With the progress of science and technology, notebook computers, microcomputers, digital cameras, mobile phones and other new electronic equipment come out one after the other. The development of new products to the storage of energy have a greater demand, the traditional graphite anode material has been unable to meet its performance needs. The spinel lithium titanate is a lithium ion battery anode material with good cycling capability, wide operating temperature range and good safety performance. However, due to the poor electrical conductivity and low lithium-ion diffusion coefficient, the rate performance is very limited. Therefore, increasing rate performance of lithium titanate anode material becomes the only way of application of lithium titanate .

In this paper, lithium titanate is prepared by coaxial electrospinning. With the High molecular weight polymer polyvinylpyrrolidone (PVP) providing high viscosity，a solution spinning solution of PVP and absolute ethanol is used as the inner layer template solution. The Part of solution with a lithium source and a titanium source set as an outer layer precursor solution. After the titanate precursor fiber filaments are calcined, with core and outer PVP are removed the hollow lithium titanate filament is finally obtained. Figure a is cycle-capacity curve of the hollow lithium titanate anode material after prepared into a button cell. The first 0.2C rate of the specific capacity is 174.9mAhg^-1 with theoretical specific capacity flat, and at the 30C specific capacity can be to 105 mAhg^-1, which can achieve that Li-ion battery immediately charge. Figure b shows that, at low charge and discharge rate, lithium titanate discharge platform is relatively stable, while platform stability is poor at the high charge and discharge rate.

Figure 1. (a) Discharge capacity curves of lithium titanate at different charge and discharge rate; (b) the first discharge profiles of lithium titanate at the different charge and discharge rate.

Reference

[1] Cho, Y., Lee, S., Lee, Y., Hong, T., & Cho, J. (2011). Spinel-layered core-shell cathode materials for li-ion batteries. Advanced Energy Materials,1(5), 821–828.

[2] A. K. Moghe, & Professor B. S. Gupta. (2008). Co‐axial electrospinning for nanofiber structures: preparation and applications. Polymer Reviews,48(2), 353-377.

[3] Tong, H., Tao, X., Wu, D., Zhang, X., Li, D., & Zhang, L. (2014). Preparation and characterization of doped tio 2, nanofibers by coaxial electrospining combined with sol–gel process. Journal of Alloys & Compounds, 586(10), 274-278.

Acknowledgment

Thanks for being funded by the Technology Research Program of the State Grid about Preparing Submicron Lithium Titanate-based Materials for Energy Storage Batteries (DG71-15-042) .