Binding Zinc Ions by Carboxyl Groups from Adjacent Molecules toward Long‐Life Aqueous Zinc–Organic Batteries

Abstract

storage. [2][3][4][5][6][7] Among them, aqueous zinc batteries have aroused extensive interest and attention, which benefits from many advantages of zinc anode, including high theoretical capacity (820 mAh g −1 ), appropriate redox potential (−0.762 V vs the standard hydrogen electrode (SHE)), and intrinsic safety in aqueous system. [8][9][10][11][12][13][14][15][16][17][18][19][20] Inspired by conventional Li + storage reaction, intercalation reaction of transition metal oxides are employed to storage Zn 2+ in the mild aqueous solution. For example, Zn 0.25 V 2 O 5 ·nH 2 O, [9] Prussian blue analogue, [15] VO 2 , [17] MnO 2 , [18] Zn 3 V 2 O 7 (OH) 2 ·2H 2 O, [19] CuV 2 O 6 [20] have been used as cathodes for zinc batteries. However, the hydrated Zn 2+ and H + usually result in large volumetric change and serious structural collapse of these inorganic compounds with the insertion of a large amount of hydrated Zn 2+ , [21][22][23][24][25] showing significant capacity fading and limited cycle life. In recent years, the organic compounds containing carbonyl groups have been employed to store Li + and Na + through reversible coordination reaction (i.e., the CO/C-O-Li + /Na + conversion), and thus many batteries based on organic electrodes were proposed by using monovalent ion (Li + /Na + ) as charge carrier. [26][27][28][29][30][31] Then, it was demonstrated that such coordination reaction can also be used to store divalent ions (e.g., Mg 2+ and Zn 2+ ), which evoked the enthusiasm for developing divalent ion batteries using organic electrode. [32][33][34][35][36][37] Very recently, Chen's group reported the first Zn-organic (C 4 Q//Zn) battery with high energy and long life. [38] Chen and co-workers work indicates that it should be a good choice for building zinc batteries to use organics as the alternative to inorganic host materials to store Zn 2+ . However, many organics with carbonyl groups (CO) and/or their reduced products (C-O-) suffer from the inherent instability and solubility in electrolyte. [39][40][41][42][43] It is well known that the solubility can lead to the crossover of electrode active materials between cathode and anode. As a result, expensive ion exchange membranes generally are required to prevent the crossover. [38] Furthermore, owing to the inevitable presence of H + in mild aqueous electrolyte (e.g., aqueous ZnSO 4 electrolyte generally shows a pH value of 4-5), H + can also react with carbonyl groups of organic compounds before or in parallel with the storage of Zn 2+ , which might aggravate the poor cycle life arising from the inherent The newly emerged aqueous Zn-organic batteries are attracting extensive attention as a promising candidate for energy storage. However, most of them suffer from the unstable and/or soluble nature of organic molecules, showing limited cycle life (≤3000 cycles) that is far away from the requirement (10 000 cycles) for grid-scale energy storage. Here, a new aqueous zinc battery is proposed by using sulfur heterocyclic quinone dibenzo[b,i]thianthrene-5,7,12,1...

Design Strategies for High‐Performance Aqueous Zn/Organic Batteries

“…[32,41] However,s ulfur heterocyclic quinone dibenzo[b,i ]thianthrene-5,7,12,14-tetraone (DTT) could reversibly store both Zn 2+ and H + . [42] Different from carbonyl compounds,animine compound, diquinoxalino [2,3a:2 ',3'-c] phenazine (HATN), can achieve H + uptake/ removal by coordination/incoordination reaction in mild electrolyte. [36] Different from n-type counterparts,p -type organic electrode materials will first undergo oxidation process.D uring the oxidation, they will loss electrons and change into cations.…”

Bioinspired Interface Design of Sewable, Weavable, and Washable Fiber Zinc Batteries for Wearable Power Textiles

“…Furthermore, some findings have suggested that H + existing in the mild aqueous electrolyte can react with carbonyl groups to form phenol before or in parallel with the storage of Zn 2+ . [39,40] Moreover, part of phenol group can release electrons when reversibly oxidized into the corresponding quinone group. [41,42] Thus, two cathodic peaks located at 0.47 and 0.85 V in the CV curve correspond to simultaneous Zn 2+ binding and the concerted reduction of o-quinone to phenol, respectively.…”

Progress of Organic Electrodes in Aqueous Electrolyte for Energy Storage and Conversion

“…The HATN//Zn battery demonstrated fast kinetics and a long‐term cycling life as a consequence of the reversible structural evolution of HATN, with a capacity retention of 93.3 % after 5 000 cycles at 5 A g −1 . Recently, our group proposed a Zn–organic battery that uses dibenzo[ b , i ]thianthrene‐5,7,12,14‐tetraone (DTT) and Zn foil as cathode and anode, respectively, with a mild electrolyte containing Zn 2+ . Using electrochemical measurements, ex situ analyses, and DFT calculation, we demonstrated that the DTT electrode can simultaneously store both H + and Zn 2+ to form DTT 2 (H + ) 4 (Zn 2+ ).…”

“…Furthermore, Compared to monovalent ions, reduced storage of divalent ions in host materials is needed to exert an equal capacity, which leads to a lower volume change of organic materials. The coordination reaction can also be used to reversibly store the hydronium (H 3 O + ), indicating the possibility of developing the organic hydronium batteries . Furthermore, the soluble organic molecules can be used as active materials for flow batteries .…”