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•High concentration MnCl2 electrolyte is applied in manganese-based flow batteries first time.•Amino acid additives promote the reversible Mn2+/MnO2 reaction without Cl2.•In-depth ...research on the impact mechanism at the molecular level.•The energy density of manganese-based flow batteries was expected to reach 176.88 Wh L-1.
Manganese-based flow batteries are attracting considerable attention due to their low cost and high safe. However, the usage of MnCl2 electrolytes with high solubility is limited by Mn3+ disproportionation and chlorine evolution reaction. Herein, the reversible Mn2+/MnO2 reaction without the generation of Mn3+ and Cl2 in the manganese-based flow batteries with the MnCl2 electrolyte is successfully achieved by adding amino acid additives. The effect and the function mechanism of a series of amino acid additives are discussed in detail via the experiment and theoretical calculation. Benefiting from the hydrogen bond between Cl- and amino acid, the chlorine evolution reaction is effectively avoided. In addition, the interaction of the Mn2+ and amino acid boosts the Mn2+/MnO2 reaction and inhibits the production of unstable Mn3+. As a result, the zinc-manganese flow battery with high-concentration MnCl2 electrolyte exhibits an outstanding performance of 82 % EE with a low capacity decay rate (1.45% per cycle over 1000 cycles) and wide temperature adaptability (from −10 ℃ to 65 ℃). This study opens a new opportunity for the application of flow batteries with high-concentration chloride electrolytes.
The criticality of cobalt (Co) has been motivating the quest for Co-free positive electrode materials for building lithium (Li)-ion batteries (LIBs). However, the LIBs based on Co-free positive ...electrode materials usually suffer from relatively fast capacity decay when coupled with conventional LiPF6-organocarbonate electrolytes. To address this issue, a 1,2-dimethoxyethane-based localized high-concentration electrolyte (LHCE) was developed and evaluated in a Co-free Li-ion cell chemistry (graphite||LiNi0.96Mg0.02Ti0.02O2). Extraordinary capacity retentions were achieved with the LHCE in coin cells (95.3%), single-layer pouch cells (79.4%), and high-capacity loading double-layer pouch cells (70.9%) after being operated within the voltage range of 2.5–4.4 V for 500 charge/discharge cycles. The capacity retentions of counterpart cells using the LiPF6-based conventional electrolyte only reached 61.1, 57.2, and 59.8%, respectively. Mechanistic studies reveal that the superior electrode/electrolyte interphases formed by the LHCE and the intrinsic chemical stability of the LHCE account for the excellent electrochemical performance in the Co-free Li-ion cells.
Lithium‐ion batteries with routine carbonate electrolytes cannot exhibit satisfactory fast‐charging performance and lithium plating is widely observed at low temperatures. Herein we demonstrate that ...a localized high‐concentration electrolyte consisting of 1.5 M lithium bis(fluorosulfonyl)imide in dimethoxyethane with bis(2,2,2‐trifluoroethyl) ether as the diluent, enables fast‐charging of working batteries. A uniform and robust solid electrolyte interphase (SEI) can be achieved on graphite surface through the preferential decomposition of anions. The established SEI can significantly inhibit ether solvent co‐intercalation into graphite and achieve highly reversible Li+ intercalation/de‐intercalation. The graphite | Li cells exhibit fast‐charging potential (340 mAh g−1 at 0.2 C and 220 mAh g−1 at 4 C), excellent cycling stability (ca. 85.5 % initial capacity retention for 200 cycles at 4 C), and impressive low‐temperature performance.
The unique solvation structure in a localized high‐concentration electrolyte can suppress co‐intercalation of ether solvent into the graphite interlayers and render fast‐charging of practical lithium‐ion batteries.
Silicon anodes with a high capacity of 4200 mAh g−1 and a low potential of 0.3 V (vs Li+/Li) enable lithium‐ion batteries with improved energy density. However, the thickened 3D solid‐electrolyte ...interphase (SEI) formation on Si particles in the liquid electrolytes consumes the electrolyte/active Si and blocks the Li+/e− transport, resulting in fast capacity fading. Herein, a high‐concentration polymer electrolyte (HCPE) is designed to build 2D SEI on the Si anode surface instead of the particles, which accommodates the volume change and maintains the continuous Li+/e− transport pathways as well. The retarding effect of NO3− lowers the polymerization rate of 1,3‐dioxolane (DOL), enabling 6 m LiFSI dissolution. The high concentration of LiFSI takes part in constructing the solvation structure and pulls the DOL away, reducing the decomposition of DOL and poly‐DOL (PDOL) and inducing the generation of a LiF‐ and Li3N‐rich SEI with high mechanical strength and fast Li+ transport capability. As a result, the cell using HCPE delivers a high capacity of 1765 mAh g−1 at 2C and maintains a high capacity of 2000 mAh g−1 after 100 cycles at 0.2C, which is superior to that of a liquid electrolyte (617 mAh g−1) and a low‐concentration polymer electrolyte (45 mAh g−1).
A high‐concentration polymer electrolyte (HCPE) with low flowability and high ionic conductivity is developed by retarding the ring‐opening polymerization of 1,3‐dioxolane (DOL) with a LiNO3 additive. The increased concentration of LiFSI in HCPE reduces the decomposition of DOL and helps induce the formation of a 2D inorganic‐rich solid‐electrolyte interphase, which accommodates the volume change and maintains the continuous Li+/e‐ transport pathways as well.
In order to solve the problems of short residence time and low diffusion of CO2 gas in microalgal solution, calcinated metal-organic framework MIL-100(Fe) were first used as CO2 adsorbents to promote ...the growth of Arthrospira platensis cells by increasing carbon fixation. The adsorbent (MIL-100(Fe)-4 h) containing unsaturated metal sites, improved the conversion of CO2 to dissolved inorganic carbon by 52.3% and concentration of HCO3– by 20.0% in culture medium, as compared to the medium without CO2 adsorbent added. The increased HCO3– concentration facilitated carboxysome accumulation (increased to 21.7 times) to activate the photosynthetic Calvin cycle in Arthrospira cells. The increased cell growth rate promoted cell volume by 132% and knot length by 102%, while the fractal dimension of the cell surface decreased by 13.5%. The biomass productivity of Arthrospira cells cultivated with the CO2 adsorbent MIL-100(Fe)-4 h remarkably increased by 81.9%.
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•Calcinated MIL-100(Fe) was used as a CO2 adsorbent to culture Arthrospira platensis.•The increased cHCO3− facilitated carboxysome accumulation to activate Calvin cycle.•The biomass yield of Arthrospira platensis with MIL-100(Fe)-4 h increased by 81.9%.
Lithium-metal anodes can theoretically enable 10× higher gravimetric capacity than conventional graphite anodes. However, Li-metal anode cycling has proven difficult due to porous and dendritic ...morphologies, extensive parasitic solid electrolyte interphase reactions, and formation of dead Li. We systematically investigate the effects of applied interfacial pressure on Li-metal anode cycling performance and morphology in the recently developed and highly efficient 4 M lithium bis(fluorosulfonyl)imide in 1,2-dimethoxyethane electrolyte. We present cycling, morphology, and impedance data at a current density of 0.5 mA/cm2 and a capacity of 2 mAh/cm2 at applied interfacial pressures of 0, 0.01, 0.1, 1, and 10 MPa. Cryo-focused ion beam milling and cryo-scanning electron microscopy imaging in cross section reveal that increasing the applied pressure during Li deposition from 0 to 10 MPa leads to greater than a fivefold reduction in thickness (and therefore volume) of the deposited Li. This suggests that pressure during cycling can have a profound impact on the practical volumetric energy density for Li-metal anodes. A “goldilocks zone” of cell performance is observed at intermediate pressures of 0.1–1 MPa. Increasing pressure from 0 to 1 MPa generally improves cell-to-cell reproducibility, cycling stability, and Coulombic efficiency. However, the highest pressure (10 MPa) results in high cell overpotential and evidence of soft short circuits, which likely result from transport limitations associated with increased pressure causing local pore closure in the separator. All cells exhibit at least some signs of cycling instability after 50 cycles when cycled to 2 mAh/cm2 with thin 50 μm Li counter electrodes, though instability decreases with increasing pressure. In contrast, cells cycled to only 1 mAh/cm2 perform well for 50 cycles, indicating that capacity plays an important role in cycling stability.
Localized high‐concentration electrolyte (LHCE) is considered to be a promising substitution for the conventional carbonate electrolytes in fast‐charging Li‐ion batteries. However, the ...rate‐determining steps (RDS) for fast‐charging electrodes (i.e., graphite anode) in LHCE remain unclear. Herein, a typical localized high‐concentration electrolyte consisting of lithium bis(fluorosulfonyl)imide in dimethoxyethane with 1,1,2,2‐tetrafluoroethyl‐2,2,3,3‐tetrafluoropropyl ether as a diluent is selected to investigate the RDS of lithiation process in graphite anode, including the diffusion of solvated Li+ in the electrolyte, the desolvation behavior of solvated Li+, the Li+ transfer in solid electrolyte interphase (SEI) on the graphite surface, and the Li+ diffusion in bulk graphite. The results indicated that the rate performance of graphite anode in LHCE lies in the balance between Li+ desolvation process and Li+ migration in SEI. Through the regulation of solvated Li+ structure and SEI component, excellent fast‐charging performance can be obtained in the LHCE. The present studies not only offer fresh insights in the mechanistic understanding of fast‐charging batteries, but also provide new clues to the performance improvement of graphite anodes.
Localized high‐concentration electrolytes (LHCEs) with varying concentrations are designed to investigate the rate‐determining steps (RDSs) in the lithiation process of graphite anodes. It is revealed that the desolvation of solvated Li+ and the Li+ transfer in solid electrolyte interphase (SEI) are the RDSs for fast‐charging of graphite. This study provides new insights into electrolyte design for the fast‐charging lithium‐ion batteries.
Tailored by flame-retardant, localized high-concentration electrolyte with relatively weakened anion-involved configuration and non-solvating fluorinated ether, the robust solid electrolyte ...interphase featuring well-balanced inorganic/organic components with lower resistance against K-ion transport is constructed, significantly enhancing long-term cyclic stability of K-storage in graphite.
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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 1400cycles (245 mA h g−1, remaining above 12mon) 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.
Photocatalysis technology has been proved to be a promising strategy to eliminate antibiotic pollution from wastewater, in spite of arduous challenges such as insufficient utilization of sunlight, ...high recombination of photogenerated charges, low efficiency of high-concentration antibiotics, and infrequent investigation on new antibiotics. Herein, we synthesized a visible-light-driven (VLD) photocatalyst by modifying dodecyl benzene sulfonate (DBS) onto graphitic carbon nitride nanosheet (CNNS), and studied its photocatalytic performance for removing high-concentration moxifloxacin (MOX), a fourth-generation quinolone antibiotic. Compared with other studies (Table S1), this catalyst broke through the bottleneck of degradation of high concentration MOX, which could remove 100 mg L−1 MOX under 30 min of irradiation. The hydrophobic dodecyl benzene group and the formed sulfonyl group with strong electron-withdrawing property were beneficial to boost the MOX enrichment from the bulk solution and suppress the recombination of photogenerated charges. The effect of pH value, MOX concentration and photocatalyst dosage was also studied in order to explore the best photocatalytic reaction condition. The superior photocatalytic durability and practical application prospects of DBS/CNNS were also demonstrated. By revealing the band structure of the DBS/CNNS hybrid, as well as the active species and the intermediate products generated in the photocatalytic process, a plausible photocatalytic mechanism was proposed. This study indicates that the DBS/CNNS hybrid is a potential VLD photocatalyst for efficient elimination of high-concentration antibiotics in wastewater.
•Dodecyl benzene sulfonate was firstly grafted onto g-C3N4 nanosheet.•Electron-withdrawing effect was promoted by sulfonyl.•Pollutants enriched by hydrophobic dodecyl benzene group.•Photocatalytic degradation of high-concentration moxifloxacin.•Excellent photocatalytic stability for multiple uses.
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