thermo-electrochemical cells using the temperature-dependent electrochemical potential of redox materials such as ferricyanide/ferrocyanide in liquid electrolyte. Recently, the temperature dependence of redox materials and electrostatic potential were utilized in a thermally regenerative electrochemical cycle to establish thermal energy harvesting systems. [ 14,[16][17][18] Differing from these effects, the Soret effect denotes a difference in molecule/ ion concentrations within a mixture as a result of molecule/ion migration driven by a temperature gradient, and thus research related to transport behaviors has been mostly focused on gas and liquid phases. [ 7,8 ] In previous report, Bonetti et al. showed very high thermally induced voltage (7 mV K −1 ) in nonaqueous electrolyte. [ 9 ] Moreover, Zhao et al. reported over 10 mV K −1 of so-called ionic Seebeck coeffi cient in liquid state polymeric electrolyte and also demonstrated the thermoelectric charging behavior of electric double layer capacitor. [ 10 ] However, electrical conductivities of these liquid-type devices were reported to be undesirably very low (1 × 10 −3 -8 × 10 −3 S m −1 ). The liquid electrolytes typically necessitate bulky packaging to prevent leakage problem, which are not favorable to wearable and portable devices. Moreover, liquid electrolytes are subject to heat convection, which makes it diffi cult to maintain temperature gradient.Here our novel approach employed a "solid-state" ionic conductor to readily maintain the temperature gradient along with a high ionic electrical so as to fully utilize the Soret effect. This paper reports a high thermo-induced voltage (8 mV K −1 ) at an outstanding electrical conductivity (9 S m −1 ), for the fi rst time, to the best of our knowledge. Furthermore, the large output voltage produced by the Soret effect was further electrochemically stored in integrated redox electrodes like a supercapacitor. Energy storing unit is important since small electrical power/ energy from this type of energy harvesting devices need to be accumulated for practical use. Here our integrated energy storing harvester can be used as a stand-alone device that can be charged simply imposing temperature gradients.

The exceptional thermal conductivity of individual carbon nanotubes have rarely materialized in bulk materials mainly due to the large thermal contact resistance between carbon nanotubes (CNTs). This can be attributed to weak van der Waals bonding at the CNT junctions where the outstanding phonon transport along the strong covalent bonding on the graphitic layer is largely impeded. In bulk materials, however, it has been extremely difficult to achieve covalently bonded junctions between CNTs. Here we report polymer composites consisting of sponge-like CNT structures whose junctions between CNTs are covalently bonded, resulting in a high thermal conductivity and a low Young's modulus, which are hard to achieve at the same time. The low modulus allows thermal interface material (TIM) to easily deform to make the surfaces of heat sink/source fully in contact, which is essential for TIM. Our facile scalable preparation process also makes our composite very attractive as TIM as well as provides insight to better utilize high thermal conductivity of CNTs.

SiC devices are considered to be the next generation power device. This paper discusses thedesign of a Variable Frequency Drive (VFD) using a 6-in-1 power module that employs SiC-DMOSFETs and SiC Schottky Barrier Diodes (SBDs). A 400V class 11kW prototype drive is designed using a 1200V/50A SiC module by Cree. In this paper, power losses of SiC 6-in-1 module are measured and results are compared with an IGBT-based VFD. Analysis shows that SiC drive does not require current derating up to 60 kHz of PWM switching frequency while standard IGBT drive needs significant derating. High dv/dt and voltage reflection effects are important when fast switching devices like SiC are used. This paper explains the design of an optimal output filter.

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