Aqueous Zn batteries are promising energy storage devices for large-scale energy-storage due to low cost and high energy density. However, their lifespan is limited by the water decomposition and Zn ...dendrite growth. Here, we suppress water reduction and Zn dendrite growth in dilute aqueous electrolyte by adding dimethyl sulfoxide (DMSO) into ZnCl2–H2O, in which DMSO replaces the H2O in Zn2+ solvation sheath due to a higher Gutmann donor number (29.8) of DMSO than that (18) of H2O. The preferential solvation of DMSO with Zn2+ and strong H2O–DMSO interaction inhibit the decomposition of solvated H2O. In addition, the decomposition of solvated DMSO forms Zn12(SO4)3Cl3(OH)15·5H2O, ZnSO3, and ZnS enriched-solid electrolyte interphase (SEI) preventing Zn dendrite and further suppressing water decomposition. The ZnCl2–H2O–DMSO electrolyte enables Zn anodes in Zn||Ti half-cell to achieve a high average Coulombic efficiency of 99.5% for 400 cycles (400 h), and the Zn||MnO2 full cell with a low capacity ratio of Zn:MnO2 at 2:1 to deliver a high energy density of 212 Wh/kg (based on both cathode and anode) and maitain 95.3% of the capacity over 500 cycles at 8 C.
Due to the non-flammable nature of water-based electrolytes, aqueous lithium-ion batteries are resistant to catching fire. However, they are not immune to the risk of explosion, since the sealing ...structure adopted by current batteries limits the dissipation of heat and pressure within the cells. Here, we report a safe aqueous lithium-ion battery with an open configuration using water-in-salt electrolytes and aluminum oxide coated anodes. The design can inhibit the self-discharge by substantially suppressing the oxygen reduction reaction on lithiated anodes and enable good cycle performance over 1000 times. Our study may open a pathway towards safer lithium-ion battery designs.
Lithium (Li) metal is a promising candidate as the anode for high‐energy‐density solid‐state batteries. However, interface issues, including large interfacial resistance and the generation of Li ...dendrites, have always frustrated the attempt to commercialize solid‐state Li metal batteries (SSLBs). Here, it is reported that infusing garnet‐type solid electrolytes (GSEs) with the air‐stable electrolyte Li3PO4 (LPO) dramatically reduces the interfacial resistance to ≈1 Ω cm2 and achieves a high critical current density of 2.2 mA cm−2 under ambient conditions due to the enhanced interfacial stability to the Li metal anode. The coated and infused LPO electrolytes not only improve the mechanical strength and Li‐ion conductivity of the grain boundaries, but also form a stable Li‐ion conductive but electron‐insulating LPO‐derived solid‐electrolyte interphase between the Li metal and the GSE. Consequently, the growth of Li dendrites is eliminated and the direct reduction of the GSE by Li metal over a long cycle life is prevented. This interface engineering approach together with grain‐boundary modification on GSEs represents a promising strategy to revolutionize the anode–electrolyte interface chemistry for SSLBs and provides a new design strategy for other types of solid‐state batteries.
Li3PO4‐infused Li6.5La3Zr1.5Ta0.5O12 via atomic layer deposition with simple annealing is demonstrated to have excellent moisture stability and interfacial stability to a lithium anode by presenting negligible interfacial resistance (≈1 Ω cm2) and a record‐high critical current density of 2.2 mA cm−2 at ambient conditions. This new surface/subsurface engineering approach stabilizes the anode–electrolyte interface for solid‐state batteries.
High‐Energy Aqueous Sodium‐Ion Batteries Jin, Ting; Ji, Xiao; Wang, Peng‐Fei ...
Angewandte Chemie International Edition,
May 17, 2021, Volume:
60, Issue:
21
Journal Article
Peer reviewed
Water‐in‐salt electrolytes (WISE) have largely widened the electrochemical stability window (ESW) of aqueous electrolytes by formation of passivating solid electrolyte interphase (SEI) on anode and ...also absorption of the hydrophobic anion‐rich double layer on cathode. However, the cathodic limiting potential of WISE is still too high for most high‐capacity anodes in aqueous sodium‐ion batteries (ASIBs), and the cost of WISE is also too high for practical application. Herein, a low‐cost 19 m (m: mol kg−1) bi‐salts WISE with a wide ESW of 2.8 V was designed, where the low‐cost 17 m NaClO4 extends the anodic limiting potential to 4.4 V, while the fluorine‐containing salt (2 m NaOTF) extends the cathodic limiting potential to 1.6 V by forming the NaF–Na2O–NaOH SEI on anode. The 19 m NaClO4–NaOTF–H2O electrolyte enables a 1.75 V Na3V2(PO4)3∥Na3V2(PO4)3 full cell to deliver an appreciable energy density of 70 Wh kg−1 at 1 C with a capacity retention of 87.5 % after 100 cycles.
A NaClO4/NaOTF electrolyte was designed for aqueous Na‐ion batteries (ASIBs). The solid electrolyte interphase (SEI) containing NaF–Na2O–NaOH forming on the anode extended the cathodic limiting potential of electrolyte to 1.6 V, and the hydrophobic anions extend the anodic to 4.4 V. A 1.75 V Na3V2(PO4)3∥Na3V2(PO4)3 cell achieved a high energy density of 70 Wh kg−1 with 87.5 % capacity retention after 100 cycles.
The development of high-performance nonprecious metal catalysts for oxygen reduction reactions is critical for the commercialization of fuel cells. In this paper, we report a non-precious catalyst ...with high-performance, in which Fe and Fe3C is embedded in nitrogen-doped carbon nanofibers (MIL-N-CNFs) by co-electrospinning Fe-MIL and polyacrylonitrile (PAN) and pyrolyzing. The mass ratio of Fe-MIL to PAN in the precursors and the pyrolysis temperature were optimized to be 1.5 and treated at 800 °C, respectively. The optimized catalyst exhibited an onset potential of 0.950 V and a half-wave potential of 0.830 V in alkaline electrolytes, thanks to the improved mass transfer kinetics in a meso-porous structure and enhanced reaction kinetics by confined Fe and Fe3C particles. Additionally, the optimized catalyst showed a better methanol tolerance than the commercial 20 wt.% Pt/C, indicating a potential application in direct methanol fuel cells. Serving as the cathode in CCM, the anion-exchange membrane fuel cell reaches a power density of 192 mW cm−2 at 428 mA cm−2 and 80 °C.
Membrane methods exhibit great potential for application in radioactive liquid waste treatment. In this work, we prepared a reduced graphene oxide using the amino-hydrothermal method (AH-rGO) that ...exhibited effective rejection rates of 99.9% for CoCl
, ZnCl
, NiCl
, and radionuclide
Co solutions with an ultrahigh water permeance of >71.9 L m
h
bar
. The thickness of the AH-rGO membranes affects the water permeance, as the membrane with a thickness of ≈250 nm has the highest water permeance of up to 125.1 L m
h
bar
with the corresponding rejection rate of 86.8%. Importantly, this is the most permeable membrane with a satisfactory level of the rejection rate for typical radioactive ions of Co
, Zn
, and Ni
. Moreover, the AH-rGO membranes presented excellent stability. These findings demonstrate the potential of reduced graphene oxide (rGO) membranes for radioactive liquid waste treatment.
Aqueous Zn batteries are promising energy‐storage devices. However, their lifespan is limited by irreversible Zn anodes owing to water decomposition and Zn dendrite growth. Here, we separate aqueous ...electrolyte from Zn anode by coating a thin MOF layer on anode and filling the pores of MOF with hydrophobic Zn(TFSI)2‐tris(2,2,2‐trifluoroethyl)phosphate (TFEP) organic electrolyte that is immiscible with aqueous Zn(TFSI)2–H2O bulk electrolyte. The MOF encapsulated Zn(TFSI)2‐TFEP forms a ZnF2‐Zn3(PO4)2 solid electrolyte interphase (SEI) preventing Zn dendrite and water decomposition. The Zn(TFSI)2‐TFEP@MOF electrolyte protected Zn anode enables a Zn||Ti cell to achieve a high average Coulombic efficiency of 99.1 % for 350 cycles. The highly reversible Zn anode brings a high energy density of 210 Wh kg−1 (of cathode and anode mass) and a low capacity decay rate of 0.0047 % per cycle over 600 cycles in a Zn||MnO2 full cell with a low capacity ratio of Zn:MnO2 at 2:1.
A highly reversible Zn anode is achieved by using a phase‐separation electrolyte, where aqueous electrolyte is separated from Zn by a MOF‐confined thin layer hydrophobic Zn(TFSI)2‐TFEP organic electrolyte and a ZnF2‐Zn3(PO4)2 solid electrolyte interphase (SEI). The Zn anode achieves a high Coulombic efficiency of 99.9 % at 1 mA cm−2 for 350 cycles and stable Zn||MnO2 batteries.
Aqueous Zn batteries are challenged by water decomposition and dendrite growth due to the absence of a dense Zn‐ion conductive solid electrolyte interphase (SEI) to inhibit the hydrogen evolution ...reaction (HER). Here, we design a low‐concentration aqueous Zn(OTF)2‐Zn(NO3)2 electrolyte to in situ form a robust inorganic ZnF2‐Zn5(CO3)2(OH)6‐organic bilayer SEI, where the inorganic inner layer promotes Zn‐ion diffusion while the organic outer layer suppresses water penetration. We found that the insulating Zn5(OH)8(NO3)2⋅2 H2O layer is first formed on the Zn anode surface by the self‐terminated chemical reaction of NO3− with Zn2+ and OH− generated via HER, and then it transforms into Zn‐ion conducting Zn5(CO3)2(OH)6, which in turn promotes the formation of ZnF2 as the inner layer. The organic‐dominated outer layer is formed by the reduction of OTF−. The in situ formed SEI enables a high Coulombic efficiency (CE) of 99.8 % for 200 h in Ti∥Zn cells, and a high energy density (168 Wh kg−1) with 96.5 % retention for 700 cycles in Zn∥MnO2 cells with a low Zn/MnO2 capacity ratio of 2:1.
Benefiting from a sacrificial Zn5(OH)8(NO3)2⋅2 H2O insulating layer, a Zn‐ion conductive and waterproof fluorine solid electrolyte interphase (SEI) is formed in situ for highly reversible Zn plating/stripping in low‐concentration aqueous electrolytes. The in situ formed SEI enables a high Coulombic efficiency of 99.8 % for 200 h in Ti∥Zn cells, and a high energy density (168 Wh kg−1) with 96.5 % retention for 700 cycles in Zn∥MnO2 cells.
In this paper, ultrathin Pt nanowires （Pt NWs） and PtNi alloy nanowires （PtNi NWs） supported on carbon were synthesized as electrocatalysts for oxygen reduction reaction （ORR）. Pt and PtNi NWs ...catalysts composed of interconnected nanoparticles were prepared by using a soft template method with CTAB as the surface active agent. The physical characterization and electrocatalytic perfor- mance of Pt NWs and PtNi NWs catalysts for ORR were investigated and the results were compared with the commercial Pt/C catalyst. The atomic ratio of Pt and Ni in PtNi alloy was approximately 3 to 1. The results show that after alloying with Ni, the binding energy of Pt shifts to higher values, indicating the change of its electronic structure, and that Pt3Ni NWs catalyst has a significantly higher electrocatalytic activity and good stability for ORR as compared to Pt NWs and even Pt/C catalyst. The enhanced electrocatalytic activity of Pt3Ni NWs catalyst is mainly resulted from the downshifted-band center of Pt caused by the interaction between Pt and Ni in the alloy, which facilitates the desorption of oxygen containing species （Oads or OHads） and the release of active sites.
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