锆粉加热纸燃烧机理研究

Combustion mechanism of Zr-BaCrO_4 heat paper

研究了热电池用Zr-BaCrO4加热纸(锆粉加热纸)的燃烧机理。X射线衍射光谱法(XRD)物相分析表明,在Zr-BaCrO4加热纸中,若Zr粉量不足,则燃烧后物相成分为BaZrO3和CrO;若Zr粉过量,物相成分还包括Zr2O。在Zr粉量不足的加热纸中,燃烧包含Zr和BaCrO4发生氧化还原反应生成BaZrO3和CrO,及BaCrO4分解的两个反应;在Zr粉过量的加热纸中,燃烧包含Zr和BaCrO4发生氧化还原反应生成BaZrO3和CrO,及产物为BaO,CrO和Zr2O的另一个氧化还原反应。计算得Zr粉过量时加热纸燃烧产物中Zr2O的标准焓变值约在-1290～-1296kJ/mol范围;经热重-差热分析(TG/DSC)、理论计算及加热纸灰烬于1200℃氧化后的物相分析都证实其热稳定性高于1200℃。Zr-BaCrO4加热纸燃烧机理的确定有助于精确设计加热纸成分、控制电池输入热量、提高电池质量及安全性,并为电池的数字化设计提供有效参数。

The thermal battery used Zr-BaCrO4 heat paper combustion mechanism has been studied. It is identified by X-ray diffraction （XRD） analysis that the main compositions of the combustion products are BaZrO3 and CrO when zirconium powder mass is insufficient, otherwise, the main compositions are BaZrO3, CrO and Zr2O. When zirconium powder mass is insufficient, the Zr-BaCrO4 heat paper combustion mechanism are Zr＋BaCrO4→ BaZrO3＋CrO＋△H and BaCrO4→＊BaO＋CrO＋O2 ↑ ＋△H, otherwise, its depends on reactions of Zr＋BaCrO→ BaZrO3＋CrO＋△H and 4 Zr＋BaCrO4→BaO＋CrO＋2 Zr2O ＋△H. When zirconium powder mass is excessive, Zr2O is one of the main results, which calculated standard formation enthalpy value （△fHZ2O（s）^θ） range is from -- 1 290 kJ/mol to --1 296 kJ/mol. The thermal stability of Zr2O is very high, which has been verified by TG/DSC analysis, thermodynamic calculations and X-ray diffraction （XRD） analysis when the combustion ashes were oxidized at the temperature of 1 200 ℃. Once the combustion mechanism has been verified, Zr-BaCrO4 heat paper combustion heat output can be designed and calculated accurately, and then the thermal batteries performance and safety can be improved greatly.