Carbon fiber/epoxy composite laminates as through-thickness thermoelectric generators

This research study demonstrates a carbon fiber reinforced polymer (CFRP) composite laminate with an embedded thermoelectric (TE) enabled glass fiber (GF) ply. The TE-enabled GF functional ply was purposely laminated to create a structural through-thickness thermoelectric generator (TEG). Simultaneously, the highly conductive carbon fiber (CF) reinforcing phase served as electrodes for the device. Tellurium nanowires (NWs) were incorporated in various mass ratios in a PEDOT:PSS matrix to produce different TE pastes. The TE pastes were deposited on the GF fabrics via a facile blade coating technique. The highest power factor (57.2 μW/m.K2, in-plane Seebeck coefficient +189 μV/K) was exhibited by the coating formed by the paste with a specific mass ratio of 1:1 (Te NWs to PEDOT:PSS). The TE-enabled GF plies were employed for the manufacturing of both 10-ply unidirectional (UD), and cross-ply composite laminates. The UD laminate generated a TE voltage (VTEG) of 8.4 mV and a TE current (Isc) of 597.4 μA for 100 K through-thickness temperature difference (ΔT) i.e., a maximum power of 1.3 μW. The temperature sensing capability of the TEG-laminate was also demonstrated. Three-point bending tests indicated a ca. 10% decrease in flexural properties with the integration of the TEG functionality for the UD configuration.