上海交大磷酸铁锂电池的高低温解决途径课件

Shanghai Jiao Tong University Approaches to improve the electrochemical performance of LiFePO4-based lithium ion batteries working in a wide temperature range Zi-FengZi-Feng Ma Ma Department of Chemical EngineeringDepartment of Chemical Engineering Shanghai Jiao Tong University, Shanghai Jiao Tong University, Shanghai 200240, ChinaShanghai 200240, China E-mail: E-mail: 磷酸铁锂动力电池的高低温性能解决途径 Shanghai Jiao Tong University Introduction Introduction 前期工作基础： 上海交通大学在LiFePO4正极材料制备新工艺方面，获得6项中国发明专利(专利号: ZL 200410018476.4等) ；2004年开始与浙江横店东磁股份有限公司合作开展产业 化技术开发，获得2006年浙江省产业化转化项目，2008年初完成中试线。 Mechanical chemical reaction Mechanical chemical reaction Fe+2FePO Fe+2FePO 4 4 +Li+Li 3 3 POPO 4 4 .0.5H.0.5H 2 2 O O 3LiFePO3LiFePO4 4 + 0.5H + 0.5H 2 2 OO u Xiao-Zhen Liao, Zi-Feng Ma*, Liang Wang, Xiao-Ming Zhang, Yi Jiang, Yu-Shi He, Electrochem. Solid-State Lett. 2004, 7(12)：A522-525 （SCI Cited 33) u Xiao-Zhen Liao, Zi-Feng Ma*, Yu-Shi He, Xiao-Ming Zhang, Liang Wang, Journal of the Electrochemical Society, 2005, 152(10):A1969-1972 (SCI cited 25) u 2008年全国优秀博士学位论文提名奖；2007年上海市优秀博士学位论文 Shanghai Jiao Tong University 现有生产能力：年产现有生产能力：年产150150吨磷酸铁锂正极材料吨磷酸铁锂正极材料 近期目标：合资建立磷酸铁锂动力电池生产线近期目标：合资建立磷酸铁锂动力电池生产线 36V12Ah Shanghai Jiao Tong University IntroductionIntroduction In winter, the electric vehicle have to be started at low temperature and the battery need to keep better performance Shanghai Jiao Tong University IntroductionIntroduction Shanghai Jiao Tong University Cathode: particle size minimization or doping Approaches to enhance the performance of LiFePO4/C cathode at low temperature Electrolyte: uSolvent selection: affects liquid temperature range and viscosity, and participating in the formation of a solid electrolyte interface (SEI), the resistance of which is main resistance in the full cell.(两元、三元或四元） uLithium salt: LiPF6, LiBF4, LiBOB et al K. Amine, J. Liu, I. Belharouak, Electrochem. Commun. 7 (2005) 669. Shanghai Jiao Tong University 1.0m(0.9LiBF40.1LiBOB) 1:1:3 PC/EC/EMC electrolyte Effect of salt ratio on the discharge voltage of Li/LiFePO4 cells, which was measured at 1C by charging the cell at 20 C and then discharging at 30 C. Discharge curves of Li/LiFePO4 cell with a 1.0m(0.9LiBF40.1LiBOB) 1:1:3 PC/EC/EMC electrolyte, which were recorded at 1C by charging the cell at 20 C and then discharging at a specific temperature. S.S.Zhang, K.Xu, T.R.Jow, J Power Sources 159(2006) 702-707 LiFePOLiFePO 4 4 /C/C低温性能研究低温性能研究 Shanghai Jiao Tong University We studied the low temperature performance of LiFePO4/C cathode in a quaternary carbonate-based electrolyte. The discharge capacities of the LiFePO4/C cathode were about 134.5 mAh/g (20), 114 mAh/g (0), 90 mAh/g (-20) and 69 mAh/g (-40) using a 1C charge-discharge rate. 1.0M LiPF6/EC+DMC+DEC+EMC (1:1:1:3, v/v) electrolyte LiFePOLiFePO 4 4 /C/C低温性能研究低温性能研究 X.-Z. Liao et al. / Electrochemistry Communications 10 (2008) 691694 Shanghai Jiao Tong University TempRs()Rp ()Rt ()D (cm2/s) 20C4.6786.968.21.7010-12 0 C5.93101.1124.31.5510-12 -20C7.88120.0315.12.0510-13 -40C13.04126.32005.42.1210-14 The improving of the reaction activity of the electrolyte-active material interface by surface modification and electrolyte optimization, increasing the lithium diffusion ability LiFePOLiFePO 4 4 /C/C低温性能研究低温性能研究 Shanghai Jiao Tong University LiFePOLiFePO 4 4 /C/C高温性能研究高温性能研究 uElectrolyte uAnode uCathode Three solutions to enhance the cycling performance of LiFePO4/C cathode working at high temperature. It is based on similar reason that is to prevent Fe() ions dissolving. Shanghai Jiao Tong University Electrolyte DesignElectrolyte Design K.Amine, J.Liu, I.Belharouak, Electrochem. Commun.7(2005)669-673 1.2M LiPF6/ EC+PC+DMC (1:1:3) electrolyte 0.7M LiBOB/ EC+PC+DMC (1:1:3) electrolyte Shanghai Jiao Tong University 1.0m(0.9LiBF40.1LiBOB) 1:1:3 PC/EC/EMC electrolyte S.S.Zhang, K.Xu, T.R.Jow, J Power Sources 159(2006) 702-707 Comparison of the cycling performance at high temperature for the Li/LiFePO4 cells with different electrolytes, in which the cells were charged and discharged at 1C. Shanghai Jiao Tong University Anode coatingAnode coating uH.-H. Chang et al. / Journal of Power Sources 185 (2008) 466472 uH.H. Chang, H.C. Wu, N.L. Wu, Electrochem. Commun.10(2008)1823-1826 Cycle performance of LiFePO4/MCMB cells with different metal coatings, including Au, Cu, Fe, Co, Ni, and Ti on the MCMB electrode surface. All the cells were cycled at 1 C charge/discharge rate at 55 C in the voltage window of 2.54.0 V. LiFePO4 particles were coated with TiO2 (molar ratio = 3%) via a solgel process Shanghai Jiao Tong University LiFe(PO4)1-xFx/C cathode LiFe（PO4）0.9F0.1/C材料的循环容量在200次循环后才开始衰减，但衰减程度明 显比其他三种材料小，到500次循环容量保持在121 mAh/g。可见掺LiF对提高材 料高温循环稳定性很有好处。 Xiao-Zhen Liao, Yu-Shi He, Zi-Feng Ma, Liang Wang, Xiao-Ming Zhang J. Power Sources 174(2007)720 Shanghai Jiao Tong University LiFePO4/C cathode modification Shanghai Jiao Tong University F 取代对LiFePO4结构的影响 掺入LiF量较少时，F元素以LiF形式固溶 到LiFePO4晶格结构中；而掺LiF量较多 的LiFe(PO4)0.9F0.1/C材料，部分LiF生成 Fe2(PO4)F，F以LiF和Fe2(PO4)F两种状 态固溶到LiFePO4晶格结构中。 XPS研究表明，Fe(2P1/2, 2P3/2)峰位随掺F量增 大而向高键合能方向偏移，可见F确实已固溶到 LiFePO4晶格结构，对晶格中的Fe有影响 Shanghai Jiao Tong University Rate capabilities of LiFePO4/C and PPy- LiFePO4/C electrodes (active material : carbon black: PVDF=75:15:10) Cycle performance of PPy- LiFePO4/C composite at different temperatures 包覆后的倍率性能从8C 提高到40C，放电平台高 PPy coating LiFePO4/C cathode Shanghai Jiao Tong University Discharge curves of LiFePO4/C and PPy-LiFePO4/C composite cathode materials at 5C working in 55C PPy-LiFePO4/C LiFePO4/C PPy coating LiFePO4/C cathode Shanghai Jiao Tong University Yang Yang, Xiao-Zhen Liao, Zi-Feng Ma, Bao-Feng Wang, Yu-Shi He, Li He Electrochem. Commun.11(2009)1277-1280 PPy coating LiFePO4/C cathode 1.The discharge curves of the cathodes at different cycles. 1.Cycling performance of the Li-LiFePO4/C cell at 5C chargedischarge rate at 55 Shanghai Jiao Tong University SummarySummary uSeveral approaches can be used to enhance the cycling performance of LiFePO4/C cathode working in a wide temperature range. The new electrolytes design and preparation are mostly significant to improve the low temperature performance. uThus improving the reaction activity of the electrolyte-active material interface by surface modification and electrolyte optimization, increasing the lithium diffusion ability by modifying the crystal structure and minimizing the particle size are considered to be effective approaches to improve the low temperature performance of LiFePO4/C cathode material. uAnode coating is effective to improve the cycling performance of the LiFePO4/C based lithium ion batteries. Shanghai Jiao Tong University 973 Program of China (2007CB209705)973 Program of China (2007CB209705) Natural Science Foundation of China (20773087) Natural Scienc