Facilitating prelithiation of silicon carbon anode by localized high-concentration electrolyte for high-rate and long-cycle lithium storage

The commercialization of silicon-based anodes is affected by their low initial Coulombic efficiency(ICE)and capacity decay,which are attributed to the formation of an unstable solid electrolyte interface(SEI)layer.Herein,a feasible and cost-effective prelithiation method under a localized highconcentration electrolyte system(LHCE)for the silicon-silica/graphite(Si-SiO_(2)/C@G)anode is designed for stabilizing the SEI layer and enhancing the ICE.The thin SiO_(2)/C layers with-NH_(2) groups covered on nano-Si surfaces are demonstrated to be beneficial to the prelithiation process by density functional theory calculations and electrochemical performance.The SEI formed under LHCE is proven to be rich in ionic conductivity,inorganic substances,and flexible organic products.Thus,faster Li+transportation across the SEI further enhances the prelithiation effect and the rate performance of Si-SiO_(2)/C@G anodes.LHCE also leads to uniform decomposition and high stability of the SEI with abundant organic components.As a result,the prepared anode shows a high reversible specific capacity of 937.5 mAh g^(-1)after 400 cycles at a current density of 1 C.NCM 811‖Li-SSGLHCE full cell achieves a high-capacity retention of 126.15 mAh g^(-1)at 1 C over 750 cycles with 84.82%ICE,indicating the great value of this strategy for Si-based anodes in large-scale applications.

Regulating solid electrolyte interphases on phosphorus/carbon anodes via localized high-concentration electrolytes for potassium-ion batteries

The resourceful and inexpensive red phosphorus has emerged as a promising anode material of potassium-ion batteries(PIBs) for its large theoretical capacities and low redox potentials in the multielectron alloying/dealloying reactions,yet chronically suffering from the huge volume expansion/shrinkage with a sluggish reaction kinetics and an unsatisfactory interfacial stability against volatile electrolytes.Herein,we systematically developed a series of localized high-concentration electrolytes(LHCE) through diluting high-concentration ether electrolytes with a non-solvating fluorinated ether to regulate the formation/evolution of solid electrolyte interphases(SEI) on phosphorus/carbon(P/C) anodes for PIBs.Benefitting from the improved mechanical strength and structural stability of a robust/uniform SEI thin layer derived from a composition-optimized LHCE featured with a unique solvation structure and a superior K+migration capability,the P/C anode with noticeable pseudocapacitive behaviors could achieve a large reversible capacity of 760 mA h g^(-1)at 100 mA g^(-1),a remarkable capacity retention rate of 92.6% over 200 cycles at 800 mA g^(-1),and an exceptional rate capability of 334 mA h g^(-1)at8000 mA g^(-1).Critically,a suppressed reduction of ether solvents with a preferential decomposition of potassium salts in anion-derived interfacial reactions on P/C anode for LHCE could enable a rational construction of an outer organic-rich and inner inorganic-dominant SEI thin film with remarkable mechanical strength/flexibility to buffer huge volume variations and abundant K+diffusion channels to accelerate reaction kinetics.Additionally,the highly reversible/durable full PIBs coupling P/C anodes with annealed organic cathodes further verified an excellent practical applicability of LHCE.This encouraging work on electrolytes regulating SEI formation/evolution would advance the development of P/C anodes for high-performance PIBs.

Mechanism of high-concentration electrolyte inhibiting the destructive effect of Mn(Ⅱ)on the performance of lithium-ion batteries

By optimizing electrolyte formulation to inhibit the deposition of transition metal ions(TMIs) on the surface of the graphite anode is an effective way to improve the electrochemical performance of lithium-ion batteries.At present,it is generally believed the formation of an effective interfacial film on the surface of the anode electrode is the leading factor in reducing the dissolution of TMIs and prevent TMIs from being embedded in the electrode.It ignores the influence of the solvation structures in the electrolyte system with different composition,and is not conducive to the design of the electrolyte formulation from the perspective of changing the concentration and the preferred solvent to inhibit the degradation of battery performance caused by TMIs deposition.In this work,by analyzing the special solvation structures of the high-concentra tion electrolyte,we study the main reason why high-concentration electrolyte inhibits the destructive effect of Mn(Ⅱ) on the electrochemical performance of LIBs.By combining the potentialresolved in-situ electrochemical impedance spectroscopy technology(PRIs-EIS) and density functional theory(DFT) calculation,we find that Mn(Ⅱ) mainly exists in the form of contact ions pairs(CIPs) and aggregates(AGGs) in high-concentration electrolyte.These solvation structures can reduce the destructive effect of Mn(Ⅱ) on battery performance from two aspects:on the one hand,it can rise the lowest unoccupied orbital(LUMO) value of the solvation structures of Mn(Ⅱ),thereby reducing the chance of its reduction;on the other hand,the decrease of Mn2+ions reduction can reduce the deposition of metallic manganese in the solid electrolyte interphase(SEI),thereby avoiding the continuous growth of the SEI.This study can be provided inspiration for the design of electrolytes to inhibit the destructive effect of TMls on LIBs.

Structural optimization and performance trade-off strategies for semi-crystalline sulfonated poly(arylene ether ketone) membranes in high-concentration direct methanol fuel cells

Direct methanol fuel cells(DMFCs) have attracted extensive attention as promising next-generation energy conversion devices. However, commercialized proton exchange membranes(PEMs) hardly fulfill the demand of methanol tolerance for DMFCs employing high-concentration methanol solutions.Herein, we report a series of semi-crystalline poly(arylene ether ketone) PEMs with ultra-densely sulfonic-acid-functionalized pendants linked by flexible alkyl chains, namely, SL-SPEK-x(where x represents the molar ratio of the novel monomer containing multiple phenyl side chain to the bisfluoride monomers). The delicate structural design rendered SL-SPEK-x membranes with high crystallinity and well-defined nanoscale phase separation between hydrophilic and hydrophobic phases. The reinforcement from poly(ether ketone) crystals enabled membranes with inhibited dimensional variation and methanol penetration. Furthermore, microphase separation significantly enhanced proton conductivity. The SL-SPEK-12.5 membrane achieved the optimum trade-off between proton conductivity(0.182 S cm^(-1), 80 ℃), water swelling(13.6%, 80 ℃), and methanol permeability(1.6 × 10^(-7)cm~2 s^(-1)). The DMFC assembled by the SL-SPEK-12.5 membrane operated smoothly with a 10 M methanol solution, outputting a maximum power density of 158.3 mW cm^(-2), nearly twice that of Nafion 117(94.2 mW cm^(-2)). Overall, the novel structural optimization strategy provides the possibility of PEMs surviving in high-concentration methanol solutions, thus facilitating the miniaturization and portability of DMFC devices.

Advanced Nonflammable Localized High-Concentration Electrolyte For High Energy Density Lithium Battery

The key to realize long-life high energy density lithium batteries is to exploit functional electrolytes capable of stabilizing both high voltage cathode and lithium anode.The emergence of localized high-concentration electrolytes(LHCEs)shows great promise for ameliorating the above-mentioned interfacial issues.In this work,a lithium difluoro(oxalate)borate(LiDFOB)based nonflammable dual-anion LHCE is designed and prepared.Dissolving in the mixture of trimethyl phosphate(TMP)/1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropylether(D_(2)),the continuously consumption of LiDFOB is suppressed by simply introducing lithium nitrate(LiNO_(3)).Meantime,as most of the TMP molecular are coordinated with Li^(+),the electrolyte does not show incompatibility issue between neither metal lithium nor graphite anode.Therefore,it demonstrates excellent capability in stabilizing the interface of Ni-rich cathode and regulating lithium deposition morphology.The Li||LiNi_(0.87)Co_(0.08)Mn_(0.05)O_(2)(NCM87)batteries exhibit high capacity retention of more than 90%after 200 cycles even under the high cutoff voltage of 4.5 V,1 C rate.This study offers a prospective method to develop safe electrolytes suitable for high voltage applications,thus providing higher energy densities.

New SOI power device with multi-region high-concentration fixed interface charge and the model of breakdown voltage

A new SOI power device with multi-region high-concentration fixed charge（MHFC） is reported. The MHFC is formed through implanting Cs or I ion into the buried oxide layer（BOX）, by which the high-concentration dynamic electrons and holes are induced at the top and bottom interfaces of BOX. The inversion holes can enhance the vertical electric field and raise the breakdown voltage since the drain bias is mainly generated from the BOX. A model of breakdown voltage is developed, from which the optimal spacing has also been obtained. The numerical results indicate that the breakdown voltage of device proposed is increased by 287% in comparison to that of conventional LDMOS.

Localized high-concentration electrolytes for lithium metal batteries:progress and prospect

With the increasing development of digital devices and electric vehicles,high energy-density rechargeable batteries are strongly required.As one of the most promising anode materials with an ultrahigh specific capacity and extremely low electrode potential,lithium metal is greatly considered an ideal candidate for nextgeneration battery systems.Nevertheless,limited Coulombic efficiency and potential safety risks severely hinder the practical applications of lithium metal batteries due to the inevitable growth of lithium dendrites and poor interface stability.Tremendous efforts have been explored to address these challenges,mainly focusing on the design of novel electrolytes.Here,we provide an overview of the recent developments of localized high-concentration electrolytes in lithium metal batteries.Firstly,the solvation structures and physicochemical properties of localized high-concentration electrolytes are analyzed.Then,the developments of localized high-concentration electrolytes to suppress the formation of dendritic lithium,broaden the voltage window of electrolytes,enhance safety,and render low-temperature operation for robust lithium metal batteries are discussed.Lastly,the remaining challenges and further possible research directions for localized highconcentration electrolytes are outlined,which can promisingly render the practical applications of lithium metal batteries.

Hybrid diluents enable localized high-concentration electrolyte with balanced performance for high-voltage lithium-metal batteries

Localized high-concentration electrolytes(LHCE) have shown good compatibility with high-voltage lithium(Li)-metal batteries, but their practicality is yet to be proved in terms of cost and safety. Here we develop a hybrid-LHCE with favorable integrated properties by combining the merits of two representative diluents, fluorobenzene(FB) and 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether(TFE). Specifically,the extremely cheap and lightweight FB significantly reduces the cost and density of electrolyte, while the fire-retardant TFE circumvents the flammable nature of FB and thus greatly improves the safety of electrolyte. Moreover, the FB–TFE mixture enhances the thermodynamic stability of hybrid-LHCE and renders a controllable defluorination of FB, contributing to the formation of a thin and durable inorganic-rich solid electrolyte interphase(SEI) with rapid ion-transport kinetics. Benefiting from the designed hybridLHCE, a Li|NCM523 battery demonstrates excellent cycling performance(215 cycles, 91% capacity retention) under challenging conditions of thin Li-anode(30 μm) and high cathode loading(3.5 m Ah/cm^(2)).

Interfacial high-concentration electrolyte for stable lithium metal anode:Theory,design,and demonstration

Lithium metal anodes hold great potential for high-energy-density secondary batteries.However,the uncontrollable lithium dendrite growth causes poor cycling efficiency and severe safety concerns,hindering lithium metal anode from practical application.Electrolyte components play important roles in suppressing lithium dendrite growth and improving the electrochemical performance of long-life lithium metal anode,and it is still challenging to effectively compromise the advantages of the conventional electrolyte(1 mol·L^(−1)salts)and high-concentration electrolyte(>3 mol·L^(−1)salts)for the optimizing electrochemical performance.Herein,we propose and design an interfacial high-concentration electrolyte induced by the nitrogen-and oxygen-doped carbon nanosheets(NO-CNS)for stable Li metal anodes.The NO-CNS with abundant surface negative charges not only creates an interfacial high-concentration of lithium ions near the electrode surface to promote chargetransfer kinetics but also enables a high ionic conductivity in the bulk electrolyte to improve ionic mass-transfer.Benefitting from the interfacial high-concentration electrolyte,the NO-CNS@Ni foam host presents outstanding electrochemical cycling performances over 600 cycles at 1 mA·cm^(−2) and an improved cycling lifespan of 1,500 h for symmetric cells.

Effects of Different Grinding Methods on the Quality of Soybean Bean Milk

[Objectives] This study was conducted to improve the nutritional value of soybean milk, enrich the variety and taste of soybean milk, and find healthy food that is more conducive to people s nutritional needs. [Methods] Whole soybean milk was prepared by grinding with a grinding wheel at a low concentration (low-concentration grinding) and a stainless steel mill at a high concentration (high-concentration grinding). The sensory, physical and chemical characteristics and anti-nutritional factors of whole soybean milk produced by different grinding methods were studied. [Results] Compared with low-concentration grinding, the protein content in soybean milk prepared by high-concentration grinding increased by 24%, and the dietary fiber content increased by 74.7%. Before and after high-pressure homogenization, the particle size D(4, 3) of soybean milk prepared by low-concentration grinding was 212.1 and 93.59 μm, respectively, and the particle size D(4, 3) of soybean milk prepared by high-concentration grinding was 134.0 and 64.64 μm, respectively. The trypsin inhibitor activity and phytic acid content of soybean milk prepared by high-concentration grinding were significantly lower than those of soybean milk prepared by low-concentration grinding. [Conclusions] This study improves the diet structure of the broad masses of people, strengthens people s physique, and provides a new idea for the implementation and development of China s "Soybean Action Programme".

Experimental Study on Treatment of High-concentrated Sulfur Wastewater by Process of Depositing Natrojarosite and Its Environmental Significance

High-concentrated sulfur wastewater with sodium and COD （chemical oxygen demand） up to 26000 mg/L from a chemical plant, Jiangsu Province of China has been treated by deposition of natrojarosite in lab. The results indicated that the COD of the wastewater was decreased sharply from 26000 mg/L to 1001 mg/L, with removal rate of COD up to 96% by twice precipitations of natrojarosite and twice oxidation of H202. The treated sulfur wastewater reached the requirement of subsequent biochemical treatment to water quality. The optimal operational parameters should be controlled on pH value between 2.50 and 3.20 and 50 g FeCly6H2O solid added in per liter wastewater. The study provided an experimental basis for pretreatment of high-concentrated sulfur wastewater and proposed a new mineralogical method on treatment of other wastewaters. Depositing process of jarosite and its analogs should be able to be used to treat wastewater from mine and other industries to remove S, Fe and other toxic and harmful elements, such as As, Cr, Hg, Pb, etc. in the water.

Outstanding performances of graphite||NMC622 pouch cells enabled by a non-inert diluent

Although high salt concentration electrolyte(HCE)can construct effective Li F-rich interphase film and solve the interphasial instability issue of graphite anode,its high cost,high viscosity and poor wettability with electrode materials limit its large-scale application.Generally,localized high concentration electrolyte(LHCE)is obtained by introducing an electrochemically inert diluent into HCE to avoid the above-mentioned problems while maintaining the high interphasial stability of HCE with graphite anode.Unlike traditional inert diluents,1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluropropyl ether(TTE)with electrochemical activity is introduced into propylene carbonate(PC)-based HCE to obtain LHCE-2(1 M LiPF_(6),PC:DMC:TTE=1:1:6.1)herein.Experimental and theoretical simulation results show that TTE participates in the oxidation decomposition and film-forming reaction at the NCM622 cathode surface,conducting a cathode electrolyte interphase(CEI)rich in organic fluorides with excellent electron insulation ability,high structural stability and low interphasial impedance.Thanks to the outstanding interphasial properties induced by LHCE-2,the graphite||NMC622 pouch cell reaches a capacity retention of 80%after 500 cycles at 1 C under room temperature.While at sub-zero temperatures,the capacity released by the cell with LHCE-2 electrolyte is significantly higher than that of HCE and conventional EC-based electrolytes.Meanwhile,the LHCE-2 electrolyte inherits the advantages of TTE flame-resistant,thus improving the safety of the battery.

Diluent decomposition-assisted formation of Li F-rich solid-electrolyte interfaces enables high-energy Li-metal batteries

Passivation by the inorganic-rich solid electrolyte interphase(SEI),especially the LiF-rich SEI,is highly desirable to guarantee the durable lifespan of Li metal batteries(LMBs).Here,we report a diluent with the capability to facilitate the formation of LiF-rich SEI while avoiding the excess consumption of Li salts.Dissimilar to most of reported inert diluents,heptafluoro-l-methoxypropane(HM) is firstly demonstrated to cooperate with the decomposition of anions to generate LiF-rich SEI via releasing Fcontaining species near Li surface.The designed electrolyte consisting of 1.8 M LiFSI in the mixture of1,2-dimethoxyethane(DME)/HM(2:1 by vol.) achieves excellent compatibility with both Li metal anodes(Coulombic efficiency~99.8%) and high-voltage cathodes(4.4 V LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)(NMC811) and 4.5 V LiCoO_(2)(LCO) vs Li^(+)/Li).The 4.4 V Li(20μm)‖NMC811(2.5 mA h cm^(-2)) and 4.5 V Li(20μm)‖LCO(2.5 mA h cm^(-2)) cells achieve capacity retentions of 80% over 560 cycles and 80% over 505 cycles,respectively.Meanwhile,the anode-free pouch cell delivers an energy density of~293 W h kg^(-1)initially and retains 70% of capacity after 100 deep cycles.This work highlights the critical impact of diluent on the SEI formation,and opens up a new direction for designing desirable interfacial chemistries to enable high-performance LMBs.

Life cycle assessment of high concentration organic wastewater treatment by catalytic wet air oxidation

There have been many studies on life cycle assessment in sewage treatment,but there are scarce few studies on the treatment of industrial wastewater in combination with advanced oxidation technology,especially in catalytic wet air oxidation(CWAO).There are no cases of using actual industrialized data onto life cycle assessment.This paper uses Simapro 9.0 software to establish a life cycle assessment model for the treatment of high-concentration organic wastewater by CWAO,and comprehensively explains the impact on the environment from three aspects:the construction phase,the operation phase and the demolition phase.In addition,sensitivity analysis and uncertainty analysis were performed.The results showed that the key factors affecting the environment were marine ecotoxicity,mineral resource consumption and global warming,the operation stage had the greatest impact on the environment,which was related to high power consumption during operation and emissions from the treatment process.Sensitivity analysis showed that electricity consumption has the greatest impact on abiotic depletion and freshwater aquatic ecotoxicity,and it also proved that global warming is mainly caused by pollutant emissions during operation phase.Monte Carlo simulations found slightly higher uncertainty for abiotic depletion and toxicity-related impact categories.

High-Con cent rat ion Electrosynthesis of Formic Acid/Formate from CO_(2):Reactor and Electrode Design Strategies

The electrochemical CO_(2)reduction reaction(CO_(2)RR),driven by renewable energy,provides a potential carbon-neutral avenue to convert CO_(2)into valuable fuels and feedstocks.Conversion of CO_(2)into formic acid/formate is considered one of the economical and feasible methods,owing to their high energy densities,and ease of distribution and storage.The separation of formic acid/formate from the reaction mixtures accounts for the majority of the overall CO_(2)RR process cost,while the increment of product concentration can lead to the reduction of separation cost,remarkably.In this paper,we give an overview of recent strategies for highly concentrated formic acid/formate products in CO_(2)RR.CO_(2)RR is a complex process with several different products,as it has different intermediates and reaction pathways.Therefore,this review focuses on recent study strategies that can enhance targeted formic acid/formate yield,such as the all-solid-state reactor design to deliver a high concentration of products during the reduction of CO_(2)in the electrolyzer.Firstly,some novel electrolyzers are introduced as an engineering strategy to improve the concentration of the formic acid/formate and reduce the cost of downstream separations.Also,the design of planar and gas diffusion electrodes(GDEs)with the potential to deliver high-concentration formic acid/formate in CO_(2)RR is summarized.Finally,the existing technological challenges are highlighted,and further research recommendations to achieve high-concentration products in CO_(2)RR.This review can provide some inspiration for future research to further improve the product concentration and economic benefits of CO_(2)RR.

Coordinated response of milk bacterial and metabolic profiles to subacute ruminal acidosis in lactating dairy cows

Background Bovine milk is an important source of nutrition for human consumption,and its quality is closely associated with the microbiota and metabolites in it.But there is limited knowledge about the milk microbiome and metabolome in cows with subacute ruminal acidosis.Methods Eight ruminally cannulated Holstein cows in mid lactation were selected for a 3-week experiment.The cows were randomly allocated into 2 groups,fed either a conventional diet(CON;40%concentrate;dry matter basis)or a high-concentrate diet(HC;60%concentrate;dry matter basis).Results The results showed that there was a decreased milk fat percentage in the HC group compared to the CON group.The amplicon sequencing results indicated that the alpha diversity indices were not affected by the HC feeding.At the phylum level,the milk bacteria were dominated by Proteobacteria,Actinobacteria,Bacteroidetes,and Firmicutes both in the CON and HC groups.At the genus level,the HC cows displayed an improved proportion of Labrys(P=0.015)compared with the CON cows.Results of both the principal components analysis and partial least squares of discriminant analysis of milk metabolome revealed that samples of the CON and HC groups clustered separately.A total of 31 differential metabolites were identified between the two groups.Of these,the levels of 11 metabolites decreased(α-linolenic acid,prostaglandin E2,L-lactic acid,L-malic acid,3-hydroxysebacic acid,succinyladenosine,guanosine,pyridoxal,L-glutamic acid,hippuric acid,and trigonelline),whereas the levels of the other 20 metabolites increased in the HC group with respect to the CON group(P<0.05).Conclusion These results suggested that subacute ruminal acidosis less impacted the diversity and composition of milk microbiota,but altered the milk metabolic profiles,which led to the decline of the milk quality.

A high-concentrated and nonflammable electrolyte for potassium ion-based dual-graphite batteries

Potassium ion-based dual-graphite batteries(KDGBs)emerge as promising devices for large-scale applications due to their high voltage,low cost,environmental friendliness.However,conventional KPF6/carbonate-based electrolytes suffer from severe oxidation decomposition,low concentration,flammability,which limit the capacity and cyclability of KDGBs.Herein,a nonflammable potassium bis(fluorosulfonyl)imide/triethyl phosphate(KFSI/TEP)electrolyte was designed for KDGBs.When the salt-to-solvent molar ratio increases to 1:1.3,graphite cathode operated at the cut-off potential of 5.2 V exhibits much enhanced capacity,excellent rate capability(26.4 mAh∙g^(−1) at 1.0 A∙g^(−1)),superior cyclability with 98%capacity retention after 350 cycles.Inorganic compounds-rich electrode/electrolyte interphase layers derived from the preferential decomposition of FSI−anions ensure good compatibility of the 1:1.3 KFSI/TEP electrolyte with K metal and graphite anodes.Based on this electrolyte,asassembled KDGBs show high operation voltage of 4.3 V and good cycling performance.This work provides feasibility for developing long-life and safe-operation DGBs.

Niacin alters the ruminal microbial composition of cattle under high-concentrate condition

To understand the effects of niacin on the ruminal microbial ecology of cattle under high-concentrate diet condition, Illumina MiSeq sequencing technology was used. Three cattle with rumen cannula were used in a 3 x 3 Latin-square design trial. Three diets were fed to these cattle during 3 periods for 3 days, respectively: high-forage diet(HF; forage-to-concentrate ratio = 80:20), high-concentrate diet(HC;forage-to-concentrate ratio=20:80), and HC supplemented with 800 mg/kg niacin(HCN). Ruminal pH was measured before feeding and every 2 h after initiating feeding. Ruminal fluid was sampled at the end of each period for microbial DNA extraction. Overall, our findings revealed that subacute ruminal acidosis(SARA) was induced and the a-diversity of ruminal bacterial community decreased in the cattle of HC group. Adding niacin in HC could relieve the symptoms of SARA in the cattle but the ruminal pH value and the Shannon index of ruminal bacterial community of HCN group were still lower than those of HF group. Whatever the diet was, the ruminal bacterial community of cattle was dominated by Bacteroidetes,Firmicutes and Proteobacteria. High-concentrate diet significantly increased the abundance of Prevotella,and decreased the abundance of Paraprevotella, Sporobacter, Ruminococcus and Treponema than HF.Compared with HC, HCN had a trend to decrease the percentage of Prevotella, and to increase the abundance of Succiniclasticum, Acetivibrio and Treponema. Increasing concentrate ratio could decrease ruminal pH value, and change the ruminal microbial composition. Adding niacin in HC could increase the ruminal pH value, alter the ruminal microbial composition.

Lithium deposition behavior in hard carbon hosts:Optical microscopy and scanning electron microscopy study

Lithium(Li)metal is an ideal anode for the next generation high-energy-density batteries.However,it suffers from dendrite growth,side reactions,and infinite relative volume change.Effective strategies are using porous carbons or surface modification carbons to guide Li deposition into their pores.While the Li deposition behavior is still ambiguous.Here,we systematically determine their deposition behavior in various surface-modified carbons and in different electrolytes via optical microscopy and scanning electron microscopy study.It is found that Li will not spontaneously deposit into the carbon pores,which is significantly dependent on the carbon surface,current density,areal capacity,and electrolyte.Thus,a“lithiophilic”modified commercial hard carbon with Ag is developed as a stable“host”and efficient surface protection derived from the localized high-concentration electrolyte exhibits a pretty low volume change(5.3%)during cycling at a current density of 2 mA·cm^(−2)and an areal capacity of 2 mAh·cm^(−2).This strategy addresses the volume change and dendrite problems by rationally designed host and electrolyte,providing a broad perspective for realizing Li-metal anode.

Advanced flame-retardant electrolyte for highly stabilized K-ion storage in graphite anode

Although graphite anodes operated with representative de/intercalation patterns at low potentials are considered highly desirable for K-ion batteries,the severe capacity fading caused by consecutive reduction reactions on the aggressively reactive surface is inevitable given the scarcity of effective protecting layers.Herein,by introducing a flame-retardant localized high-concentration electrolyte with retentive solvation configuration and relatively weakened anion-coordination and non-solvating fluorinated ether,the rational solid electrolyte interphase characterized by well-balanced inorganic/organic components is tailored in situ.This effectively prevented solvents from excessively decomposing and simultaneously improved the resistance against K-ion transport.Consequently,the graphite anode retained a prolonged cycling capability of up to 1400 cycles(245 mA h g,remaining above 12 mon)with an excellent capacity retention of as high as 92.4%.This is superior to those of conventional and high-concentration electrolytes.Thus,the optimized electrolyte with moderate salt concentration is perfectly compatible with graphite,providing a potential application prospect for K-storage evolution.