Modeling of Sulfation in a Flooded Lead-Acid Battery and Prediction of its Cycle Life

Abstract

A major cause of failure of a lead acid battery (LAB) is sulfation, i.e. accumulation of lead sulfate in the electrodes over repeated recharging cycles. Charging converts lead sulfate formed during discharge into active materials by reduction of Pb2+ ions. If this is controlled by mass transfer of the ions to the electrochemically active area, charging voltage can far exceed the OCV of a charged battery. Then, charge is partly consumed to electrolyse water, and for evolution of hydrogen and oxygen. It causes sulfation since regeneration of active materials will be incomplete. A mathematical model is developed incorporating resistance to mass transfer of Pb2+ ions into the rate of charge transfer reactions, changes in areas of active materials and sulfate particles, and dependence of electrodes’ resistance on content of lead sulfate. It was used to show that this mechanism of sulfation does lead to failure of flooded LABs because of increased resistance of electrodes, and to predict cycle life. Capacity fade, and increased cycle life when recharging protocol uses lower DoD are other features of degradation which the model predicts. The model also predicts the observed increase in cycle life when conducting additives are added to the negative electrode.

Multiphysics modeling of lithium-ion, lead-acid, and vanadium redox flow batteries

“…Lead-acid batteries are deployed in uninterruptable power systems. Side reactions in these systems can be avoided by predicting gas evolution [33,198,206] or by completely revising the battery design [37,[214][215][216]. VRF batteries are utilized in large-scale energy storage applications, however, recent efforts are still directed towards cell-level improvements, as discussed earlier.…”

“…Both variants consist of a Pb negative electrode and a PbO 2 positive electrode in contact with 4.8 M H 2 SO 4 electrolyte when the battery is fully charged [198][199][200][201]. The half-reactions of these electrodes are given by (Eqs.…”

“…The transport of dissolved O 2 is also modeled [33,206,212]. These side reactions consume electrons otherwise intended for the main reactions, so they also contribute to sulfation or the irrecoverable formation of PbSO 4 [198,213].…”

Sizing and Lifecycle Assessment of Electrochemical Batteries for Electric Vehicles and Renewable Energy Storage Systems

“…Also, the cycle life of these batteries is comparatively short (< 2000 cycles) [62]. Sulfation is one of the major causes of this lower cycle life, which impedes recharging and causes cracking into the electrode plate [63]. This incident causes inadequate charging during regular operation due to amorphous lead sulfate deposits on the negative electrode, which turns into a crystalline structure in a progression.…”

Valve Regulated Lead Acid Battery Evaluation under Peak Shaving and Frequency Regulation Duty Cycles

“…The charge-discharge reactions for lead acid battery at the positive and negative electrodes are given in Equations ( 1) and (2) respectively, while Equation (3) shows the overall cell reaction [9,10]. PbSO…”