Dismantling and chemical characterization of spent Peltier thermoelectric devices for antimony, bismuth and tellurium recovery

Abstract

International audienceMajor uses of thermoelectricity concern refrigeration purposes, using Peltier devices, mainlycomposed of antimony, bismuth and tellurium. Antimony was identified as a critical rawmaterial by EU and resources of bismuth and tellurium are not inexhaustible, so it is necessaryto imagine the recycling of thermoelectric devices. That for, a complete characterization isneeded, which is the aim of this work. Peltier devices were manually dismantled in three parts:the thermoelectric legs, the alumina plates on which remain the electrical contacts and thesilicone paste used to connect the plates. The characterization was performed using five Peltierdevices. It includes mass balances of the components, X-ray diffraction analysis of thethermoelectric legs and elemental analysis of each part of the device. It appears that aluminarepresents 45% of a Peltier device in weight. The electrical contacts are mainly composed ofcopper and tin, and the thermoelectric legs of bismuth, tellurium and antimony. Thermoelectriclegs appear to be Se-doped Bi2Te3 and (Bi0,5Sb1,5)Te3 for n type and p type semiconductors,respectively. This work shows that Peltier devices can be considered as a copper ore and thatthermoelectric legs contain high amounts of bismuth, tellurium and antimony compared totheir traditional resources