Explain why diamonds are useful for electrodes in batteries

Diamonds have a broader potential window of 3 to 5 volts.

Explanation:

The minimum voltage required for electrolysis is called potential window. Electrodes such as titanium electrodes and those made of noble metals have a potential window of about 2 volts. Diamond has a potential window of 3 to 5 volts that makes it preferentially start a redox reaction of a substance that is difficult to electrolyze. This facilitates electrolysis of substance that were difficult to decompose in normal electrochemical systems.