Nanosupercapacitors with fractal structures: searching designs to push the limit

Abstract

Microsupercapacitors (MSCs) are of increasing interest for powering microelectronic systems, while their applications are still limited by insufficient energy densities due to relatively large sizes. To address this critical challenge,...

Recent status and future perspectives of ultracompact and customizable micro-supercapacitors

“…Importantly, fractal microelectrode configuration was also valid to enhance the performance by maximizing the electrode material utilization [101,106,107]. Therefore, several kinds of fractal NSCs were fabricated based on space-filling curves of different iterated orders by the same FIB method [22]. It is demonstrated that the fractal NSCs exhibited marked enhancement of capacitances compared with interdigital NSCs, attributed to the stronger electric field intensity coming from the abundant corners of fractal designs, testified by COMSOL simulations (Fig.…”

“…FIB technology is an integral part of micro/nano-fabrication technology and semiconductor integrated circuit, which can achieve sub-micrometer resolution patterns in a mask-free process by selective ablating and removing material or inducing chemical reactions of target films [18,19,21,22,31,105]. Majumder's group prepared graphene-based MSCs by converting the directly written GO film into precise rGO pattern using FIB technology [18].…”

“…For instance, when the electrode size was reduced to the critical size of 25 μm, the electrochemical performance of resulting MSCs can be visibly boosted, in which the reaction dynamics can be effectively controlled by the change of diffusion geometry from linear to radial or edge transmission mechanism [20]. When the devices are manufactured to nano-supercapacitors, the specific capacitance will be greatly enhanced owing to the powerful inner electric field strength between nano-electrodes [21,22]. Additionally, MSCs at micrometer or sub-micrometer scales are expected to improve the time and frequency response, together with the characteristic of high capacitance and lower space occupancy, enabling them potential candidates to replace conventional dielectric capacitors as alternating current (AC) line application [23,24].…”

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

“…The richer sharp corners of electrodes yield the stronger electric field intensity as demonstrated by COMSOL Multiphysics simulations, thus enhancing the charge storage ability. 20 Third, the in-plane design can effectively utilize the space by making use of microelectrode gaps (or called interspaces) instead of separators required by conventional sandwich architecture. As a result, the ion-transport resistance of energy storage devices can be decreased and a high-frequency response can be obtained.…”

“…Second, the in-plane design can provide abundant sharp corners in comparison with other designs. The richer sharp corners of electrodes yield the stronger electric field intensity as demonstrated by COMSOL Multiphysics simulations, thus enhancing the charge storage ability . Third, the in-plane design can effectively utilize the space by making use of microelectrode gaps (or called interspaces) instead of separators required by conventional sandwich architecture.…”