Interfacial chemistry of anode/electrolyte interface for rechargeable magnesium batteries

Rechargeable magnesium batteries(RMBs),as a low-cost,high-safety and high-energy storage technology,have attracted tremendous attention in large-scale energy storage applications.However,the key anode/electrolyte interfacial issues,including surface passivation,uneven Mg plating/stripping,and pulverization after cycling still result in a large overpotential,short cycling life,poor power density,and possible safety hazards of cells,severely impeding the commercial development of RMBs.In this review,a concise overview of recently advanced strategies to address these anode/electroyte interfacial issues is systematically classified and summarized.The design of magnesiophilic substrates,construction of artificial SEI layers,and modification of electrolyte are important and effective strategies to improve the uniformity/kinetics of Mg plating/stripping and achieve the stable anode/electrolyte interface.The key opportunities and challenges in this field are advisedly put forward,and the insights into future directions for stabilizing Mg metal anodes and the anode/electrolyte interface are highlighted.This review provides important references fordeveloping the high-performance and high-safety RMBs.

Simultaneous regulation on coordination environment and interfacial chemistry via taurine for stabilized Zn metal anode

Aqueous Zn-ion batteries(AZIBs)are the potential options for the next-generation energy storage scenarios due to the cost effectiveness and intrinsic safety.Nevertheless,the industrial application of AZIBs is still impeded by a series of parasitic reactions and dendrites at zinc anodes.In this study,taurine(TAU)is used in electrolyte to simultaneously optimize the coordination condition of the ZnSO4electrolyte and interfacial chemistry at the anode.TAU can preferentially adsorb with the zinc metal and induce an in situ stable and protective interface on the anode,which would avoid the connection between H_(2)O and the zinc metal and promote the even deposition of Zn^(2+).The resulting Zn//Zn batteries achieve more than 3000 hours long cyclic lifespan under 1 mA cm^(-2)and an impressive cumulative capacity at 5 mA cm^(-2).Moreover,Zn//Cu batteries can realize a reversible plating/stripping process over 2,400cycles,with a desirable coulombic efficiency of 99.75%(1 mA cm^(-2)).Additionally,the additive endows Zn//NH_(4)V_(4)O_(10)batteries with more stable cyclic performance and ultrafast rate capability.These capabilities can promote the industrial application of AZIBs.

EXTRACTION KINETICS,SYNERGISTIC EFFECTS AND INTERFACIAL CHEMISTRY FOR D_2 EHPA MPA-Fe^(3+) MIXED EXTRACTION SYSTEM

The thermodynamics of micella formation,interfacial characteristics,synergistic effects and interfacial kinetics for synergistic extraction system D_2 EHPA-MPA-Fe^(3+) have been studied.It was found that D_2EHPA in the mixed system strongly exhibits the effect on the micella formation thermodynamics and interracial characteristics of MPA.Some ther- modynamic parameters for constants of micelles formation(K_m).free energies of micelles formation(ΔG_m)and critical micella concentrations(CMC)were obtained.The inter- facial adsorption behaviour of D_2EHPA is opposite to that of MPA.The emulsification for single MPA and the mixed system was discussed.The synergistic effects were found in this mixed extraction system.It is proved that the process of the Fe^(3+) extraction for non-mixed extraction system is controlled by chemical reaction and the controlling reaction occurs at the interface.

Insights into interfacial speciation and deposition morphology evolution at Mg-electrolyte interfaces under practical conditions

Rechargeable magnesium(Mg)battery technologies show the promise of low cost,less safety concerns and relatively higher energy density.Interrogating the critical issues on the Mg stripping/plating performance as well as the Mg metal anode-electrolyte interfacial chemistry is one great importance under the practical areal capacity and rate conditions.In this work,we systematically investigate the electrochemistry of Mg stripping/plating processes within four distinctive Mg-ion electrolytes and the Mg anodeelectrolyte interfacial chemistry under practical conditions.Electrochemical results show that the cycle life of Mg//Cu asymmetric cells using these above electrolytes is significantly shortened(less than 10 cycles)when tested at a practical areal capacity of 10 mAh cm^-2.Further optical and electron microscopic analyses reveal that the gradual growth of the Mg deposits is susceptible to detachment from the copper substrate,where the initial nucleation process might occur.In spite of showing an interconnected particle-like morphology,the Mg deposits could easily penetrate the porous separator,leading to cell failure.The co-deposition of metallic Al is revealed from surface region to bulk,while the Cl-containing species exist in the near surface of Mg deposits.Our work not only highlights the critical impacts of areal capacity on the performances of Mg stripping/plating process,but calls for further efforts to eliminating the safety concerns of Mg anode under practical conditions.

Engineering electrolyte additives for stable zinc-based aqueous batteries:Insights and prospects

Zn-based aqueous batteries(ZABs) are gaining widespread popularity due to their low cost and high safety profile. However, the application of ZABs faces significant challenges, such as dendrite growth and parasitic reactions of metallic Zn anodes. Therefore, achieving high-energy–density ZABs necessitates addressing the fundamental thermodynamics and kinetics of Zn anodes. Various strategies are available to mitigate these challenges, with electrolyte additive engineering emerging as one of the most efficient and promising approaches. Despite considerable research in this field, a comprehensive understanding of the intrinsic mechanisms behind the high performance of electrolyte additives remains limited. This review aims to provide a detailed introduction to functional electrolyte additives and thoroughly explore their underlying mechanisms. Additionally, it discusses potential directions and perspectives in additive engineering for ZABs, offering insights into future development and guidelines for achieving high-performance ZABs.

Tailoring Electrode–Electrolyte Interface Using an Electron-Deficient Borate-Based Additive in MgTFSI_(2)-MgCl_(2)/DME Electrolyte for Rechargeable Magnesium Batteries

Rechargeable magnesium metal batteries need an electrolyte that forms a stable and ionically conductive solid electrolyte interphase(SEI)on the anodes.Here,we used molecular dynamic simulation,density functional theory calculation,and X-ray photoelectron spectroscopy analysis to investigate the solvation structures and SEI compositions in electrolytes consisting of dual-salts,magnesium bis(trifluoromethanesulfonyl)imide(MgTFSI_(2)),and MgCl_(2),with different additives in 1,2-dimethoxyethane(DME)solvent.We found that the formed[Mg_(3)(μ-Cl)_(4)(DME)mTFSI_(2)](m=3,5)inner-shell solvation clusters in MgTFSI_(2)-MgCl_(2)/DME electrolyte could easily decompose and form a MgO-and MgF_(2)-rich SEI.Such electron-rich inorganic species in the SEI,especially MgF_(2),turned out to be detrimental for Mg plating/stripping.To reduce the MgF_(2)and MgO contents in SEI,we introduce an electron-deficient tri(2,2,2-trifluoroethyl)borate(TFEB)additive in the electrolyte.Mg//Mg cells using the MgTFSI_(2)-MgCl_(2)/DME-TFEB electrolyte could cycle stably for over 400 h with a small polarization voltage of~150 mV.Even with the presence of 800 ppm H_(2)O,the electrolyte with TFEB additive could still preserve its good electrochemical performance.The optimized electrolyte also enabled stable cycling and high-rate capability for Mg//Mo6S8 and Mg//CuS full cells,showing great potential for future applications.

Critical Review on cathode-electrolyte Interphase Toward High-Voltage Cathodes for Li-Ion Batteries

The thermal stability window of current commercial carbonate-based electrolytes is no longer sufficient to meet the ever-increasing cathode working voltage requirements of high energy density lithium-ion batteries.It is crucial to construct a robust cathode-electrolyte interphase(CEI)for high-voltage cathode electrodes to separate the electrolytes from the active cathode materials and thereby suppress the side reactions.Herein,this review presents a brief historic evolution of the mechanism of CEI formation and compositions,the state-of-art characterizations and modeling associated with CEI,and how to construct robust CEI from a practical electrolyte design perspective.The focus on electrolyte design is categorized into three parts:CEI-forming additives,anti-oxidation solvents,and lithium salts.Moreover,practical considerations for electrolyte design applications are proposed.This review will shed light on the future electrolyte design which enables aggressive high-voltage cathodes.

Cyanoethyl cellulose-based eutectogel electrolyte enabling high-voltage-tolerant and ion-conductive solid-state lithium metal batteries

Solid-state polymer electrolytes are an important factor in the deployment of highsafety and high-energy-density solid-state lithium metal batteries.Nevertheless,use of the traditional polyethylene oxide-based solid-state polymer electrolyte is limited due to its inherently low ionic conductivity and narrow electrochemical stability window.Herein,for the first time,we specifically designed a cyanoethyl cellulosein-deep eutectic solvent composite eutectogel as a promising candidate for hybrid solid-state polymer electrolytes.It is found that the proposed eutectogel electrolyte achieves high ionic conductivity(1.87×10^(−3) S cm^(−1) at 25℃),superior electrochemical stability(up to 4.8 V),and outstanding lithium plating/striping behavior(low overpotential of 0.04 V at 1mAcm^(−2) and 1mAh cm^(−2) over 300 h).With the eutectogel-based solid-state polymer electrolyte,a 4.45 V LiCoO_(2)/Li metal battery delivers prominent long-term lifespan(capacity retention of 85%after 200 cycles)and high average Coulombic efficiency(99.5%)under ambient conditions,significantly outperforming the traditional carbonate-based liquid electrolyte.Our work demonstrates a promising strategy for designing eutectogel-based solid-state polymer electrolytes to realize high-voltage and high-energy lithium metal batteries.

1,3,5-Trifluorobenzene endorsed EC-free electrolyte for high-voltage and wide-temperature lithium-ion batteries

Ethylene carbonate(EC)is susceptible to the aggressive chemistry of nickel-rich cathodes,making it undesirable for high-voltage lithium-ion batteries(LIBs).The arbitrary elimination of EC leads to better oxidative tolerance but always incurs interfacial degradation and electrolyte decomposition.Herein,an EC-free electrolyte is deliberately developed based on gradient solvation by pairing solvation-protection agent(1,3,5-trifluorobenzene,F_(3)B)with propylene carbonate(PC)/methyl ethyl carbonate(EMC)formulation.F_(3)B keeps out of inner coordination shell but decomposes preferentially to construct robust interphase,inhibiting solvent decomposition and electrode corrosion.Thereby,the optimized electrolyte(1.1 M)with wide liquid range(-70–77℃)conveys decent interfacial compatibility and high-voltage stability(4.6 V for LiNi_(0.6)Mn_(0.2)Co_(0.2)O_(2),NCM622),qualifying reliable operation of practical NCM/graphite pouch cell(81.1%capacity retention over 600 cycles at 0.5 C).The solvation preservation and interface protection from F_(3)B blaze a new avenue for developing high-voltage electrolytes in next-generation LIBs.

Rational Design of Electrode–Electrolyte Interphase and Electrolytes for Rechargeable Proton Batteries

Rechargeable proton batteries have been regarded as a promising technology for next-generation energy storage devices,due to the smallest size,lightest weight,ultrafast diffusion kinetics and negligible cost of proton as charge carriers.Nevertheless,a proton battery possessing both high energy and power density is yet achieved.In addition,poor cycling stability is another major challenge making the lifespan of proton batteries unsatisfactory.These issues have motivated extensive research into electrode materials.Nonetheless,the design of electrode–electrolyte interphase and electrolytes is underdeveloped for solving the challenges.In this review,we summarize the development of interphase and electrolytes for proton batteries and elaborate on their importance in enhancing the energy density,power density and battery lifespan.The fundamental understanding of interphase is reviewed with respect to the desolvation process,interfacial reaction kinetics,solvent-electrode interactions,and analysis techniques.We categorize the currently used electrolytes according to their physicochemical properties and analyze their electrochemical potential window,solvent(e.g.,water)activities,ionic conductivity,thermal stability,and safety.Finally,we offer our views on the challenges and opportunities toward the future research for both interphase and electrolytes for achieving high-performance proton batteries for energy storage.

Rationalizing Na-ion solvation structure by weakening carbonate solvent coordination ability for high-voltage sodium metal batteries

Commercial carbonate-based electrolytes feature highly reactive activities with alkali metals,yielding low Coulombic efficiencies and poor cycle life in lithium metal batteries,which possess much higher chemical activity in the rising star sodium metal batteries.To be motivated,we have proposed that decreasing the solvent solvation ability in carbonate-based electrolytes stepwise could enable longterm stable cycling of high-voltage sodium metal batteries.As the solvation capacity reduces,more anions are enticed into the solvation sheath of Na^(+),resulting in the formation of the more desirable interphase layers on the surface of the anode and the cathode.The inorganic-dominated interphases allow highly efficient Na^(+)deposition/stripping processes with a lower rate of dead sodium generation,as well as maintain a stable structure of the high-voltage cathode material.Specifically,the assembled Na||Na_(3)V_(2)(PO_(4))_(2)F_(3)battery exhibits an accelerated ion diffusion kinetics and achieves a higher capacity retention of 85.9%with during the consecutive 200 cycles under the high voltage of 4.5 V.It is anticipated that the tactics we have proposed could be applicable in other secondary metal battery systems as well.

Stable interphase chemistry of textured Zn anode for rechargeable aqueous batteries

Despite the advances of aqueous zinc(Zn)batteries as sustainable energy storage systems,their practical application remains challenging due to the issues of spontaneous corrosion and dendritic deposits at the Zn metal anode.In this work,conformal growth of zinc hydroxide sulfate(ZHS)with dominating(001)facet was realized on(002)plane-dominated Zn metal foil fabricated through a facile thermal annealing process.The ZHS possessed high Zn^(2+)conductivity(16.9 mS cm^(-1))and low electronic conductivity(1.28×10^(4)Ωcm),and acted as a heterogeneous and robust solid electrolyte interface(SEI)layer on metallic Zn electrode,which regulated the electrochemical Zn plating behavior and suppressed side reactions simultaneously.Moreover,low self-diffusion barrier along the(002)plane promoted the 2D diffusion and horizontal electrochemical plating of metallic Zn for(002)-textured Zn electrode.Consequently,the as-achieved Zn electrode exhibited remarkable cycling stability over 7000 cycles at 2 mA cm^(-2)and 0.5 mAh cm^(-2)with a low overpotential of 25 mV in symmetric cells.Pairing with a MnO_(2)cathode,the as-achieved Zn electrode achieved stable cell cycling with 92.7%capacity retention after 1000 cycles at 10 C with a remarkable average Coulombic efficiency of 99.9%.

Narrow-bandgap light-absorbing conjugated polybenzobisthiazole:Massive interfacial synthesis,robust solar-thermal evaporation and thermoelectric power generation

Exploiting advanced light-absorbing conjugated polymers is of great significance to achieve the blue dream of low-energy solar steam generation and clean water collection.Herein,an interfacial chemistry strategy is developed to massively synthetize conjugated polybenzobisthiazole(CP)microspheres with a narrow bandgap of 0.274 eV and high solar absorbance of 94.0%.The CP microspheres are combined with the polyvinyl alcohol(PVA)hydrogel to form a Janus evaporator.The evaporation rate and energy efficiency of the CP@PVA solar evaporator reach 2.96 kg m^(-2) h^(-1) and 98.8%with a low coating content of 5 mg cm^(-2).The evaporation performance of the Janus CP@PVA evaporator is applicable to seawater,sewage,and acid/alkali water.The efficient evaporator with portable collector can be simply assembled to produce drinking water from real seawater and sewage.Additionally,the Janus evaporator is also equipped with a thermoelectric module to generate the steam and electricity simultaneously.The power output achieves 1.04 W m^(-2 )in real seawater while the evaporation rate remains 2.23 kg m^(-2) h^(-1) under 1 sun,demonstrating the remarkable capacity to utilize the solar energy.

三功能共晶溶剂添加剂用于高性能锂金属电池

Rational carbonate electrolyte chemistry is critical for the development of high-voltage lithium metal batteries(LMBs).However,the implementation of traditional carbonate electrolyte is greatly hindered by the generation of an unstable electrode interphase and corrosive by-product(HF).Herein,we propose a triple-function eutectic solvent additive of N-methylacetamide(NmAc)with LiNO_(3) to enhance the stability and compatibility of carbonate electrolyte.Firstly,the addition of NmAc significantly improves the solubility of LiNO_(3) in carbonate electrolyte by forming an eutectic pair,which regulates the Li~+solvation structure and leads to dense and homogenous Li plating.Secondly,the hydrolysis of acidic PF_5 is effectively alleviated due to the strong complexation of NmAc with PF_5,thus reducing the generation of corrosive HF.In addition,the optimized cathode electrolyte interphase layer decreases the structural degradation and transition metal dissolution.Consequently,Li||LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)(NCM622)cells with the designed electrolyte deliver superior long-term cycle reversibility and excellent rate capability.This study unveils the rationale for incorporating eutectic solvent additives within carbonate electrolytes,which significantly contribute to the advancement of their practical application for high-voltage LMBs.

Advancement in porphyrin/phthalocyanine compounds-based perovskite solar cells

Porphyrin and phthalocyanine compounds belong to a class of large and aromatic macrocyclic compounds.Owing to their unique structures and electronic properties,they have found widespread applications in optoelectronic devices.In recent years,the doping of porphyrins and phthalocyanines into perovskite solar cells(PSCs)has emerged as an effective strategy to enhance device performance and stability.This doping strategy enables the modulation of perovskite film crystallization and surface defects,thereby improving charge transfer and enhancing the photo-conversion efficiency.As sensitizers,porphyrins and phthalocyanines absorb light in the visible and near-infrared spectral ranges,providing an advantage to the light absorption characteristics of PSCs.Additionally,their roles in interface modification and defect repair contribute to the long-term stability of the devices.The central metal of porphyrin can also adsorb ions and prevent the migration of harmful ions.This review summarizes the recent progress in the research on porphyrin and phthalocyanine-doped PSCs,empha-sizing their potential value in enhancing optoelectronic performance,increasing stability and expanding the application scope of these devices.

Tailored ZnF_(2)/ZnS-rich interphase for reversible aqueous Zn batteries

The urgent need for highly safe and sustainable large-scale energy storage systems for residential buildings has led to research into aqueous zinc ion batteries.However,when zinc is used in aqueous zinc ion batteries,it suffers from severe irreversibility due to its low Coulombic efficiency,dendrite growth,and side reactions.To address these challenges,we take advantage of organic cation to induce trifluoromethanesulfonate decomposition to build zinc fluoride/zinc sulfide-rich solid electrolyte interphase(SEI)that not only can adapt to a high areal capacity of deposition/stripping disturbance but also adjust zinc ion deposition path to eliminate dendrite.As a result,the unique interface can promote the Zn battery to achieve excellent electrochemical performance:high levels of plating/stripping Coulombic efficiency(99.8%),stability life(6,600 h),and cumulative capacity(66,000 mAh·cm^(−2))at 68%zinc utilization(20 mAh·cm^(−2)).More importantly,the SEI significantly enhances the cyclability of full battery under limited Zn,lean electrolyte,and high areal capacity cathode conditions.

NASICON solid electrolyte coated by indium film for all-solid-state Li-metal batteries

The application of all-solid-state Li-metal batteries with solid oxide electrolytes is hindered by interfacial issues,especially the solid electrolyte/Li-metal interface.This work introduced a uniform indium film layer on the surface of Na^(+)super ionic conductor(NASICON)solid electrolyte Li_(1.5)Al_(0.5)Ge_(1.5)P_(3)O_(12)(LAGP),which promotes the intimate contact between Li metal and solid electrolyte and hinders the side reactions at the interface.Electrochemical impedance spectra show that the battery with coated solid electrolyte presents a smaller interfacial resistance and maintains stability after a long cycling time.By contrast,the baseline battery with a pure LAGP pellet shows a contact loss after cycling with the vibration of interfacial impedance.The Li symmetric cells with indium-modified solid electrolyte present stable cycling behavior over 400 h at 0.1 and 0.2 mA·cm^(−2).The all-solid-state Li-metal batteries with a Li anode,indium coating LAGP and two kinds of cathodes,namely carbon nanotubes(CNTs)and LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811),are prepared and tested.The CNTs cathode for Li-O2 and Li-air batteries has a higher specific capacity than traditional Li-ion battery cathodes.The Li-NCM811 batteries deliver an initial Coulombic efficiency of about 75%,with 82%capacity retention after 20 cycles.

On the role of surface carbonate species in determining the cycling performance of all-solid-state batteries

This short perspective summarizes recent findings on the role of residual lithium present on the surface of layered Ni-rich oxide cathode materials in liquid-and solid-electrolyte based batteries,with emphasis placed on the carbonate species.Challenges and future research opportunities in the development of carbonate-containing protective nanocoatings for inorganic solid-state battery applications are also discussed.