Porous diatomite-mixed 1,4,5,8-NTCDA nanowires as high-performance electrode materials for lithium-ion batteries

Abstract

A porous composite electrode composed of diatomite-mixed 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTCDA) is prepared by electrostatic spinning technology. Compared with traditional coated electrodes without diatomite mixing, the obtained composite electrode materials have higher porosity, larger specific surface area and faster lithium ion transport channels, which makes them exhibit better electrochemical performance, such as smaller impedance, higher capacity, and better cycling stability and rate performance. The electrospun diatomite-mixed 1,4,5,8-NTCDA composite (ED-1,4,5,8-NTCDA) electrode shows an initial coulombic efficiency of 77.2%, which is much higher than that of the electrospun 1,4,5,8-NTCA (E-1,4,5,8-NTCDA) electrode without diatomite mixing (63.8%) and the coated 1,4,5,8-NTCA (C-1,4,5,8-NTCDA) electrode (48.3%). Moreover, the ED-1,4,5,8-NTCDA electrode displays an initial discharge capacity of 1106.5 mA h g⁻¹, which is much higher than that of the E-1,4,5,8-NTCDA electrode (546.0 mA h g⁻¹) and the C-1,4,5,8-NTCDA electrode (185.4 mA h g⁻¹). After 200 cycles, the capacity of the ED-1,4,5,8-NTCDA electrode remains at 1008.5 mA h g⁻¹ with a retention ratio of 91.2%, which is also much higher than that of 753.2 mA h g⁻¹ for the E-1,4,5,8-NTCDA electrode and 288.1 mA h g⁻¹ for the C-1,4,5,8-NTCDA electrode. Even at a higher current density of 1500 mA g⁻¹, its capacity remains above 508.9 mA h g⁻¹. The ED-1,4,5,8-NTCDA electrode presents superior performance, which opens up a promising new approach for further utilization of organic materials as electrode materials in rechargeable lithium-ion batteries.