A simple, low-cost and scale-up synthesis strategy of spherical-graphite/Fe2O3 composites as high-performance anode materials for half/full lithium ion batteries

Abstract

Spherical-graphite/Fe2O3 composites have been synthesized through a facile and cost-effective strategy which contains initial co-precipitation reaction along with subsequent calcination process. The core-shell structure of composites is formed by coating some Fe2O3 nanorods on the surface of spherical-graphite. This work verifies the optimal coating amount of Fe2O3, which is most beneficial for improvement of lithium storage performance. Indeed, all the composites deliver excellent rate capability and cycling stability in half-cell. The optimal spherical-graphite/Fe2O3 composite with 8.7 wt% of Fe2O3 exhibits a high reversible capacity of 540 mAh g−1 at 0.5 A g−1 and 376 mAh g−1 at 2 A g−1 after 200 and 1000 cycles, respectively. The electrochemical performance of full-cell with optimal composite as anode and LiFePO4 as cathode has been investigated, which can retain 288 mAh g−1 at 0.1 A g−1 after 30 cycles. The outstanding lithium storage performance is lied in the synergistic effect of spherical-graphite and Fe2O3 nanorods. The outer Fe2O3 nanorods can significantly improve the lithium storage capacity, meanwhile the high-conductive spherical-graphite can suppress the volume changes of Fe2O3. The above results demonstrate that the low-cost and simple synthesis strategy to prepare spherical-graphite/Fe2O3 composites has sufficient potential to replace graphite for high performance lithium ion batteries.