传统液体温差电池较低的热电转换性能一直无法得到有效改善,亟需寻找新的热电转换机制来提升热电转换效率。本文采用分子动力学(MD)方法,数值模拟研究了不同温度下以不同配比的甘油-水为溶剂的氯化钠溶液在碳纳米管(CNT)内离子、分子分布情况。结果表明:离子、分子的分布受温度影响较大,近壁面净电荷、电势分布随温度升高出现明显的分层。根据模拟结果提出以CNT为电极材料,甘油氯化钠溶液或甘油水氯化钠溶液为电解质溶液组成温差电池。其热电转换性能远优于大多数温差电池,同时温度适用范围也显著增加。以多孔碳为电极材料,甘油氯化钠溶液为电解质溶液组成的热电转换装置实验验证了可行性。
The thermoelectric performance of traditional thermogalvanic cells is relatively low and a more efficient conversion mechanism is required. In this paper, the distribution of glycerol/glycerin in an aqueous sodium chloride solution in a carbon nanotube (CNT) is investigated by molecular dynamics (MD) simulation. The distributions of ions, molecule net charge, and electrical potential of the system are markedly affected by temperature. We propose a novel nanofluid thermoelectric conversion method based on the CNT and glycerol/glycerin aqueous sodium chloride solution. The thermoelectric performance of the proposed system is much higher than that of most of current liquid thermogalvanic cells, and the application temperature range is also widened considerably. A preliminary thermal-to-electrical energy conversion experiment based on nanoporous carbon withmixtures of sodiumchloride and glycerol is also conducted to qualitatively verify the numerical results.