The difference between lead-acid batteries and lithium batteries

Lithium batteries and lead-acid batteries are two types of batteries that are currently widely used. Some people call lithium batteries a "substitute" for lead-acid batteries, but I think lithium batteries can only be said to be better than lead-acid batteries in some respects as new energy materials, such as cost and discharge performance, but some areas are lead-acid. The battery is still the mainstream. Therefore, there is still a long way to go before the lithium battery can replace the lead-acid battery. The following will focus on the difference between the lithium battery and the lead-acid battery.

First, lithium battery introduction

A lithium battery is a type of battery using a lithium metal or a lithium alloy as a negative electrode material and using a nonaqueous electrolyte solution. Lithium metal batteries were first proposed and studied by Gilbert N. Lewis in 1912. In the 1970s, MSWhitTIngham proposed and began researching lithium-ion batteries . Due to the very active chemical properties of lithium metal, the processing, storage and use of lithium metal are very demanding on the environment. Therefore, lithium batteries have not been used for a long time.

Lithium-ion battery works:

A lithium ion battery is generally a battery using a lithium alloy metal oxide as a positive electrode material, graphite as a negative electrode material, and a nonaqueous electrolyte.

The reaction occurring on the charged positive electrode is: LiCoO2==Li(1-x)CoO2+XLi++Xe-(electron)

The reaction occurring on the charging negative electrode is: 6C+XLi++Xe-=LixC6

Rechargeable battery total reaction: LiCoO2+6C=Li(1-x)CoO2+LixC6

positive electrode

Cathode material: There are many optional cathode materials, and most of the mainstream products use lithium iron phosphate. Different cathode material comparisons:

Positive electrode reaction: Lithium ions are embedded during discharge, and lithium ions are deintercalated during charging. When charging: LiFePO4→Li1-xFePO4+xLi++xe-discharge: Li1-xFePO4+xLi++xe-→LiFePO4.

negative electrode

Anode material: Graphite is mostly used. New research has found that titanate may be a better material.

Negative electrode reaction: Lithium ion is deintercalated during discharge, and lithium ions are embedded during charging.

When charging: xLi++xe-+6C→LixC6

When discharging: LixC6→xLi++xe-+6C

Second, lead acid battery introduction

A lead-acid battery (VRLA) is a battery whose electrode is mainly made of lead and its oxide, and the electrolyte is a sulfuric acid solution. When the lead-acid battery is discharged, the main component of the positive electrode is lead dioxide, and the main component of the negative electrode is lead. In the state of charge, the main components of the positive and negative electrodes are lead sulfate.

A single-cell lead-acid battery has a nominal voltage of 2.0V, can be discharged to 1.5V, and can be charged to 2.4V. In the application, six single-cell lead-acid batteries are often used in series to form a lead-acid battery nominally 12V. There are also 24V, 36V, 48V and so on.

Lead acid battery main characteristics

1, safety seal

In normal operation, the electrolyte does not leak out of the terminals or housing of the battery. No free acid

The special aspirating separator keeps the acid inside and there is no free acid inside the battery, so the battery can be placed in any position.

2, the gas system

After the internal pressure of the battery exceeds the normal level, the VRLA battery will release excess gas and automatically reseal it to ensure that there is no excess gas in the battery.

3, simple maintenance

Since the gas compounding system converts the generated gas into water, no water is added during the use of the VRLA battery.

4, long service life

A lead-calcium alloy VRLA battery with a corrosion-resistant structure can be floated for 10-15 years.

5, stable quality, high reliability

Using advanced production technology and strict quality control system, VRLA battery has stable quality and reliable performance. Voltage, capacity and seals are 100% tested on-line.

6, safety certification

All VRLA batteries are UL listed.

Lead acid battery application field

As a backup power source

(1) Telecommunications

(2) Solar energy system

(3) Electronic switch system

(4) Communication equipment: base station, PBX, CATV, WLL, ONU, STB, cordless telephone, etc.

(5) Backup power: UPS, ECR, computer backup system, Sequence, ETC, etc.

(6) Emergency equipment: emergency lights, fire burglary, fire dampers

As the main power source

(1) Communication equipment: transceiver

(2) Power control locomotives: collecting vehicles, automatic transport vehicles, electric wheelchairs, cleaning robots, electric vehicles, etc.

(3) Machine tool starters: lawn mowers, hedgetrimmers, cordless drills, electric screwdrivers, electric skis, etc.

(4) Industrial equipment / instruments

(5) Camera: flash, VTR/VCR, movie lights, etc.

Third, the difference between lithium battery and lead-acid battery

We know that general comparison of energy storage products should be carried out from the perspectives of weight energy density, volumetric energy density, service life, price, applicability, national policy, etc.:

1, weight energy density

The current lithium battery energy density is generally 200~260wh/g, lead acid is generally 50~70wh/g, then the weight energy density lithium battery is 3~5 times of lead acid, which means lead in the same capacity. The acid battery is 3 to 5 times that of the lithium battery, so the lithium battery has an absolute advantage in energy storage devices.

2, volume energy density

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

3, the use cycle

At present, the more popular material systems are ternary and iron-lithium. The number of cycles of ternary power lithium batteries is usually more than 1000 times, the number of cycles of lithium iron phosphate batteries is more than 2000 times, and the number of cycles of lead-acid batteries is usually only 300~350. The time is about three times, so the service life of the lithium battery is about 3-6 times that of the lead-acid battery.

4, the price

At present, the price of lithium batteries is more expensive than lead acid, which is about 3 times. However, combined with the analysis of service life, the same cost is still used, and the life cycle of lithium batteries is still longer.

5, applicability

Lithium batteries are slightly worse than lead-acid batteries because of their safety. Therefore, various safety precautions must be taken during use, such as preventing external batteries or accidents from causing damage to lithium batteries, as this may cause fire or explosion; Temperature applicability is also very good, so in other aspects of adaptability, lithium batteries are no less inferior to lead-acid batteries.

6, use occasions

Lead-acid battery: car starter, electric car battery,

Lithium batteries: mobile phones, computers, power tools, and now also used in electric car batteries.

7, internal materials

The positive and negative electrodes of lead-acid batteries are lead oxide, metal lead, and the electrolyte is concentrated sulfuric acid.

The positive and negative electrodes of lithium battery are lithium cobalt oxide/lithium iron phosphate/lithium manganate, graphite, and an organic electrolyte.