Enhancing the HRPSoC Cycling Performance of Pure Lead Foil Lead-Acid Batteries Using Lysine as an Electrolyte Additive

In this study, lysine (Lys) was used as an electrolyte additive for lead acid batteries (LABs), with pure lead foil replacing the conventional negative grid to regulate electrode-electrolyte interface reactions. The lysine molecule significantly enhanced the solubility of PbSO 4 by binding with Pb 2+ ions and promoted the diffusion of electrolyte into the electrode plate. This finally increased electrode redox activity, reduced plate resistance, and effectively suppressed irreversible sulfation in the battery. The HRPSoC cycle life of the battery extended to 12,588 cycles at a lysine concentration of 0.03 mol·L -1 , representing a 3.9-fold increase compared to the blank battery (without electrolyte additive). The hydrogen evolution current density at -1.6 V potential decreased from 0.0210 A·g -1 to 0.0073 A·g -1 as determined by linear sweep voltammetry (LSV). Through comparing the effects of other amino acids with same amino/carboxyl functional groups but different alkyl chain lengths on battery performance, the relationship between lysine's functional group composition and its enhancement of lead-acid battery performance was investigated, further revealing its mechanism of action. Results indicate that the alkyl chain length of amino acids inversely correlates with the enhancement of lead-acid battery cycle life at identical electrolyte additive concentrations. Shorter alkyl chains significantly suppress irreversible sulfation in batteries, which promotes the conversion between lead sulfate and lead.