What Are The Advantages, Disadvantages And Differences between Lead-acid Batteries And Lithium Batteries?

Lithium batteries are a type of battery that uses lithium metal or lithium alloy as positive/negative electrode materials and uses non-aqueous electrolyte solutions. Lithium batteries can be roughly divided into two categories: lithium metal batteries and lithium-ion batteries. Lithium-ion batteries do not contain metallic lithium and are rechargeable.

Lead-acid batteries are batteries whose electrodes are mainly made of lead and its oxides, and whose electrolyte is sulfuric acid solution. In the discharge state of lead-acid batteries, the main component of the positive electrode is lead dioxide, and the main component of the negative electrode is lead; in the charging state, the main components of the positive and negative electrodes are both lead sulfate. The nominal voltage of a single-cell lead-acid battery is 2.0V, which can be discharged to 1.5V and charged to 2.4V; in applications, 6 single-cell lead-acid batteries are often connected in series to form a nominal 12V lead-acid battery, as well as 24V, 36V, 48V, etc.

1. Gravimetric energy density

The current energy density of lithium batteries is generally 200~360wh/g, and that of lead-acid batteries is generally 50~70wh/g. Therefore, the gravimetric energy density of lithium batteries is 3~5 times that of lead-acid batteries, which means that under the same capacity, lead-acid batteries are 3~5 times that of lithium batteries. Therefore, lithium batteries have an absolute advantage in lightweight energy storage devices.

2. Volumetric energy density

The volumetric capacity density of lithium batteries is usually about 1.5 times that of lead-acid batteries. Therefore, under the same capacity, the volume of lithium batteries is about 30% smaller than that of lead-acid batteries.

3. Use cycle

The more popular material systems at present are ternary and iron lithium. The number of cycles of ternary power lithium batteries is usually more than 1,000 times, the number of cycles of lithium iron phosphate batteries is more than 2,000 times, and the number of cycles of lead-acid batteries is usually only about 300~350 times, so the service life of lithium batteries is about 3-6 times that of lead-acid batteries.

4. Price

Currently, lithium batteries are more expensive than lead-acid batteries, about twice as expensive. However, combined with the service life analysis, with the same investment, the service life of lithium batteries is still longer.

5. Applicability

Because lithium batteries are slightly less safe than lead-acid batteries, various safety precautions need to be taken during use, such as preventing external forces or accidents from damaging lithium batteries, as this may cause fire or explosion; currently, the temperature applicability of lithium batteries is also very good, so in other aspects of adaptability, lithium batteries are not inferior to lead-acid batteries.

6. National policy

Because the production process or waste batteries of lead-acid batteries cause serious harm to the environment, from the perspective of national policy orientation, the expansion of reinvestment in lead-acid batteries has been restricted, or the use of lead-acid batteries has been restricted in some areas. In the future, the trend of lithium batteries replacing lead-acid batteries will become more and more obvious, and the progress will gradually accelerate.