The structure and principle of Ni-mh battery
- Apr 09, 2018 -

The structure and principle of Ni-mh battery:

Ni-MH battery cathode active material is ni (OH) 2 (called NiO electrode), the negative active substance is metal hydride, also known as hydrogen storage alloy (electrode is called hydrogen storage electrode), electrolyte is 6mol/l potassium hydroxide solution. The main process of the active substances forming electrode electrodes are sintering type, slurry type, nickel foam type, fiber nickel type and infiltration type, etc., the electrodes prepared by different process have large difference in capacity and large current discharge performance, and the battery is produced generally according to different process of using conditions. Most of the civilian batteries used in the communication, such as pull-type cathode, foam nickel-type anode to form a battery. Charge and discharge chemical reactions are as follows :

Cathode: Ni(OH)2+OH-=NiOOH+H2O+e-

E-negative: M+H2O+e-=MHab+OH-

total reaction: Ni(OH)2+M=NiOOH+MH

Note: M: hydrogen alloy; Hab: adsorbed hydrogen; reaction-type process from left to right is charge process; The process from right to left is the discharge process. 

The NI (OH) 2 and oh-reaction of the positive electrode generate NIOOH and H2O when charging, at the same time release e- MH and oh-, the total reaction is Ni (OH) 2 and M generation Niooh, hydrogen storage alloy hydrogen storage; In contrast to this discharge, Mhab releases H+, H+ and oh-  generate H2O and e-, Niooh, H2O and e- regenerate Ni (OH) 2 and oh-. The standard EMF of the battery is 1.319V.