Comparison of lithium batteries and lead-acid batteries for electric vehicles

1) Battery system

Lithium battery
Lithium batteries used in electric vehicles are mainly three battery systems, lithium iron phosphate battery, lithium manganese acid lithium iron battery, ternary lithium battery, to make finished battery packs.
Various battery systems have their own advantages, the price, three yuan > Lithium iron manganate battery > Lithium iron phosphate battery, low temperature performance is the best ternary lithium iron phosphate, lithium iron phosphate is the worst, if it is in the north, the temperature is in a cold state for a long time, it is best to choose a ternary lithium battery.

Lead-acid battery:
A lead-acid battery (VRLA) is a battery whose electrodes are mainly made of lead and its oxides, and whose electrolyte is a sulfuric acid solution. In the discharge state of lead-acid battery, 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 lead sulfate.

The nominal voltage of a single cell lead-acid battery is 2.0V, can discharge to 1.5V, can charge to 2.4V; In applications, 6 single-cell lead-acid batteries are often connected in series to form a nominal lead-acid battery of 12V, as well as 24V, 36V, 48V, and so on.

2) Weight energy density (high lithium battery)

At present, the energy density of lithium battery packs is generally 100~200wh/kg, and lead acid is generally 50~70wh/kg, so the weight energy density of lithium batteries is 2~4 times that of lead acid, which means that in the case of the same capacity, lead-acid batteries are 2~4 times that of lithium batteries, so in the light weight of energy storage devices, lithium batteries occupy an absolute advantage.

3) Volume energy density (high lithium battery)

The volume capacity density of lithium battery packs is usually about 1.5 times that of lead-acid batteries, so in the case of the same capacity, lithium batteries are about 30% smaller than lead-acid batteries.

4) Life cycle (lithium battery long)

At present, the more popular material system is ternary and lithium iron, ternary power type lithium battery cycles are usually more than 1000 times, lithium iron phosphate battery cycles are more than 2000 times, lead-acid battery cycles are usually only about 300 to 350 times, so the service life of lithium battery is about 3-6 times that of lead-acid battery. People who have used lead-acid batteries know that the capacity of lead-acid batteries will be reduced by about half for a year, and the power and battery life will be greatly reduced. The average life of lithium batteries is about three years, which is more durable.

5) Price (long-term conversion of lithium batteries is low)

At present, lithium batteries are more expensive than lead acid in price, about 3 times more expensive, but combined with the service life analysis, the same cost is invested, and the service cycle of lithium batteries is still longer. Taking a brand of 72V20AH battery as an example, the price of lithium battery and lead-acid battery is 1968 yuan and 1238 yuan, respectively. The average cost of lithium batteries is 656 yuan/year, while the average cost of lead-acid batteries is 1238 yuan/year.

6) Applicability (Wide range of lithium batteries)

Because the safety of lithium batteries is slightly worse than that of lead-acid batteries, it is necessary to do a variety of safety prevention work in use, such as preventing external forces or accidents from causing damage to lithium batteries, because it may cause fire or explosion; At present, 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.

7) Durability (high lithium battery)

Lead-acid batteries are generally deep charged and deep discharged within 400 times, have memory, and have a service life of about two years. And the lead-acid battery contains liquid, battery consumption after a period of time, you need to replenish the liquid; Lithium battery is different, its durability is stronger than lead-acid battery, consumption is very slow, deep charging and deep discharge more than 500 times, and it is still no memory, the general life is basically about 3 to 5 years.

8) National policy (lithium battery in line with the development direction)

Lead-acid batteries because of the production process or waste batteries caused by the harm to the environment is quite serious, and lithium batteries are relatively environmentally friendly, so from the national policy orientation, has restricted the expansion of lead-acid batteries reinvestment, or in some areas to limit the use of lead-acid batteries, the future lithium battery replacement trend will become more obvious, the progress will gradually accelerate.

9) Safety performance (slightly higher lead acid)

But no one is perfect and nothing is complete. The higher the energy density of lithium batteries, the lower the stability.

With the development of the lithium industry, different brands of lithium technology and quality are uneven. Some inferior lithium batteries are prone to fire and even explosion in high temperature environments. Therefore, when choosing lithium battery products, we must choose regular manufacturers and brand lithium batteries, because safety is fundamental.