Flexible in-plane zinc-ion hybrid capacitors with synergistic electrochemical behaviors for self-powered energy systems

Abstract

Multifunctional energy integration has drawn booming attention for portable devices and wearable electronics. Self-powered energy systems are considered as advanced integrated energy systems that can harvest and store sustainable environmental energy to stably power electronics. However, achieving synergistic or matchable electrochemical performance output for energy storage device parts remains challenging, which directly restricts further energy output of self-powered energy systems. Herein, we report flexible in-plane zinc-ion hybrid capacitors (ZIHCs) with synergistic electrochemical behaviors for self-powered energy systems. By designing and optimizing asymmetric interdigitated microelectrodes with favorable structures, an optimal device capacitance of 92.5 mF cm⁻², a high energy density of 25.2 μW h cm⁻², a moderate operating voltage of 1.6 V and an outstanding cycling stability (92% capacitance retention after 10 000 cycles) are achieved for ZIHCs. Owing to the outstanding and synergistic electrochemical performance of ZIHCs, self-powered energy systems integrated with in-plane ZIHCs and triboelectric nanogenerators deliver a desirable self-charging process and exceptional discharging ability in powering various electronics in the long term. These advances illustrate a great significance of in-plane ZIHCs for future advanced energy storage applications.