Research on LiResearch on Li33VV22(PO(PO44))33/Li/Li44TiTi55OO1212/C /C

composite cathode material for lithium ion batteriescomposite cathode material for lithium ion batteries

指导教师：唐致远教授学生：王利娟

High discharge voltage and energy density

Good cyclic performance

Good thermal stability

High ionic diffusion coefficient

1. Introduction about 1. Introduction about LVP

Advantages

Unsatisfactory rate capability

Disadvantages

High lithium ion diffusion coefficient

Stable high-temperature performance

Good rate capability

A zero-strain material

2. Introduction about 2. Introduction about LTO

Advantages

3. Experimental3. Experimental

Mixing NH4VO3 and oxalic acid Solution A

Mixing LiOH·H2O, NH4H2PO4 and beta-cyclodextrin

Solution BAdding to

Solution C

Heating at 80℃

Sol

Suspension of Li4Ti5O12

Adding into

Gel

Preheating and sintering

Li3V2(PO4)3/ Li4Ti5O12/C

Heating at 80℃

4. Results and discussion4. Results and discussion ：：XRD

SEM

TEM

TEM

EDS

SAED

Fig .2(a) Charge-discharge curves of LVP/LTO/C at different currents; (b) Cyclic performance of LVP/LTO/C at different currents.

此方法制备的LVP/LTO/C可以在 25C-

50C充放电电流下循环

LVP/CDc:4.9×10-10cm2 s-1

Dc’: 4.0×10-10 cm2 s-1

LVP/LTO/CDc:7.7×10-10cm2 s-1

Dc’: 6.4×10-10 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

LTO的包覆提高了

LVP/C的离子扩散速率

5. Conclusions5. Conclusions ：：

1) 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.

Thank you!