Explain how understanding this relaship can help desighn more efficient technologist

Metals are good conductor of electricity, because as per there structure they have free electrons which help them to move freely within the metal thus helps to maintain a good flow of electricity.

This theory has really helped engineers especially for making powerful batteries. As good batteries means amount of electricity drawn from it will be great and that too for longer time.

Hence such metals are used to make batteries that has more number of free electrons and thus can contribute to generate more electricity.