Tailored Hierarchical Porous Carbon through Template Modification for Antifreezing Quasi‐Solid‐State Zinc Ion Hybrid Supercapacitors

Abstract

Aqueous zinc ion hybrid supercapacitors (ZHSCs) have emerged and are regarded as promising candidates for energy storage due to their environmental friendlessness and cost‐effectiveness. However, the development of a satisfying positive electrode with high performance still poses challenges. Herein, a hierarchical porous carbon with a fast‐ion‐transport feature is rationally reported via a facile template modification strategy. By adjusting the content of the template, the physiochemical characteristics and microstructures of carbon can be reasonably optimized. As proof of concept, the produced carbon electrode can deliver a high specific capacitance of 294.8 F g−1 at a current density of 0.2 A g−1, long cycling stability with ≈100% capacitance retention over 20 000 cycles, and a maximum power density of 13.2 kW kg−1 at 30.8 W h kg−1. Significantly, a superior areal capacitance of 3390 mF cm−2 is offered with a mass loading of 21 mg cm−2. When coupled with a unique antifreezing hydrogel electrolyte, the constructed quasi‐solid‐state ZHSC can not only endure −15 °C, but also exhibits outstanding durability and an ultralow self‐discharging rate, demonstrating its potential prospect for extreme conditions. This work may bring light on the preparation of carbon materials and the fabrication of multifunctional devices.

High-Energy Density Aqueous Zinc–Iodine Batteries with Ultra-long Cycle Life Enabled by the ZnI2 Additive

“…The hierarchical porous carbon material ZC-mK 2 CO 3 was prepared by our previously reported method . The modified K 2 CO 3 , which is derived from KHCO 3 , was employed as a template for the precursor ZDMA.…”

“…The hierarchical porous carbon material ZC-mK 2 CO 3 was prepared by our previously reported method. 40 The modified K 2 CO 3 , which is derived from KHCO 3 , was employed as a template for the precursor ZDMA. After being carbonized at 800 °C for 2 h, product ZC-mK 2 CO 3 was then heated with iodine according to a weight ratio of 1:1 at 80 °C to prepare ZC-mK 2 CO 3 @I 2 .…”

“…As shown in Figure 2d,e, N 2 adsorption and desorption isotherms of ZC-mK 2 CO 3 exhibit typical characteristics of type VI, which indicates the existence of micro-/mesopores and macropores. 40,41 Conversely, there are only rare mesopores and macropores existing in the ZC-mK 2 CO 3 @I 2 . On the basis of Brunauer−Emmett− Teller methods, the SSA value of ZC-mK 2 CO 3 can be calculated as 1850 m 2 g −1 , while ZC-mK 2 CO 3 @I 2 delivers a low value of 63.5 m 2 g −1 .…”

Nitrogen-doped hollow carbon nanoboxes in zwitterionic polymer hydrogel electrolyte for superior quasi-solid-state zinc-ion hybrid supercapacitors

“…This indicates that the aqueous Zn//APZC ZHSC possesses favorable transport kinetics at high rates, which originates from ideal ionic and electronic transport channels offered by the unique hierarchically porous structure of APZC. 42 To better clarify the charge storage mechanism, the representative states ((A)-(E), Fig. 3d) in the initial GCD curves were selected to track the electrode change by ex situ XRD and XPS.…”

“…3f). 42,45 The intensity of the 33.4 peak goes up/ down with the discharge process from 1.8 to 0.2 V and the subsequent charge process from 0.2 to 1.8 V, reecting a highly reversible formation/dissolution of the produced Zn 12 (CF 3 -SO 3 ) 9 (OH) 15 $nH 2 O. 46 Ex situ XPS characterization at different charge-discharge voltage points was executed to reveal the surface chemical structure transformation of the Zn anode.…”