Facile Assembly of Hybrid Micro-Supercapacitors for a Sunlight-Powered Energy Storage System

Abstract

Herein, hybrid micro-supercapacitors (MSCs), consisting of positive CoNi layer double hydroxides (LDHs) decorated on carbon nanotubes (CoNi LDHs@CNTs) and negative CNT electrodes, were assembled by facile drop-coated and electrodeposition methods. The as-fabricated MSCs were optimized in view of electrochemical performance, and the CoNi LDHs-2@CNTs//CNT MSC exhibited a favorable performance and was thus chosen to be the candidate for MSC device package. The packaged CoNi LDHs-2@CNTs//CNT MSC demonstrated a large areal capacitance of 11.0 mF·cm–2 at a current density of 0.08 mA·cm–2, a good rate performance (56% areal capacitance retained at a higher current density of 0.4 mA·cm–2), and a favorable cycling stability and reversibility (92% of the original areal capacitance was retained after 5000 cycles). Furthermore, the MSC device recorded an energy density of 1.5 μWh·cm–2 at a power density of 42.5 μW·cm–2 and was successfully applied for the storage of energy supplied by solar cells to operate a red light-emitting diode. All these findings demonstrated the promising practical energy storage application of the as-fabricated hybrid MSC devices in the construction of sunlight-powered energy storage systems.

Interlayer Injection of Low‐Valence Zn Atoms to Activate MXene‐Based Micro‐Redox Capacitors With Battery‐Type Voltage Plateaus

“…Thus, the PS-MRCs can still deliver a high capacity retention of 69.2% after 50 000 s, demonstrating the high resistance to self-discharge (Figure S8, Supporting Information). The acquired superior energy efficiency of the PS-MRCs, regarding high area energy/power density, good rate performance, wide voltage win-dow, as well as unprecedented power output stability, is summarized with Radar plots in Figure 3e, which is compared with the MSCs, respectively, based purely on MXene film electrodes and MXene/SNWs hybrid film electrodes without experiencing activation process, as well as the previously reported stateof-the-art symmetric [58][59][60][61][62] /asymmetric [63][64][65][66][67][68] MXene-based MSCs (Figure 3f). Being able to deliver high performance for all critical metrics, it is evident that the PS-MRCs is a promising new-type device architecture to address the bottleneck issues confronting MSCs and has strong competitiveness for a micro-power solution.…”

Rapid and Facile Method for the Synthesis of a Nanoarray Hierarchical Composite and Its Application in Flexible Self-Chargeable Supercapacitors

“…Impressively, at a power density of 0.76 mW cm –2 , the FSSC achieved a maximum energy density of 195.54 μW h cm –2 , and even at the high power density of 3.07 mW cm –2 , it maintains an energy density of 50.83 μW h cm –2 . As shown in Figure d, these values are highly competitive in comparison with the majority of previously reported supercapacitors based on the graphene–LDH composite. − Furthermore, the durability of the as-obtained FSSC was also tested at 5 mA cm –2 . After 9000 cycles, the FSSC can retain about 92% of its original capacitance and retain 100% of the initial Coulombic efficiency (Figure c).…”