(东北大学 材料与冶金学院， 沈阳 110004)
摘 要: 用溶胶-凝胶法制备了NaCo2O4及(Na1-yMy)1.6Co2O4(M=K, 0.05≤y≤0.35; M= Ca, Sr, 0.10≤y≤0.40)的氧化物。 研究结果表明: 掺杂Ca、 Sr的NaCo2O4样品的Seebeck系数都有一定提高； 而掺杂K的NaCo2O4样品的Seebeck系数无明显提高， 且掺K使NaCo2O4的功率因子降低； 对NaCo2O4掺杂Ca的量0＜y＜0.30时， 功率因子有所提高， 在y＝0.1时， 功率因子最大为1.68×10-4 W·m-1·K-2， 比掺杂前提高11％； 当Sr掺杂量y＝0.1时， 功率因子的极大值为2.26×10-4 W·m-1·K-2， 比掺杂前提高50％。 掺杂金属Sr的NaCo2O4材料热电性能效果最好， 实验结果说明选择合适的元素及最佳的掺杂量进行掺杂能大大提高氧化物材料NaCo2O4的热电性能。
关键字: 热电材料； 电学性能； 溶胶-凝胶法； 掺杂； NaCo2O4； Seebeck系数
(Na1-yMy)1.6Co2O4(M=K, Ca, Sr)
（ School of Materials and Metallurgy, Northeastern University,
Shenyang 110004, China）
Abstract: NaCo2O4 and (Na1-yMy)1.6Co2O4(M=K, 0.05≤y≤0.35; M= Ca, Sr, 0.10≤y≤0.40) is synthesized by the sol-gel method. The results show that Seebeck coefficient of NaCo2O4 is increased by doping with Ca and Sr but K, and its power factor is reduced by doping with K and increased by doping with Ca (0＜y＜0.30), and the power factor is at its maximum value of 1.68×10-4 W·m-1·K-2 by doping with Ca (y=0.1) and increased 11% compared with that without doping elements. The maximum value of power factor is 2.26×10-4 W·m-1·K-2 in case by doping with Sr (y=0.1) and is increased by 50% compared with that without doping with Sr. The thermoelectric property of NaCo2O4 after doping with Sr is the best. The experimental results show that the appropriate doping elements and doping amount can improve consumedly the thermoelectric properties of NaCo2O4.
Key words: thermoelectric materials; electric properties; sol-gel method; doping; NaCo2O4; Seebeck coefficient
