Enhanced Electrochemical Performance of Micro-Supercapacitors Via Laser-Scribed Cobalt/Reduced Graphene Oxide Hybrids

Abstract

The evolution of "smart life," which connects all internet-of-things (IoT) microdevices and microsensors under wireless communication grids, requires microscale energy storage devices with high power and energy density and long-term cyclability to integrate them with sustainable power generators. Instead of Li-ion batteries with a short lifetime, pseudocapacitors with longer or infinite cyclability and high-power density have been considered as efficient energy storage devices for IoT. However, the design and fabrication of microscale pseudocapacitors have difficulties in patterning microscale electrodes when loading active materials at specific points of the electrodes using conventional microfabrication methods. Here, we developed a facile, one-step fabrication method of micro-supercapacitors (MSCs) through the in situ formation of Co metals and the reduced graphene oxides (rGOs) in a one-pot laser scribing process. The prepared Co/rGO MSC thus exhibited four times higher capacitance than the rGO MSC, due to the Faradaic charge capacitance behavior of the Co/rGO composites.

Laser-Induced Interdigital Structured Graphene Electrodes Based Flexible Micro-Supercapacitor for Efficient Peak Energy Storage

“…The CV curves even at high scan rate of 100 mV/s continue to display the rectangular shape without any degradation, signifying a fast charge transfer capability within the electrode materials and relatively low equivalent series resistance (ESR) of this MSC. This flexible MSC also exhibits wide potential window up to 2.0 V with better rate performance compared to other interdigital structural MSCs [ 4 , 26 , 27 , 28 ]. The linear increase of capacitive current with increase of scan rates from 5 mV/s to 100 mV/s for this LIG-MSC is also observed, which suggests its fast electrolyte ions diffusion, fast charge transport and high-power output ability [ 29 , 30 ].…”

“…Recently, the rapid growing development and demand of miniaturized portable and wearable electronics has expressively amplified the importance for lightweight, stretchable, microscale and efficient power storage systems [ 1 , 2 , 3 ]. Modern life is also becoming more expedient day by day by the extensively utilization of fast remote-control smart devices, gadgets and recent development of internet-of-things (IoT) systems [ 4 , 5 ]. An IoT system needs lot of devices and sensors to be useful in large scale industrial purposes.…”

“…Alternatively, electrochemical capacitors or supercapacitors (SCs) have drawn lot of interest as a novel ESSs over MBs due to promising advantages such as high-power density, fast charge–discharge rates, long cycle life (>10,000) and ease of integration with various electronic components. Recent research has found that the MSCs are particularly attractive as one of the most competitive high-power sources for future miniaturized IoT technologies due to high power density, small size, controllable patterning, large scale on-chip integration ability and long cycle life [ 4 , 12 ]. Usually, MSCs can be fabricated by different ways such as stacked thin films of the cell components or planar interdigitated methods, etc., and it has also been observed that the nanostructured functional materials such as polymer films, graphene, carbon-based nanocomposites electrodes based thin-film flat MSCs can be advanced components for modern integrated circuits.…”

Laser Processing of Flexible In-Plane Micro-supercapacitors: Progresses in Advanced Manufacturing of Nanostructured Electrodes

“…In addition to conductive transition metallic NPs for current collectors, other transition metallic NPs with pseudocapacitive features can also be achieved in ambient air for in-plane MSC electrodes by laser reduction, such as the above-mentioned metallic Ru, metallic Co, etc. In 2021, Lee et al 142 developed a facile manufacturing method of in-plane MSCs through the use of CW near-infrared laser for the in situ reduction of LrGO and metallic Co NPs from the GO/cobalt hydroxide (Co(OH) 2 ) composite in a one-pot laser scribing process. XPS data analysis of the processed product confirmed the generation of metallic Co embedded in the LrGO film.…”

Spin-Coated Heterogenous Stacked Electrodes for Performance Enhancement in CMOS-Compatible On-Chip Microsupercapacitors

“…Furthermore, rGO can be combined with several functionalization agents to improve the capability of MSCs in the above-mentioned terms. 32 Spin-coated MSCs geared toward CMOS compatibility have been fabricated by Huang et al 33 through laser cutting patterns on a Kapton tape mask on a Si substrate. The material is spin coated on the exposed surfaces to fabricate interdigitated electrodes.…”