热电池用NiS_2的水热合成及放电性能

以EDTA-2Na为螯合剂,NiCl2·6H2O和Na2S2O3·5H2O为反应物,在不同pH下,水热合成不同形貌的NiS2。利用X射线衍射仪、扫描电子显微镜、激光粒度分布仪、全自动微机差热仪对NiS2进行表征。在不同条件下对LiSi/NiS2体系单体电池进行了放电测试。结果表明,在酸性条件(pH=1、4)下产物形貌均为近立方体型,中性条件(pH=7)下产物均为球形,在碱性条件(pH=9、11)产物呈片状。颗粒尺寸随pH增加先增大后减小,NiS2最高分解温度比FeS2高60℃,近立方体型NiS2的放电性能最好。NiS2锂化后有效消除了电压尖峰,提高了放电电压的稳定性。

Hydrothermal Synthesis and Discharge Performance of NiS2 Used for Thermal Battery

Abstract： NiS2 with different morphologies was synthesized by hydrothermal process under different pH values employing sodium thiosulfate pentahydrate （Na2S2O3 · 5H2O） and Nickel chloride hexahydrate （NiC12 · 6H2O ） as Reactants and ethylenediaminetetraacetic acid disodium （EDTA-2Na） as chelating agent. NiS2 was characterized by X-ray diffraction （ XRD）, scanning electron microscopy （SEM） and laser particle size analyzer, fully auto- matic microcomputer differential thermal instrument. The single cell （LiSi/LiC1-KC1/ NiS2） discharged under different conditions. The results show that the morphologies of the products could be tuned by the pH values of solutions. The NiS2 with nearly cubic shaped morphology is obtained in acid environment （pH = 1,4） ,the products are spherical in neu- tral conditions （pH = 7 ）. The flake-like samples are obtained in alkaline environment （ pH = 9,11 ）. With pH values increasing, particle size of NiS2 first increases, then decrea- ses. Peak decomposition temperature of NiS2 is 60℃higher than that of FeS2. Cubic shape NiS2 showed best performance. Lithiationed NiS2 effectively eliminate voltage peak, discharge voltage stability is improved.