Hybrid ionic/electronic interphase enabling uniform nucleation and fast diffusion kinetics for stable lithium metal anode

Lithium(Li)dendrite issue,which is usually caused by inhomogeneous Li nucleation and fragile solid electrolyte interphase(SEI),impedes the further development of high-energy Li metal batteries.However,the integrated construction of a high-stable SEI layer that can regulate uniform nucleation and facilitate fast Li-ion diffusion kinetics for Li metal anode still falls short.Herein,we designed an artificial SEI with hybrid ionic/electronic interphase to regulate Li deposition by in-situ constructing metal Co clusters embedded in LiF matrix.The generated Co and LiF both enable fast Li-ion diffusion kinetics,meanwhile,the lithiophilic properties of Co clusters can serve as Li-ion nucleation sites,thereby contributing to uniform Li nucleation and non-dendritic growth.As a result,a dendrite-free Li deposition with a low overpotential(16.1 mV)is achieved,which enables an extended lifespan over 750 h under strict conditions.The full cells with high-mass-loading LiFePO_(4)(11.5 mg/cm^(2))as cathodes exhibit a remarkable rate capacity of 84.1 mAh/g at 5 C and an improved cycling performance with a capacity retention of 96.4%after undergoing 180 cycles.

Diffusion Kinetics of Components of Asphalt Into Waste Rubber

The use of waste crumb rubber powder as a modifier for modified asphalt can recycle waste rubber to ease pressure on the environment and improve the performance of asphalt. Diffusion of components of asphalt into waste rubber is of vital importance to improve the performance of rubber modified asphalt,while the related researches are scarce. Diffusion of components of asphalt into waste rubber at different temperatures has been investigated in this work. Rectangle rubber was immersed in asphalt at certain temperature for a period of time. And the mass increment of rubber was measured to determine the diffusion rate of components of asphalt into rubber. The experimental results indicated that the diffusion rate of components of asphalt into waste rubber increases along the temperature,but the diffusion rate of components of fractions oil which is distillated from catalytic cracking slurry is much higher than that of components of asphalt. Compared with asphalt,fractions oil enjoys lower viscosity and better permeability with higher content of saturates and aromatics. All the characteristics are contributed to the efficient diffusion of components of fractions into waste rubber.

Diffusion Kinetics Study of Lithium Ion in the Graphdiyne Based Electrode

Herein,we report a comparative investigation of the electrochemical lithium diffusion within graphidyne(GDY)based electrodes.The transfer kinetic behaviors of lithium ions during the insertion/extraction process are analyzed through different methods including the galvanostatic intermittent titration technique(GITT)and the electrochemical impedance spectroscopy(EIS).GDY with the morphology of nanosheets(GDY NS)shows lithium diffusion coefficients in the orders range of 10^(−12)-10^(−13) cm^(2)/s through the GITT method.Meanwhile,EIS indicates quite a lower value of lithium diffusion coefficients between 10^(−13) and 10^(−15) cm^(2)/s,which indicates that the analysis technique has an influence on the evaluation of GDY-based electrodes.In addition,under the same measurement condition of GITT,GDY nanoparticles(GDY NP)exhibit a lower value of Li+diffusion coefficient(10^(−14)-10^(−16) cm^(2)/s)during the charge-discharge process compared to those of GDY NS,which can be ascribed to the wide distributing range of particle size in GDY NP based electrodes.The analysis results in this work reveal that the aggregating forms of GDY electrode material have an important effect on the diffusion process of lithium ions,which provides a pathway to optimize the performance of GDY-based energy storage devices.

Construction of cobalt vacancies in cobalt telluride to induce fast ionic/electronic diffusion kinetics for lithium-ion half/full batteries

Designing novel electrode materials with unique structures is of great significance for improving the performance of lithium ion batteries(LIBs).Herein,copper-doped Co_(1-x)Te@nitrogen-doped carbon hollow nanoboxes(Cu-Co_(1-x)Te@NC HNBs)have been fabricated by chemical etching of Cu Co-ZIF nanoboxes,followed by a successive high-temperature tellurization process.The as-synthesized Cu-Co_(1-x)Te@NC HNBs composite demonstrated faster ionic and electronic diffusion kinetics than the pristine Co Te@NC HNBs electrode.The existence of Co-vacancy promotes the reduction of Gibbs free energy change(ΔG_(H^(*)))and effectively improves the Li~+diffusion coefficient.XPS and theoretical calculations show that performance improvement is ascribed to the electronic interactions between Cu-Co_(1-x)Te and nitrogen-doped carbon(NC)that trigger the shift of the p-band towards facilitation of interfacial charge transfer,which in turn helps boost up the lithium storage property.Besides,the proposed Cu-doping-induced Co-vacancy strategy can also be extended to other conversion-type cobalt-based material(CoSe_(2))in addition to asobtained Cu-Co_(1-x)Se_(2)@NC HNBs anodes for long-life and high-capacity LIBs.More importantly,the fabricated LiCoO_(2)//Cu-Co_(1-x)Te@NC HNBs full cell exhibits a high energy density of 403 Wh kg^(-1)and a power density of 6000 W kg^(-1).We show that the energy/power density reported herein is higher than that of previously studied cobalt-based anodes,indicating the potential application of Cu-Co_(1-x)Te@NC HNBs as a superior electrode material for LIBs.

Water molecules and oxygen-vacancy modulation of vanadium pentoxide with fast kinetics toward ultrahigh power density and durable flexible all-solid-state zinc ion battery

Aqueous zinc ion battery(ZIB)with many virtues such as high safety,cost-effective,and good environmental compatibility is a large-scale energy storage technology with great application potential.Nevertheless,its application is severely hindered by the slow diffusion of zinc ions in desirable cathode materials.Herein,a technique of water-incorporation coupled with oxygen-vacancy modulation is exploited to improve the zinc ions diffusion kinetics in vanadium pentoxide(V_(2)O_5)cathode for ZIB.The incorporated water molecules replace lattice oxygen in V_(2)O_5,and function as pillars to expand interlayer distance.So the structural stability can be enhanced,and the zinc ions diffusion kinetics might also be promoted during the repeated intercalation/deintercalation.Meanwhile,the lattice water molecules can effectively enhance conductivity due to the electronic density modulation effect.Consequently,the modulated V_(2)O_5(H-V_(2)O_5)cathode behaves with superior rate capacity and stable durability,achieving 234 mA h g^(-1)over 9000 cycles even at 20 A g^(-1).Furthermore,a flexible all-solid-state(ASS)ZIB has been constructed,exhibiting an admirable energy density of 196.6 Wh kg^(-1)and impressive power density of 20.4 kW kg^(-1)as well as excellent long-term lifespan.Importantly,the assembled flexible ASS ZIB would be able to work in a large temperature span(from-20 to 70℃).Additionally,we also uncover the energy storage mechanism of the H-V_(2)O_5 electrode,offering a novel approach for creating high-kinetics cathodes for multivalent ion storage.

Hierarchically porous Co@N-doped carbon fiber assembled by MOF-derived hollow polyhedrons enables effective electronic/mass transport:An advanced 1D oxygen reduction catalyst for Zn-air battery

Developing advanced oxygen reduction reaction(ORR)electrocatalysts with rapid mass/electron transport as well as conducting relevant kinetics investigations is essential for energy technologies,but both still face ongoing challenges.Herein,a facile approach was reported for achieving the highly dispersed Co nanoparticles anchored hierarchically porous N-doped carbon fibers(Co@N-HPCFs),which were assembled by core-shell MOFs-derived hollow polyhedrons.Notably,the unique one-dimensional(1D)carbon fibers with hierarchical porosity can effectively improve the exposure of active sites and facilitate the electron transfer and mass transfer,resulting in the enhanced reaction kinetics.As a result,the ORR performance of the optimal Co@N-HPCF catalysts remarkably outperforms that of commercial Pt/C in alkaline solution,reaching a limited diffusion current density(J)of 5.85 m A cm^(-2)and a half-wave potential(E_(1/2))of 0.831 V.Particularly,the prepared Co@N-HPCF catalysts can be used as an excellent air-cathode for liquid/solid-state Zn-air batteries,exhibiting great potentiality in portable/wearable energy devices.Furthermore,the reaction kinetic during ORR process is deeply explored by finite element simulation,so as to intuitively grasp the kinetic control region,diffusion control region,and mixing control region of the ORR process,and accurately obtain the relevant kinetic parameters.This work offers an effective strategy and a reliable theoretical basis for the engineering of first-class ORR electrocatalysts with fast electronic/mass transport.

Effect of Homogenization Treatment on the Corrosion Behavior and Mechanism of Mg-Y Alloys

The effect of homogenization treatment on the corrosion behavior and corrosion mechanism of Mg-Y alloys in 3.5 wt% NaCl solution was investigated by electrochemical characterization, immersion testing and SEM observations. The diffusion kinetics model of Mg-Y alloy was established, and the homogenization system was determined. With increasing of homogenization temperature and time, the Mg24Y5 phase gradually decreased, which increased the self-corrosion potential and the high-frequency arc radius. The corrosion resistance of the five alloys could be given as follow: Mg-0.25Y < Mg-8Y < Mg-15Y < Mg-5Y < Mg-2.5Y. The Mg- (0.25, 2.5 and 5) Y show localized corrosion in a wide range and small depth, while Mg- (8 and 15) Y showed localized corrosion in a smaller range and larger depth.

Structural properties and electrochemical performance of different polymorphs of Nb_(2)O_(5) in magnesium-based batteries

The selection of the most suitable crystal structure for ions storage and the investigation of the corresponding reaction mechanism is still an ongoing challenge for the development of Mg-based batteries.In this article,high flexible graphene network supporting different crystal structures of Nb2 O5(TTNb_(2)O_(5)@rGO and T-Nb_(2)O_(5)@rGO) are successfully synthesized by a spray-drying-assisted approach.The three-dimensional graphene framework provides high conductivity and avoids the aggregation of Nb2 O5 nanoparticles.When employed as electrode materials for energy storage applications,TT-Nb_(2)O_(5) delivers a higher discharge capacity of 129.5 mAh g^(-1), about twice that of T-Nb_(2)O_(5) for Mg-storage,whereas,T-Nb_(2)O_(5) delivers a much higher capacity(162 mAh g^(-1)) compared with TT-Nb_(2)O_(5)(129 mAh g^(-1)) for Li-storage.Detailed investigations reveal the Mg intercalation mechanism and lower Mg^(2+) migration barriers,faster Mg^(2+) diffusion kinetics of TT-Nb_(2)O_(5) as cathode material for Mg-storage,and the faster Li+ diffusion kinetics,shorter diffusion distance of T-Nb_(2)O_(5) as cathode material for Li-storage.Our work demonstrates that exploring the proper crystal structure of Nb2 O5 for different ions storage is necessary.

Ni0.85 Se hexagonal nanosheets as an advanced conversion cathode for Mg secondary batteries

Mg secondary batteries are promising scalable secondary batteries for next-generation energy storage.However,Mg-storage cathode materials are greatly demanded to construct high-performance Mg batteries.Electrochemical conversion reaction provides plenty of cathode options,and strategy for cathode selection and performance optimization is of special significance.In this work,Ni0.85Se with nanostructures of dispersive hexagonal nanosheets(D-Ni0.85Se)and flower-like assembled nanosheets(F-Ni0.85Se)is synthesized and investigated as Mg-storage cathodes.Compared with F-Ni0.85Se,D-Ni0.85Se delivers a higher specific capacity of 168 mAh g^-1 at 50 mA g^-1 as well as better rate performance,owing to its faster Mg^2+-diffusion and lower resistance.D-Ni0.85Se also exhibits a superior cycling stability over 500cycles.An investigation on mechanism indicates an evolution of Ni0.85Se towards NiSe with cycling,and the Mg-storage reaction occurs between NiSe and metallic Ni^0.The present work demonstrates that advanced conversion-type Mg battery cathode materials could be constructed by soft selenide anions,and the electrochemical properties could be manipulated by rational material morphology optimization.

Application of low-temperature thermochronology on ore deposits preservation framework in South China:a review

South China can be divided into four metallogenic belts:The Middle-Lower Yangtze Metallogenic Belt(MLYB),Qinzhou-Hangzhou Metallogenic Belt(QHMB),Nanling Metallogenic Belt(NLMB),and Wuyi Metallogenic Belt(WYMB).The major mineralization in the four metallogenic belts is granite-related Cu–Au–Mo and porphyrite Fe-apatite,porphyry Cu(Au),and epithermal Pb–Zn–Ag,hydrothermal Cu–Au–Pb–Zn–Ag,and granite-related skarn-type and quartz-veins W–Sn,respectively.Low-temperature thermochronology,including fissiontrack and U-Th/He dating,has been widely used to constrain tectonic thermal evolution and ore deposits preservation.Understanding fission-track annealing and He diffusion kinetics in accessory minerals,such as zircon and apatite,is essential for dating and applications.In this study,previous zircon fission-track(ZFT)and apatite fission-track(AFT)ages in South China were collected.The result shows that the ZFT ages are mainly concentrated at140–90 Ma,and the AFT ages are mainly distributed at70–40 Ma.The age distribution and inversion temperature–time paths reveal heterogeneous exhumation histories in South China.The MLYB experienced Late CretaceousCenozoic extremely slow exhumation after rapid cooling in the Early Cretaceous.The northern QHMB(i.e.from southern Anhui province to the Hangzhou Bay)had a relatively faster rate of uplifting and denudation than the southern QHMB in the Cretaceous.Subsequently,the northern QHMB rapidly exhumed,while the continuously slow exhumation operated the southern QHMB in the Cenozoic.The southern NLMB had a more rapid cooling rate than the northern NLMB during the Cretaceous time,and the whole NLMB experienced rapid cooling in the Cenozoic,except that the southern Hunan province had the most rapid cooling rate.The WYMB possibly had experienced slow exhumation since the Late Cretaceous.The exhumation thickness of the four metallogenic belts since90 Ma is approximately calculated as follows:the MLYB≤3.5 km,the northern QHMB concentrated at3.5–5.5 km,and the southern QHMB usually less than3.5 km,the NLMB 4.5–6.5 km and the WYMB<3.5 km.The exhumation thickness of the NLMB is corresponding to the occurrence of the world-class W deposits,which were emplaced into a deeper depth of 1.5–8 km.As such,we infer that the uplifting and denudation processes of the four metallogenic belts have also played an important role in dominated ore deposits.

Modelling the mechanism and kinetics of ascorbic acid diffusion in genipin-crosslinked gelatin and chitosan networks at distinct pH

Crosslinked biopolymers were prepared for controlled release to investigate the diffusion of ascorbic acid from swelling high-solid networks in neutral and acidic pH conditions.Polymer swelling was measured at pH 2.8 and pH 6.8 and change in microstructural properties,including network mesh size and average molecular weight between crosslinks of genipin-crosslinked gelatin and genipin-crosslinked chitosan systems,were predicted.Variable mathematical modelling was applied to the first 60%of ascorbic acid diffusion and statistical analysis was used to determine the model that best fits the experimental data.Molecular transport from the gelatin-based networks was best described by the Peppas-Sahlin model whereas the distinct effect of pH on chitosan structure formation brought into consideration the zero-order model.Mathematical modelling of bioactive compound release from swelling biopolymer matrices at different pH conditions is essential for the design of efficient targeted delivery matrices for functional food and nutraceutical applications.

Boosting rate performance of layered lithium-rich cathode materials by oxygen vacancy induced surface multicomponent integration

The rapid development of electric vehicles and portable energy storage systems demands improvements in the energy density and cost-effectiveness of lithium-ion batteries,a domain in which Lithium-rich layered cathode(LLO)materials inherently excel.However,these materials face practical challenges,such as low initial Coulombic efficiency,inferior cycle/rate performance,and voltage decline during cycling,which limit practical application.Our study introduces a surface multi-component integration strategy that incorporates oxygen vacancies into the pristine LLO material Li1.2Mn_(0.6)Ni_(0.2)O_(2).This process involves a brief citric acid treatment followed by calcination,aiming to explore rate-dependent degradation behavior.The induced surface oxygen vacancies can reduce surface oxygen partial pressure and diminish the generation of O_(2)and other highly reactive oxygen species on the surface,thereby facilitating the activation of Li ions trapped in tetrahedral sites while overcoming transport barriers.Additionally,the formation of a spinel-like phase with 3D Li+diffusion channels significantly improves Li^(+)diffusion kinetics and stabilizes the surface structure.The optimally modified sample boasts a discharge capacity of 299.5 mA h g^(-1)at a 0.1 C and 251.6 mA h g^(-1)at a 1 C during the initial activation cycle,with an impressive capacity of 222.1 mA h g^(-1)at a 5 C.Most notably,it retained nearly 70%of its capacity after 300 cycles at this elevated rate.This straightforward,effective,and highly viable modification strategy provides a crucial resolution for overcoming challenges associated with LLO materials,making them more suitable for practical application.

Improving Na^(+)transport kinetics and Na^(+)storage of hierarchical rhenium-nickel sulfide(ReS_(2)@NiS_(2))hollow architecture by assembling layered 2D-3D heterostructures

Mixed metal sulfides have been widely used as anode material of sodium-ion batteries(SIBs)because of their excellent conductivity and sodium ion storage performance.Herein,ReS_(2)@NiS_(2)heterostructures have been triumphantly designed and prepared through anchoring ReS_(2)nanosheet arrays on the surface of NiS_(2)hollow nanosphere.Specifically,the carbon nanospheres was used as hard template to synthesize NiS_(2)hollow spheres as the substrate and then the ultrathin two-dimensional ReS_(2)nanosheet arrays were uniformly grown on the surface of NiS_(2).The internal hollow property provides sufficient space to relieve the volume expansion,and the outer two-dimensional nanosheet realizes the rapid electron transport and insertion/extraction of Na^(+).Owing to the great improvement of the transport kinetics of Na^(+),NiS_(2)@ReS_(2)heterostructure electrode can achieve a high specific capacity of 400 mAh/g at the high current density of 1 A/g and still maintain a stable cycle stability even after 220 cycles.This hard template method not only paves a new way for the design and construct binary metal sulfide heterostructure electrode materials with outstanding electrochemical performance for Na^(+)batteries but also open up the potential applications of anode materials of SIBs.

Multi-scale boron penetration toward stabilizing nickel-rich cathode

Nickel-rich layered oxides LiNi_(x)Co_(y)Mn_(1-x-y)O_(2)(x≥0.8)have been recognized as the preferred cathode materials to develop lithium-ion batteries with high energy density(>300 Wh kg^(−1)).However,the poor cycling stability and rate capability stemming from intergranular cracks and sluggish kinetics hinder their commercialization.To address such issues,a multi-scale boron penetration strategy is designed and applied on the polycrystalline LiNi_(0.83)Co_(0.11)Mn_(0.06)O_(2)particles that are pre-treated with pore construction.The lithium-ion conductive lithium borate in grain gaps functions as the grain binder that can bear the strain/stress from anisotropic contraction/expansion,and provides more pathways for lithium-ion diffusion.As a result,the intergranular cracks are ameliorated and the lithium-ion diffusion kinetics is improved.Moreover,the coating layer separates the sensitive cathode surface and electrolyte,helping to suppress the parasitic reactions and related gas evolution.In addition,the enhanced structural stability is acquired by strong B-O bonds with trace boron doping.As a result,the boron-modified sample with an optimized boron content of 0.5%(B5-NCM)exhibits a higher initial discharge capacity of 205.5 mAh g^(−1)at 0.1C(1C=200 mA g^(−1))and improved capacity retention of 81.7%after 100 cycles at 1C.Furthermore,the rate performance is distinctly enhanced by high lithium-ion conductive LBO(175.6 mAh g^(−1)for B5-NCM and 154.6 mAh g^(−1)for B0-NCM at 5C)

Microstructure evolution of spray deposited and as-cast 2195 Al-Li alloys during homogenization

In this paper,a comparative study on the spray deposited and as-cast 2195 alloy was carried out to reveal their microstructure evolutions and differences during the homogenization process.The dissolution of the secondary particles and the diffusion of solute were studied based on microstructure characterization and kinetics analysis.The precipitation behavior of Al3Zr dispersoids and its influence on recrystallization were investigated by using TEM and EBSD characterization.It was found that the large-size particles at triangular grain boundaries dissolve slower than the intragranular phases and other grain boundary phases.The required homogenization time depends on the dissolution processes of the large-size phases at grain boundaries.The size of grain boundary phases in the spray deposited alloy is much smaller than that in the as-cast alloy,so the homogenization time required for the spray deposited alloy is significantly shorter.Two-stage and ramp heating homogenization processes can promote the precipitation of Al3Zr dispersoids in the two alloys.In the spray deposited alloy,the dispersoids tend to precipitate at the positions of the T1 plates dissolved,which causes a non-uniform distribution and decreases the recrystallization resistance of the alloy.However,the distribution of the dispersoids in the as-cast alloy is more uniform after the homogenization,which brings a stronger inhibition on the recrystallization.According to the microstructural characterization and kinetics analysis results,it can be concluded that the homogenization with a slow ramp heating is suitable for the two 2195 alloys,and a shorter holding time can be used for spray deposited alloy,e.g.12 h at 500℃,while the holding time for the as-cast alloy is no less than 35 h at 500℃.

Effects of Homogenization Treatment on the Microsegregation of a Ni-Co Based Superalloy Produced by Directional Solidification

To reduce microsegregation,a series of homogenization treatments were carried out on a Ni-Co based superalloy prepared through directional solidification(DS).The element segregation characteristics and microstructural evolution were investigated by optical microscopy(OM),scanning electron microscopy(SEM),and electron probe microanalysis(EPMA).The results show that the elements are non-uniformly distributed in the solidified superalloy,in which W and Ti have the greatest tendency of microsegregation.Furthermore,severe microsegregation leads to complicated precipitations,includingη-Ni_(3) Ti and eutectic(γ+γ’).EPMA results show that Al and Mo are uniformly distributed between the eutectic(γ+γ’)andγmatrix,whereas Ti is segregated in the eutectic(γ+γ’)andηphases.The positive segregation element Ti,which is continuously rejected into the remaining liquid duringγmatrix solidification,promotes the formation of eutectic(γ+γ’)and the transformation of theηphase.According to the homogenization effect,the optimal single-stage homogenization process of this alloy is 1180℃for 2 h because of the sufficient diffusion segregation of the elements.In the present study,a kinetic diffusion model was built to reflect the degree of element segregation during homogenization,and the diffusion coefficients of W and Ti were estimated.

Morphology mediation of MoS_(2) nanosheets with organic cations for fast sodium ion storage

Ion diffusion kinetics,depending on the size,tortuosity,connectivity of the channels,greatly affects the rate performance of the electrodes.Two-dimensional materials(2DMs) has emerged as promising electrode materials in the past decades.Howeve r,the applications of 2DMs electrodes are limited by the strong restacking problem,which leads to a poor rate capability.In this work,we for the first time mediated the mo rphology of molybdenum disulfide(MoS_(2)) nanosheets via a facile coagulation method;abundant sheet crumples were induced,which greatly enhance their surface accessibility and thus benefit the ion diffusion kinetics.Consequently,the crumpled-MoS_(2) electrodes follow a capacitive Na-ion charge-storage mechanism to a large extent.Importantly,we demonstrate the special role of organic cations in the inter-sheet assembly configuration,in sharp contrast with that of alkali/alkaline-earth ones.We propose that organic cations cause edge/face contact of the sheets,instead of the face/face contact,thus affording a house-of-cards structure.

Constructing ultrastable electrode/electrolyte interface for rapid potassium ion storage capability via salt chemistry and interfacial engineering

Conversion/alloying anode materials exhibiting high K storage capacities suffer from large volume variations and unstable electrode/electrolyte interfaces upon cycling.Herein,taking SnS/reduced graphene oxide(SnS/rGO)anodes as an example,the electrochemical performance of SnS/rGO could significantly be improved via employing potassium bis(fluorosulfonyl)imide(KFSI)salt in electrolytes and ultrathin TiO_(2) coating.KF-rich inorganic layer was demonstrated to help form robust SEI layer,which could suppress the side reactions to increase the Coulombic efficiency.The formed potassiated K_(x)TiO_(2) coating layer was constructed to boost charge transfer capability and K-ion diffusion kinetics.The as-prepared SnS/rGO@TiO_(2)-20 electrode in KFSI electrolyte delivers the high CE of 99.1%and 424 mAh·g^(−1) after 200 cycles with an ultrahigh capacity retention of 98.5%.