Bleiakkus

Bleiakkus, in English lead-acid batteries, are rechargeable electrochemical cells that use lead dioxide on the positive plate, sponge lead on the negative plate, and a sulfuric acid electrolyte. They were the first commercially viable rechargeable batteries and remain widely used due to low cost, high surge current capability, and robustness in varying temperatures.

A typical lead-acid cell consists of two plates immersed in the electrolyte. During discharge, the positive plate reacts with the electrolyte to form lead sulfate, as does the negative plate, and water is formed, releasing electrical energy. The overall reaction is PbO2 + Pb + 2 H2SO4 → 2 PbSO4 + 2 H2O. Charging reverses this process, restoring the original materials. The nominal voltage of a single cell is about 2.0 to 2.1 volts; a common 12-volt battery contains six cells.

There are several types. Flooded lead-acid batteries are vented and require maintenance with electrolyte checks and watering. Valve-regulated lead-acid (VRLA) batteries come in absorbed glass mat (AGM) and gel variants and are designed to be sealed with minimal gas venting. VRLA batteries are often used in automotive and stationary applications where maintenance is limited.

Performance characteristics include relatively low energy density, good high-current capability, and long cycle life when operated within recommended depths of discharge. They are sensitive to deep discharges and high temperatures, which shorten lifespan.

Applications span automotive starting-lighting-ignition systems, uninterruptible power supplies, and stationary energy storage for renewable energy and backup power. Environmental considerations emphasize recycling, as lead and acids are hazardous but highly recoverable, contributing to a well-established global recycling system.