The differences between lead-acid batteries and lithium batteries

Lead-acid Batteries: They are mainly composed of lead and its oxides, sulfuric acid electrolyte, etc. The positive electrode is lead dioxide, the negative electrode is spongy lead, and the electrolyte is an aqueous solution of sulfuric acid.

Lithium Batteries: Generally, lithium metal or lithium alloy is used as the negative electrode material. The positive electrode materials usually include lithium cobaltate, lithium manganate, lithium iron phosphate, etc. The electrolyte is an organic electrolyte or polymer electrolyte.

Lead-acid Batteries: They have a relatively low energy density, usually around 30 - 50Wh/kg. This means that for a lead-acid battery and a lithium battery of the same weight, the lead-acid battery stores less electrical energy and has relatively weak endurance.

Lithium Batteries: They have a relatively high energy density, generally reaching 100 - 260Wh/kg or even higher. For example, the energy density of some high-end ternary lithium batteries can exceed 300Wh/kg. Therefore, under the same volume or weight, lithium batteries can provide a longer usage time and driving range.

Lead-acid Batteries: Their charge and discharge efficiency is relatively low, generally around 70% - 80%. The charging time is long, usually taking 8 - 10 hours or even longer to fully charge. The depth of discharge is also limited, and it is generally not advisable to exceed 80%, otherwise, it will affect the battery life.

Lithium Batteries: Their charge and discharge efficiency is relatively high, which can reach more than 90%. The charging speed is relatively fast, and some lithium batteries support fast charging technology, which can charge a large amount of electricity in a short time. The depth of discharge can be relatively high. Under reasonable usage conditions, deep discharge can be carried out frequently, but the discharge characteristics of different types of lithium batteries vary.

Lead-acid Batteries: Their cycle life is relatively short, generally around 300 - 500 times. As the number of charge and discharge cycles increases, the battery capacity will gradually decrease. When the capacity drops to a certain extent, the battery needs to be replaced.

Lithium Batteries: Their cycle life is usually longer. The cycle life of lithium iron phosphate batteries can reach more than 2000 times, and the cycle life of ternary lithium batteries can generally reach about 1000 times. However, the cycle life of lithium batteries will also be affected by factors such as usage conditions and depth of discharge.

Lead-acid Batteries: They are relatively safe, with mature technology. As long as they are used and maintained correctly, serious safety problems generally will not occur. However, the sulfuric acid in lead-acid batteries is corrosive, and once it leaks, it may cause harm to the human body and the environment.

Lithium Batteries: If there are improper designs, manufacturing processes, usage methods, or charging processes, there may be potential safety hazards, such as overheating, fire, or even explosion. However, with the continuous progress of technology, the safety of lithium batteries has been greatly improved. Through the adoption of appropriate battery management systems, safety designs, and other measures, the safety risks can be effectively reduced.

Lead-acid Batteries: Their manufacturing cost is relatively low, the raw material cost is relatively stable, and the production process is mature, so the price is relatively cheap. This makes lead-acid batteries have certain advantages in some application fields that are sensitive to cost, such as low-speed electric vehicles and emergency lighting.

Lithium Batteries: Due to their high material cost, strict production process requirements, and large R & D investment, the price of lithium batteries is relatively high. But with the continuous expansion of the lithium battery industry scale and the continuous progress of technology, their cost is gradually decreasing.

Lead-acid Batteries: They contain harmful substances such as heavy metals lead and sulfuric acid. If not properly disposed of, they will cause serious pollution to the environment. Discarded lead-acid batteries need to be professionally recycled to avoid lead pollution of soil and water sources.

Lithium Batteries: They are relatively more environmentally friendly and do not contain heavy metal harmful substances such as lead, mercury, and cadmium. However, some chemical substances in lithium batteries may also have a certain impact on the environment. Therefore, discarded lithium batteries also need to be recycled reasonably to achieve resource recycling and environmental protection.