What's the advantages and disadvantages of Lifepo4 batteries?

2024-12-13

Brief Introduction

Lithium iron phosphate battery, also known as lithium iron phosphate lithium-ion battery, refers to lithium-ion batteries that use lithium iron phosphate as the positive electrode material. Here are the naming rules for batteries in the industry. Currently, we usually use positive electrode materials to name batteries, and negative electrodes are usually made of graphite. For example, ternary batteries refer to NCM or NCA used as positive electrode materials, while lithium cobalt oxide batteries refer to lithium cobalt oxide used as positive electrode materials. Similarly, lithium iron phosphate refers to lithium iron phosphate materials used as positive electrodes.

What's the advantages and disadvantages of Lifepo4 batteries? 1

Advantages of Lithium iron phosphate battery

High security performance

The P-O bond in lithium iron phosphate crystals is stable and difficult to decompose. Even at high temperatures or overcharging, it will not collapse, heat up, or form strong oxidizing substances like lithium cobalt oxide. The decomposition temperature of lithium iron phosphate is about 600 ℃, so it has good safety. Although there have been incidents of combustion and explosion during overcharging, its overcharging safety has greatly improved compared to ordinary liquid electrolyte lithium cobalt oxide batteries and ternary batteries.

Long lifespan

The cycle life of lead-acid batteries is around 500 times, with a maximum of about 800 times, while lithium iron phosphate power batteries have a cycle life of over 2500 times, and can reach 2000-7000 times when used with standard charging (0.2C, 5 hours). Lead acid batteries of the same quality have a lifespan of "half a year for new, half a year for old, and half a year for repair and replenishment", with a maximum of 1-1.5 years. On the other hand, lithium iron phosphate batteries, when used under the same conditions, have a theoretical lifespan of 7-10 years. Overall, the performance price ratio is theoretically more than four times that of lead-acid batteries. High current discharge can quickly charge and discharge at a high current of 2C. With a dedicated charger, the battery can be fully charged within 40 minutes at 1.5C, and the starting current can reach 2C. However, lead-acid batteries do not have this performance.

Good high-temperature performance

The peak temperature of lithium iron phosphate can reach 350 ℃ -500 ℃, while lithium manganese oxide and lithium cobalt oxide are only around 200 ℃. The working temperature range is wide (-20C -+75C), and it has high temperature resistance. The electric heating peak of lithium iron phosphate can reach 350 ℃ -500 ℃, while lithium manganese oxide and lithium cobalt oxide are only around 200 ℃.

Large capacity

It has a larger capacity than ordinary batteries (such as lead-acid batteries), and the energy density of lead-acid batteries is about 40WH/kg. The mainstream lithium iron phosphate batteries on the market have an energy density of over 100WH/kg.

No memory effect

Rechargeable batteries often operate under conditions of being fully charged but not fully discharged, and their capacity quickly drops below the rated capacity value. This phenomenon is called the memory effect. Nickel metal hydride and nickel cadmium batteries have memory properties, while lithium iron phosphate batteries do not have this phenomenon (lithium-ion batteries generally do not have memory effects). The battery can be charged and used at any time regardless of its state, without the need to discharge it before charging.

Light weight

The volume of a lithium iron phosphate battery with the same specification capacity is 2/3 of that of a lead-acid battery, its weight is 1/3 of that of a lead-acid battery, and its energy density is several times that of a lead-acid battery.

Environmentally friendly

This battery is generally considered to be free of any heavy metals and rare metals (nickel hydrogen batteries require rare metals), non-toxic (SGS certified), pollution-free, in compliance with European RoHS regulations, and is a green and environmentally friendly battery. One important reason why lithium batteries are favored by the industry is environmental considerations.

Comparison of other materials

The most promising positive electrode materials for power lithium-ion batteries currently include modified lithium manganese oxide (LiMn2O4), lithium iron phosphate (LiFePO4), and nickel cobalt lithium manganese oxide (Li (Ni, Co, Mn) O2) ternary materials. Nickel cobalt manganese oxide ternary materials are generally considered difficult to become the mainstream of lithium-ion batteries for electric vehicles due to the lack of cobalt resources, high cost of nickel and cobalt, and large price fluctuations. However, they can be mixed with spinel lithium manganese oxide within a certain range.

Disadvantages of Lithium iron phosphate battery

Lithium iron phosphate batteries also have their drawbacks, such as poor low-temperature performance, low tap density of positive electrode materials, and larger volume of lithium-ion batteries such as lithium cobalt oxide for equal capacity. Therefore, they do not have advantages in micro batteries. When used for power batteries, lithium iron phosphate batteries, like other batteries, need to face battery consistency issues.

Applications

Due to the above characteristics of lithium iron phosphate power batteries and the production of various batteries with different capacities, they have been widely used. Its main application areas include:

Large electric vehicles: buses, electric vehicles, boats, sightseeing buses, and hybrid vehicles, etc;
Light electric vehicles: electric bicycles, golf carts, small flatbed electric scooters, forklifts, cleaning vehicles, electric wheelchairs, etc;
Electric tools: drills, chainsaws, lawn mowers, etc;
Remote controlled toys such as cars, boats, airplanes, etc;
Energy storage equipment for solar and wind power generation;
UPS and emergency lights, warning lights, and mining lights (with the best safety);
Replace the 3V disposable lithium battery and 9V nickel cadmium or nickel hydrogen rechargeable battery in the camera (with identical size);
Small medical equipment and portable devices, etc.