are the typical TR features.We highlight that latent thermal instability occurs before the macro-level TR,suggesting that suppressing phase transitions caused by early thermal instability is a cru-cial direction for material optimization.Our findings can also be used for early warning of battery thermal runaway.
查看更多>>摘要：The rapid increase in the power conversion efficiency(PCE)of perovskite solar cells(PSCs)is closely related to the development of deposition techinique for perovskite layer.The high-quality perovskite film enables efficient charge transportation and less trap states,which are eventually translated into enhanced device performance.Seed-assisted growth(SAG)is a potential technique for depositing highly-crystallized perovskite films with preferential crystal orientation among the numerous approaches related to crystallization modulation.In this review,we summarize the recent advances in the SAG technique for both one-step and two-step processed perovskite films.Additionally,seeding at the buried interface and on the top surface are also introduced.We present different seeds and their cor-responding seeding mechanism in detail,such as inorganic nanomaterials,organic ammoniums,alkali metal halides,and perovskite seeds.Finally,challenges and perspectives are proposed to investigate the potential expansion of seeding engineering in high-performance PSCs,particularly large-area devices.
查看更多>>摘要：As global municipal solid waste(MSW)quantities continue to escalate,serious socio-environmental challenges arise,necessitating innovative solutions.Waste-to-hydrogen(WTH)via two-stage gasification-reforming(TSGR)presents an emergent technology for MSW upcycling,offering to ease waste management burdens and bolster the burgeoning hydrogen economy.Despite early initiatives to advance TSGR technology,a cohesive and critical analysis of cutting-edge knowledge and strategies to enhance hydrogen production remains lacking.This review aggregates literature on MSW upcycling to hydrogen via TSGR,with a focus on optimizing process control and catalytic efficiency.It underscores technological avenues to augment hydrogen output,curtail catalyst costs,and refine system perfor-mance.Particularly,the review illuminates the potential for integrating chemical and calcium looping into TSGR processes,identifying opportunities,and pinpointing challenges.The review concludes with a summary of the current state of techno-economic analysis for this technology,presenting outstanding challenges and future research directions,with the ultimate goal of transitioning WTH from theoretical to practical application.
查看更多>>摘要：The use of low-dimensional(LD)perovskite materials is crucial for achieving high-performance per-ovskite solar cells(PSCs).However,LD perovskite films fabricated by conventional approaches give rise to full coverage of the underlying 3D perovskite films,which inevitably hinders the transport of charge carriers at the interface of PSCs.Here,we designed and fabricated LD perovskite structure that forms net-like morphology on top of the underlying three-dimensional(3D)perovskite bulk film.The net-like LD perovskite not only reduced the surface defects of 3D perovskite film,but also provided channels for the vertical transport of charge carriers,effectively enhancing the interfacial charge transfer at the LD/3D hetero-interface.The net-like morphological design comprising LD perovskite effectively resolves the contradiction between interfacial defect passivation and carrier extraction across the hetero-interfaces.Furthermore,the net-like LD perovskite morphology can enhance the stability of the underly-ing 3D perovskite film,which is attributed to the hydrophobic nature of LD perovskite.As a result,the net-like LD perovskite film morphology assists PSCs in achieving an excellent power conversion efficiency of up to 24.6％with over 1000 h long-term operational stability.
查看更多>>摘要：Gel-based polymer electrolytes are limited by the polarity of the residual solvent,which restricts the coupling-breaking behaviour during Li+conduction,resulting in the Li+transport kinetics being greatly affected.Here,we designed anion competitive gel polymer electrolyte(ACPE)by introducing lithium difluoro(oxalato)borate(LiDFOB)anion into the 1,3-dioxolane(DOL)in situ polymerisation system.ACPE enhances the ionic dipole interaction between Li+and the solvent molecules and synergizes with Li+across the solvation site of the polymer ethylene oxide(EO)unit,combination that greatly improves the Li+transport efficiency.As a result,ACPE exhibits 1.12 mS cm-1 ionic conductivity and 0.75 Li+trans-fer number at room temperature.Additionally,this intra-polymer solvation sheath allows preferential desolvation of DFOB-,which contributes to the formation of kinetically stable anion-derived interphase and effectively mitigates side reactions.Our results demonstrate that the assembled Li||NCM622 solid-state battery exhibits lifespan of over 300 cycles with average Coulombic efficiency of 98.8％and capacity retention of 80.3％.This study introduces a novel approach for ion migration and interface design,paving the way for high-safety and high-energy-density batteries.
查看更多>>摘要：Ammonia(NH3)is an important raw material for modern agriculture and industry,being widely demanded to sustain the sustainable development of modern society.Currently,the industrial produc-tion methods of NH3,such as the traditional Haber-Bosch process,have drawbacks including high energy consumption and significant carbon dioxide emissions.In recent years,the electrocatalytic nitrate reduc-tion reaction(NO3RR)powered by intermittent renewable energy sources has gradually become a mul-tidisciplinary research hotspot,as it allows for the efficient synthesis of NH3 under mild conditions.In this review,we focus on the research of electrocatalysts with atomic-level site,which have attracted attention due to their extremely high atomic utilization efficiency and unique structural characteristics in the field of NO3RR.Firstly,we introduce the mechanism of nitrate reduction for ammonia synthesis and discuss the in-situ characterization techniques related to the mechanism study.Secondly,we review the progress of the electrocatalysts with atomic-level site for nitrate reduction and explore the structure-activity relationship to guide the rational design of efficient catalysts.Lastly,the conclusions of this review and the challenges and prospective of this promising field are presented.
查看更多>>摘要：It is widely recognized that the development of ZABs is impeded by the kinetic bottleneck of oxygen evo-lution reaction(OER)and oxygen reduction reaction(ORR).The application of conformational entropy strategy to oxides often involves introducing multiple elements with different properties,thereby provid-ing outstanding bifunctional catalytic activity for OER/ORR.Nevertheless,the possible underlying cat-alytic pathways and potential interactions between various components are still poorly understood.This paper presents an excellent medium-entropy perovskite oxide,Sr(FeCoNiMo)1/4O3-δ(lower overpo-tential of 301 mV at 10 mA cm-2).Zinc-air batteries employing it as a cathode catalyst demonstrate excellent round-trip efficiency(62％).By combining theoretical calculation with experiments,we aim to establish the link between the electronic structure of perovskite oxides with different elemental com-positions and their OER mechanism.Research reveals that the conformational entropy strategy can simultaneously shift the O 2p-band center and metal d-band center of perovskite oxide towards the vicin-ity of the Fermi energy level,thereby triggering a more favorable lattice oxygen-participated mechanism(LOM)during the OER process.The outcomes of this work provide crucial insights into the role of confor-mational entropy strategies in oxygen catalysis and offer potential avenues for constructing efficient and stable electrocatalysts.
查看更多>>摘要：The significant decrease in battery performance at low temperatures is one of the critical challenges that electric vehicles(EVs)face,thereby affecting the penetration rate in cold regions.Alternating current(AC)heating has attracted widespread attention due to its low energy consumption and uniform heating advantages.This paper introduces the recent advances in AC heating from the perspective of practical EV applications.First,the performance degradation of EVs in low-temperature environments is intro-duced briefly.The concept of AC heating and its research methods are provided.Then,the effects of var-ious AC heating methods on battery heating performance are reviewed.Based on existing studies,the main factors that affect AC heating performance are analyzed.Moreover,various heating circuits based on EVs are categorized,and their cost,size,complexity,efficiency,reliability,and heating rate are elab-orated and compared.The evolution of AC heaters is presented,and the heaters used in brand vehicles are sorted out.Finally,the perspectives and challenges of AC heating are discussed.This paper can guide the selection of heater implementation methods and the optimization of heating effects for future EV applications.
查看更多>>摘要：Indium selenide has garnered significant attention for high volumetric capacities,but is currently plagued by the sluggish charge transfer kinetics,severe volume effect,and rapid capacity degradation that hinder their practical applications.Herein,we design,synthesize,and characterize a multi-kernel-shell structure comprised of indium selenide encapsulated within carbon nanospheres(referred to as m-K-S In2Se3@C)through an integrated approach involving a hydrothermal method followed by a gaseous selenization process.Importantly,experimental measurements and density functional theory calculations confirm that the m-K-S In2Se3@C not only improve the adsorption capability for Li-ions but also lower the energy barrier for Li-ions diffusion.Profiting from numerous contact points,shorter diffusion distances and an improved volume buffering effect,the m-K-S In2Se3@C achieves an 800 mA h g-1 capacity over 1000 loops at 1000 mA g-1,a 520 mA h g-1 capacity at 5000 mA g-1 and an energy density of 270 Wh kg-1 when coupled with LiFePO4,surpassing most related anodes reported before.Broadly,the m-K-S struc-ture with unique nano-micro structure offers a new approach to the design of advanced anodes for LIBs.
查看更多>>摘要：Aqueous Zn-ion batteries(AZIBs)are recognized as a promising energy storage system with intrinsic safety and low cost,but its applications still rely on the design of high-capacity and stable-cycling cath-ode materials.In this work,we present an intercalation mechanism-based cathode materials for AZIB,i.e.the vanadium oxide with pre-intercalated manganese ions and lattice water(noted as MVOH).The syn-ergistic effect between Mn2+and lattice H2O not only expands the interlayer spacing,but also signifi-cantly enhances the structural stability.Systematic in-situ and ex-situ characterizations clarify the Zn2+/H+co-(de)intercalation mechanism of MVOH in aqueous electrolyte.The demonstrated remarkable structure stability,excellent kinetic behaviors and ion-storage mechanism together enable the MVOH to demonstrate satisfactory specific capacity of 450 mA h g-1 at 0.2 A g-1,excellent rate performance of 288.8 mA h g1 at 10 A g-1 and long cycle life over 20,000 cycles at 5 A g-1.This work provides a practical cathode material,and contributes to the understanding of the ion-intercalation mechanism and struc-tural evolution of the vanadium-based cathode for AZIBs.
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