Battery storage is becoming an increasingly popular addition to solar energy systems. Two of the most common battery chemistry types are lithium-ion and lead acid. As their names imply, lithium-ion batteries are made with the metal lithium, while lead-acid batteries are made with lead. How do lithium-ion and lead acid batteries work?
During discharge, electrons are passed externally through the load while internal chemical reactions at the interface of the electrolyte and the electrodes work to balance the charge equilibrium. Figure 3 illustrates the chemical states of a fully charged and discharged lead acid battery.
Some AGM (Absorbent Glass Mat) or high-performance lead-acid batteries can handle moderate discharge rates up to 0.5C or slightly higher. Lead-acid batteries may experience voltage sag and reduced capacity when subjected to high discharge rates, the discharge rate of lithium is stable, and the lead acid is gradually lost to 60%.
Lithium-ion batteries offer many advantages that make them a smarter choice over lead-acid batteries. A significant number of lithium-ion batteries also offer greater value based on price, depending on your application. All applications benefit from higher battery efficiency when using lithium-ion.
Most renewable energy battery charge controllers and discharge inverters are capable of being adjusted between lead acid and lithium-ion. Charge controller and inverter manufacturers and lithium-ion companies can assist in ensuring system compatibility. 12 Lead Acid versus Lithium-ion White Paper Figure 10: Voltage comparison 4. Case Study
Lead-acid batteries rely primarily on lead and sulfuric acid to function and are one of the oldest batteries in existence. At its heart, the battery contains two types of plates: a lead dioxide (PbO2) plate, which serves as the positive plate, and a pure lead (Pb) plate, which acts as the negative plate.