Rational design of a flexible inorganic composite membrane with an interconnected porous structure as a high-performance lithium ion capacitor electrode

Abstract

High-performance lithium-ion capacitors (LICs) have received great attention as a promising power source in the field of portable and wearable electronic devices. However, research on high energy-storage properties and flexibility of LIC electrodes is scarce. Herein, we proposed a novel flexible Cu_xONW/graphene/AgNW (CGA) composite membrane with a uniformly interconnected porous structure for LIC electrodes. Without destroying the CuNW/GO/AgNW membrane structure, the synergism of multiple components (Cu, Cu₂O, and CuO) in the Cu_xONWs and the bonding strength between the three materials can be accurately controlled to achieve a high-performance energy storage electrode. The symmetrical solid-state supercapacitor (SSS) based on CGA-225 membranes exhibited good flexibility (a bending radius of 10 mm) and remarkable electrochemical performance. The LIC assembled with prelithiated CGA-225 presented a large potential window (1–4.5 V), high energy density/power density (maximum, 166 W h kg⁻¹/3,747 W kg⁻¹), and excellent cycling stability (92.6% of the initial capacitance after 10 000 cycles at 20 mA cm⁻²).