Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency , 7 Gobancho, Chiyodaku, Tokyo 102-0076, Japan.
J Am Chem Soc. 2016 Aug 24;138(33):10502-7. doi: 10.1021/jacs.6b04923. Epub 2016 Aug 10.
Thermo-electrochemical cells have potential to generate thermoelectric voltage 1 order higher than that given by semiconductor materials. To overcome the current issues in thermoelectric energy conversion, it is of paramount importance to grow and fulfill the full potential of thermo-electrochemical cells. Here we report a rational supramolecular methodology that yielded the highest Seebeck coefficient of ca. 2.0 mV K(-1) around ambient temperatures. This is based on the encapsulation of triiodide ions in α-cyclodextrin, whose equilibrium is shifted to the complexation at lower temperatures, whereas it is inverted at elevated temperatures. This temperature-dependent host-guest interaction provides a concentration gradient of redox ion pairs between two electrodes, leading to the eminent performance of the thermo-electrochemical cells. The figure of merit for this system, zT reached a high value of 5 × 10(-3). The introduction of host-guest chemistry to thermoelectric cells thus provides a new perspective in thermoelectric energy conversion.
热电化学电池具有产生比半导体材料高出 1 个数量级的热电电压的潜力。为了克服热电能量转换中的当前问题，充分发挥热电化学电池的潜力至关重要。在这里，我们报告了一种合理的超分子方法，在环境温度下产生了约 2.0 mV K(-1) 的最高塞贝克系数。这是基于三碘化物离子在α-环糊精中的封装，其平衡在较低温度下向络合转移，而在较高温度下则反转。这种温度依赖的主客体相互作用在两个电极之间提供了氧化还原离子对的浓度梯度，从而实现了热电化学电池的卓越性能。该系统的品质因数 zT 达到了 5×10(-3)的高值。因此，将主客体化学引入热电电池为热电能量转换提供了新的视角。
