Nickel Metal Hydride Battery For Electric Vehicles

Both lead acid batteries and nickel metal hydride nimh batteries are mature battery technologies.

Nickel metal hydride battery for electric vehicles.

Nimh became the enabling technology for the high power wide operating temperature range hybrid electric vehicle hev application. Nickel is an essential component for the cathodes of many secondary battery designs including li ion as seen in the table below. However they are now considered to be obsolete with regards to their uses as the main source of energy storage in bevs. Nickel metal hydride batteries are for use only in hybrids at least those from toyota which has used more of the batteries than any other maker by far.

The division is pretty clear. The honda insight s battery pack made up of 120 panasonic 1 2 volt nickel metal hydride d cells is capable of 100a discharge and 50a charge rates. The system limits the usable capacity to 4ah. Nickel metal hydride batteries are now considered a relatively mature technology.

A nickel metal hydride battery abbreviated nimh or ni mh is a type of rechargeable battery the chemical reaction at the positive electrode is similar to that of the nickel cadmium cell nicd with both using nickel oxide hydroxide niooh. Toyota continues to stay the course with nickel metal hydride battery cells for many of its hybrid vehicles even though most other hybrid vehicles from other brands have moved on to using lithium. However the negative electrodes use a hydrogen absorbing alloy instead of cadmium a nimh battery can have two to three times the capacity of an. While less efficient 60 70 in charging and discharging than even lead acid they have a specific energy of 30 80 wh kg far higher than lead acid.

Several different battery chemistries including lead acid nickel zinc nizn and nickel metal hydride nimh were explored and nimh was selected for further development. When used properly nickel metal hydride batteries can have exceptionally long lives as has been demonstrated in their use in hybrid cars and in the surviving. These types of batteries were originally used in early electric vehicles such as general motor s ev1.