A metal-dissolved oxygen seawater battery(SWB)uses metal and dissolved oxygen as the reactants,and it is ideal for use as a long-time low-power distributed power supply in deep sea,due to its advantages of open struct...A metal-dissolved oxygen seawater battery(SWB)uses metal and dissolved oxygen as the reactants,and it is ideal for use as a long-time low-power distributed power supply in deep sea,due to its advantages of open structure in service without electrolyte.However,several simulating deep-sea environmental factors,such as flow rate,dissolved oxygen concentration,and temperature of seawater may af fect the oxygen reduction reaction(ORR)rate and the stability of electrochemically modified polyacrylonitrile-based carbon fiber brush(MPAN-CFB)cathode,which was studied by steady-state polarization and galvanostatic discharge methods.In addition,the scales formed on MPAN-CFB surface were characterized by SEM and XRD.Results show that the ORR rate increased quickly with the increase of the seawater flow rate up to 3 cm/s,and then gradually stabilized.Moreover,the ORR rate was largely af fected by dissolved oxygen concentration,and the concentration of>3 mg/L was favorable.Compared with surface layer temperature of 15℃,the low temperature of deep sea(4℃)has a negligible ef fect on ORR rate.When the working current is too high,it will lead to the formation of CaCO_3 scales(aragonite)of at the cathodic surface,resulting in the decrease of ORR rate,and consequently the damage to the long-time stability of MPAN-CFB.展开更多
Microstructure characterization, corrosion behavior, and electrochemical properties of magnesium anode materials containing 1-3 wt.% Sn in AZ61 alloy were studied by optical microscopy, X-ray diffraction （XRD）, scan...Microstructure characterization, corrosion behavior, and electrochemical properties of magnesium anode materials containing 1-3 wt.% Sn in AZ61 alloy were studied by optical microscopy, X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and energy-dispersive spec- troscopy （EDS）, constant current method, potential polarization, and drainage. The results showed that amount of Mg2Sn phase increased, and recrystallization ratio of Sn-contained Mg alloys during rolling process was improved with increasing of Sn content. This resulted in uniform and refined gains. The results also demonstrated that discharge potential was improved and hydrogen release rate was reduced with the addition of Sn. As the current density increased, the release hydrogen rate was rising, owing to negative variance effect of magnesium alloys. The current efficiency gets to 87% at 20 mA/cm2. The main components of the corrosion products are easy-to-peel-off MgO and Al2O3 that can lead to more negative and stable work potential and accelerate battery reaction continuously.展开更多
基金Supported by the National Major Scientific Instruments Development Project of the National Natural Science Foundation of China(No.41427803)the Zhuang Fa Yu Yan Program(No.41421020401)
文摘A metal-dissolved oxygen seawater battery(SWB)uses metal and dissolved oxygen as the reactants,and it is ideal for use as a long-time low-power distributed power supply in deep sea,due to its advantages of open structure in service without electrolyte.However,several simulating deep-sea environmental factors,such as flow rate,dissolved oxygen concentration,and temperature of seawater may af fect the oxygen reduction reaction(ORR)rate and the stability of electrochemically modified polyacrylonitrile-based carbon fiber brush(MPAN-CFB)cathode,which was studied by steady-state polarization and galvanostatic discharge methods.In addition,the scales formed on MPAN-CFB surface were characterized by SEM and XRD.Results show that the ORR rate increased quickly with the increase of the seawater flow rate up to 3 cm/s,and then gradually stabilized.Moreover,the ORR rate was largely af fected by dissolved oxygen concentration,and the concentration of>3 mg/L was favorable.Compared with surface layer temperature of 15℃,the low temperature of deep sea(4℃)has a negligible ef fect on ORR rate.When the working current is too high,it will lead to the formation of CaCO_3 scales(aragonite)of at the cathodic surface,resulting in the decrease of ORR rate,and consequently the damage to the long-time stability of MPAN-CFB.
文摘Microstructure characterization, corrosion behavior, and electrochemical properties of magnesium anode materials containing 1-3 wt.% Sn in AZ61 alloy were studied by optical microscopy, X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and energy-dispersive spec- troscopy （EDS）, constant current method, potential polarization, and drainage. The results showed that amount of Mg2Sn phase increased, and recrystallization ratio of Sn-contained Mg alloys during rolling process was improved with increasing of Sn content. This resulted in uniform and refined gains. The results also demonstrated that discharge potential was improved and hydrogen release rate was reduced with the addition of Sn. As the current density increased, the release hydrogen rate was rising, owing to negative variance effect of magnesium alloys. The current efficiency gets to 87% at 20 mA/cm2. The main components of the corrosion products are easy-to-peel-off MgO and Al2O3 that can lead to more negative and stable work potential and accelerate battery reaction continuously.
基金supported by the National Natural Science Foundation of China(52172223,52272230,and 51972223)the Young Elite Scientists Sponsorship Program by Tianjin(TJSQNTJ-202011)+3 种基金the National Key Research and Development Program of China(2021YFF0500600 and 2022YFB2404500)the National IndustryEducation Integration Platform of Energy Storagethe Haihe Laboratory of Sustainable Chemical Transformationsthe Fundamental Research Funds for the Central Universities。
