Study On Electrolytes And Products In Aluminum-air Fuel Cells

Aluminum-air fuel cells have the advantages of high specific energy,abundant resources,safe and pollution-free,which make it have the broad prospects for development in many fields,such as vehicle power,back-up power and so on.But the corrosion of aluminum anode in strong alkaline solution as well as the polarization of the cell are very significant.It hinders the commercialization of aluminum-air fuel cells.Researches on electrolyte additives for aluminum-air cells to reduce corrosion and promote aluminum electrode performance are of great importance.It provides a theoretical support for the reduction of the polarization of the cell as well as a method for discharge products' post-treatment by studying the variation of electrolyte composition during battery discharge.And the investigation on discharge products is performed to explore the application value and increase the economic value added of battery.It is promising to establish a new mode for the commercialization of aluminum-air cells.Firstly,using stannate sodium and casein as hybrid inhibitors were first introduced to suppress anode corrosion of aluminum-air cells in strong alkaline electrolyte.The effects of this hybrid inhibitors on anode corrosion and batteries performance were tested by gas gathering experiment and electrochemical experiment.The surface morphology was detected,trying to make a reasonable explanation on the inhibition mechanism of hybrid inhibitors.It showed that the optimal concentration of hybrid inhibitors was 0.05 M Na2SnO3 and 0.6 g·L-1 casein,which decreased the hydrogen evolution rate by about one order of magnitude.The electrochemical performance tests indicated that it was a cathodic hybrid inhibitor.It alleviated corrosion mostly by depressing the rate of cathode area.Besides,it activated the anode.The discharge performance was clearly promoted,according to the battery discharge results,especially,the battery capacity increased twice.The hybrid inhibitors worked by adsorption and deposition on the surface active sites of anode according to the crystallization phase and morphology analysis.Then,the IR,NMR,Raman and UV were adopted to explore the influence of the relative discharge conditions on the component variation of electrolyte during the battery discharge.It concluded that Al(OH)4-was dominant in solution all the time,and other oligomeric radical ions were emerged at the expense of it.Concentrations of alkaline solution,the temperature,and the current density had no effect on the coordination numbers of Al(?),but impacted their types and numbers.Moreover,the four-coordinated aluminate occupied the utterly leading role.Especially,the Al(OH)4-was the main reason aggravating polarization.Lastly,the possibility of fabrication alumina in high-end market via discharge product was primarily explored on the basis of electrolyte component investigation during discharge.The 99.99% and 100 nm high purity and superfine alumina could be obtained via only changing the discharge conditions.Additives such as gels and fibers could decrease the size down to 50-100 nm or so.It verified the probability to prepare high purity and superfine alumina by aluminum-air cells.