摘要
以四氯化锆为前驱体,乙醇为溶剂,采用火焰喷雾热解法(FSP)制备纳米二氧化锆(ZrO_(2))粉体,研究了前驱体溶液浓度、进料速度和氢气流量等工艺参数对粉体粒径、比表面积及微观形貌的影响,并探究了ZrO_(2)的最佳合成工艺参数及其对高镍三元正极材料的包覆改性效果。利用Brunauer-Emmett-Teller方法、透射电子显微镜、X射线衍射、激光粒度分析仪等表征手段测试了粉体的物化特性。结果表明:当前驱体溶液浓度为0.16 mol/L、氢气流量为3.3 L/min、进料速度为3 m L/min时,得到的ZrO_(2)粉体粒径最小(5~20 nm),比表面积最大(71 m^(2)/g)。将其应用于LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)正极材料包覆改性,改性后的正极材料在1 C下的首次放电比容量为188.45 m Ah/g,经历200次循环后,其容量保持率提升了约14%。
Introduction A high-nickel ternary cathode material of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)has a high energy density.However,this material suffers from interfacial/structural instability,leading to a loss of more than 10%of its capacity during cycling.Cathode materials can be surface coated to improve their overall performance,in which nano-powder of zirconium dioxide can be used as a coating material to effectively improve the structural stability of high nickel ternary materials.However,the method for zirconia preparation has some disadvantages like complicated process flow,high production cost,and easy particle agglomeration.Flame spray pyrolysis(FSP)is simple in operation,fast in reaction speed,high in product quality,and easy to scale up production.In this paper,a variety of metal-based nanomaterials with small particle sizes and well-dispersity were prepared via FSP.The effect of process parameters(i.e.,precursor solution concentration,feed rate and hydrogen flow rate)on the particle size,morphology and specific surface area of the powder was investigated.The synthesis process parameters of ZrO_(2)were optimized,and the effect of optimal parameters on the coating modification of high-nickel ternary cathode materials was analyzed.Methods A certain amount of ZrCl_(4)was weighed and dissolved in ethanol,and stirred at 40℃to dissolve it completely and formulate precursor solutions at different concentrations(i.e.,0.16,0.50,and 1.00 mol/L).At different hydrogen flow rates(3.3,6.6,and 9.9 L/min)and feed rates(3,5,and 7 mL/min),the precursor solutions with different concentrations were injected into a flame spray pyrolysis unit by a syringe pump.Finally,ZrO_(2)powder was collected through a filter.The physical and chemical properties of the powders were determined by Brunauer-Emmett-Teller(BET)surface area analysis,transmission electron microscopy(TEM),X-ray diffraction(XRD),and laser particle size(DLS)analysis.Results and discussion The specific surface area of ZrO_(2)is inversely proportional to the feed ra
作者
杨澜
胡彦杰
YANG Lan;HU Yanjie(Academic of Materials Science and Engineering,East China University of Science and Technology,Shanghai 200030,China)
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2024年第12期3781-3788,共8页
Journal of The Chinese Ceramic Society
基金
国家自然科学基金(22378128)。
关键词
火焰喷雾热解法
纳米二氧化锆
正极包覆
flame spray pyrolysis
nano zirconium dioxide
coating of cathode materials
