Modulating charge distribution of MIL@CuFe-Se by in-situ interface engineering for high performance supercapacitors
Ziyun Zhang, Lei Li, Xiaomin Chen, Wentao Ding, Sheng Han, Jibo Jiang
Abstract
Designing hybrid materials with ideal interfacial interactions derived from metal-organic frameworks (MOFs) remains significant but challenging for the realm of energy storage. Herein, a controllable dual interface engineering concept is proposed with the objective of eliminating the non-ideal effects by augmenting the interfacial contact area, enhancing the efficacy of charge transfer across interfaces. Specifically, electrode materials with dual interface (FeSe/Cu 2 Se and MIL/CuFe-Se) were well-designed by co-precipitation and in-situ selenide, where the FeSe/Cu 2 Se heterogeneous interface by in-situ selenitisation of CuFe prussian blue analogue (PBA) increases the surface roughness of nanocubes, enlarging the dual interfacial contact area of MIL/CuFe-Se and eliminating non-interfacial effects. Density Functional Theory (DFT) calculations confirm that the prepared electrodes exhibit both excellent rate performance and the ability to regulate interfacial charge transfer. Based on these advantages, the synthesised nanomaterials have a specific capacity of 913C/g at 1 A/g and a capacity retention of 86 % after 10,000 charge/discharge tests at 20 A/g. In addition, a hybrid supercapacitor (HSC) made of MIL@CuFe-Se (cathode) and activated carbon (AC, anode) has an energy density of 90 Wh kg −1 at 800 W kg −1 and a capacitance retention of 85.24 % after 10,000 cycles at 20 A/g. Remarkably, two MIL@CuFe-Se//AC HSC in series can illuminate a light emitting diode (LED) lamp, implying the potential application prospects. This study aims to identify a viable method for advancing the development of high-performance supercapacitor applications.