Some Differences Between Ni-Cd Battery and Ni-MH Battery

As an Emergency Lighting Products Supplier, let's talk about the difference between Ni-Cd Battery and Ni-MH Battery.

1. Different battery materials:

(1) The active material on the Ni-Cd Battery positive electrode plate is composed of nickel oxide powder and graphite powder, and its main function is to enhance conductivity. The active material on the negative electrode plate is composed of cadmium oxide powder and iron oxide powder. The function of the iron oxide powder is to make the cadmium oxide powder have high diffusibility, prevent agglomeration, and increase the capacity of the electrode plate.

(2) Ni-MH Battery positive active material is Ni(OH)2 (called NiO electrode), negative electrode active material is metal hydride, also called hydrogen storage alloy (electrode called hydrogen storage electrode), electrolyte is 6mol/L hydrogen Potassium oxide solution.

2. Different classifications:

Ni-MH Battery is divided into high-voltage nickel-metal hydride batteries and low-voltage nickel-metal hydride batteries. There are no other classifications for nickel-cadmium batteries.

Ni-Cd Battery

3. Charge and discharge requirements are different:

(1) Ni-Cd Battery can withstand overcharging or overdischarging.

(2) Ni-MH Battery should not be overcharged during use. This is because overcharge easily causes the positive and negative electrodes to swell, causing the active material to fall off and the diaphragm to be damaged, the conductive network to be broken, and the ohmic polarization of the battery to become large.

4. Different life spans:

(1) Nickel-cadmium batteries can provide more than 500 charge and discharge cycles, and the service life is almost equivalent to the service period of equipment using such batteries.

(2) Ni-MH Battery has a long cycle life of thousands of times.

5. Different characteristics:

Ni-MH Battery has good specific characteristics. Its mass specific capacity is 60A·h/kg, which is five times that of cadmium nickel batteries.