Chemical Binding is due to electrical forces between electrons and nuclei, and  between electrons. It should therefore be possible to convert differences in chemical binding ( as happens in chemical reaction) to electrical energy ( electrochemical cells ). Conversely electrical energy can cause chemical changes ( e.g. electrolysis ). This large field is called electrochemistry and is properly studied as part of chemistry.

        When there is an electric potential difference between the ends of a conductor, an electric current flows in it. Now suppose that there is a temperature difference between its ends.  We know that heat or thermal energy flows then from hotter to colder end. This flow is also described as heat current or energy current. Clearly, if some of this energy is carried by the free electrons of the conductor, there will also be an electrical current. At the hotter end, electrons have a slightly higher average kinetic energy ( they are moving faster ). So one expects a net flow of electrons towards the lower temperature end, i. e. an electric current due to a thermal gradient . This is qualitatively, the reasons for various thermoelectric effects.