High‐Performance and Flexible Co‐Planar Integrated Microsystem of Carbon‐Based All‐Solid‐State Micro‐Supercapacitor and Real‐Time Temperature Sensor

Abstract

With the rapid development of flexible and portable microelectronics, the extreme demand for miniaturized, mechanically flexible, and integrated microsystems are strongly stimulated. Here, biomass‐derived carbons (BDCs) are prepared by KOH activation using Qamgur precursor, exhibiting three‐dimensional (3D) hierarchical porous structure. Benefiting from unobstructed 3D hierarchical porous structure, BDCs provide an excellent specific capacitance of 433 F g−1 and prominent cyclability without capacitance degradation after 50 000 cycles at 50 A g−1. Furthermore, BDC‐based planar micro‐supercapacitors (MSCs) without metal collector, prepared by mask‐assisted coating, exhibit outstanding areal‐specific capacitance of 84 mF cm−2 and areal energy density of 10.6 μWh cm−2, exceeding most of the previous carbon‐based MSCs. Impressively, the MSCs disclose extraordinary flexibility with capacitance retention of almost 100% under extreme bending state. More importantly, a flexible planar integrated system composed of the MSC and temperature sensor is assembled to efficiently monitor the temperature variation, providing a feasible route for flexible MSC‐based functional micro‐devices.

Recent Progress of Energy-Storage-Device-Integrated Sensing Systems

“…In addition to the simple integration of temperature sensor and energy storage unit [ 101 , 102 , 103 , 104 ], some energy storage units can realize temperature sensing themselves [ 105 , 106 ]. For example, a Cu-Zn galvanic cell with both Ni 2+ -containing elastomers and Zn 2+ -containing elastomers as solid electrolyte layers was developed by Wang [ 106 ] ( Figure 6 a), which exhibited excellent temperature sensing performance in the range of 25–60 °C according to the Arrhenius relationship between current density and temperature.…”

A Biodegradable High-Performance Microsupercapacitor for Environmentally Friendly and Biocompatible Energy Storage

“…The rapid development of “Internet of Things” and information technology has stimulated the explosion of miniaturized and smart electronic devices, which have gradually entered all aspects of our work and life, and brought increasing influence. , Typically, multiple-node sensors allow us to monitor real-time information about surrounding environments, smart labels can help us establish digital connections among all the things, and implantable medical electronics endow the opportunity to cure diseases more accurately. , These emerging applications have provided great convenience, while putting forward higher requirements for compatible energy storage devices, in terms of electrochemical performance and functional properties. In this regard, microsupercapacitors (MSCs) with a small projection area mainly from square micrometer to square millimeter or with micrometer-scale microelectrode thickness have recently received wide attention due to their intrinsic characteristics of high power density, , fast charge/discharge capability, and long operating life. − …”

Localized Electron Density Regulation Effect for Promoting Solid–Liquid Ion Adsorption to Enhance Areal Capacitance of Micro‐Supercapacitors

“…Miniaturization of energy storage systems is fundamental to the advancement of portable energy devices and flexible electronics. [1,2] Planar microsupercapacitors (MSCs) have emerged as one of the most attractive candidates for the next generation of sustainable energy devices due to their distinct size advantages, high power density, and long cycle stability. [3,4] It is extremely difficult to achieve high energy output by loading a relatively thick layer of active material into a limited volume space of interdigital electrodes, which is the primary reason why large-scale applications are still elusive.…”

“…[19] Typically, GQDs are mostly applied as an additional additive or composite with various active materials to enhance the capacitive performance of MSCs. [2,4,20,21] Furthermore, the "edge effect" of oxygen functional groups (hydroxyl and carboxyl) in modified graphene quantum dots has rarely been reported on the enhanced electrostatic adsorption effect of ions in MSCs…”