文献类型：期刊文献

中文题名：火焰喷雾热解法制备纳米ZrO_(2)及其正极包覆应用

英文题名：Coating Cathode Material LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)with Nano ZrO_(2)Prepared via Flame Spray Pyrolysis

作者：杨澜[1];胡彦杰[1]

机构：[1]华东理工大学材料科学与工程学院,上海200030

年份：2024

卷号：52

期号：12

起止页码：3781

中文期刊名：硅酸盐学报

外文期刊名：Journal of The Chinese Ceramic Society

收录：CSTPCD;;Scopus;北大核心:【北大核心2023】；CSCD:【CSCD2023_2024】；

基金：国家自然科学基金(22378128)。

语种：中文

中文关键词：火焰喷雾热解法;纳米二氧化锆;正极包覆

外文关键词：flame spray pyrolysis;nano zirconium dioxide;coating of cathode materials

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 rate,and the particle size of ZrO_(2)is directly proportional to the feed rate.The specific surface area of ZrO_(2)powder decreases from 54.89 m^(2)/g to 28.99 m^(2)/g as the feed rate of precursor increases from 3 m L/min to 7 mL/min.Also,the distribution of particle size gradually becomes wider,and the average particle size obtained from the fitting increases from 7 nm to 18 nm.The specific surface area of ZrO_(2)is inversely proportional to the hydrogen flow rate,and the particle size of ZrO_(2)is directly proportional to the hydrogen flow rate.The uniformity of the particle size distribution of ZrO_(2)nanoparticles decreases,and the fitted average particle size gradually increases from 7 nm to 10 nm,while the specific surface area of the product decreases from 61.57 m^(2)/g to 44.73 m^(2)/g as the hydrogen flow rate increases from 3.3 L/min to 9.9 L/min.The specific surface area of ZrO_(2)is inversely proportional to the precursor concentration,and the particle size of ZrO_(2)is proportional to the precursor concentration.The specific surface area of ZrO_(2)gradually decreases from 71.58 m^(2)/g to 45.29 m^(2)/g,the particle size gradually increases from 6 nm to 11 nm,meanwhile,and the large-size particles increases significantly as the precursor concentration increases from 0.16 mol/L to 1.00 mol/L.Conclusions Zirconium dioxide nanoparticles with a high specific surface area,a small particle size and a good dispersibility could be prepared via flame spray pyrolysis with ZrCl_(4)as a precursor,ethanol as a solvent at a feed rate of 3 mL/min,a hydrogen flow rate of 3.3 L/min,and the concentration of precursor solution of 0.16 mol/L.The feed rate,hydrogen flow rate and precursor concentration all affected the particle size and specific surface area of the product,and the effect of the feed rate was dominant.A lower feed rate was favorable for the synthesis of ZrO_(2)particles with a smaller particle size and a larger specific surface area.A high hydrogen flow rate exacerbated the agglomeration of ZrO_(2)particles and reduced their specific surface area.A high concentration of precursor solution induced the generation of more large-sized particles,resulting in a decrease in the specific surface area.Zirconia obtained under the optimal process conditions of 0.2%(mass fraction)coating on the surface of NCM811 cathode material could increase the capacity retention of the battery by 14%at 1 C and 2.7–4.3 V.Nano-sized powder of zirconium dioxide was prepared via flame spray pyrolysis at suitable process parameters,providing a promising method for the preparation of zirconium dioxide powder with a small particle size and a high specific surface.In addition,the application in anode capping could also improve the comprehensive performance of the battery.