Preparation Of TPU Based Membrane And Their Application In Lithium Air Batteries

In recent years,it needs to seek a new and renewable energy along with the advent of energy crisis and environmental deterioration.Lithium air batteries attracts the worldwide attention for its high specific energy.But according to the current research,the application of lithium air batteries is limited by the high charge and discharge overpotential,the instability of electrolyte,the lithium corrosion and these fators leads to poor cycling stability.So this paper studied the electrolyte,cathode,charge-discharge system of batteries firstly,it found that cycling performance of lithium air batteries can not be improved obviously,the interplay between cathode and anode maybe is the reason.Secondly,we composited TPU with borosilicate glass fiber membrane and got the TPU-composited membrane,at the same time,added the propylene carbonate,polycarbonate and SiO₂ and got the modified membrane.Lastly,we packed a battery with the best of the composited membranes and got the membrane which improved the cycling stability of lithium air battery obviously.?1?Packed batteries with carbon material as the cathode,compared the DMSO/LiClO₄,DME/LiTFSI with TEGDME/LiTFSI electrolyte in electrochemical property,it found that the carbon material's electrochemical property in DMSO/LiClO₄ electrolyte is the best.And added the LiI,TEMPO,DBBQ respectively in DMSO/LiClO₄,the LiI is the best one which can improve the cycling nmuber from 40 to 60.And packed batteries with Au@MWNTs,SWCNTs,MWCNTs,MWCNTs-COOH,MWCNTs-KOH,MWCNTs-NH₃,MWCNTs-PANI as the cathodes respectively,it found that MWCNTs-COOH showed the low overpotential and good cycling stability?70 circles?,but it can't meet the actual application.And then adopted the SEM,XRD,FTIR to characterize the failure battery,and we speculated the lithium corrosion maybe the reason.?2?In order to prevent the interplay between cathode and anode,it needed to prepare the polymer composite separator such as TPU-series composited separators?including TPU-composited separators,propylene carbonate/TPU-composited separators,GO-Li/TPU-composited separators,GO-Li/propylene carbonate/TPU-composited separators,Cation exchange resin/TPU-composited separators?,polycarbonate/TPU-seriescompositedseparators?including polycarbonate/TPU=1/3,1/1,3/1?,SiO₂/TPU-series composited separators(including SiO₂/TPU-compositedseparators,PANI/SiO₂-compositedseparators,SiO₂?modified?-composited separators,propylene carbonate/SiO₂/TPU-composited separators.And adopted SEM,contact angle measure,EIS,constant charge-discharge to characterize these separators,it found that the propylene carbonate/TPU-composited separators,the polycarbonate/TPU-composited separators,the propylene carbonate/SiO₂/TPU-composited separators is the best in electrochemical property of three serieses respectively.Packed the propylene carbonate/TPU-composited separator,the polycarbonate/TPU-composited separator,the propylene carbonate/SiO₂/TPU-composited separator and primary separator as membranes,and compared their electrochemical properties,it found that the propylene carbonate/SiO₂/TPU-composited separator can improve the cycling stability from 60 to 306.?3?Then analysized the cathodes,anodes,separators in different circles by SEM,adopted XRD to analysize the discharge product on the cathode,it found that the composited membrane can hinder the interplay,once the membrane was broken the battery would lost effiency.