摘要
莫来石-刚玉质匣钵广泛应用于焙烧三元正极材料,但由于多次循环使用和高温正极材料的侵蚀导致匣钵性能下降、结构破损。为提升莫来石-刚玉质匣钵的性能并延长其使用寿命,探讨了不同含锂侵蚀产物对其抗折强度、烧结性能、物相组成及显微结构的影响。研究发现,添加含锂侵蚀产物能够显著增强匣钵的综合性能。当引入γ-LiAlO_(2)时,匣钵的整体性能达到最佳:显气孔率为17.74%、常温抗折强度为28.98 MPa,强度保持率达到85.54%。通过XRD和SEM-EDS分析,证实了γ-LiAlO_(2)的加入促进了物相间固溶体的形成,显著增强了骨料与基质间的结合强度。研究结果为莫来石-刚玉质匣钵的优化设计及性能提升提供了理论依据。
Mullite-corundum saggars are critical containers for the calcination of ternary cathode materials in lithium-ion batteries,and their performance optimization is essential for ensuring the quality and cost-effectiveness of cathode material production.During high-temperature calcination processes,Li+released from the cathode materials infiltrates the saggar matrix through pores or cracks,reacting with its components to form lithium compounds such as lithium aluminate(LiAlO_(2)),lithium nepheline(LiAlSiO_(4)),spodumene(LiAlSi_(2)O_(6)),and lithium silicates(Li_(2)SiO_(3),Li_(4)SiO_(4)).These lithium compounds exhibit a thermal expansion coefficient mismatch with the saggar matrix materials,and leading to spalling and damage under repeated thermal shocks.In addition,the inherent limitations in thermal shock resistance of the saggar itself resulted in cracking and failure during prolonged cyclic use,thereby shortening its service life and compromising cathode material quality.Therefore,enhancing the performance of mullite-corundum saggars is crucial for prolonging their lifespan and ensuring the quality of cathode materials.To address these challenges,researchers introduce external additives such as CaO·6Al2O_(3) and KAlSi2O_(6) into saggar formulations to enhance their mechanical and thermal shock resistance.However,these additional materials may affect the quality of the anode materials.To enhance the physical performance of mullite-corundum saggars,this study proposes utilizing lithium compounds generated during saggar service as external raw materials to fabricate novel mullite-corundum composites.First,four single-phase lithium compounds of α-LiAlO_(2),γ-LiAlO_(2),LiAlSiO_(4) and LiAlSi_(2)O_(6) were synthesized via high-temperature solid-state synthesis method.Then,these compounds were individually incorporated as additives into the raw materials for saggar fabrication.A series of mullite-corundum composites were prepared through four processes,including mixing,pressing,drying and roasting.For the prepared specimens,the effects of different lithium compounds on the flexural strength,sintering properties,phase composition,and microstructure of the composites were systematically investigated.The results demonstrate that the mullite-corundum specimens incorporating lithium compounds exhibite significantly superior physical properties compared to those without additives.Among them,the sample prepared by adding γ-LiAlO_(2) has achieved optimal performance,with an apparent porosity of 17.74%,the cold modulus of rupture of 28.98 MPa,and the residual strength rate of 85.54%.Through XRD and SEM-EDS analysis,it is shown that the addition ofγ-LiAlO_(2) can further generate Li2O·Al_(2)O_(3)·nSiO_(2) phase with the mullite phase in the saggar,and can promote the formation of solid solution,significantly enhance the bonding strength between the aggregate and the matrix,and reduce the change physical properties of the material caused by the erosion between the saggar and the lithium compounds during the subsequent use.The research results can provide a theoretical basis for optimal design and performance improvement of mullite-corundum saggar.
作者
吴琳琳
孙振华
王晨晔
李会泉
邢鹏
刘明坤
WU Linlin;SUN Zhenhua;WANG Chenye;LI Huiquan;XING Peng;LIU Mingkun(College of Environmental and Chemical Engineering,Dalian University,Dalian 116622,Liaoning,China;CAS Key Laboratory of Green Process and Engineering,National Engineering Research Center of Green Recycling for Strategic Metal Resources,Institute of Process Engineering,CAS,Beijing 100190,China;School of Chemical Engineering,University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《有色金属(冶炼部分)》
北大核心
2025年第7期59-67,共9页
Nonferrous Metals(Extractive Metallurgy)
基金
国家自然科学基金资助项目(52204425)
中国科学院青年创新促进会项目(2021045)。
关键词
莫来石-刚玉
抗热震性
匣钵
含锂侵蚀产物
mullite-corundum
thermal shock resistance
saggar
lithium compounds
