Lead acid batteries are used to supply high surge currents in automotive applications, emergency exit signs, children’s toys and computers battery backup systems. They are a type of rechargeable energy storage system, and their electrolyte is a dilute solution of sulfuric acid. The negative electrode of the battery consists of sponge lead, while the positive is composed of lead dioxide.
Lead-acid batteries have a low power-to-weight ratio and a lower energy-to-volume ratio, but remain in use due to their inexpensive manufacturing costs. They are available in various sizes and voltages to meet the power requirements of a wide range of applications. Sealed lead-acid batteries are also the preferred choice for uninterruptible power supplies, based on their robustness and long lifetime.
While all lead-acid batteries produce hydrogen and oxygen gas during charging, flooded cells allow these gases to escape into the air, while sealed lead-acid batteries have their gases contained inside of the cell compartments. Depending on how the battery is used, these gases can become dangerously explosive and must be vented to prevent explosions in an enclosed space.
The safety of find lead acid batteries in Malta depends on the proper handling procedures and maintenance practices. Accidental spilling of the sulfuric acid can cause chemical burns on skin, eyes and clothing. It is recommended to wear face shields and plastic or rubber aprons when working with these batteries. If any acid gets on skin or clothing, immediately wash the area with clean water and seek medical attention. A bicarbonate of soda solution can be used to neutralize any acid spills.
Car batteries and other larger lead-acid batteries cannot be placed in household trash or recycling bins because of their hazardous materials content. They must be recycled through a battery recycler, your local solid waste authority or call the national Call2cycle program for locations to drop-off your batteries for free recycling.
Battery recycling is a complex process. The first step is to shred the batteries into pieces with a hammer mill or by hand. Then the pieces are put into a tank with a layer of polypropylene plastic that floats. Then the lead plates sink to the bottom and are separated from the plastic. The lead is transported to a plastic recycler where it is melted and refined. It is then cast into ingots that are used to manufacture new batteries.
The European Union (EU) has set a target of 90.9 % for the recovery of lead from used batteries and accumulators by 2021. In addition to meeting the EU’s climate change targets, a high recycling efficiency also saves on raw material imports and reduces environmental hazards from lead mining. Battery recycling has increased significantly in the EU since 2009.