What is nickel-metal hydride battery?

Nickel-metal hydride batteries are improved from nickel-cadmium batteries, a metal that can absorb hydrogen instead of cadmium. Mainly because of the development and use of fossil fuels is becoming less and less, people began to use hydrogen energy, it can be the same price than nickel-cadmium batteries to provide more capacity, not obvious memory effect (memory effect is simply to remember the daily use of the battery mode, such as charging and discharging mode, etc., cannot be significantly change this pattern), and lower environmental pollution.

Nickel-metal hydride battery is a good storage battery, mainly divided into high-voltage nickel-metal hydride batteries and low-voltage nickel-metal hydride batteries, nickel-metal hydride batteries, the positive active material for Ni (OH) (known as NiO electrode), the negative active material metal oxides, also known as hydrogen storage alloy.

Classification of nickel-metal hydride batteries

1. Low-voltage nickel-metal hydride batteries

The battery voltage is between 1.2V and 1.3V, with high energy density, can be charged and discharged quickly, and is safe and reliable, no pollution to the environment.

2. High-voltage nickel-metal hydride batteries

High-voltage nickel-metal hydride batteries are highly reliable, with good over-discharge and charging protection, long cycle life and excellent low-temperature performance.

What is lithium battery?

Lithium batteries are divided into lithium metal batteries and lithium-ion batteries, lithium-ion batteries and lithium iron phosphate batteries, lithium cobalt batteries and lithium manganate batteries, etc., we are mainly introduced to lithium iron phosphate batteries.

Lithium iron phosphate battery

Lithium iron phosphate battery is a kind of lithium battery, lithium iron phosphate battery is a kind of lithium-ion battery using lithium iron phosphate as the anode material, carbon as the anode material, monomer rated voltage of 3.2V, charging up to the voltage of 3.6V to 3.65V. During charging, lithium ions in lithium iron phosphate are dislodged and transferred to the negative electrode via the electrolyte and embedded in the negative electrode material, while electrons are released from the positive electrode and reach the negative electrode from the external circuit to maintain the balance of the chemical reaction. In the discharge process, lithium ions from the negative electrode off, through the electrolyte transfer to the positive electrode, while releasing electrons from the negative electrode, from the external circuit to reach the positive electrode, to provide energy for the outside world.

The difference between lithium iron phosphate batteries and nickel-metal hydride batteries

1. In terms of safety performance

Nickel-metal hydride batteries are a little more secure, mainly because the specific heat capacity and energy density of nickel-metal hydride batteries are relatively low, the melting point is as high as 400 ℃, when subjected to collision, extrusion, puncture, short-circuit and so on, the temperature of the battery will not rise sharply and lead to spontaneous combustion. The safety of lithium iron phosphate battery is also good, in normal use there will be no explosion phenomenon, only the battery receives external force puncture or short circuit, the battery may appear combustion phenomenon, and in the overcharging of the voltage is higher than the standard voltage several times may occur when the explosion phenomenon.

2. From the service life

The service life of lithium iron phosphate batteries can reach about 10 years, the number of cycles can reach more than 10,000 times, maintenance in daily life, the service life of the battery will be longer. Nickel-metal hydride battery service life of about 2 years, the number of cycles of about 300 times. So it is still the service life of lithium iron phosphate battery is longer.

3. From the high temperature performance

Lithium iron phosphate batteries can reach 350 ℃ to 500 ℃ peak electric heat, for lithium manganate and lithium cobalt only about 200 ℃. Nickel-metal hydride batteries have lower high temperature resistance and can only work at about 60℃.

4. From the protection of the environment

Lithium iron phosphate batteries are not polluted either in production or use, lithium iron phosphate batteries are generally considered to be free of any heavy metals and rare metals, non-toxic (SGS certified), non-polluting, for the absolute green battery. Nickel-metal hydride batteries are less polluting to the environment and do not cause pollution when used, and may be polluted when recycled.

5. From the memory effect

Lithium iron phosphate batteries, no matter what state, can be charged with the use of the battery, no need to discharge and then charge, no memory effect. Nickel-metal hydride batteries have a memory effect, the battery will memorize the user’s daily charging and discharging amplitude and mode, it is difficult to change this pattern over time, and can no longer do a substantial charge or discharge.

6. Charging speed

The charging speed of lithium iron phosphate battery can be fully charged in about 3 hours, which can effectively save time and better use of the battery. Nickel-metal hydride batteries have a slower charging speed and need to be charged for a day to be fully charged.

Advantages of nickel-metal hydride batteries

1. Nickel-metal hydride batteries are cheaper than lithium iron phosphate batteries, the development and production costs are lower, less than 50% of lithium iron phosphate batteries, and the cost of maintenance is also low.

2. Nickel-metal hydride batteries do not harm the environment and reduce pollution of the environment.

3. Nickel-metal hydride batteries can be highly compatible with a variety of equipment

4. Nickel-metal hydride batteries have less active material and are therefore more stable

5. Nickel-metal hydride batteries have a long shelf life, the latest nickel-metal hydride batteries have a self-discharge characteristic of about 20% in 12 months.

Disadvantages of nickel-metal hydride batteries

1. Nickel-metal hydride batteries have high self-discharge rate.

2. Nickel-metal hydride batteries have memory effect, which will affect the performance of the battery.

3. There is a risk of liquid leakage

4. Short use cycle

5. Not suitable for long time storage

Conclusion:

Lithium iron phosphate batteries and nickel metal hydride batteries are used in different fields, lithium iron phosphate batteries are more widely used, nickel metal hydride batteries are mainly used in controllers and small electrical equipment, we recommend the use of lithium iron phosphate batteries.