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

Due to the fact that fossil fuels are less and less in the case of large-scale development and utilization by humans, the development and utilization of hydrogen energy has received increasing attention in recent years. As an important direction of hydrogen energy application, nickel-metal hydride batteries are attracting more and more attention. Although the Ni-MH battery is indeed a battery with good performance, the Ni-MH battery for aerospace is a high-voltage Ni-MH battery. Such high-pressure hydrogen gas is easy to explode when stored in a thin-walled container, and the Ni-MH battery also needs precious metals as catalysts. Make its cost become very expensive, and this just is difficult to be accepted by the civilian, therefore, the low-voltage Ni-MH battery of civilian use has been explored abroad since the 1970s. Ni-MH batteries are divided into high-voltage Ni-MH batteries and low-voltage Ni-MH batteries. High-voltage nickel-metal hydride batteries were first developed by M.Klein and JF Stockel in the United States in the early 1970s. The trend of replacing nickel-cadmium batteries with nickel-metal hydride batteries and applying them to various satellites has been formed.