低品位蓝晶石制备锂离子电池窑炉用莫来石轻质隔热材料

Light-weight mullite insulation materials prepared using low-grade kyanite for lithium battery kilns

为实现对低品位蓝晶石的综合利用,以低品位蓝晶石、α-Al_(2)O_(3)微粉和黏土为主要原料,在10 MPa下机压成型,分别经1450和1500℃保温3 h热处理,通过燃尽物法制备了莫来石轻质隔热材料。研究了黏土加入量(加入质量分数分别为5%、10%、15%、20%)和热处理温度(1450、1500℃)对试样体积密度、显气孔率、常温耐压强度、热导率以及抗锂离子电池正极材料侵蚀性能和显微结构的影响。结果表明:黏土的引入促进了试样的致密化和莫来石化反应,提高了试样体积密度、热导率和强度,添加20%(w)黏土的试样经1450℃烧后物理性能最佳,其体积密度为0.88 g·cm^(-3),常温耐压强度为21.0 MPa,热导率为0.25 W·(m·K)^(-1);当热处理温度为1450℃,黏土加入量为10%(w)时,试样具有较好的抗锂离子电池正极材料侵蚀性能。

In order to realize the comprehensive utilization of low-grade kyanite,light-weight mullite insulation materials were prepared by burnout method with low-grade kyanite,α-Al_(2)O_(3) micropowder and clay as main raw materials,machine-pressing under 10 MPa,and hot treating at 1450 or 1500℃for 3 h.Effects of the clay addition(5%,10%,15%and 20%,by mass)and hot treatment temperature on the bulk density,apparent porosity,cold crushing strength,thermal conductivity of samples,as well as the corrosion resistance to lithium battery cathode materials and microstructure were studied.The results show that the introduction of clay promotes the densification and mullitization reaction of the samples,and enhances the bulk density,thermal conductivity,and strength of the samples;the samples with 20%clay hot treated at 1450℃perform the best physical properties:bulk density 0.88 g·cm^(-3),cold crushing strength 21.0 MPa,thermal conductivity 0.25 W·(m·K)^(-1).The samples with 10%clay hot treated at 1450℃have good corrosion resistance to lithium battery cathode materials.