Partially carbonised melamine sponge coated with metal–organic framework-derived CuCo2O4/C composite as a flexible anode for lithium-ion batteries

Abstract

The poor conductivity of melamine sponges limits their applications as flexible electrode substrates for lithium-ion batteries (LIBs). Coating metals on the surface of the electrode increases its weight, which, in turn, lowers the capacity. Furthermore, complete carbonisation at high temperatures causes a loss of flexibility. Herein, we report the design and synthesis of a novel flexible anode for LIBs with a metal–organic framework (MOF)-derived CuCo2O4/C composite coated on the surface of a partially carbonised melamine sponge (PCMS). The PCMS gives good flexibility to the electrode and is compatible with growth of a MOF-derived CuCo2O4/C composite on its surface. As a carbon-based composite with good conductivity, the continuous MOF-derived CuCo2O4/C composite coating on the surface of the PCMS considerably improved its conductivity. As a flexible anode for LIBs, the composite with the MOF-derived CuCo2O4/C on the surface of the PCMS had capacities of 521 mAh g−1 and 348 mAh g−1 at current densities of 100 mA g−1 and 2000 mA g−1, respectively. Here, the MOF-derived CuCo2O4/C composite contributed a high capacity of 1002 mAh g−1.