Advanced Li-Ion Batteries with High Rate, Stability, and Mass Loading Based on Graphene Ribbon Hybrid Networks

Chemistry. 2019 Apr 1;25(19):5022-5027. doi: 10.1002/chem.201805869. Epub 2019 Mar 12.

Abstract

To optimize the cycle life and rate performance of lithium-ion batteries (LIBs), ultra-fine Fe2 O3 nanowires with a diameter of approximately 2 nm uniformly anchored on a cross-linked graphene ribbon network are fabricated. The unique three-dimensional structure can effectively improve the electrical conductivity and facilitate ion diffusion, especially cross-plane diffusion. Moreover, Fe2 O3 nanowires on graphene ribbons (Fe2 O3 /GR) are easily accessible for lithium ions compared with the traditional graphene sheets (Fe2 O3 /GS). In addition, the well-developed elastic network can not only undergo the drastic volume expansion during repetitive cycling, but also protect the bulk electrode from further pulverization. As a result, the Fe2 O3 /GR hybrid exhibits high rate and long cycle life Li storage performance (632 mAh g-1 at 5 A g-1 , and 471 mAh g-1 capacity maintained even after 3000 cycles). Especially at high mass loading (≈4 mg cm-2 ), the Fe2 O3 /GR can still deliver higher reversible capacity (223 mAh g-1 even at 2 A g-1 ) compared with the Fe2 O3 /GS (37 mAh g-1 ) for LIBs.

Keywords: Li-ion batteries; graphene ribbon; superior cyclability; ultra-fine Fe2O3 nanowires.