Dismantling and chemical characterization of spent Peltier thermoelectric devices for antimony, bismuth and tellurium recovery
Abstract
Major uses of thermoelectricity concern refrigeration purposes, using Peltier devices, mainly
composed of antimony, bismuth and tellurium. Antimony was identified as a critical raw
material by EU and resources of bismuth and tellurium are not inexhaustible, so it is necessary
to imagine the recycling of thermoelectric devices. That for, a complete characterization is
needed, 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 the
silicone paste used to connect the plates. The characterization was performed using five Peltier
devices. It includes mass balances of the components, X-ray diffraction analysis of the
thermoelectric legs and elemental analysis of each part of the device. It appears that alumina
represents 45% of a Peltier device in weight. The electrical contacts are mainly composed of
copper and tin, and the thermoelectric legs of bismuth, tellurium and antimony. Thermoelectric
legs 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 that
thermoelectric legs contain high amounts of bismuth, tellurium and antimony compared to
their traditional resources.