Modulating Carrier Type for Enhanced Thermoelectric Performance of Single-Walled Carbon Nanotubes/Polyethyleneimine Composites

Abstract

Thermoelectric (TE) generators consisting of flexible and lightweight p- and n-type single-walled carbon nanotube (SWCNT)-based composites have potential applications in powering wearable electronics using the temperature difference between the human body and the environment. Tuning the TE properties of SWCNTs, particularly p- versus n-type control, is currently of significant interest. Herein, the TE properties of SWCNT-based flexible films consisting of SWCNTs doped with polyethyleneimine (PEI) were evaluated. The carrier type of the SWCNT/PEI composites was modulated by regulating the proportion of SWCNTs and PEI using simple mixing techniques. The as-prepared SWCNT/PEI composite films were switched from p- to n-type by the addition of a high amount of PEI (>13.0 wt.%). Moreover, interconnected SWCNTs networks were formed due to the excellent SWNT dispersion and film formation. These parameters were improved by the addition of PEI and Nafion, which facilitated effective carrier transport. A TE generator with three thermocouples of p- and n-type SWCNT/PEI flexible composite films delivered an open circuit voltage of 17 mV and a maximum output power of 224 nW at the temperature gradient of 50 K. These promising results showed that the flexible SWCNT/PEI composites have potential applications in wearable and autonomous devices.

Direct Pre-lithiation of Electropolymerized Carbon Nanotubes for Enhanced Cycling Performance of Flexible Li-Ion Micro-Batteries

“…More recently, rapid research progress has been made in exploring flexible anode materials delivering high storage capacity and remarkable long-term cyclability [15][16][17]. As an allotrope of carbon, CNT electrodes offer several outstanding properties, such as excellent flexibility, fast charge transport, large surface-to-volume ratio, good chemical stability, high electrical conductivity and high reversible capacity [18][19][20][21][22][23][24][25][26]. Several methods to synthesize CNT have been demonstrated, e.g., chemical vapor deposition (CVD) [25,27], pyrolysis [28], arc 2 of 16 discharge [29,30], laser ablation [31] and electrolysis [32].…”

Enhanced Thermoelectric Performance of Indacenodithiophene-Benzothiadiazole Copolymer Containing Polar Side Chains and Single Wall Carbon Nanotubes Composites

“…CPs/inorganic thermoelectric composites are one of the major types of organic thermoelectric materials which combine the large Seebeck coefficient feature of CPs with the low thermal conductivity and high electrical conductivities of inorganic nanomaterials [26][27][28][29][30][31][32][33]. Single wall carbon nanotubes (SWCNTs) are one type of attractive carbon nanomaterial for forming thermoelectric composites, attributed to their high electric conductivity and excellent flexibility [27].…”

“…Single wall carbon nanotubes (SWCNTs) are one type of attractive carbon nanomaterial for forming thermoelectric composites, attributed to their high electric conductivity and excellent flexibility [27]. Therefore, various kinds of CPs/SWCNTs composites have been prepared and their thermoelectric properties were investigated [26][27][28][29][30][31][32][33]. It was found that the interfacial interactions between SWCNTs and CPs are crucial to enhance the charge carrier mobility for the composites.…”

Carbon-Based Polymer Nanocomposites for High-Performance Applications

“…In recent work, the thermoelectric performance of SWCNT flexible films doped with polyethyleneimine (PEI) and Nafion were assessed. The nanocomposites were manufactured via simple solution casting followed by vacuum filtration [33]. The SWCNT/PEI nanocomposites were switched from p-to n-type upon addition of PEI contents higher than 13 wt %.…”