The rational design and interface engineering of an electrolyte and current collector for a stable and high‐performance aqueous supercapacitor

Abstract

Characterized by low cost, easy assembly, and excellent ionic properties, the aqueous supercapacitors have been considered promising energy storage devices. However, the absence of any solution for interface engineering between the electrode and electrolyte has been an ongoing performance limitation. Hence, the influence of the electrolyte (KOH and H 2 SO 4 ) and current collector (SUS and graphite) on the electrochemical performance of supercapacitors operating in aqueous electrolytes is examined. Specifically, and for the first time, the outstanding energy-storing performance of an H 2 SO 4 -based acidic system is described, including excellent ionic properties that provide a large number of electroactive sites and enhanced ionic diffusion performance. Further, an improvement in the cycling stability is achieved by using the graphite current collector to enable the prevention of surface oxidation in the presence of the acidic electrolyte. This strategy results in an outstanding electrochemical performance, including a high specific capacity of 238 F g À1 at a current density of 0.1 A g À1 , an excellent high-rate capability, and a remarkable cycling stability of 93% after 3000 cycles. These results suggest that interface engineering using an acidic electrolyte system along with a graphite current collector could be a reasonable strategy for the practical application of aqueous supercapacitors.

Improved‐quality graphene film decorated with ultrafine MnO 2 nanoparticles as a multifunctional current collector for high‐reversibility zinc‐ion batteries

“…Here, the C 1s spectra of the GF, IQGF, and UFM@IQGF exhibit peaks at $284.5, 286.2, and 288.5 eV due to the C C, C O, and C═O bonds, respectively. 55,56 In particular, the C 1s spectra of the IQGF (Figure 5B,E) and the UFMP@IQGF (Figure 5C,F) indicate the removal of oxygen-containing groups from both the surface and interior compared to the GF (Figure 5A,D) due to the reduction process. The calculated specific percentages of surface and internal oxygen-containing groups in the GF, IQGF, and UFMP@IQGF are indicated in Figure 5G.…”

Improvement of structural stability of cathode by manganese additive in electrolyte for zinc‐ion batteries

“…Among batteries involving such technologies, aqueous zinc‐ion batteries (ZIBs) are characterized by Zn 2+ ‐based electrochemistry and a two‐electron transfer mechanism, which leads to the high energy density and outstanding safety of these batteries 9‐11 . Furthermore, the use of an aqueous electrolyte in ZIBs helps keep the battery cost low, improve the ease of assembly of the battery, and achieve outstanding ionic properties, which can provide efficient charge transfer during cycling 12 . These benefits are significant in the transportation market.…”

“…[9][10][11] Furthermore, the use of an aqueous electrolyte in ZIBs helps keep the battery cost low, improve the ease of assembly of the battery, and achieve outstanding ionic properties, which can provide efficient charge transfer during cycling. 12 These benefits are significant in the transportation market. ZIBs have a high potential for use in large-scale energy storage devices, where safety is a crucial factor.…”

Stable anode enabled by an embossed and punched structure for a high‐rate performance Zn‐ion hybrid capacitor

“…The LIBs are primary candidates owing to their high technical maturity and high energy density, whereas the SCs are assisted by high power density, outstanding cycling stability, and high safety 6‐9 . Therefore, the SCs are key to bridging the gap in terms of effective energy leveling and potentially enhancing the performance and stability of the ESS 10 . As well as the aforementioned high power density, the SCs can deliver a rapid charge‐discharge rate, a long cycle life, and a broad application temperature range 11,12 .…”

“…[6][7][8][9] Therefore, the SCs are key to bridging the gap in terms of effective energy leveling and potentially enhancing the performance and stability of the ESS. 10 As well as the aforementioned high power density, the SCs can deliver a rapid charge-discharge rate, a long cycle life, and a broad application temperature range. 11,12 Therefore, they have become indispensable ESS components in various fields including transportation and electronics.…”