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Research on Li 3 V 2 (PO 4 ) 3 /Li 4 Ti 5 O 12 /C composite cathode material for lithium ion batteries. 指导教师:唐致远教授 学生:王利娟. High ionic diffusion coefficient. Good cyclic performance. Good thermal stability. 1. Introduction about LVP. High discharge voltage and energy density. Advantages.
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Research on Li3V2(PO4)3/Li4Ti5O12/C composite cathode material for lithium ion batteries 指导教师:唐致远教授 学生:王利娟
High ionic diffusion coefficient Good cyclic performance Good thermal stability 1. Introduction about LVP High discharge voltage and energy density Advantages
Low electronic conductivity Disadvantages Unsatisfactory rate capability
A zero-strain material High lithium ion diffusion coefficient Stable high-temperature performance Good rate capability 2. Introduction about LTO Advantages
3. Experimental Mixing LiOH·H2O, NH4H2PO4 andbeta-cyclodextrin Mixing NH4VO3 and oxalic acid Solution B Adding to Solution A Solution C Suspension of Li4Ti5O12 Heating at 80℃ Adding into Sol Heating at 80℃ Gel Preheating and sintering Li3V2(PO4)3/ Li4Ti5O12/C
4. Results and discussion: EDS TEM XRD SAED TEM SEM
此方法制备的LVP/LTO/C可以在25C-50C充放电电流下循环此方法制备的LVP/LTO/C可以在25C-50C充放电电流下循环 Fig .2(a) Charge-discharge curves of LVP/LTO/C at different currents; (b) Cyclic performance of LVP/LTO/C at different currents.
LTO的包覆提高了LVP/C的离子扩散速率 LVP/LTO/C Dc:7.7×10-10cm2 s-1 Dc’: 6.4×10-10 cm2 s-1 LVP/C Dc:4.9×10-10cm2 s-1 Dc’: 4.0×10-10 cm2 s-1 Fig. 3(a) Cyclic voltammograms of Li3V2(PO4)3/Li4Ti5O12/C composite and (b) Li3V2(PO4)3/C material at different scanning rates in the range of 3.0-4.3 V. Relationship of peak current (Ip) and the square root of scanning rate (v1/2) for (c) Li3V2(PO4)3/Li4Ti5O12/C composite and (d) Li3V2(PO4)3/C material
5. Conclusions: • The Li3V2(PO4)3/Li4Ti5O12/C (LVP/LTO/C) material, • with unexceptionable rate capability and cyclic • performance has been firstly synthesized via a sol-gel • method. 2) The appealing results are related to the existence of the carbon and the LTO with high lithium ion diffusion coefficient.