A N, O co-doped hierarchical carbon cathode for high-performance Zn-ion hybrid supercapacitors with enhanced pseudocapacitance

Deng, Xiaoyang; Li, Jiajun; Zhu, Shuang; Sha, Junwei; Ma, Liying; Zhao, Naiqin

doi:10.1039/d0ta02770g

“…Chemie Forschungsartikel 9700 www.angewandte.de previous reports, [44][45][46][47][48][49][50][51][52][53][54][55][56][57][58] we calculated the energy density (Wh kg À1 )o ft he MOF-PC//Zn cells only based on the mass of active material (i.e., MOF-PC) in cathode without considering the mass of Zn anode.A ss hown in Figure 4b,t he cell with the mass loading of 1mgcm À2 shows ah igh energy density of 58.1 Wh kg À1 at 112 Wkg À1 ,a nd the cell with the mass loading of 10 mg cm À2 exhibits an energy density of 48.6 Wh kg À1 at 113 Wkg À1 (see green lines in Figure 4b). Obviously,when calculated only based on the mass of MOF-PC in cathode,t he energy density achieved at al ow mass loading (1 mg cm À2 )issuperior to that achieved at ahigh mass loading (10 mg cm À2 ).…”

Section: Methodsmentioning

confidence: 99%

Towards High‐Performance Zinc‐Based Hybrid Supercapacitors via Macropores‐Based Charge Storage in Organic Electrolytes

Wang

¹

,

Wang

²

,

Wang

³

et al. 2021

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Zn‐based aqueous supercapacitors are attracting extensive attention. However, most of the reported long‐life and high‐power performances are achieved with low Zn‐utilization (<0.6 %) and low mass loading in cathode (<2 mg cm−2). And, many obtained high energy densities are generally evaluated without considering the mass of Zn‐anode. Herein, we propose a Zn‐based hybrid supercapacitor, involving a metal organic framework derived porous carbon cathode, a Zn‐anode and an N, N‐dimethylformamide (DMF)‐based electrolyte containing Zn2+. We demonstrate that the charge storage of cathode mainly occurs in macropores, showing high rate performance at high mass loading (40 mg cm−2). Furthermore, the aprotic nature of electrolyte and formation of Zn2+‐DMF complex avoid the Zn‐corrosion and dendrite formation. Therefore, the supercapacitor shows a long‐life (9,000 cycles) with a high Zn‐utilization (2.2 %). When calculated with the total mass of cathode (40 mg cm−2) and Zn‐anode, the energy density reaches 25.9 Wh kg−1.

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“…For instance, some researches consider Zn 2+ cation adsorption/desorption on carbon cathodes, but ignore anion storage behaviors and their effects on electrochemical properties of ZHS cathodes. Meanwhile, basic zinc sulfate nanoflakes with chemical formula of Zn 4 SO 4 (OH) 6 •nH 2 O are always observed on carbon cathodes during charge/discharge processes of carbon// Zn ZHSs [14,22,37,38], but their formation is difficult to understand merely based on simple ion adsorption/desorption theory on carbon surface. Since currently reported carbon cathodes are generally composed of carbon active materials, conductive additives, binder and metal current collectors, existence of the latter three components affects phase identification of carbon cathodes at different charge/ discharge states, thus hindering energy storage mechanism investigation of ZHS cathodes.…”

Section: Introductionmentioning

confidence: 99%

Towards High-Energy and Anti-Self-Discharge Zn-Ion Hybrid Supercapacitors with New Understanding of the Electrochemistry

Li

¹

,

Yang

²

,

Yang

³

et al. 2021

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Aqueous Zn-ion hybrid supercapacitors (ZHSs) are increasingly being studied as a novel electrochemical energy storage system with prominent electrochemical performance, high safety and low cost. Herein, high-energy and anti-self-discharge ZHSs are realized based on the fibrous carbon cathodes with hierarchically porous surface and O/N heteroatom functional groups. Hierarchically porous surface of the fabricated free-standing fibrous carbon cathodes not only provides abundant active sites for divalent ion storage, but also optimizes ion transport kinetics. Consequently, the cathodes show a high gravimetric capacity of 156 mAh g−1, superior rate capability (79 mAh g−1 with a very short charge/discharge time of 14 s) and exceptional cycling stability. Meanwhile, hierarchical pore structure and suitable surface functional groups of the cathodes endow ZHSs with a high energy density of 127 Wh kg−1, a high power density of 15.3 kW kg−1 and good anti-self-discharge performance. Mechanism investigation reveals that ZHS electrochemistry involves cation adsorption/desorption and Zn4SO4(OH)6·5H2O formation/dissolution at low voltage and anion adsorption/desorption at high voltage on carbon cathodes. The roles of these reactions in energy storage of ZHSs are elucidated. This work not only paves a way for high-performance cathode materials of ZHSs, but also provides a deeper understanding of ZHS electrochemistry.

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“…In recent years, many Zn‐based hybrid supercapacitors with promising performances have been reported [39–58] . However, their practical application still faces many obstacles.…”

Section: Introductionmentioning

confidence: 99%

“…Secondly, in the mild aqueous electrolyte containing Zn 2+ (pH 4–5), the undesired H 2 evolution and irreversible by‐products on anode aggravate corrosion of Zn electrode and issue of dendrites [18] . In fact, most of the reported long‐term cycling stability of Zn‐based aqueous batteries and hybrid supercapacitors were achieved by much excessive Zn anode, showing extremely low Zn‐utilization (less than 0.6 %) [47–58] . Especially, almost all the reported batteries and supercapacitors with excellent energy densities are evaluated only based on the active mass of cathode [44–58] .…”

Section: Introductionmentioning

confidence: 99%

Towards High‐Performance Zinc‐Based Hybrid Supercapacitors via Macropores‐Based Charge Storage in Organic Electrolytes

Qiu

¹

,

Wang

²

,

Wang

³

et al. 2021

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Zn‐based aqueous supercapacitors are attracting extensive attention. However, most of the reported long‐life and high‐power performances are achieved with low Zn‐utilization (<0.6 %) and low mass loading in cathode (<2 mg cm−2). And, many obtained high energy densities are generally evaluated without considering the mass of Zn‐anode. Herein, we propose a Zn‐based hybrid supercapacitor, involving a metal organic framework derived porous carbon cathode, a Zn‐anode and an N, N‐dimethylformamide (DMF)‐based electrolyte containing Zn2+. We demonstrate that the charge storage of cathode mainly occurs in macropores, showing high rate performance at high mass loading (40 mg cm−2). Furthermore, the aprotic nature of electrolyte and formation of Zn2+‐DMF complex avoid the Zn‐corrosion and dendrite formation. Therefore, the supercapacitor shows a long‐life (9,000 cycles) with a high Zn‐utilization (2.2 %). When calculated with the total mass of cathode (40 mg cm−2) and Zn‐anode, the energy density reaches 25.9 Wh kg−1.

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A N, O co-doped hierarchical carbon cathode for high-performance Zn-ion hybrid supercapacitors with enhanced pseudocapacitance

Abstract: A novel carbon cathode was fabricated for high-performance Zn-ion supercapacitors with enhanced pseudocapacitance.

Cited by 162 publications

References 41 publications

Towards High‐Performance Zinc‐Based Hybrid Supercapacitors via Macropores‐Based Charge Storage in Organic Electrolytes

Towards High‐Performance Zinc‐Based Hybrid Supercapacitors via Macropores‐Based Charge Storage in Organic Electrolytes

Towards High-Energy and Anti-Self-Discharge Zn-Ion Hybrid Supercapacitors with New Understanding of the Electrochemistry

Towards High‐Performance Zinc‐Based Hybrid Supercapacitors via Macropores‐Based Charge Storage in Organic Electrolytes

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