Compacting Electric Double Layer Enables Carbon Electrode with Ultrahigh Zn Ion Storage Capability

Abstract

Carbon‐based cathodes for aqueous zinc ion hybrid supercapacitors (ZHSCs) typically undergo low Zn ion storage capability due to their electric double layer capacitance (EDLC) energy storage mechanism that is restricted by specific surface area and thickness of electric double layer (EDL). Here, we report a universal surface charge modulation strategy to effectively enhance the capacitance of carbon materials by decreasing the thickness of EDL. Amino groups with lone pair electrons were chosen to increase the surface charge density and enhanced the interaction between carbon electrode and Zn ions, thus effectively compacting the EDL. Consequently, amino functionalized porous carbon based ZHSCs can deliver an ultrahigh capacity of 255.2 mAh g−1 along with excellent cycling stability (95.5 % capacity retention after 50 000 cycles) in 1 M ZnCl2 electrolyte. This study demonstrates the feasibility of EDL modified carbon as Zn2+ storage cathode and great prospect for constructing high performance ZHSCs.

Advanced Aqueous Ammonium-Ion Batteries Enabled by Hydrogen Bond Modulation

“…Aqueous ion batteries (AIBs) appear attractive in the energy storage field, particularly in large-scale energy storage, because of their intrinsic merits such as cost-effectiveness and high safety. − Conventionally, metallic ions, that is, Li + , Na + , K + , Zn 2+ , Mg 2+ , Ca 2+ , and Al 3+ , are considered as charge carriers and have been well-studied. − Nevertheless, potential problems such as earth abundance and metal contamination have somewhat raised people’s concerns about metal-ion batteries . Alternatively, the nonmetallic ammonium ion is being energetically investigated for AIBs because of its reproducible and environmentally friendly nature. − In addition, the NH 4 + ion exhibits exciting physicochemical properties, including low molar mass (18 g mol –1 ) and small hydrated radius (3.31 Å). , To date, several pioneering works have proved the possibility of aqueous ammonium-ion batteries (AAIBs) by developing Prussian blue analogues, metal oxides, and organic materials as electrodes. − However, these AAIBs still suffer from low working voltage window and capacity, which hinder the further application of AAIBs.…”

Robust and Wide Temperature‐Range Zinc Metal Batteries with Unique Electrolyte and Substrate Design

“…Zinc metal capacitor were assembled using commercial active carbon (AC) cathodes to evaluate the electrochemical performance of this unique γ‐valerolactone‐based electrolyte and Al@C substrate. AC cathodes have promising applications in the field of scale energy storage owing to the low cost and excellent cycling stability compared with common cathode materials such as MnO 2 and V 2 O 5 [28] . To ensure that the area‐specific capacity of the cathode electrode can meet the practical requirements, cathodes with high AC loading were prepared, whose capacities were all higher than 0.8 mAh cm −2 at room temperature (13–17 mg cm −2 ).…”

“…AC cathodes have promising applications in the field of scale energy storage owing to the low cost and excellent cycling stability compared with common cathode materials such as MnO 2 and V 2 O 5 . [28] To ensure that the area-specific capacity of the cathode electrode can meet the practical requirements, cathodes with high AC loading were prepared, whose capacities were all higher than 0.8 mAh cm À 2 at room temperature (13-17 mg cm À 2 ). As shown in Figure 6a, the Zn j j AC capacitor with γ-valerolactone-based electrolyte can be stably cycled more than 5000 times in comparison with the rapid failure of the capacitor with the aqueous electrolyte after 90 cycles (Figure S32).…”

In‐situ Construction of CNTs Decorated Titanium Carbide on Ti Mesh Towards the Synergetic Improvement of Energy Storage Properties for Aqueous Zinc Ion Capacitors

“…In addition to providing a lighter charging capability, the capacitor's performance is comparable to that of reported asymmetric supercapacitors. [43][44][45][46][47][48][49][50][51][52][53][54][55] Moreover, an ultra-long cycling test up to 50000 cycles was performed to verify the stability of Zn//TCT-x devices. Specifically, ZIC device based on TCT-1 cathode displays superior cycle stability with 6.3 % decay after 50000 charge/discharge cycles at 1.0 A g À 1 , compared with capacitance retention of 81.6 % and 87.1 % of Zn//TCT-2 and Zn//TCT-3, respectively (Figure 4f).…”