Research Of Electrode Polarization And Its Inhibition Of Alkaline Batteries At Heavy Load Discharge

Further improving the power density is the leading edge of the alkaline batteries. Inorder to clarify the reasons why the power density of heavy duty alkaline battery is muchhigher than that of conventional battery， we studied the method of simultaneousdetermination of its two electrodes potential change in the battery when it works. By usingthe selected method, the bipolar potential change of high-power alkaline batteries andordinary alkaline batteries in the heavy load discharge are determined. The differences ofpositive and negative potential changes of the two batteries in the discharge process arefound out. Further more, We used different zinc powder and electrolyte, different amountof additive A and ZnO, different electrolytic manganese dioxide to produce batteries. Thenwe researched the bipolar potential curves of the batteries during discharge time in heavyload discharge. The impact and effect of different materials on the electrode potentialchanges were discussed. At last, we explored the ways to further improve the alkalinebattery power density.Compared to the method of built-in platinum wire parameters electrode, It was foundout that external Hg-HgO reference electrode’s curve fluctuation is much smaller. Inanalysis of potential drop, It is more accurate. By using the method of external of Hg-HgOreference electrode, the two battery poles potential curve in1.5W constant powerdischarge conditions were simultaneously determined. From the test results, it can bedrawn that the battery pulse voltage drop and the rate of change are the major factors toaffect the pulse discharge performance of the battery. The method clearly revealed that thehigh-rate battery was better at inhibitions of pulse voltage drop of battery and its increaserates. Especially, the anode and cathode voltage drops (increase) and their increasing rateswere slowed down effectively at the interim and finally discharge periods of the battery. Potential changing curves of the anode were gained synchronously using electrodestest. Potential changing curves of different anode materials were researched at theintermittent discharging of1A. It was found that increasing the content of fine zincpowder particles and specific surface area are useful for the heavy load discharge, Potentialchanging curves of the anode show that electrode potential drop values were smaller in themid-and late discharging. There was no sudden rising at the electrolyte concentration of31%and33%, the negative potential drop upward trend is stable, when the electrolyteconcentration is greater than35%, there will be a sudden increasing in mid-and late athigh-rate discharging, The reason may be that the electrolyte concentration is too large inthe late of discharging, the negative polarization was suddenly increased, resulting in thepotential drop was suddenly increased. The main role of the additive A in the high-ratedischarging is that additive A could slow down the electrode polarization in the mid-andlate discharging. But the dosage should be appropriate, if the dosage was too little, theeffect of inhibition of polarization could not be good, if the dosage was too much, therewill be a negative effect; ZnO in the electrolyte to the battery anode zinc powder plays acertain degree of inhibition, but by itself does not have activity in the alkaline batteries,excessive consumption causes the battery voltage drops, and will affect the battery whenthe intermittent discharge voltage recovery, the amount of the ZnO in the electrolyteconcentration of2%-3%of the most appropriate.Potential changing curves of the cathode were gained synchronously using electrodetest. Two different EMD were researched at the constant power discharging of1.5W andintermittent discharge of1A, the battery cut-off potential is0.85V. The discharge time ofthe LR6battery at the constant power discharging of1.5W which used A as its cathodewas more than53.5%to normal EMD, The discharge time of the battery at the intermittentdischarging of1A was more than10.9%to normal EMD, The reason is that the A in themiddle of the discharge process, the cathode potential drop and the cathode potential dropsubstantially were decreased, thereby prolonging the manganese dioxide dischargeplatform, improving the utilization of manganese dioxide. the properties of the two materials was tested, founding that there were too much difference, for example, theparticle, the appearance，the crystal types and the composition of powder moisture content,which may be an important factor leading to differences in electrical properties of the twomaterials.Simultaneous determination and analysis of the change curve of electrode potential inthe heavy load discharge process, one can clearly observed the role of different cellmaterials in the battery during the reaction. There are some guidance in battery materialselection and optimization of battery formula.