The difference between lead-acid batteries and lithium batteries in electric vehicles

Firstly, the quantity of lead-acid battery of electric vehicle battery in the market is higher than that of lithium battery at present. The reason may be that the cost of lithium battery is still relatively high. Therefore, in the design of the existing "lithium tram" products, the capacity configuration of reducing lithium battery is often adopted to reduce the implementation cost of the vehicle, which makes the existing "lithium tram" product model too simple.

Lead-acid battery and lithium battery can not be simply good or bad, both have their own advantages and disadvantages, adapt to different needs of the population. At present, lithium electric products in the market are mostly "e-bike" and the range is not very far, but such as four-wheel electric vehicle, four-wheel elderly electric scooter these are far range of the current situation or more suitable for "lead-acid battery".

Second, lithium ions mainly rely on lithium ions to move between the positive and negative poles to work. During the charging and discharging process, Li+ is embedded and delinked back and forth between the two electrodes. In a rechargeable battery, Li+ is delinked from the positive pole and embedded into the negative pole through the electrolyte. Discharge is the opposite. Generally, lithium materials are used as the electrode of the battery, and graphite is the most commonly used negative electrode at this stage. Compared with lead-acid battery, lithium battery has the advantages of light weight, large specific capacity and long cycle life, etc. As an electric power source for the elderly, it is not only lightweight, portable and convenient to charge, but also conducive to the "lightweight and simplified" design of the vehicle products.

The electrode of lead-acid battery is mainly made of lead and its oxide, and the electrolyte is sulfuric acid solution. Lead dioxide is the main component of the positive electrode and lead is the main component of the negative electrode of the lead-acid battery. In the state of discharge, the main components of positive and negative electrodes are lead sulfate.

The two kinds of batteries are different except that they are energy storage devices. Lead-acid batteries are safer and cheaper, but they have a lower energy density than lithium, so lead-acid batteries are bigger. At this stage, the battery (storage) technology research has not been able to obtain a breakthrough, "low cost, high performance" that the battery has not yet been put into commercial application, existing lead-acid battery and lithium battery can be together the excellent characteristic of transformation and upgrading, as at present and the future for a period of major research topic. It is believed that the future of the elderly electric scooter, or even the development of the entire electric scooter industry has a clearer direction.

Lead acid batteries for general electric vehicles. Mainly because of its high cost performance.

If everything else is the same and the battery capacity is the same, then maybe lithium is a little bit better. Why? Because lithium is lighter, the whole car is lighter, so it goes a little bit further.

But I still recommend lead acid. The main reasons are:

One, cheap. Generally speaking, a group of lead acid as long as a few hundred pieces, a group of lithium electricity, casually more than 1,000 nearly 2,000 pieces.

Two, security. Still remember the year before last nanjing that woman ride a lithium battery electric car, because the day is too hot, the rear seat of the lithium battery explosion, blow up the rear of the news?

Three, lead acid is enough. The current lead acid generally lasts for 50 or 60 kilometers, which is enough for domestic use. Lithium is unnecessary.

Lead acid batteries are preferred. The reason:

1. Strong overload capacity and impact resistance. The resistance in the running of an electric vehicle changes at any time, or even stops suddenly. Lead-acid batteries also exhibit a remarkable ability to overload when a car starts, with a couple hundred amperes of current in a few seconds of ignition. Lead-acid batteries are safe, but lithium batteries are not.

2. Simple charging management. Plug in the charger, no special conditions regardless of the basic. The lithium charge, you have to be careful.

Lead-acid batteries live much longer than lithium ones in such harsh environments.

4. Cheap price. A set of lead-acid batteries costs several hundred yuan, while lithium batteries cost about two thousand yuan.

Lithium ion battery lead-acid battery

1. Rechargeable battery (alkaline battery -- lead-acid battery)

2. Cycle life (1200 ~ 2000 times -- 500 ~ 900 times)

3. Specific energy (150W·h/kg -- 40W·h/kg)

4. Charging time (2 ~ 4h -- quick charging 3 ~ 6h (quick charging technology is not mature yet)

5. Charging and discharging energy efficiency (conversion efficiency of charging and discharging energy of lithium ion battery can be greater than 97% -- conversion efficiency of charging and discharging energy of lead-acid battery is about 80%)

6. Price (higher 24V/10Ah price: 750 ~ 1200 yuan -- lower 24V/12Ah price: 200 ~ 300 yuan)

7. Volume (the volume of small lithium ion battery is 2/3 of that of lead-acid battery -- large)

8. Weight (only 1/3 ~ 1/4 of the weight of lead-acid battery)

9. Driving range (power -- environmental protection)

10. There is no pollution in production and use (there is pollution in production -- there is a large amount of lead in lead-acid batteries, which will pollute the environment if not handled properly after being discarded).

11. Lithium ion battery (charge in constant current and constant voltage mode -- lithium battery is vulnerable to overcharge, deep discharge and short circuit)

12. Charging and maintenance (complex, high maintenance cost -- simple, open circuit provided with low maintenance cost)

13. Power supply (small open circuit power supply provided, more series connection -- large open circuit power supply provided)

"Lithium battery" is a kind of battery with lithium metal or lithium alloy as negative electrode material and non-aqueous electrolyte solution. In 1912, lithium metal batteries were first proposed and studied by Gilbert n. Lewis. In the 1970s, M. S. Whittingham proposed and began to study lithium-ion batteries. Due to the very lively chemical properties of lithium metal, the processing, preservation and use of lithium metal have very high requirements for the environment. So lithium batteries have not been used for a long time. With the development of science and technology, lithium battery has become the mainstream.

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. The fifth generation of rechargeable lithium metal battery was born in 1996. Its safety, specific capacity, self-discharge rate and performance/price ratio are all better than lithium ion battery. Because of its own high technology requirements, only a few companies in a few countries now produce the lithium metal battery.

Durability:

Lead-acid battery generally deep charge and discharge within 400 times, memory, life of about two years. If the use of maintenance-free lead-acid battery, it is important to note that the battery water loss is small, the use of generally do not need to add distilled water. Lithium battery is durable, slow consumption, charge and discharge more than 500 times, and no memory, the general life of 4-5 years.

According to experts, in terms of durability, lithium battery has good seismic resistance, the battery in the fully charged state is safely fixed, vibrates at the amplitude of 4mm and frequency of 16.7hz for 1 hour, no leakage, no expansion and rupture of the battery, and the open circuit voltage is normal; Good overcharge resistance, 25 c, fully charged battery 0.1ca charging 48 hours, no leakage, no battery expansion and rupture, open circuit voltage normal, capacity maintenance rate of more than 95%; Good resistance to large current, fully charged battery 2CA discharge 5 minutes or 10CA discharge 5 seconds, no conductive part fuse, no appearance deformation.

Volume and quality:

General lead-acid battery pack weight is 16-30 kg, large volume; Lithium battery is generally in 2-6 kg, the volume is relatively small, so riding light, easy to carry. As far as quality is concerned, it is difficult to define which is better or worse. Consumers can buy batteries produced by regular manufacturers according to their own needs.

Price, warranty period:

At present, the mainstream battery in the market is 48 volts. If it is replaced, the lead-acid battery will cost about 700 yuan and the warranty period is one year. Lithium batteries are relatively expensive, costing around 1,200 yuan, but with a three-year warranty.

Driving km:

With the same 48-v battery, both lead-acid and lithium-battery electric cars can travel 30 to 40 kilometers on a full charge. The speed depends largely on the size of the motor used.

Battery capacity:

The lead-acid battery has a capacity of about 20 hours. Lithium battery capacity for any configuration.

Environmental protection:

In 2012, the state issued the "lead-acid battery industry access conditions", after the restructuring and integration of the lead-acid industry, most manufacturers have adopted the internalization of cadmium and arsenic free green production, more environmental protection, more energy saving, only in the recycling process, if the method is not appropriate may cause pollution; Lithium batteries are relatively green in production and recycling.

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