Aqueous rechargeable zinc metal batteries display high theoretical capacity along with economical effectiveness,environmental benignity and high safety.However,dendritic growth and chemical corrosion at the Zn anodes ...Aqueous rechargeable zinc metal batteries display high theoretical capacity along with economical effectiveness,environmental benignity and high safety.However,dendritic growth and chemical corrosion at the Zn anodes limit their widespread applications.Here,we construct a Zn/Bi electrode via in-situ growth of a Bi-based energizer upon Zn metal surface using a replacement reaction.Experimental and theoretical calculations reveal that the Bi-based energizer composed of metallic Bi and ZnBi alloy contributes to Zn plating/stripping due to strong adsorption energy and fast ion transport rates.The resultant Zn/Bi electrode not only circumvents Zn dendrite growth but also improves Zn anode anti-corrosion performance.Specifically,the corrosion current of the Zn/Bi electrode is reduced by 90%compared to bare Zn.Impressively,an ultra-low overpotential of 12mV and stable cycling for 4000h are achieved in a Zn/Bi symmetric cell.A Zn–Cu/Bi asymmetric cell displays a cycle life of 1000 cycles,with an average Coulombic efficiency as high as 99.6%.In addition,an assembled Zn/Bi-activated carbon hybrid capacitor exhibits a stable life of more than 50,000 cycles,an energy density of 64Wh kg−1,and a power density of 7kWkg−1.The capacity retention rate of a Zn/Bi–MnO_(2)full cell is improved by over 150%compared to a Zn–MnO_(2)cell without the Bi-based energizer.Our findings open a new arena for the industrialization of Zn metal batteries for large-scale energy storage applications.展开更多
Arc sprayed zinc （Zn） anode on concrete surfaces has been an emerging technology for protecting reinforced concrete structures from rebar corrosion in coastal environments. Many cathodic protection （CP） systems wi...Arc sprayed zinc （Zn） anode on concrete surfaces has been an emerging technology for protecting reinforced concrete structures from rebar corrosion in coastal environments. Many cathodic protection （CP） systems with arc sprayed Zn anodes will reach or exceed their design life in the near future and thus may function improperly or insufficiently, making it necessary to replace the aged anodes. However, prior to this study, little was known about the most effective profile for the concrete surface, for either new concrete or old concrete with existing Zn anodes removed. This work develops criteria to properly prepare the concrete surface before the application of new Zn anode. Experimental studies were conducted both in the laboratory and for a field structure in Oregon. Artificial neural network was used to achieve better understanding of the complex cause-and-effect relationships inherent in the Zn-mortar or Zn-concrete systems and was successful in finding meaningful, logical results from the bond strength data. The goal is to achieve strong initial bond strength of new Zn to concrete, which is essential for long-term performance of the CP system. The results from this case study suggest that it is necessary to adjust the anode removal and surface sandblasting based on the electrochemical age of the existing concrete. In all cases of sandblasting, minimize the exposure of large aggregates （e.g., those bigger than 19 mm in diameter）.展开更多
基金the startup funding support from the Fundamental Research Funds for the Central Universities(Grant KY2060000150,WK2060000040)the support from USTC Center for Micro and Nanoscale Research and Fabrication and NEWAREThe authors also acknowledge the advanced computing resources provided by the Supercomputing Center of the USTC.
文摘Aqueous rechargeable zinc metal batteries display high theoretical capacity along with economical effectiveness,environmental benignity and high safety.However,dendritic growth and chemical corrosion at the Zn anodes limit their widespread applications.Here,we construct a Zn/Bi electrode via in-situ growth of a Bi-based energizer upon Zn metal surface using a replacement reaction.Experimental and theoretical calculations reveal that the Bi-based energizer composed of metallic Bi and ZnBi alloy contributes to Zn plating/stripping due to strong adsorption energy and fast ion transport rates.The resultant Zn/Bi electrode not only circumvents Zn dendrite growth but also improves Zn anode anti-corrosion performance.Specifically,the corrosion current of the Zn/Bi electrode is reduced by 90%compared to bare Zn.Impressively,an ultra-low overpotential of 12mV and stable cycling for 4000h are achieved in a Zn/Bi symmetric cell.A Zn–Cu/Bi asymmetric cell displays a cycle life of 1000 cycles,with an average Coulombic efficiency as high as 99.6%.In addition,an assembled Zn/Bi-activated carbon hybrid capacitor exhibits a stable life of more than 50,000 cycles,an energy density of 64Wh kg−1,and a power density of 7kWkg−1.The capacity retention rate of a Zn/Bi–MnO_(2)full cell is improved by over 150%compared to a Zn–MnO_(2)cell without the Bi-based energizer.Our findings open a new arena for the industrialization of Zn metal batteries for large-scale energy storage applications.
文摘Arc sprayed zinc （Zn） anode on concrete surfaces has been an emerging technology for protecting reinforced concrete structures from rebar corrosion in coastal environments. Many cathodic protection （CP） systems with arc sprayed Zn anodes will reach or exceed their design life in the near future and thus may function improperly or insufficiently, making it necessary to replace the aged anodes. However, prior to this study, little was known about the most effective profile for the concrete surface, for either new concrete or old concrete with existing Zn anodes removed. This work develops criteria to properly prepare the concrete surface before the application of new Zn anode. Experimental studies were conducted both in the laboratory and for a field structure in Oregon. Artificial neural network was used to achieve better understanding of the complex cause-and-effect relationships inherent in the Zn-mortar or Zn-concrete systems and was successful in finding meaningful, logical results from the bond strength data. The goal is to achieve strong initial bond strength of new Zn to concrete, which is essential for long-term performance of the CP system. The results from this case study suggest that it is necessary to adjust the anode removal and surface sandblasting based on the electrochemical age of the existing concrete. In all cases of sandblasting, minimize the exposure of large aggregates （e.g., those bigger than 19 mm in diameter）.
