| Nickel-hydrogen battery is one of the alkaline batteries.Compared to nickel-cadmium battery,it has larger capacity density,which was 1.5?2 times under same size.Besides,it has no cadmium pollution.It also has better safety than Lithium Ion Battery.A Nickel-hydrogen battery is composed by positive electrode,negative electrode,separator and electrolyte.As a key component of Nickel-hydrogen batteries,separator has a great influence on discharge voltage,self-discharge,cycles,etc.Therefore,the separator directly determined the performance of battery.What's more,cut cost of the separator can directly lower the total cost of battery.However,the inland separators are all relied imports as there is a big gap between the inland separator and the oversea.This article used non-rolling composite technology that composite the spun-bonded and melt-blown nonwovens for Nickel-hydrogen battery separator,which shows environmentally friendly and excellent performances.The spun-bonded layer mainly contributes strength to the material while melt-blown nonwoven balances the pore size and porosity.These two kind of nonwoven materials are composite by spun-lace progress with a special S/M/S structure,which the interlayer is melt-blown nonwoven while the top and bottom layer is spun-bonded nonwoven.In order to compare the effects of hydrophilia to separator,the sample was sulfonated.This article also chooses a commercial separator as the control sample.It is found that the composite SMS nonwoven fabric No.2 and No.3 exhibited good physical properties and cell performance.The surface density of No.2 and No.3 were 85.2 g/m2?61.6 g/m2 respectively,the mean pore size of these two were 54.8?m and 54?m,the absorption rate of these two were 364%and 870%,the corresponding tensile strength were 10.74N/15mm and 6.98N/15mm,and the areal resistance were 119Q·cm2 and 0.05?·cm2.By contrast,the commercial separator No.4,which was made by wet-laid process,had a surface density of 46.3 g/m2,the porosity was 53.3%,the maximum pore size was 22?m,the absorption rate was 335.3%,tensile strength was 29.77 N/15mm,and the areal resistance was 0.065?·cm2.The cell performance of Ni-MH batteries packed with different separators was studied as well.The two samples had discharge volumes of 221 mAh/g and 297 mAh/g after tested the cell performances,while the commercial separator No.4 was 246.9 mAh/g.Besides,the retention rate of discharge volumes of No.2,No.3 and No.4 were 59.3%,46.8%,53.7%respectively.From these properties,we can draw a conclusion that the absorption ability has an obvious influence on the cell performance of battery.While the absorption capacity affected by the pore size,porosity and areal resistance.In a word,based on the high absorption rate,the pore size should be in the lower.Consequently,the hydroentangling process is effective to obtain a composite SMS nonwoven fabric with strong mechanical strength and suitable pore size which used as Nickel-hydrogen battery separator. |
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