What Are NiMH Batteries?

Ni-MH battery is a kind of battery with good performance. Ni-MH batteries are divided into high-voltage Ni-MH batteries and low-voltage Ni-MH batteries. The positive electrode active material of Ni-MH battery is Ni (OH) ₂ (called NiO electrode), the negative electrode active material is metal hydride, also called hydrogen storage alloy (electrode called hydrogen storage electrode), and the electrolyte is 6mol / L potassium hydroxide solution. As an important aspect of hydrogen energy application, nickel-metal hydride batteries have attracted more and more attention. ^[1]

As fossil fuels become less and less in the context of large-scale development and utilization by human beings, in recent years, the development and utilization of hydrogen energy has received increasing attention. As an important aspect of hydrogen energy application, nickel-metal hydride batteries have attracted more and more attention. Although the nickel-metal hydride battery is indeed a good-performance battery, the nickel-metal hydride battery for aerospace is a high-voltage nickel-metal hydride battery. Such high-pressure hydrogen is easily exploded when stored in a thin-walled container, and the nickel-metal hydride battery also requires a precious metal as a catalyst. Making its cost very expensive, it is difficult to be accepted by civilians. Therefore, foreign countries have begun to explore civilian low-voltage nickel-hydrogen batteries since the 1970s. Ni-MH batteries are divided into high-voltage Ni-MH batteries and low-voltage Ni-MH batteries. The high-voltage nickel-metal hydride battery was first developed by M. Klein and JFStockel of the United States in the early 1970s. The trend is to replace nickel-cadmium batteries with nickel-metal hydride batteries and apply them to various satellites.

The positive electrode active material of Ni-MH battery is Ni (OH) ₂ (called NiO electrode), the negative electrode active material is metal hydride, also called hydrogen storage alloy (electrode called hydrogen storage electrode), and the electrolyte is 6mol / L potassium hydroxide solution. The active material forms the electrode pole pieces mainly by sintering type, slurry type, foam nickel type, fiber nickel type, and infiltration type. Electrodes prepared by different processes have large differences in capacity and high current discharge performance. Generally, Production of batteries according to different conditions of use. Communications and other civilian batteries are mostly battery-pulled anodes and foamed nickel anodes. Charge and discharge chemical reactions are as follows ^[1]

Ni-MH batteries are divided into high-voltage Ni-MH batteries and low-voltage Ni-MH batteries.

Low-voltage nickel-metal hydride batteries have the following characteristics: (1) the battery voltage is 1.2 ~ 1.3V, which is equivalent to nickel-cadmium batteries; (2) the energy density is high, which is more than 1.5 times that of nickel-cadmium batteries; Good performance; (4) can be sealed, strong resistance to overcharge and discharge; (5) no dendritic crystals can be formed to prevent short circuit in the battery; (6) safe and reliable, no pollution to the environment, no memory effect, etc. ^[1]

Ni-MH batteries should be maintained during use.

(1) Avoid overcharging during use. During the cycle life, avoid overcharging during use. This is because overcharging can easily cause the positive and negative electrodes to swell, causing active matter to fall off and damage to the separator, damage to the conductive network, and large ohmic polarization of the battery.

(2) Prevent electrolyte deterioration. During the cycle life of nickel-metal hydride batteries, hydrogen evolution of the batteries should be suppressed.

(3) Storage of Ni-MH batteries. Storage of nickel-metal hydride batteries should be stored for a long time after the battery is fully stored. If the battery is not stored for a long time, the function of the negative hydrogen storage alloy of the battery will be weakened, and the battery life will be shortened. ^[1]

Nickel-metal hydride batteries are already a mature product. At present, the number of nickel-metal hydride batteries produced in the international market is about 700 million. The scale and output of the Japanese nickel-metal hydride battery industry have always been among the highest in the world. The battery field has also been developed and developed for many years. China has rich resources of rare earth metals for the manufacture of nickel-metal hydride batteries, and its proven reserves account for more than 80% of the world s proven total reserves. At present, domestic research and development of nickel-metal hydride battery raw material processing technology is becoming increasingly mature. Nickel-metal hydride batteries can be used interchangeably with zinc-manganese batteries and cadmium-nickel batteries. In the future, round batteries will mainly develop in terms of product specifications and commercialization, while the development of square batteries will focus on power sources for power vehicles. ^[1]