Three-dimensional hierarchical Ca3Co4O9 hollow fiber network as high performance anode material for lithium-ion battery

Transition metal oxides have high specific capacity as anode materials for lithium-ion battery. But aggregation of particles and volume expansion during lithiation/delithiation restrict their application. In this work, a three-dimensional hierarchical Ca3Co4O9 hollow fiber network assembled by nanosheets is prepared by a electrospinning combining with heat treatment method to overcome these issues and to boost its lithium storage performance. As-synthesized sample possesses excellent cyclic stability (578.6 mA h g(-1) at 200 mA g(-1) after 500 cycles) and rate performance (293.5 mA h g(-1) at 5000 mA g(-1)), much better than those of commercial Co3O4. Furthermore, the fast kinetics of the three-dimensional Ca3Co4O9 hollow fiber network is also confirmed by the variable scan rates CV tests and the EIS measurements, which is dedicated to the specific hierarchical hollow fiber network structure that provides shorter ion transport distances and higher electrical conductivity. This work supplies a universal approach to improve the electrochemical performance of transition metal oxides for lithium ion batteries.