| In recent years,with the development of communication technology,wind power and photovoltaic energy storage technology,and electric bicycle market,the application field of valve-regulated sealed lead-acid batteries(hereinafter referred to as VRLA)is rapidly expanding.While increasing the market share of VRLA batteries,VRLA battery cycle performance puts forward higher requirements.Under these conditions,VRLA batteries have exposed problems of short cycle life and poor reliability,which limits their wider application.According to the analysis,the cycle failure mode of VRLA battery is mainly the softening and falling off of positive lead paste.In order to improve the softening and falling off of positive electrode paste of VRLA battery and improve the cycle performance of VRLA battery,this research takes VRLA battery cycle performance research as research direction.A suitable positive electrode additive is introduced to improve the softening and falling off of the positive lead paste of the VRLA battery and improve the cycle performance of the VRLA battery.By studying the effects of positive electrode additives on the specific surface area,material composition,microstructure and 100% DOD cycle life of lead paste,it is determined that the additives Sn SO4,Sb2O3 and 4BS can significantly improve the cycle performance of the battery,based on the quality of lead powder.The addition amount of Sn SO4 is preferably 0.10%,the addition amount of Sb2O3 is 0.05%,and the addition amount of 4BS is preferably 1.00%.After the additive additive schemes of Sn SO4,Sb2O3 and 4BS are combined,the cycle performance of the battery is significantly improved compared with the single additive due to the synergistic effect of the additive.The compound additive formulation to be used is Sn SO4+Sb2O3 or Sn SO4+Sb2O3+4BS,and the battery is in accordance with the C10 capacity.After the 100% DOD cycle is 450 times,the effective capacity is about 105% of the rated C10 capacity.Compared with the blank battery,the cycle performance is improved by about 125%.From the additive analysis of lead paste performance,the additive should be able to improve the specific surface area of the raw lead paste,improve the 3BS crystal content in the raw lead paste,and the cooked lead paste has a certain amount of α-Pb O2 crystal,in order to effectively improve the cycle life of the battery.After the battery cycle of the composite additive was introduced,according to the electrode potential analysis,the negative electrode was the control electrode of the battery capacity.After dissection,it was found that the negative electrode had obvious sulfation phenomenon.The test data showed that the Pb SO 4 content in the negative electrode paste was about 14%-20%,and XRD test analysis,the negative lead paste contains a large amount of Pb SO4 crystals,indicating that after the introduction of the composite additive,the cycle failure mode of the battery is th e negative electrode sulfation. |
