A Fast Proton‐Induced Pseudocapacitive Supercapacitor with High Energy and Power Density

Abstract

Electrochemical proton storage provides high energy, fast kinetics, safety, and environmental friendliness for grid‐scale energy storage. However, the development of pseudocapacitive proton supercapacitors with fast chargeability and high stability is still challenging because of the unclear electrochemical reaction mechanism and unsuitable construction strategy. Here it is shown that a multi‐metallic Prussian blue analog—Cu0.82Co0.18HCF, which possesses enhanced electronic structure and ion transport path—can intercalate/de‐intercalate large amounts of proton at high rates. Ion‐induced transformation of magnetism, fast solid‐state proton transport, and reversible insertion/de‐insertion of protons lead to extremely excellent rate capacities and cycling stability for proton storage. An asymmetric pseudocapacitive proton supercapacitor (Cu0.82Co0.18HCF//WO3·nH2O) is fabricated with a voltage window of 1.7 V, delivering a maximum energy density of 35 Wh kg−1 and an energy density of 22 Wh kg−1 at a high power density of 26 kW kg−1. Combining systematical material design and mechanism study, this work not only broadens the preparation of electrode materials but also brings light to the construction of high‐performance devices for efficient proton storage.

The Semicoherent Interface and Vacancy Engineering for Constructing Ni(Co)Se2@Co(Ni)Se2 Heterojunction as Ultrahigh‐Rate Battery‐Type Supercapacitor Cathode

“…The comparison of energy and power density with data studied in the previous literature is illustrated in the Ragone plot (Figure 8g). It is much superior to those of the previously reported similar HSC devices such as Ni-Co-S/G// PCNS (43.3 Wh kg -1 at 0.8 kW kg -1 ), [66] Ni-Co oxide//G/ MMCS (52.6 Wh kg -1 at 1.6 kW kg -1 ), [67] HPCS@MnO 2 //HPCS (60.8 Wh kg -1 at 1.4 kW kg -1 ), [68] NiNTAs@MnO 2 //NiNTAs@ Fe 2 O 3 (34.1 Wh kg -1 at 3.19 kW kg -1 ), [69] CC@NiCo 2 Al-LDH// CC@ZPC (44 Wh kg -1 at 0.462 kW kg -1 ), [70] H-NiCoSe 2 // AC (25.5 Wh kg -1 at 3.75 kW kg -1 ), [18] NiCoP/NiCo-OH30// PC (34 Wh kg -1 at 0.775 kW kg -1 ), [27] Cu 0.82 Co 0.18 HCF// WO 3 •nH 2 O (35 Wh kg -1 at 0.54 kW kg -1 ), [71] MnO 2 //T-Fe 2 O 3 / PPy (42 Wh kg -1 at 8.3 kW kg -1 ), [72] MnO 2 -CNB//CNB (29.24 Wh kg -1 at 0.485 kW kg -1 ). [73] In addition, as a significant demand for assessing the durability of the HSC for commercial applications, long-term cycling stability is indispensable.…”

Electrochemical Proton Storage: From Fundamental Understanding to Materials to Devices

“…An organic–inorganic all-pseudocapacitive supercapacitor with a MXene anode and a 2,5-dihydroxy-1,4-benzoquinone (DBQ)@rGO cathode was also investigated by Boota et al [ 105 ]. Recently, our group reported an all proton pseudocapacitor with a Prussian analog (Cu 0.82 Co 0.18 HCF) as cathode and WO 3 ·nH 2 O as anode with a voltage of 1.7 V, which delivered an energy density of 22 Wh kg −1 at a high power density of 26 kW kg −1 [ 106 ].

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A sequential process to synthesize Fe3O4@MnO2 hollow nanospheres for high performance supercapacitors

“…[7][8][9] Hence, there is a need to develop other electrode materials with high specific capacitance and environmental benignity. 10 As the most abundant transition metal element throughout the earth's crust, iron-based materials are expected to be more advantageous than other counterparts. Usually, iron has several oxide phases, such as Fe 2 O 3 , FeO, and Fe 3 O 4 .…”

“…7–9 Hence, there is a need to develop other electrode materials with high specific capacitance and environmental benignity. 10…”