查看更多>>摘要：Rechargeable lithium-sulfur(Li-S)batteries,featuring high energy density,low cost,and environmental friendliness,have been dubbed as one of the most promising candidates to replace current commercial rechargeable Li-ion batteries.However,their practical deployment has long been plagued by the infamous"shuttle effect"of soluble Li polysulfides(LiPSs)and the rampant growth of Li dendrites.Therefore,it is important to specifically elucidate the solvation structure in the Li-S system and systematically summarize the feasibility strategies that can simultaneously suppress the shuttle effect and the growth of Li dendrites for practical applications.This review attempts to achieve this goal.In this review,we first introduce the importance of developing Li-S batteries and highlight the key challenges.Then,we revisit the working principles of Li-S batteries and underscore the fundamental understanding of LiPSs.Next,we summarize some representative characterization techniques and theoretical calculations applied to characterize the solvation structure of LiPSs.Afterward,we overview feasible designing strategies that can simultaneously suppress the shuttle effect of soluble LiPSs and the growth of Li dendrites.Finally,we conclude and propose personal insights and perspectives on the future development of Li-S batteries.We envisage that this timely review can provide some inspiration to build better Li-S batteries for promoting practical applications.
查看更多>>摘要：Solid-state lithium batteries(SSLBs)with high safety have emerged to meet the increasing energy density demands of electric vehicles,hybrid electric vehicles,and portable electronic devices.However,the dendrite formation,high interfacial resistance,and deleterious interfacial reactions caused by solid-solid contact between electrode and electrolyte have hindered the commercialization of SSLBs.Thus,in this review,the state-of-the-art developments in the rational design of solid-state electrolyte and their progression toward practical applications are reviewed.First,the origin of interface instability and the sluggish charge carrier transportation in solid-solid interface are presented.Second,various strategies toward stabilizing interfacial stability(reducing interfacial resistance,suppressing lithium dendrites,and side reactions)are summarized from the physical and chemical perspective,including building protective layer,constructing 3D and gradient structures,etc.Finally,the remaining challenges and future development trends of solid-state electrolyte are prospected.This review provides a deep insight into solving the interfacial instability issues and promising solutions to enable practical high-energy-density lithium metal batteries.
查看更多>>摘要：Lithium-sulfur batteries(LSBs)are widely regarded as promising next-generation batteries due to their high theoretical specific capacity and low material cost.However,the practical applications of LSBs are limited by the shuttle effect of lithium polysulfides(LiPSs),electronic insulation of charge and discharge products,and slow LiPSs conversion reaction kinetics.Accordingly,the introduction of catalysts into LSBs is one of the effective strategy to solve the issues of the sluggished LiPS conversion.Because of their nearly 100％atom utilization and high electrocatalytic activity,single-atom catalysts(SACs)have been widely used as reaction mediators for LSBs'reactions.Excitingly,the SACs with asymmetric coordination structures have exhibited intriguing electronic structures and superior catalytic activities when compared to the traditional M-N4 active sites.In this review,we systematically describe the recent advancements in the installation of asymmetrically coordinated single-atom structure as reactions catalysts in LSBs,including asymmetrically nitrogen coordinated SACs,heteroatom coordinated SACs,support effective asymmetrically coordinated SACs,and bimetallic coordinated SACs.Particularly noteworthy is the discussion of the catalytic conversion mechanism of LiPSs spanning asymmetrically coordinated SACs.Finally,a perspective on the future developments of asymmetrically coordinated SACs in LSB applications is provided.
Peng ZhangYanmeng PengQizhen ZhuRazium Ali Soomro...
60-69页
查看更多>>摘要：MXenes are emerging rapidly as promising electrode materials for energy storage due to their high electronic conductivity and rich surface chemistry,but their potassium storage performance is unsatisfactory because of the large size of K+and irreversible interfacial reaction.Here,a developed 3D foam-like MXene scaffold(3D-FMS)is constructed via an electrostatic neutralization of Ti3C2Tx with positive-charged melamine followed with calcination,which offers massive surface-active sites and facilitates fast K+transfer for boosting the potassium-ion storage capacity and dynamics.In addition,using KFSI-based electrolyte,the formation of a robust solid electrolyte interface layer with more inorganic components on MXene anode is revealed for enhancing the Coulombic efficiency.Consequently,the 3D-FMS with KFSI-based electrolyte delivers enhanced potassium-ion storage performance in terms of capacity(161.4 mAh g-1 at 30 mA g-1),rate capability(70 mAh g-1 at 2 A g-1),and cycling stability(80.5 mAh g-1 at 1 A g-1 after 2000 cycles).Moreover,the assembled 3D-FMS//activated carbon potassium-ion hybrid supercapacitor delivers a high energy density of 57 Wh kg-1 at a power density of 290 W kg-1.These excellent performances demonstrate the great superiority of 3D-FMS in KFSI-based electrolyte and may accelerate the development of MXene-based materials for potassium storage systems.
查看更多>>摘要：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 X 10-3 S cm-1 at 30 ℃)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‖LiFePO4 full cell stably cycles with a capacity retention of 85％after 500 cycles.the Li‖LiFePO4 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.
查看更多>>摘要：For protonic ceramic fuel cells,it is key to develop material with high intrinsic activity for oxygen activation and bulk proton conductivity enabling water formation at entire electrode surface.However,a higher water content which benefitting for the increasing proton conductivity will not only dilute the oxygen in the gas,but also suppress the O2 adsorption on the electrode surface.Herein,a new electrode design concept is proposed,that may overcome this dilemma.By introducing a second phase with high-hydrating capability into a conventional cobalt-free perovskite to form a unique nanocomposite electrode,high proton conductivity/concentration can be reached at low water content in atmosphere.In addition,the hydronation creates additional fast proton transport channel along the two-phase interface.As a result,high protonic conductivity is reached,leading to a new breakthrough in performance for proton ceramic fuel cells and electrolysis cells devices among available air electrodes.
查看更多>>摘要：All-solid-state lithium metal batteries(ASSLMBs)with solid electrolytes(SEs)have emerged as a promising alternative to liquid electrolyte-based Li-ion batteries due to their higher energy density and safety.However,since ASSLMBs lack the wetting properties of liquid electrolytes,they require stacking pressure to prevent contact loss between electrodes and SEs.Though previous studies showed that stacking pressure could impact certain performance aspects,a comprehensive investigation into the effects of stacking pressure has not been conducted.To address this gap,we utilized the Li6PS5Cl solid electrolyte as a reference and investigated the effects of stacking pressures on the performance of SEs and ASSLMBs.We also developed models to explain the underlying origin of these effects and predict battery performance,such as ionic conductivity and critical current density.Our results demonstrated that an appropriate stacking pressure is necessary to achieve optimal performance,and each step of applying pressure requires a specific pressure value.These findings can help explain discrepancies in the literature and provide guidance to establish standardized testing conditions and reporting benchmarks for ASSLMBs.Overall,this study contributes to the understanding of the impact of stacking pressure on the performance of ASSLMBs and highlights the importance of careful pressure optimization for optimal battery performance.
查看更多>>摘要：Due to a high energy density,layered transition-metal oxides have gained much attention as the promising sodium-ion batteries cathodes.However,they readily suffer from multiple phase transitions during the Na extraction process,resulting in large lattice strains which are the origin of cycled-structure degradations.Here,we demonstrate that the Na-storage lattice strains of layered oxides can be reduced by pushing charge transfer on anions(O2).Specifically,the designed O3-type Ru-based model compound,which shows an increased charge transfer on anions,displays retarded O3-P3-O1 multiple phase transitions and obviously reduced lattice strains upon cycling as directly revealed by a combination of ex situ X-ray absorption spectroscopy,in situ X-ray diffraction and geometric phase analysis.Meanwhile,the stable Na-storage lattice structure leads to a superior cycling stability with an excellent capacity retention of 84％and ultralow voltage decay of 0.2 mV/cycle after 300 cycles.More broadly,our work highlights an intrinsically structure-regulation strategy to enable a stable cycling structure of layered oxides meanwhile increasing the materials'redox activity and Na-diffusion kinetics.
查看更多>>摘要：Silicon oxide(SiOx,0＜x ≤ 2)has been recognized as a prominent anode material in lithium-ion batteries and sodium-ion batteries due to its high theoretical capacity,suitable electrochemical potential,and earth abundance.However,it is intrinsically poor electronic conductivity and excessive volume expansion during potassiation/depotassiation process hinder its application in potassium-ion batteries.Herein,we reported a hierarchical porous C/SiOx potassium-ion batteries anode using lignite as raw material via a one-step carbonization and activation method.The amorphous C skeleton around SiOx particles can effectively buffer the volume expansion,and improve the ionic/electronic conductivity and structural integrity,achieving outstanding rate capability and cyclability.As expected,the obtained C/SiOx composite delivers a superb specific capacity of 370 mAh g-1 at 0.1 A g-1 after 100 cycles as well as a highly reversible capacity of 208 mAh g-1 after 1200 cycles at 1.0 A g-1.Moreover,the potassium ion storage mechanism of C/SiOx electrodes was investigated by ex-situ X-ray diffraction and transmission electron microscopy,revealing the formation of reversible products of K6.8Si45.3 and K4SiO4,accompanied by generation of irreversible K2O after the first cycle.This work sheds light on designing low-cost Si-based anode materials for high-performance potassium-ion batteries and beyond.
查看更多>>摘要：Organosulfur materials containing sulfur-sulfur bonds are an emerging class of high-capacity cathodes for lithium storage.However,it remains a great challenge to achieve rapid conversion reaction kinetics at practical testing conditions of high cathode mass loading and low electrolyte utilization.In this study,a Li-rich pyrolyzed polyacrylonitrile/selenium disulfide(pPAN/Se2S3)composite cathode is synthesized by deep lithiation to address the above challenges.The Li-rich molecular structure significantly boosts the lithium storage kinetics by accelerating lithium diffusivity and improving electronic conductivity.Even under practical test conditions requiring a lean electrolyte(Electrolyte/sulfur ratio of 4.1 μL mg-1)and high loading(7 mg cm-2 of pPAN/Se2S3),DL,pPAN/Se2S3 exhibits a specific capacity of 558 mAh g-1,maintaining 484 mAh g-1 at the 100th cycle with an average Coulombic efficiency of near 100％.Moreover,it provides(electro)chemically stable Li resources to offset Li consumption over charge-discharge cycles.As a result the as-fabricated anode-free cell shows a superior cycling stability with 90％retention of the initial capacity over 45 cycles.This study provides a novel approach for fabricating high-energy and stable Li-SPAN cells.
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