Nickel Metal Hydride Battery For Electric Vehicles

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.

Nickel metal hydride battery for electric vehicles.

Secondary batteries come in a number of varieties such as the lead acid battery found in automobiles nicd nickel cadmium nimh nickel metal hydride and li ion lithium ion. Tesla claims that the nickel in its vehicles is 100 reusable at the end of life but refused to disclose to the guardian where the nickel in its car batteries is sourced from. These types of batteries were originally used in early electric vehicles such as general motor s ev1. 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.

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. 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. Nickel metal hydride batteries are more widely used in hybrid electric vehicles but are also used successfully in some all electric vehicles hybrid electric vehicles do not derive power from an external plug in source and instead rely on fuel to recharge the battery which excludes them from the definition of an electric car.

Several different battery chemistries including lead acid nickel zinc nizn and nickel metal hydride nimh were explored and nimh was selected for further development. The division is pretty clear. However they are now considered to be obsolete with regards to their uses as the main source of energy storage in bevs. Both lead acid batteries and nickel metal hydride nimh batteries are mature battery technologies.

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. The system limits the usable capacity to 4ah. 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.