水热晶化工艺可以显著减轻产物颗粒团聚的不利影响。以硫酸亚铁为铁源的磷酸铁锂水热合成法,所耗氢氧化锂达到化学计量的3倍,严重浪费锂资源。研究发现以碳酸亚铁为铁源,在合适的酸度条件下,可以通过水热晶化工艺制备出颗粒团聚轻微的磷酸铁锂正极材料,与硫酸亚铁水热法相比能有效节省2/3的锂源,在0.1C条件下,包覆3%(wt,质量分数)碳制得的磷酸铁锂正极材料具有较高的放电比容量,达到161mAh/g。
Hydrothermal crystallization may significantly alleviate the negative effects due to aggregation of product particles.The hydrothermal synthesis of LiFePO4 using ferrous sulfate as the iron source consumed lithium hydroxide to three times of its stoichiometric amount,which wasted lithium resource.LiFePO4 with less-aggregated particles may be hydrothermally synthesized at suitable acidity using ferrous carbonate as the iron source was found,which effectively saved 2/3 of the lithium source compared with the hydrothermal method using ferrous sulfate.The lithium iron phosphate coated with 3wt% carbon exhibitd a high discharge capacity of 161mAh/g at 0.1C.
[1] Qin X,Yang G,Gao J,et al.LiFePO4/C cathode material modified by polyacrylamide[J].J Inorg Mater,2016,31(5):517-522.
[2] Major K,Veilleux J,Brisard G.Lithium iron phosphate powders and coatings obtained by means of inductively coupled thermal plasma[J].J Therm Spray Technol,2016,25(1/2):357-364.
[3] Ha S,Ramani V,Lu W,et al.Optimization of inactive material content in lithium iron phosphate electrodes for high power applications[J].Electrochim Acta,2016,191:173-182.
[4] Lee J,Shen H,Li C.Three-phase inductive-coupled structures for contactless PHEV charging system[J].Int J Electron,2016,103(7):1083-1097.
[5] 刘曰锋.中低速磁浮列车锂电池的选型分析[J].科技经济导刊,2016(6):108-108.
[6] 聂小勇,蒋兴,陈波波,等.并联磷酸铁锂电池在110kV变电站的应用研究[J].电源技术,2016,40(5):979-981.
[7] Wang J,Sun X.Understanding and recent development of carbon coating on LiFePO4 cathode materials for lithiumion batteries[J].Energy Environ Sci,2012,5(1):5163-5185.
[8] Liu Z,Xu B,Xing Y,et al.Determination of the relationship between particle size and electrochemical performance of uncoated LiFePO4 materials[J].J Nanopart Res,2015,17(3):1-12.
[9] Li H,Zhou H.Enhancing the performances of Li-ion batteries by carbon-coating:present and future[J].Chem Commun,2012,48(9):1201-1217.
[10] Shi Y,Chou S,Wang J,et al.Graphene wrapped LiFePO4/C composites as cathode materials for Li-ion batteries with enhanced rate capability[J].J Mater Chem,2012,32(22):16465-16470.
[11] Liu Z,Li J,Xing Y,et al.LiFePO4/C composites derived from precipitated FePO4 precursor:effects of mixing processes[J].Ionics,2014,20(11):1511-1516.
[12] Shahid R,Murugavel S.Synthesis and characterization of olivine phosphate cathode material with different particle sizes for rechargeable lithium-ion batteries[J].Mater Chem Phys,2013,140(2/3):659-664.
[13] Nan C,Lu J,Li L,et al.Size and shape control of LiFePO4 nanocrystals for better lithium ion battery cathode materials[J].Nano Res,2013,6(7):469-477.
[14] Ferrari S,Lavall R L,Capsoni D,et al.Influence of particle size and crystal orientation on the electrochemical behavior of carbon-coated LiFePO4[J].J Phys Chem C,2010,114(29):12598-12603.
[15] Fan C,Li Q,Chen S,et al.Poly(vinylpylrrolidone) as surfactant in the sol-gel preparation of lithium iron phospate/carbon cathodes for lithium-ion batteries[J].Energy Technol,2016,4(8):973-979.
[16] Chen J,Whittingham M S.Hydrothermal synthesis of lithium iron phosphate[J].Electrochem Commun,2006,8(5):855-858.
[17] 唐姣君,董晓利,高晓梅.锂电池正极材料磷酸铁锂前驱体碳酸亚铁的制备方法:CN 105552329A[P].2016-05-04.
[18] Sing K S W,Everett D H,Haul R A W,et al.Reporting physisorption pata for gas/solid systems with special reference to the determination of surface area and porosity[J].Pure & Appl Chem,1985,57(4):603-619.
基金资助
国家自然科学基金(U1204202);河南省高等学校青年骨干教师资助计划项目(#2013GGJS-112);郑州轻工业学院第五批大学生创新实验项目(#5-49);郑州轻工业学院第十一批教改与研究项目(#11-13)
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