Nickel–zinc battery

A nickel -zinc battery, abbreviated NiZn battery pack is a rechargeable battery.

History

Although this accumulator was patented in 1901 by Thomas Alva Edison, was only from the 2000s technologically the zinc electrode can be stabilized so that this type of battery was practically usable. First Nickel -zinc batteries had only a small number of charge cycles until the zinc electrode lost its function by passivation. In the 1960s, nickel -zinc batteries have been considered as an alternative to silver-zinc batteries in military applications considered, because of their small number of cycles but rejected again.

As of early 2011 NiZn cells are available in the shape of a AA cell ( called AA cell ) for general applications. The most interesting aspect is the voltage of about 1.6 V per cell, which constitutes an advantage for devices which are designed for alkaline manganese batteries and battery 1.5V. Conventional batteries in AA cells form such as nickel - cadmium batteries or nickel -metal hydride batteries are indeed cheaper, but on only a cell voltage of 1.2V. Due to the different voltages, special chargers are however necessary for NiZn cells.

Meanwhile, prismatic 12 -V nickel -zinc batteries for use in hybrid vehicles will be manufactured and tested.

Electrochemistry

In the charging process, it is with the direction of arrow to the right, and with the discharging direction of the arrow to the left, is the reaction formula in the positive electrode which provides 0.49 V:

And at the negative electrode which delivers 1.24 V:

The overall reaction is given by:

The open-circuit voltage after charge is 1.73 V, the charge voltage is about 1.90 V, the discharge voltage is about 1.2 V. The specific energy is 65-120 Wh / kg, which is about the same as nickel - metal hydride storage batteries, however, less than in the lithium ion secondary battery.