The development of thermoelectric materials and their applications on renewable energy

C.L.Chen¹, Yang-Yuan Chen^1*

¹Institute of physics, Academia Sinica, Taipei, Taiwan

* Presenter:Yang-Yuan Chen, email:cheny2@phys.sinica.edu.tw

Renewable energy (or named Green energy) is one of the variable solutions to resolve the global warming crisis originated from massive CO2 emission of burning fossil fuel. In general, green energy is mainly from the solar energy and its derivatives such as wind power, photovoltaic and plant biomass. Here I will introduce a new material to recover energy from waster heat and its development up to date. Thermoelectric (TE) materials are capable of transforming heat to electricity and conversely converting electricity to temperature gradients according to Seebeck effect and Peltier effect respectively. The heat-electricity conversion efficiency of TE is represented by the Figure of Merit ZT = (σS² T)/(κ_e+ κ_L), where S is Seebeck coefficient, σ is electrical conductivity and κe and κL are electron and lattice phonon thermal conductivities respectively. From the first discovery thermoelectric material in the early 20th century, the figure of merit ZT has been increased tremendously from ~0.2 to 2.6 (SnSe single crystal) in 2014. The corresponding efficiency of heat-electricity conversion of SnSe single crystal is above 15%. This efficiency rivals that of solar cell. In addition, TE materials are solid state devices that are compact, silent, with no coolant and moving mechanical parts. Obviously, these materials could be fashioned into electrical thermoelectric generator (TEG). At present, the applications of mobile 3C electronics is limited by the electricity supply --- specifically, the capacity of the battery installed. Here, we propose a self-charging battery of TEG for 3C electronic devices for solving the limitation of charge capacity.

Keywords: Renewable energy, Thermoelectric materials, Seebeck effect, Peltier effect, thermoelectric generator