The unavoidable dendrite growth and shuttle effect have long been stranglehold challenges limiting the safety and practicality of lithium-sulfur batteries.Herein,we propose a dual-action strategy to address the lithium dendrite issue in stages by constructing a multifunctional surface-negatively-charged nanodiamond layer with high ductility and robust puncture resistance on polypropylene (PP) separator.The uniformly loaded compact negative layer can not only significantly enhance electron transmission efficiency and promote uniform lithium deposition,but also reduce the formation of dendrite during early deposition stage.Most importantly,under the strong puncture stress encountered during the deterioration of lithium dendrite growth under limiting current,the high ductility and robust puncture resistance(145.88 MPa) of as-obtained nanodiamond layer can effectively prevent short circuits caused by unavoidable lithium dendrite.The Li||Li symmetrical cells assembled with nanodiamond layer modified PP demonstrated a stable cycle of over 1000 h at 2 mA cm^(-2)with a polarization voltage of only 29.3 mV.Additionally,the negative charged layer serves as a physical barrier blocking lithium polysulfide ions,effectively mitigating capacity attenuation.The improved cells achieved a capacity decay of only 0.042%per cycle after 700 cycles at 3 C,demonstrating effective suppression of dendrite growth and capacity attenuation,showing promising prospect.
Jun JiangZhenjie LuYanwen DingShujun LiuZhijie QiTian TangYunfan ZhangZhiyuan MaJingwen SunLiang XueWenyao ZhangPan XiongXin WangJunwu ZhuYongsheng Fu
Aqueous zinc ion batteries are regarded as one of the most promising candidates for large-scale energy stor-age due to their high safety,cost-effectiveness,and environ-mental friendliness.However,uncontrolled zinc dendrite growth and side reactions of the zinc anode decrease the sta-bility of Zn batteries.We report the synthesis of an air-oxid-ized carbon nanotube(O-CNT)film by chemical vapor de-position followed by heat treatment in air which is used as a protective layer on the Zn foil to suppress zinc dendrite growth.The increase in the hydrophilicity of the O-CNT film caused by air oxidation facilitates zinc deposition between the film and the anode instead of deposition on the film surface.The porous structure of the O-CNT film homogenizes the Zn^(2+)ion flux and the electric field on the surface of the Zn foil,leading to the uniform deposition of Zn.As a result,a O-CNT@Zn symmetric cell has a much better cycling stability with a life of more than 3000 h at 1 mA cm^(−2) with a capacity of 1 mAh cm^(−2),and values of more than 2000 h and 1 mAh cm^(−2) at 5 mA cm^(−2).In addition,a O-CNT@Zn||Mn^(2+)inserted hydrated vanadium pentoxide(MnVOH)full cell has a better rate per-formance than a Zn||MnVOH cell,achieving a high discharge capacity of 194 mAh g^(−1) at a high current density of 8 A g^(−1).In a long-term cycling test,the O-CNT@Zn||MnVOH full cell has a capacity retention of 58.8%after 2000 cycles at a current density of 5 A·g^(−1).
LI Pin-xiangYI Zhe-hanWANG Ye-xingHE ChangLIANG JiHOU Feng
Aqueous Zn ion batteries(ZIBs)have received extensive attention due to their intrinsic safety,high abundance,and low cost.However,uncontrolled dendrite growth and water-induced side reactions at electrod e/electrolyte interfaces hinder the advancement of ZIBs.Herein,density functional theory(DFT)calculation indicates that Zn heptafluorobutyrate can facilitate uniform Zn^(2+)deposition by leveraging the abundant zincophilic groups(e.g.,-COO^(-)and-CF)and inhibit water-induced side reactions due to the presence of hydrophobic carbon chains.A Zn heptafluorobutyrate protective layer(denoted as ZFA)is constructed on the metallic Zn surface in situ by acid etching process to control Zn^(2+)desolvation and nucleation behaviors,ensuring enhanced reversibility and stability of Zn anodes.Consequently,the Zn@ZFA anode demonstrates stable operation for more than 2200 h at 1 mA cm^(-2)and over 7300cycles at 40 mA cm^(-2),with high Coulombic efficiency of 99.8%over 1900 cycles at 5 mA cm^(-2).Impressively,Zn@ZFA‖VO_(2)full cell achieves exceptional cycle life(204 mA h g^(-1)after 750 cycles at 3 A g^(-1))and remarkable rate performance(236 mA g^(-1)at 10 A g^(-1)).This work provides an insightful guidance for constructing a protection layer of dendrite-free Zn anodes for high-performance ZIBs.
Lithium metal is one of the most promising anodes for lithium batteries because of their high theoretical specific capacity and the low electrochemical potential.However,the commercialization of lithium metal anodes(LMAs)is facing significant obstacles,such as uncontrolled lithium dendrite growth and unstable solid electrolyte interface,leading to inferior Coulombic efficiency,unsatisfactory cycling stability and even serious safety issues.Introducing low-cost natural clay-based materials(NCBMs)in LMAs is deemed as one of the most effective methods to solve aforementioned issues.These NCBMs have received considerable attention for stabilizing LMAs due to their unique structure,large specific surface areas,abundant surface groups,high mechanical strength,excellent thermal stability,and environmental friendliness.Considering the rapidly growing research enthusiasm for this topic in the last several years,here,we review the recent progress on the application of NCBMs in stable and dendrite-free LMAs.The different structures and modification methods of natural clays are first summarized.In addition,the relationship between their modification methods and nano/microstructures,as well as their impact on the electrochemical properties of LMAs are systematically discussed.Finally,the current challenges and opportunities for application of NCBMs in stable LMAs are also proposed to facilitate their further development.
Lithium metal batteries(LMBs)with high energy density are impeded by the instability of solid electrolyte interface(SEI)and the uncontrolled growth of lithium(Li)dendrite.To mitigate these challenges,optimizing the SEI structure and Li deposition behavior is the key to stable LMBs.This study novelty proposes a facile synthesis of MgF_(2)/carbon(C)nanocomposite through the mechanochemical reaction between metallic Mg and polytetrafluoroethylene(PTFE)powders,and its modified polypropylene(PP)separator enhances LMB performance.The in-situ formed highly conductive fluorine-doped C species play a crucial role in facilitating ion/electron transport,thereby accelerating electrochemical kinetics and altering Li deposition direction.During cycling,the in-situ reaction between MgF_(2)and Li leads to the formation of LiMg alloy,along with a LiF-rich SEI layer,which reduces the nucleation overpotential and reinforces the interphase strength,leading to homogeneous Li deposition with dendrite-free feature.Benefiting from these merits,the Li metal is densely and uniformly deposited on the MgF_(2)/C@PP separator side rather than on the current collector side.Furthermore,the symmetric cell with MgF_(2)/C@PP exhibits superb Li plating/stripping performance over 2800 h at 1 mA cm^(-2)and 2 mA h cm^(-2).More importantly,the assembled Li@MgF_(2)/C@PPILiFePO4full cell with a low negative/positive ratio of 3.6delivers an impressive cyclability with 82.7%capacity retention over 1400 cycles at 1 C.
Rechargeable aqueous zinc-metal batteries (AZMBs) are promising candidates for large-scale energy storage systems due to their low cost and high safety.However,their performance and sustainability are significantly hindered by the sluggish desolvation kinetics at the electrode/electrolyte interface and the corresponding hydrogen evolution reaction where active water molecules tightly participate in the Zn(H_(2)O)_(6)^(2+)solvation shell.Herein,learnt from self-generated solid electrolyte interphase (SEI) in anodes,the dielectric but ion-conductive zinc niobate nanoparticles artificial layer is constructed on metallic Zn surface (ZNB@Zn),acting as a rapid desolvation promotor.The zincophilic and dielectric-conductive properties of ZNB layer accelerate interfacial desolvation/diffusion and suppress surface corrosion or dendrite formation,achieving uniform Zn plating/stripping behavior,as confirmed by electronic/optical microscopies and interface spectroscopical measurements together with theoretical calculations.Consequently,the as-prepared ZNB@Zn electrode exhibits excellent cycling stability of over 2000 h and robust reversibility (99.54%) even under high current density and depth of discharge conditions.Meanwhile,the assembled ZNB@Zn-based full cell displays high capacity-retention rate of 80.21%after 3000 cycles at 5 A g^(-1)and outstanding rate performance up to 10 A g^(-1).The large-areal pouch cell is stabilized for hundreds of cycles,highlighting the bright prospects of the dielectric but ion-conductive layer in further application of AZMBs.
Sodium metal,with a high theoretical specific capacity(~1165 mA h g^(−1))and a low redox potential(−2.71 V vs.SHE)as well as low cost,becomes an attractive option for high‐energy‐density sodium secondary batteries.However,the practical application of sodium metal anodes is hindered by dendrite growth,which results in low energy efficiency,poor lifetime and serious safety issues.To address this challenge,researchers propose various strategies,including the formation of sodium alloys(Na‐M alloys,M=Sn,Sb,Bi,In,etc.)through alloying reaction.The alloying effect has a positive impact in terms of reducing the local current density,mitigating the volume expansion,and inhibiting the dendrite growth.It is thus an effective solution for constructing high‐performance sodium secondary batteries.This review systematically de-scribes the mechanism of dendrite growth and the alloying process of Na‐M alloys,summarizes recent research progress and strategies for applying Na‐M alloys to create dendrite‐free sodium secondary batteries,as well as pre-sents prospects for the development of Na‐M alloys and offers clear sugges-tions for future research.This review aims to inspire further efforts to build dendrite‐free,high‐performance sodium secondary batteries and broaden a new aspect for the next‐generation battery systems.
