Study On The Negative Electrode Of Lead Acid Battery For Start/Stop

Start-stop lead-acid battery is a device used under partial state of charge(PSo C),and effectively recycling the power generated from decelerating and braking.The working condition results in irreversible sulfation in the negative plate,which could terminate the battery.Therefore,cycling life test under high rate partial state of charge(HRPSo C)was demonstrated to optimize and filter the negative formula for long life.The interaction mechanism of carbon materials in the negative plate and the effect between additives was studied in detail.In this paper,carbon material that are cost-effective on the market and suitable for mass production are selected,at the same time,and combined conductivity and specific surface area.There are six carbon material,respectively,a high specific surface area carbon materials(CB),in accordance with the specific surface integral high,medium and low(GC1>CC>GC2),three conductive carbon material and two common carbon material.Physical characterization of six types of carbon materials(GC1?GC2?CB?CC?LC?AC)were carried on by XRD,SEM,BET.And the real specific surface area(RSSA)of carbon-Pb SO4 composite electrode was measured by square wave potential technique.The results show that the RSSA of all the composite electrodes grow larger with the rank of CC > CB > AC > GC2 > GC1 > LC > PS.Linear sweep voltammetry(LSV)was carried out to detect the influence of these carbon materials to the transformation from Pb SO4 to Pb.It is found that the addition of carbon materials contributes the transformation,and the order is CC > CB > AC > GC2 > GC1 > LC > PS.On the other hand,the addition of carbon materials would elevate the hydrogen evolution current,while CB performed worst and CC did best.Three kinds of carbon materials(GC1?CB?CC)were chosen and added into negative active material with four amounts(0.25 wt%?0.50 wt%?1.00 wt%?1.50 wt%).Testing battery was made of two sheets of positive plates on the side and single negative plate in the middle.In addition,Ag/Ag2SO4 reference electrode was used to study the potential of each electrode.The effect of these three kinds of carbon materials on the charging voltage at the end of battery formation.It is found that hydrogen evolution in the battery become easier while the amount of carbon materials increased.Battery with CB has the most hydrogen evolution,while CC has the least and GC1 in the middle.Battery with 1.00 wt% and 1.50 wt% CC performs best in the HRPSo C cycling life test.GC1 shows worse performance and CB the worst.XRD,SEM characterization of negative plate and positive /negative plate potential monitoring were carried out after HRPSo C cycling life test.It is observed that sulfation of lower part present much worse than upper part of the plate.The influence of affinity between carbon materials and negative active materials to HRPSo C cycling life was analysed,while CC shows the best affinity and CB the worst with GC1 in the middle.Orthogonal test with four factors interaction in two levels(L8(27))was carried on CC,barium sulfate,lignin and humic acid.It is found that there is interaction function between barium sulfate and lignin,barium sulfate and humic acid during the rate capability test and HRPSo C cycling life test.The formula of additives in high rates discharge(4C1 and 3C1)is different from low rates discharge(2C1,1C1,0.5C1,0.25C1 and C20)The best formula for HRPSo C cycle is composed of 2.00 wt% barium sulfate,0.20 wt% lignin,0.20 wt% humic acid and 1.00 wt% carbon materials.It is proved that there is interaction function between barium sulfate and lignin,barium sulfate and humic acid.