Viability of all-solid-state lithium metal battery coupled with oxide solid-state electrolyte and high-capacity cathode

Owing to the utilization of lithium metal as anode with the ultrahigh theoretical capacity density of 3860 mA h g^(-1)and oxide-based ceramic solid-state electrolytes(SE),e.g.,garnet-type Li7La_(3)Zr_(2)O_(12)(LLZO),all-state-state lithium metal batteries(ASLMBs)have been widely accepted as the promising alternatives for providing the satisfactory energy density and safety.However,its applications are still challenged by plenty of technical and scientific issues.In this contribution,the co-sintering temperature at 500℃is proved as a compromise method to fabricate the composite cathode with structural integrity and declined capacity fading of LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2)(NCM).On the other hand,it tends to form weaker grain boundary(GB)inside polycrystalline LLZO at inadequate sintering temperature for LLZO,which can induce the intergranular failure of SE during the growth of Li filament inside the unavoidable defect on the interface of SE.Therefore,increasing the strength of GB,refining the grain to 0.4μm,and precluding the interfacial defect are suggested to postpone the electro-chemo-mechanical failure of SE with weak GB.Moreover,the advanced sintering techniques to lower the co-sintering temperature for both NCM-LLZO composite cathode and LLZO SE can be posted out to realize the viability of state-of-the-art ASLMBs with higher energy density as well as the guaranteed safety.

Reinforced interface endows the lithium anode with stable cycle at high-temperature of 80℃

Embracing ultrahigh theoretical capacity of 3860 mA h g^(-1)and the lowest reduction potential of-3.04 V(versus standard hydrogen electrode),lithium(Li) is considered as the "holy grail" material for pursuing higher energy density,of which application has been challenged due to the unstable interface caused by the non-uniform electrodeposition as well as high chemical activity.Operating at higher temperature can be recommended to uniform electrodeposition of Li metal.Nevertheless,the intrinsic side-reaction between Li metal anode and electrolyte is inevitably aggravated and thus fosters the failure of Li metal anode rapidly with uneven electrodeposition.Here,a kind of temperature-tolerated ionic liquid(1-methyl-3-ethylimidazole bis(fluorosulfo nyl)imide/lithium bis(trifluoromethylsulfo nyl)imide,EF/LT)based electrolyte that matrixed with poly(vinylidene fluoride-hexafluoropropylene) was designed to maintain the interfacial stabilization of Li metal due to the weak interfacial reaction and uniform electrodeposition at high temperature of 80℃.It is the matter that the 660-h cycle with lower polarization is achieved with EF/LT-based electrolyte at temperature of 80 ℃ and the full cell embraces outstanding cyclic performance,without capacity fading within 100 cycles.Delighting,a door for practical application of Li metal anode for higher energy density as the carbon neutrality progresses in the blooming human society has been opened gradually.

Electro-chemo-mechanical design of polymer matrix in composited LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) cathode endows solid-state batteries with superior performance

Nickel-rich LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811) cathode material has been widely concerned due to its high voltage,high specific capacity and excellent rate performance,which is considered as one of the most promising cathode materials for the next generation of high-energy-density solid-state lithium batteries.However,serious electro-chemo-mechanical degradation of Nickel-rich cathode during cycling,especially at a high voltage(over 4.5 V),constrains their large-scale application.Here,using the multiphysical simulation,highly-conductive polymer matrix with spontaneous stress-buffering effect was uncovered theoretically for reinforcing the electrochemical performance of composited NCM81 1 cathode through the visualization of uniform concentration distribution of Li-ion coupled with improved stress field inside NCM811 cathode.Thereupon,polyacrylonitrile(PAN) and soft polyvinylidene fluoride(PVDF) were selected as the polymer matrix to fabricate the composited NCM811 cathode(PVDFPAN@NCM811) for improving the electrochemical performance of the solid-state NMC811|Li full cells,which can maintain high capacity over 146.2 mA h g^(-1)after 200 cycles at a high voltage of 4.5 V.Suggestively,designing a multifunctional polymer matrix with high ionic conductivity and mechanical property can buffer the stress and maintain the integrity of the structure,which can be regarded as the door-opening avenue to realize the high electrochemical performance of Ni-rich cathode for solidstate batteries.

The impact of water quality on the formation of halogenated benzoquinones and the adsorption efficiency by activated carbon

Halogenated benzoquinones(HBQs)could cause bladder cancer,but there were few related studies on the generation and control.In this study,the impact of different precursors,pH,bromide concentration,and algae-derived organic matters on the formation of HBQs and the removal efficiency by activated carbon were investigated.It was found that the chlorination of bisphenol A produced the most 2,6-dichloro-1,4-benzoquinone(2,6-DCBQ),reaching 14.86μg/L at 1 hr,followed by tyrosine,2-chlorophenol,P-hydroxybenzoic acid,trichlorophenol,and N-methylaniline.The production of 2,6-DCBQ increased first and then decreased from 0 to 36 hr(chlorination doses 0-20 mg/L),indicating that HBQs were unstable in water.Trihalomethanes(THMs)were detected during chlorination,and the concentration increased with prolongation of reaction time.2,6-DCBQ production decreased and 2,6-dibromo-1,4-benzoquinone(2,6-DBBQ)production increased with increment bromide concentration and the bromide promoted the formation of tribromomethane.The production of 2,6-DCBQ decreased with increase of pH,and the maximum production was 141.38μg/L at pH of 5.Microcystis aeruginosa,Chlorella algae cells,and intracellular organic matters(IOM)could be chlorinated as potential precursors for HBQs.The most amount of 2,6-DCBQ was generated from algae cells of Microcystis aeruginosa,followed by Chlorella algae cells,Microcystis aeruginosa IOM,and Chlorella IOM.This study compared the removal efficiency of HBQs by granular activated carbon(GAC)and columnar activated carbon(CAC)under different carbon doses and initial concentrations of HBQs.It was found that the removal efficiency by GAC(80.1%)was higher than that by CAC(51.8%),indicating that GAC has better control for HBQs.

Carbonitride MXene Ti_(3)CN(OH)_(x)@MoS_(2)hybrids as efficient electrocatalyst for enhanced hydrogen evolution

Renewable energy powered electrocatalytic water splitting is a promising strategy for hydrogen generation,and the design and development of high-efficiency and earth-abundant electrocatalysts for hydrogen evolution reaction(HER)are highly desirable.Herein,MoS2 nanoflowers decorated two-dimensional carbonitride-based MXene Ti3CN(OH)x hybrids have been constructed by etching and post-hydrothermal methods.The electrochemical performance of the as-obtained Ti_(3)CN(OH)_(x)@MoS_(2)hybrids having a quasi core-shell structure is fascinating:An overpotential of 120 mV and a Tafel slope of 64 mV∙dec^(−1)can be delivered at a current density of 10 mA∙cm^(−2).And after 3,000 cyclic voltammetry cycles,it can be seen that there is no apparent attenuation.Both the experimental results and density functional theory(DFT)calculations indicate that the synergetic effects between Ti_(3)CN(OH)x and MoS_(2)are responsible for the robust electrochemical HER performance.The electrons of-OH group in Ti_(3)CN(OH)x are transferred to MoS_(2),making the adsorption energy of the composite for H almost vanish.The metallic Ti_(3)CN(OH)x is also beneficial to the fast charge transfer kinetics.The construction of MXene-based hybrids with optimal electronic structure and unique morphology tailored to the applications can be further used in other promising energy storage and conversion devices.

Characterization of disinfection byproduct formation potential in 13 source waters in China

The formation potential of four trihalomethanes （THMFP） and seven haloacetic acids （HAA7FP） in 13 source waters taken from four major water basin areas in China was evaluated using the simulated distribution system （SDS） chlorination method. The specific ultraviolet absorbance （SUVA254： the ratio of UV254 to dissolved organic carbon （DOC））, which ranged between 0.9 and 5.0 L/（mg.m）, showed that the organic compounds in different source waters exhibited different reactivities with chlorine. The HAA7FP of source waters ranged from 20 to 448 μg/L and the THMFP ranged from 29 to 259 μg/L. The HAA7FP concentrations were higher than the THMFP concentrations in all but one of the samples. Therefore, the risks of haloacetic acids （HAAs） should be of concern in some source waters. TCM （chloroform） and BDCM （bromodichloromethane） were the major THM constituents, while TCAA （trichloroacetic acid） and DCAA （dichloroacetic acid） were the major HAA species. Br-THM （brominated THM species） were much higher than Br- HAA （brominated HAA species）, and the formation of Br-DBP （Br-THM and Br-HAA） should be of concern when the bromide concentration is over 100 μg/L.

Advanced oxidation of bromide-containing drinking water: A balance between bromate and trihalomethane formation control

Addition of H2O2 has been employed to repress bromate formation during ozonation of bromide-containing source water. However, the addition of H2O2 will change the oxidation pathways of organic compounds due to the generation of abundant hydroxyl radicals, which could affect the removal efficacy of trihalomethane precursors via the combination of ozone and biological activated carbon （O3-BAC）. In this study, we evaluated the effects of H2O2 addition on bromate formation and trihalomethane formation potential （THMFP） reduction during treatment of bromide-containing （97.6-129.1 μg/L） source water by the O3-BAC process. At an ozone dose of 4.2 mg/L, an H2O2/O3 （g/g） ratio of over 1.0 was required to maintain the bromate concentration below 10.0 μg/L, while a much lower H2O2/O3 ratio was sufficient for a lower ozone dose. An H2O2/O3 （g/g） ratio below 0.3 should be avoided since the bromate concentration will increase with increasing H2O2 dose below this ratio. However, the addition of H2O2 at an ozone dose of 3.2 mg/L and an H2O2/O3 ratio of 1.0 resulted in a 43% decrease in THMFP removal when compared with the O3-BAC process. The optimum H2O2/O3 （g/g） ratio for balancing bromate and trihalomethane control was about 0.7-1.0. Fractionation of organic materials showed that the addition of H2O2 decreased the removal efficacy of the hydrophilic matter fraction of DOC by ozonation and increased the reactivity of the hydrophobic fractions during formation of trihalomethane, which may be the two main reasons responsible for the decrease in THMFP reduction efficacy. Overall, this study clearly demonstrated that it is necessary to balance bromate reduction and THMFP control when adopting an H2O2 addition strategy.

Addition of hydrogen peroxide for the simultaneous control of bromate and odor during advanced drinking water treatment using ozone

Complete removal of the characteristic septic/swampy odor from Huangpu River source water could only be achieved under an ozone dose as high as 4.0 mg/L in an ozone-biological activated carbon （O3- BAC） process, which would lead to the production of high concentrations of carcinogenic bromate due to the high bromide content. This study investigated the possibility of simultaneous control of bromate and the septic/swampy odor by adding H2O2 prior to the O3-BAC process for the treatment of Huangpu River water. H2O2 addition could reduce the bromate concentration effectively at an H2O2/O3 （g/g） ratio of 0.5 or higher. At the same time, the septic/swampy odor removal was enhanced by the addition of H2O2, although optimization of the H2O2/O3 ratio was required for each ozone dose. At an ozone dose of 2.0 mg/L, the odor was removed completely at an H2O2/O3 ratio of 0.5. The results indicated that H2O2 application at a suitable dose could enhance the removal of the septic/swampy odor while suppressing the formation of bromate during ozonation of Huangpu River source water.

Highly efficient and selective removal of low-concentration antibiotics from aqueous solution by regenerable Mg（OH）2

The prevalent presence of fluoroquinolone antibiotics in aquatic environments has attracted considerable attention because of their harmful effects on humans and the ecological environment.Magnesium hydroxide nanocrystals were found to act as a simple and effective adsorbent to remove low-concentration ciprofloxacin(CIP)in aqueous solution.The as-prepared Mg(OH)2 nanocrystals exhibited excellent CIP adsorption performance and high selectivity toward CIP molecules compared with other antibiotics or aromatics,e.g.,norfloxacin(NOR)and eosin B(EB).The adsorbent showed pH-dependent adsorption,indicating that the adsorption process is probably dominated by an electrostatic interaction mechanism.In addition,structural analysis of the adsorbent indicated that coordination and hydrogen bonding between CIP and Mg(OH)2 nanocrystal might also be involved in the adsorption process.Moreover,the adsorbent could be easily recovered by pyrolysis and hydration without significant reduction of adsorption capacity.The superior adsorption behavior of Mg(OH)2 nanocrystal indicates that it may serve as a potential adsorbent material candidate for the selective removal of CIP from aquatic environments.

Assembly of SPS/MgSi assisted by dopamine with excellent removal performance for ciprofloxacin

In this work,magnesium silicate-based sulfonated polystyrene sphere composites(SPS/MgSi)were synthesized by one-step(SMD1)and two-step(SMD2)methods.For SMD1,MgSi particles were densely assembled on the surface of SPS,assisted by complexation between Fe^3+and hydroxyl phenol.For SMD2,SPS/SiO2 was firstly obtained by the same method as SMD1,and then SPS/SiO2 was transformed directly to SPS/MgSi under hydrothermal conditions.Therefore,MgSi obtained by the two-step method had an interwoven structure.Compared to SPS,MgSi and SMD1,SMD2 presented a larger specific surface area and more negative surface charges.Therefore,SMD2 showed superior adsorption performance toward CIP with concentrations of 5,10 and 50 mg/L,and for 50 mg/L,the equilibrium adsorption capacity could reach 329.7 mg/g.The adsorption process is fast and can be described by the pseudo-second-order kinetic model.The relationship between pH value and Zeta potential demonstrated that electrostatic interaction dominated the adsorption process.In addition,competitive adsorption showed that the effect of Na^+was negligible but the effect of Ca^2+was dependent on its concentration.Humid acid(HA)could slightly promote the absorption of CIP by SMD2.After five rounds of adsorption-desorption,the equilibrium adsorption capacity of SMD2 still remained at 288.6 mg/L for 50 mg/L CIP.Notably,SMD2 presented likewise superior adsorption capacity for CIP with concentrations of 10 and 50 mg/L in Minjiang source water.All the results indicated that this synthesis method is universal and that SMD2 has potential as an adsorbent for CIP removal from aquatic environments.