A comprehensive comparison - lifepo4 vs lead acid

1. Introduction

In general, the requirements of rechargeable batteries are high capacity, high output voltage, good charge and discharge cycle performance, stable output voltage, high current charge and discharge, electrochemical stability performance. Also, the rechargeable batteries, such as 18650 rechargeable battery, require use of safety (will not cause combustion or explosion due to improper operation such as overcharge, overdischarge and short circuit), wide operating temperature range, non-toxic or less toxic, no pollution to the environment.

To compare lifepo4 vs lead acid, lithium iron phosphate batteries using lithium iron phosphate (lifepo4) as the cathode electrode are outstanding in these performance requirements, especially in high current discharge (5 ~ 10C discharge), discharge voltage is stable, safety (no combustion, no explosion), life (cycle life), no pollution to the environment; it is currently the best high-current output power battery that can be mass-produced. The main concepts and performance indicators of lifepo4 vs lead acid are briefly described as follows;

2. Product overview of lifepo4 vs lead acid

Lithium iron phosphate battery: Lithium iron phosphate battery (lifepo4) refers to the lithium ion battery using lithium iron phosphate as the cathode material. The nominal voltage of the lithium iron phosphate battery (LiFePO4) is 3.2V, the stop charging voltage is 3.6V, and the stop discharge voltage is 2.0V.

Lead acid battery: Lead-acid battery (VRLA), is a kind of electrode mainly made of lead and its oxides, the electrolyte is a sulfuric acid solution of the battery. In the discharge state of the lead acid battery, the cathode electrode is lead dioxide, the anode electrode is lead, and the main component of the cathode and anode electrode is lead sulfate.

3. Comprehensive performance evaluation indicators for lifepo4 vs lead acid

4. The characteristics of lithium iron phosphate battery

Compared with lifepo4 vs lead acid, the characteristics of lithium iron phosphate can be summarized below；

● High efficiency output:

The standard discharge is 2~5C, continuous high current discharge up to 10C, and instantaneous pulse discharge (10S) up to 20C;

● Good performance at high temperature:

When the external temperature is 65℃, the internal temperature is as high as 95℃, and the battery discharge temperature at the end of the battery can reach 160℃, and the structure of the battery is safe and intact;

● Safety:

Even if the battery is damaged inside or outside, the battery does not burn, explode and is best safe;

● Excellent cycle life:

After 500 cycles, its discharge capacity is still greater than 95%; After 2000 cycles, the discharge capacity is still more than 85%; After 3000 cycles, its discharge capacity is still greater than 65%.

● Overdischarge:

Overdischarge to zero volt without damage; Fast charging: fast charging with high current;

● No memory effect:

Rechargeable batteries often work under the condition of full and not finished, and the capacity will quickly fall below the rated capacity value, which is called the memory effect. Nickel-metal hydride, nickel-cadmium batteries have memory, while lithium iron phosphate batteries do not have this phenomenon, no matter what state the battery is in, it can be charged with the use, without the need to finish before charging.

● Small volume, light weight:

In lifepo4 vs lead acid, the volume of the lithium iron phosphate battery with the same Wh value is 1 / 3 of the volume of the lead-acid battery, and the weight is 1 / 3 of the lead-acid battery.

● No pollution to the environment:

Lifepo4 vs lead acid, lifepo4 battery does not contain any heavy metals and rare metals (nickel-metal hydride batteries require rare metals), non-toxic (SGS certification), pollution-free, in line with the European ROHS regulations Set, for the absolute green environmental protection battery. There is a large amount of lead in lead acid batteries, and if not properly treated after waste, it will still form a secondary pollution to the environment, but without lithium iron phosphate material In the production and use process, there are no pollution.

5. Advantages of lithium iron phosphate batteries over lead-acid batteries

① Weight and volume comparison

Mass-specific energy (Wh / kg):

• Lithium iron phosphate batteries: 100~150
• Lead-acid battery: 30~50

Volume-specific energy (Wh / L):

• Lithium iron phosphate batteries: 200~250
• Lead-acid battery: 60 ~90

② Cycle life comparison

• Lead-acid battery: 300 ~500
• Lithium iron phosphate batteries: 4000

③ Comparison of discharge characteristics

• Lead acid battery discharge characteristics: For the same fully charged lead-acid battery, at the same temperature, using different times of the discharge current, its discharge output characteristics are very different.
• Discharge characteristics of lithium iron phosphate battery: for the same fully charged lithium iron phosphate battery, at the same temperature, using different times of the discharge current, its discharge output characteristics are very stable.

④ Safety and environmental protection comparison

• Lead-acid battery: containing lead, antimony and other heavy metals, causing serious pollution to the environment, the use and maintenance is prone to leakage, internal sulfuric acid spillover caused by equipment corrosion and personnel injury accidents.
• Lithium iron phosphate battery: pollution-free, does not contain any heavy metal elements harmful to human body; high safety, is currently the safest lithium-ion battery.

6. Main application fields of lifepo4 battery

• Large electric vehicles: buses, electric vehicles, scenic spots and tourist vehicles, hybrid electric vehicles and RV battery;
• Light electric vehicle: electric bicycle, electric motorcycle, golf cart batteries, small logistics vehicle, forklift, clean washing car, electric wheelchair, etc.;
• Power tools: electric drill, electric saw, lawn mower, etc.;
• Remote control of cars, ships, aircraft and other toys;
• Energy storage equipment for solar energy and wind power generation;
• UPS and emergency lights, warning lights and mine lights (best safety);
• 3V disposable lithium battery and 9V nickel-cadmium or nickel-metal hydride rechargeable batteries;
• Small medical instruments and portable instruments, etc.

7. Application examples of replacing lead acid battery with lithium iron phosphate power battery

For lifepo4 vs lead acid, using 36V/10Ah (360Wh) lead-acid battery, its weight is about 12kg, it can walk about 50km with a single charge, the number of charges is about 100 times, and the use time is about 1 year. If the lithium iron phosphate power battery is used, the same 360Wh energy, its weight is about 4kg, it can walk about 80km at a time, the number of charges can reach more than 2000 times, and the service life can reach 3 to 5 years.

Related articles: lithium battery vs other batteries, long lasting battery, agm battery