热电池复合阴极材料NiCl2/NiF2放电性能的研究-中国材料进展

文章信息/Info

Title:: Research on the Discharge Characteristics of NiCl2/NiF2 Composite Cathode Materials in Thermal Batteries

Author(s):: MA Shiping; CAO Yong; ZHANG Xiaoqiang; WEI Kaiyuan; WU Tao; WANG Chao; CUI Yanhua; (Institute of Electronic Engineering, China Academy of Engineering Physics, Mianyang 621000, China)

Keywords:: thermal batteries; cathode materials; composite materials; NiCl2/NiF2

摘要:: NiCl2阴极材料具有高的理论放电电压和理论比能量，作为一种新型热电池阴极材料而被广泛研究。NiCl2阴极材料在放电过程中会产生LiCl等物质，这将导致含LiCl的熔盐电解质出现成分偏析，并产生较大的极化阻抗，从而使NiCl2阴极材料的放电性能明显下降。通过添加不同含量的NiF2构建NiCl2/NiF2双活性复合阴极材料，能够抑制NiCl2阴极材料在放电过程中造成的熔盐成分偏析。研究结果表明，当添加的NiF2质量分数为30%时，在电流密度为100 mA·cm-2下NiCl2/NiF2双活性复合阴极材料的放电比容量达到291.2 mAh·g-1，比能量密度达0.701 Wh·g-1（截止电压≥2 V），比能量密度分别是NiCl2和NiF2阴极材料的1.67和2.11倍。

Abstract:: NiCl2 has been widely studied as a new cathode material for thermal batteries due to its high theoretical discharge voltage and specific energy. However, LiCl generates during the discharge process of NiCl2 cathode, which results in composition segregation and larger polarization resistance of the molten salt electrolyte containing LiCl. It makes a significant reduction for the discharge performance of NiCl2 cathode. In this contribution, NiF2 was adopted as an additive to construct a NiCl2/NiF2 dual active composite cathode in order to suppress the composition segregation of molten salt electrolyte during the discharge process. The research results show that when the content of NiF2 is 30wt%, the specific discharge capacity and specific energy density of NiCl2/NiF2 composite cathode respectively reach 291.2 mAh·g-1 and 0.701 Wh·g-1 at the cut-off voltage over 2 V and the discharge current density of 100 mA·cm-2. The specific energy density of NiCl2/NiF2 composite cathode is 1.67 and 2.11 times of NiCl2 and NiF2 cathode, respectively.