Applications and functions of rare-earth ions in perovskite solar cells

The emerging perovskite solar cells have been recognized as one of the most promising new-generation photovoltaic technologies owing to their potential of high efficiency and low production cost. However, the current perovskite solar cells suffer from some obstacles such as non-radiative charge recombination, mismatched absorption, light induced degradation for the further improvement of the power conversion efficiency and operational stability towards practical application. The rare-earth elements have been recently employed to effectively overcome these drawbacks according to their unique photophysical properties. Herein, the recent progress of the application of rare-earth ions and their functions in perovskite solar cells were systematically reviewed. As it was revealed that the rare-earth ions can be coupled with both charge transport metal oxides and photosensitive perovskites to regulate the thin film formation, and the rare-earth ions are embedded either substitutionally into the crystal lattices to adjust the optoelectronic properties and phase structure, or interstitially at grain boundaries and surface for effective defect passivation. In addition, the reversible oxidation and reduction potential of rare-earth ions can prevent the reduction and oxidation of the targeted materials. Moreover, owing to the presence of numerous energetic transition orbits, the rare-earth elements can convert low-energy infrared photons or high-energy ultraviolet photons into perovskite responsive visible light, to extend spectral response range and avoid high-energy light damage. Therefore, the incorporation of rare-earth elements into the perovskite solar cells have demonstrated promising potentials to simultaneously boost the device efficiency and stability.

Influence of rare-earth ions on structural and magnetic properties of CdFe_2O_4 ferrites

Nano-sized powders of rare-earth ions added CdFe2O4 ferrites were synthesized by oxalate co-precipitation method.The influence of R ions（R = Sm3＋, Y3＋, and La3＋） on the microstructure and magnetic properties of CdFe2O4 ferrites was studied.XRD, SEM, FTIR, and magnetic hysteresis loops were used for analyzing the samples.The addition of R ions alters the structure of the powders and decreases the crystalline size, lattice constant, and grain size.The magnetic properties such as saturation magnetization, remanent magnetization, and magnetic moment increased due to addition of rare-earth ions in CdFe2O4 ferrite.The formation of secondary phase on the grain boundaries supports the abnormal growth.FTIR spectra show two absorption bands.Results suggest that the magnetic properties depend on the particular method of preparation and additives.

Simulating resonance-mediated two-photon absorption enhancement in rare-earth ions by a rectangle phase modulation

Improving the up-conversion luminescence efficiency crucial in several related application areas. In this work, of rare-earth ions via the multi-photon absorption process is we theoretically propose a feasible scheme to enhance the resonance-mediated two-photon absorption in Er3＋ ions by shaping the femtosecond laser field with a rectangle phase modulation. Our theoretical results show that the resonance-mediated two-photon absorption can be decomposed into the on-resonant and near-resonant parts, and the on-resonant part mainly comes from the contribution of laser central frequency components, while the near-resonant part mainly results from the excitation of low and high laser frequency components. So, the rectangle phase modulation can induce a constructive interference between the two parts by properly designing the modulation depth and width, and finally realizes the resonance-mediated two-photon absorption enhancement. More- over, our results also show that the enhancement efficiency of resonance-mediated two-photon absorption depends on the laser pulse width （or laser spectral bandwidth）, final state transition frequency, and intermediate and final state absorption bandwidths. The enhancement efficiency modulation can be attributed to the relative weight manipulation of on-resonant and near-resonant two-photon absorption in the whole excitation process. This study presents a clear physical insight for the quantum control of resonance-mediated two-photon absorption in the rare-earth ions, and there will be an important significance for improving the up-conversion luminescence efficiency of rare-earth ions.

Simulation of Intermediate State Absorption Enhancement in Rare-Earth Ions by Polarization Modulated Femtosecond Laser Field

We extend the third perturbation theory to study the polarization control behavior of the intermediate state absorption in Nd^（3＋）ions. The results show that coherent interference can occur between the single-photon and three-photon excitation pathways, and depends on the central frequency of the femtosecond laser field. Moreover,single-photon and three-photon absorptions have different polarization control efficiencies, and the relative weight of three-photon absorption in the whole excitation processes can increase with increasing the laser intensity.Therefore, the enhancement or suppression of the intermediate state absorption can be realized and manipulated by properly designing the intensity and central frequency of the polarization modulated femtosecond laser field.This research can not only enrich theoretical research methods for the up-conversion luminescence manipulation of rare-earth ions, but also can provide a clear physical picture for understanding and controlling multi-photon absorption in a multiple energy level system.

Additive Effects of Rare-Earth Ions in Sodium Aluminoborate Glasses Using ²³Na and ²⁷Al Magic Angle Spinning Nuclear Magnetic Resonance

We conducted structural analysis of xNa2O-yY2O3-5B2O3-3Al2O3 and xNa2O-yLa2O3-5B2O3-3Al2O3 glasses to elucidate the additive effects of rare-earth ions in these sodium aluminoborate glasses, and investigated the local environment surrounding Na+ in them by using 23Na and 27Al magic angle spinning?nuclear magnetic resonance (MAS NMR) spectroscopy. The amount of higher-coordinated Al species ([5]Al and [6]Al) gradually increased in response to an increase in the ratios of Y2O3 to Al2O3 and La2O3 to Al2O3 in each type of glass, respectively. Moreover, the difference in the cation field strength (CFS) between Y3+ and La3+ was observed to affect the generation of [5]Al and [6]Al, especially when the amount of these ions in the glasses increased. In addition to the above, the coordination number of Na+ ions increased with an increase in the number of rare earth ions, confirmed by comparing results with NMR spectra of crystalline Na2Al2B2O7. The latter possibly occurred due to the oxygen concentration on Al[5] and Al[6]. Finally, it was confirmed that the formation of [5]Al and [6]Al decreases molar volume in oxide glasses, which might be partially due to better atomic packing of [5]Al and [6]Al.

Study on the hydrogen absorption properties of a YGdTbDyHo rare-earth high-entropy alloy

This study investigated the microstructure and hydrogen absorption properties of a rare-earth high-entropy alloy(HEA),YGdTbDyHo.Results indicated that the YGdTbDyHo alloy had a microstructure of equiaxed grains,with the alloy elements distributed homogeneously.Upon hydrogen absorption,the phase structure of the HEA changed from a solid solution with an hexagonal-close-packed(HCP)structure to a high-entropy hydride with an faced-centered-cubic(FCC)structure without any secondary phase precipitated.The alloy demonstrated a maximum hydrogen storage capacity of 2.33 H/M(hydrogen atom/metal atom)at 723 K,with an enthalpy change(ΔH)of-141.09 kJ·mol^(-1)and an entropy change(ΔS)of-119.14 J·mol^(-1)·K^(-1).The kinetic mechanism of hydrogen absorption was hydride nucleation and growth,with an apparent activation energy(E_(a))of 20.90 kJ·mol^(-1).Without any activation,the YGdTbDyHo alloy could absorb hydrogen quickly(180 s at 923 K)with nearly no incubation period observed.The reason for the obtained value of 2.33 H/M was that the hydrogen atoms occupied both tetrahedral and octahedral interstices.These results demonstrate the potential application of HEAs as a high-capacity hydrogen storage material with a large H/M ratio,which can be used in the deuterium storage field.

Solid-state quantum nodes based on color centers and rare-earth ions coupled with fiber Fabrye-Pérot microcavities

High-performance optical quantum memories serving as quantum nodes are crucial for the distribution of remote entanglement and the construction of large-scale quantum networks.Notably,quantum systems based on single emitters can achieve deterministic spin–photon entanglement,which greatly simplifies the difficulty of constructing quantum network nodes.Among them,optically interfaced spins embedded in solid-state systems,as atomic-like emitters,are important candidate systems for implementing long-lived quantum memory due to their stable physical properties and robustness to decoherence in scalable and compact hardware.To enhance the strength of light-matter interactions,optical microcavities can be exploited as an important tool to generate high-quality spin–photon entanglement for scalable quantum networks.They can enhance the photon collection probability and photon generation rate of specific optical transitions and improve the coherence and spectral purity of emitted photons.For solid-state systems,open Fabry–Pérot cavities can couple single emitters that are not in proximity to the surface,avoiding significant spectral diffusion induced by the interfaces while maintaining the wide tunability,which enables addressing of multiple single emitters in the frequency and spatial domain within a single device.This review described the characteristics of single emitters as quantum memories with a comparison to atomic ensembles,the cavity-enhancement effect for single emitters and the advantages of different cavities,especially fiber Fabry–Pérot microcavities.Finally,recent experimental progress on solid-state single emitters coupled with fiber Fabry–Pérot microcavities was also reviewed,with a focus on color centers in diamond and silicon carbide,as well as rare-earth dopants.

Critical current degradation in an epoxy-impregnated rare-earth Ba_(2)Cu_(3)O_(7-x)coated conductor caused by damage during a quench

High-temperature superconducting(HTS)rare-earth Ba_(2)Cu_(3)O_(7-x)(REBCO)coated conductors(CCs)have significant potential in high-current and high-field applications.However,owing to the weak interface strength of the laminated composite REBCO CCs,the damage induced by the thermal mismatch stress under a combination of epoxy impregnation,cooling,and quenching can cause premature degradation of the critical current.In this study,a three-dimensional(3D)electromagnetic-thermal-mechanical model based on the H-formulation and cohesive zone model(CZM)is developed to study the critical current degradation characteristics in an epoxy-impregnated REBCO CC caused by the damage during a quench.The temperature variation,critical current degradation of the REBCO CC,and its degradation onset temperature calculated by the numerical model are in agreement with the experimental data taken from the literature.The delamination of the REBCO CC predicted by the numerical model is consistent with the experimental result.The numerical results also indicate that the shear stress is the main contributor to the damage propagation inside the REBCO CC.The premature degradation of the critical current during a quench is closely related to the interface shear strength inside the REBCO CC.Finally,the effects of the coefficient of thermal expansion(CTE)of the epoxy resin,thickness of the substrate,and substrate material on the critical current degradation characteristics of the epoxy-impregnated REBCO CC during a quench are also discussed.These results help us understand the relationship between the current-carrying degradation and damage in the HTS applications.

Rare-earth ions coordination enhanced ratiometric fluorescent sensing platform for quantitative visual analysis of antibiotic residues in real samples

Levofloxacin(LVFX)as a representative drug of quinolone antibiotics is widely used in clinical,and its residues enriched in water bodies and sideline products seriously damage human health.It is imperative to develop a real-time/on-site sensing method for monitoring residual antibiotics.Here,we report a portable sensing platform by utilizing a composite fluorescent nanoprobe constructed by the cerium ions(Ce^(3+))coordination functionalized Cd Te quantum dots(QDs)for the visual and quantitative detection of LVFX residues.This fluorescent probe provides a distinct color variation from red to green,which shows a good linear relationship to LVFX residues concentrations in the range of 0-6.0μmol/L with a sensitive limit of detection(LOD)of 16.3 nmol/L.The smartphone platform with Color Analyzer App installed,which could accomplish quantified detection of LVFX in water,milk,and raw pork with a LOD of 27.9nmol/L.The facile sensing method we proposed realizes rapid visualization of antibiotics residual in the environment and provides a practical application pathway in food safety and human health.

Na^(+)/K^(+)-ATPase:ion pump,signal transducer,or cytoprotective protein,and novel biological functions

Na^(+)/K^(+)-ATPase is a transmembrane protein that has important roles in the maintenance of electrochemical gradients across cell membranes by transporting three Na^(+)out of and two K^(+)into cells.Additionally,Na^(+)/K^(+)-ATPase participates in Ca^(2+)-signaling transduction and neurotransmitter release by coordinating the ion concentration gradient across the cell membrane.Na^(+)/K^(+)-ATPase works synergistically with multiple ion channels in the cell membrane to form a dynamic network of ion homeostatic regulation and affects cellular communication by regulating chemical signals and the ion balance among different types of cells.Therefo re,it is not surprising that Na^(+)/K^(+)-ATPase dysfunction has emerged as a risk factor for a variety of neurological diseases.However,published studies have so far only elucidated the important roles of Na^(+)/K^(+)-ATPase dysfunction in disease development,and we are lacking detailed mechanisms to clarify how Na^(+)/K^(+)-ATPase affects cell function.Our recent studies revealed that membrane loss of Na^(+)/K^(+)-ATPase is a key mechanism in many neurological disorders,particularly stroke and Parkinson's disease.Stabilization of plasma membrane Na^(+)/K^(+)-ATPase with an antibody is a novel strategy to treat these diseases.For this reason,Na^(+)/K^(+)-ATPase acts not only as a simple ion pump but also as a sensor/regulator or cytoprotective protein,participating in signal transduction such as neuronal autophagy and apoptosis,and glial cell migration.Thus,the present review attempts to summarize the novel biological functions of Na^(+)/K^(+)-ATPase and Na^(+)/K^(+)-ATPase-related pathogenesis.The potential for novel strategies to treat Na^(+)/K^(+)-ATPase-related brain diseases will also be discussed.

Covalent Organic Framework with 3D Ordered Channel and Multi-Functional Groups Endows Zn Anode with Superior Stability

Achieving a highly robust zinc(Zn)metal anode is extremely important for improving the performance of aqueous Zn-ion batteries(AZIBs)for advancing“carbon neutrality”society,which is hampered by the uncontrollable growth of Zn dendrite and severe side reactions including hydrogen evolution reaction,corrosion,and passivation,etc.Herein,an interlayer containing fluorinated zincophilic covalent organic framework with sulfonic acid groups(COF-S-F)is developed on Zn metal(Zn@COF-S-F)as the artificial solid electrolyte interface(SEI).Sulfonic acid group(-SO_(3)H)in COF-S-F can effectively ameliorate the desolvation process of hydrated Zn ions,and the three-dimensional channel with fluoride group(-F)can provide interconnected channels for the favorable transport of Zn ions with ion-confinement effects,endowing Zn@COF-S-F with dendrite-free morphology and suppressed side reactions.Consequently,Zn@COF-S-F symmetric cell can stably cycle for 1,000 h with low average hysteresis voltage(50.5 m V)at the current density of 1.5 m A cm^(-2).Zn@COF-S-F|Mn O_(2)cell delivers the discharge specific capacity of 206.8 m Ah g^(-1)at the current density of 1.2 A g^(-1)after 800 cycles with high-capacity retention(87.9%).Enlightening,building artificial SEI on metallic Zn surface with targeted design has been proved as the effective strategy to foster the practical application of high-performance AZIBs.

Plasma‐oxidized 2D MXenes subnanochannel membrane for high‐performance osmotic energy conversion

Nanofluidic channels inspired by electric eels open a new era of efficient harvesting of clean blue osmotic energy from salinity gradients.Limited by less charge and weak ion selectivity of the raw material itself,energy conversion through nanofluidic channels is still facing considerable challenges.Here,a facile and efficient strategy to enhance osmotic energy harvesting based on drastically increasing surface charge density of MXenes subnanochannels via oxygen plasma is proposed.This plasma could break Ti–C bonds in the MXenes subnanochannels and effectively facilitate the formation of more Ti–O,C═O,O–OH,and rutile with a stronger negative charge and work function,which leads the surface potential of MXenes membrane to increase from 205 to 430 mV.This significant rise of surface charge endows the MXenes membrane with high cation selectivity,which could make the output power density of the MXenes membrane increase by 248.2%,reaching a high value of 5.92Wm^(−2) in the artificial sea‐river water system.Furthermore,with the assistance of low‐quality heat at 50℃,the osmotic power is enhanced to an ultrahigh value of 9.68Wm^(−2),which outperforms those of the state‐of‐the‐art two‐dimensional(2D)nanochannel membranes.This exciting breakthrough demonstrates the enormous potential of the facile plasma‐treated 2D membranes for osmotic energy harvesting.

Heterointerface Engineering-Induced Oxygen Defects for the Manganese Dissolution Inhibition in Aqueous Zinc Ion Batteries

Manganese-based material is a prospective cathode material for aqueous zinc ion batteries(ZIBs)by virtue of its high theoretical capacity,high operating voltage,and low price.However,the manganese dissolution during the electrochemical reaction causes its electrochemical cycling stability to be undesirable.In this work,heterointerface engineering-induced oxygen defects are introduced into heterostructure MnO_(2)(δa-MnO_(2))by in situ electrochemical activation to inhibit manganese dissolution for aqueous zinc ion batteries.Meanwhile,the heterointerface between the disordered amorphous and the crystalline MnO_(2)ofδa-MnO_(2)is decisive for the formation of oxygen defects.And the experimental results indicate that the manganese dissolution ofδa-MnO_(2)is considerably inhibited during the charge/discharge cycle.Theoretical analysis indicates that the oxygen defect regulates the electronic and band structure and the Mn-O bonding state of the electrode material,thereby promoting electron transport kinetics as well as inhibiting Mn dissolution.Consequently,the capacity ofδa-MnO_(2)does not degrade after 100 cycles at a current density of 0.5 Ag^(-1)and also 91%capacity retention after 500cycles at 1 Ag^(-1).This study provides a promising insight into the development of high-performance manganese-based cathode materials through a facile and low-cost strategy.

Design of multifunctional polymeric binders in silicon anodes for lithium‐ion batteries

Silicon(Si)is a promising anode material for lithium‐ion batteries(LIBs)owing to its tremendously high theoretical storage capacity(4200 mAh g−1),which has the potential to elevate the energy of LIBs.However,Si anodes exhibit severe volume change during lithiation/delithiation processes,resulting in anode pulverization and delamination with detrimental growth of solid electrolyte interface layers.As a result,the cycling stability of Si anodes is insufficient for commercialization in LIBs.Polymeric binders can play critical roles in Si anodes by affecting their cycling stability,although they occupy a small portion of the electrodes.This review introduces crucial factors influencing polymeric binders'properties and the electrochemical performance of Si anodes.In particular,we emphasize the structure–property relationships of binders in the context of molecular design strategy,functional groups,types of interactions,and functionalities of binders.Furthermore,binders with additional functionalities,such as electrical conductivity and self‐healability,are extensively discussed,with an emphasis on the binder design principle.

Polymer engineering for electrodes of aqueous zinc ion batteries

With the increasing demand for scalable and cost-effective electrochemical energy storage,aqueous zinc ion batteries(AZIBs)have a broad application prospect as an inexpensive,efficient,and naturally secure energy storage device.However,the limitations suffered by AZIBs,including volume expansion and active materials dissolution of the cathode,electrochemical corrosion,irreversible side reactions,zinc dendrites of the anode,have seriously decelerated the civilianization process of AZIBs.Currently,polymers have tremendous superiority for application in AZIBs attributed to their exceptional chemical stability,tunable structure,high energy density and outstanding mechanical properties.Considering the expanding applications of AZIBs and the superiority of polymers,this comprehensive paper meticulously reviews the benefits of utilizing polymeric applied to cathodes and anodes,respectively.To begin with,with adjustable structure as an entry point,the correlation between polymer structure and the function of energy storage as well as optimization is deeply investigated in respect to the mechanism.Then,depending on the diversity of properties and structures,the development of polymers in AZIBs is summarized,including conductive polymers,redox polymers as well as carbon composite polymers for cathode and polyvinylidene fluoride-,carbonyl-,amino-,nitrile-based polymers for anode,and a comprehensive evaluation of the shortcomings of these strategies is provided.Finally,an outlook highlights some of the challenges posed by the application of polymers and offers insights into the potential future direction of polymers in AZIBs.It is designed to provide a thorough reference for researchers and developers working on polymer for AZIBs.

Mechanical reliable,NIR light-induced rapid self-healing hydrogel electrolyte towards flexible zinc-ion hybrid supercapacitors with low-temperature adaptability and long service life

Hydrogel electrolytes hold great potential in flexible zinc ion supercapacitors(ZICs)due to their high conductivity,good safety,and flexibility.However,freezing of electrolytes at low temperature(subzero)leads to drastic reduction in ionic conductivity and mechanical properties that deteriorates the performance of flexible ZICs.Besides,the mechanical fracture during arbitrary deformations significantly prunes out the lifespan of the flexible device.Herein,a Zn^(2+)and Li^(+)co-doped,polypyrrole-dopamine decorated Sb_(2)S_(3)incorporated,and polyvinyl alcohol/poly(N-(2-hydroxyethyl)acrylamide)double-network hydrogel electrolyte is constructed with favorable mechanical reliability,anti-freezing,and self-healing ability.In addition,it delivers ultra-high ionic conductivity of 8.6 and 3.7 S m^(-1)at 20 and−30°C,respectively,and displays excellent mechanical properties to withstand tensile stress of 1.85 MPa with tensile elongation of 760%,together with fracture energy of 5.14 MJ m^(-3).Notably,the fractured hydrogel electrolyte can recover itself after only 90 s of infrared illumination,while regaining 83%of its tensile strain and almost 100%of its ionic conductivity during−30–60°C.Moreover,ZICs coupled with this hydrogel electrolyte not only show a wide voltage window(up to 2 V),but also provide high energy density of 230 Wh kg^(-1)at power density of 500 W kg^(-1)with a capacity retention of 86.7%after 20,000 cycles under 20°C.Furthermore,the ZICs are able to retain excellent capacity even under various mechanical deformation at−30°C.This contribution will open up new insights into design of advanced wearable flexible electronics with environmental adaptability and long-life span.

Hierarchically Structured Nb_(2)O_5 Microflowers with Enhanced Capacity and Fast-Charging Capability for Flexible Planar Sodium Ion Micro-Supercapacitors

Planar Na ion micro-supercapacitors(NIMSCs) that offer both high energy density and power density are deemed to a promising class of miniaturized power sources for wearable and portable microelectron-ics. Nevertheless, the development of NIMSCs are hugely impeded by the low capacity and sluggish Na ion kinetics in the negative electrode.Herein, we demonstrate a novel carbon-coated Nb_(2)O_5 microflower with a hierarchical structure composed of vertically intercrossed and porous nanosheets, boosting Na ion storage performance. The unique structural merits, including uniform carbon coating, ultrathin nanosheets and abun-dant pores, endow the Nb_(2)O_5 microflower with highly reversible Na ion storage capacity of 245 mAh g^(-1) at 0.25 C and excellent rate capability.Benefiting from high capacity and fast charging of Nb_(2)O_5 microflower, the planar NIMSCs consisted of Nb_(2)O_5 negative electrode and activated car-bon positive electrode deliver high areal energy density of 60.7 μWh cm^(-2),considerable voltage window of 3.5 V and extraordinary cyclability. Therefore, this work exploits a structural design strategy towards electrode materials for application in NIMSCs, holding great promise for flexible microelectronics.

Synthesis and Modulation of Low-Dimensional Transition Metal Chalcogenide Materials via Atomic Substitution

In recent years,low-dimensional transition metal chalcogenide(TMC)materials have garnered growing research attention due to their superior electronic,optical,and catalytic properties compared to their bulk counterparts.The controllable synthesis and manipulation of these materials are crucial for tailoring their properties and unlocking their full potential in various applications.In this context,the atomic substitution method has emerged as a favorable approach.It involves the replacement of specific atoms within TMC structures with other elements and possesses the capability to regulate the compositions finely,crystal structures,and inherent properties of the resulting materials.In this review,we present a comprehensive overview on various strategies of atomic substitution employed in the synthesis of zero-dimensional,one-dimensional and two-dimensional TMC materials.The effects of substituting elements,substitution ratios,and substitution positions on the structures and morphologies of resulting material are discussed.The enhanced electrocatalytic performance and photovoltaic properties of the obtained materials are also provided,emphasizing the role of atomic substitution in achieving these advancements.Finally,challenges and future prospects in the field of atomic substitution for fabricating low-dimensional TMC materials are summarized.

Phase-engineering modulation of Mn-based oxide cathode for constructing super-stable sodium storage

The Mn-based oxide cathode with enriched crystal phase structure and component diversity can provide the excellent chemistry structure for Na-ion batteries.Nevertheless,the broad application prospect is obstructed by the sluggish Na^(+)kinetics and the phase transitions upon cycling.Herein,we establish the thermodynamically stable phase diagram of various Mn-based oxide composites precisely controlled by sodium content tailoring strategy coupling with co-doping and solid-state reaction.The chemical environment of the P2/P'3 and P2/P3 biphasic composites indicate that the charge compensation mechanism stems from the cooperative contribution of anions and cations.Benefiting from the no phase transition to scavenge the structure strain,P2/P'3 electrode can deliver long cycling stability(capacity retention of 73.8%after 1000 cycles at 10 C)and outstanding rate properties(the discharge capacity of 84.08 mA h g^(-1)at 20 C)than P2/P3 electrode.Furthermore,the DFT calculation demonstrates that the introducing novel P'3 phase can significantly regulate the Na^(+)reaction dynamics and modify the local electron configuration of Mn.The effective phase engineering can provide a reference for designing other high-performance electrode materials for Na-ion batteries.

Regulation of Lithium-Ion Flux by Nanotopology Lithiophilic Boron-Oxygen Dipole in Solid Polymer Electrolytes for Lithium-Metal Batteries

Inhomogeneous lithium-ion(Li^(+))deposition is one of the most crucial problems,which severely deteriorates the performance of solid-state lithium metal batteries(LMBs).Herein,we discovered that covalent organic framework(COF-1)with periodically arranged boron-oxygen dipole lithiophilic sites could directionally guide Li^(+)even deposition in asymmetric solid polymer electrolytes.This in situ prepared 3D cross-linked network Poly(ACMO-MBA)hybrid electrolyte simultaneously delivers outstanding ionic conductivity(1.02×10^(-3)S cm^(-1)at 30°C)and excellent mechanical property(3.5 MPa).The defined nanosized channel in COF-1 selectively conducts Li^(+)increasing Li^(+)transference number to 0.67.Besides,The COF-1 layer and Poly(ACMO-MBA)also participate in forming a boron-rich and nitrogen-rich solid electrolyte interface to further improve the interfacial stability.The Li‖Li symmetric cell exhibits remarkable cyclic stability over 1000 h.The Li‖NCM523 full cell also delivers an outstanding lifespan over 400 cycles.Moreover,the Li‖LiFePO_(4)full cell stably cycles with a capacity retention of 85%after 500 cycles.the Li‖LiFePO_(4)pouch full exhibits excellent safety performance under pierced and cut conditions.This work thereby further broadens and complements the application of COF materials in polymer electrolyte for dendrite-free and high-energy-density solid-state LMBs.