Reconfiguring the Hydrogen Networks of Aqueous Electrolyte to Stabilize Iron Hexacyanoferrate for High-Voltage Decoupled Cell.

Prussian blue analogs (PBAs) as insertion-type cathodes have attracted significant attention in various aqueous batteries to accommodate metal or non-metal ions while suffering from serious dissolution and consequent inferior lifespan. Herein, we reveal that the dissolution of PBAs primarily originates from the locally elevated pH of electrolytes that are caused by proton co-insertion during discharge. To address this issue, a water-locking electrolyte (WLE) has been strategically implemented, which interrupts the generation and Grotthuss diffusion of protons by breaking the well-connected hydrogen bonding network in aqueous electrolytes. As a result, the WLE enables the iron hexacyanoferrate to endure over 1000 cycles at a 1C rate and supports a high-voltage decoupled cell with an average voltage of 1.95 V. These findings provide insights for mitigating dissolution problems in electrode materials, thereby enhancing the viability and performance of aqueous batteries.

Revealing Hydrogen Bond Effect in Rechargeable Aqueous Zinc-Organic Batteries.

The surrounding hydrogen bond (H-bond) interaction around the active sites plays indispensable functions in enabling the organic electrode materials (OEMs) to fulfill their roles as ion reservoirs in aqueous zinc-organic batteries (ZOBs). Despite important, there are still no works could fully shed its real effects light on. Herein, quinone-based small molecules with a H-bond evolution model has been rationally selected to disclose the regulation and equilibration of H-bond interaction between OEMs, and OEM and the electrolyte. It has been found that only a suitable H-bond interaction could make the OEMs fully liberate their potential performance. Accordingly, the 2,5-diaminocyclohexa-2,5-diene-1,4-dione (DABQ) with elaborately designed H-bond structure exhibits a capacity of 193.3 mAh g-1 at a record-high mass loading of 66.2 mg cm-2 and 100 % capacity retention after 1500 cycles at 5 A g-1. In addition, the DABQ//Zn battery also possesses air-rechargeable ability by utilizing the chemistry redox of proton. Our results put forward a specific pathway to precise utilization of H-bond to liberate the performance of OEMs.

Spatial Structure Design of Thioether-Linked Naphthoquinone Cathodes for High-Performance Aqueous Zinc-Organic Batteries.

Organic electrode materials (OEMs) have gathered extensive attention for aqueous zinc-ion batteries (AZIBs) due to their structural diversity and molecular designability. However, the reported research mainly focuses on the design of the planar configuration of OEMs and does not take into account the important influence of the spatial structure on the electrochemical properties, which seriously hamper the further performance liberation of OEMs. Herein, this work has designed a series of thioether-linked naphthoquinone-derived isomers with tunable spatial structures and applied them as the cathodes in AZIBs. The incomplete conjugated structure of the elaborately engineered isomers can guarantee the independence of the redox reaction of active groups, which contributes to the full utilization of active sites and high redox reversibility. In addition, the position isomerization of naphthoquinones on the benzene rings changes the zincophilic activity and redox kinetics of the isomers, signifying the importance of spatial structure on the electrochemical performance. As a result, the 2,2'-(1,4-phenylenedithio) bis(1,4-naphthoquinone) (p-PNQ) with the smallest steric hindrance and the most independent redox of active sites exhibits a high specific capacity (279 mAh g-1), an outstanding rate capability (167 mAh g-1 at 100 A g-1), and a long-term cycling lifetime (over 2800 h at 0.05 A g-1).

In Situ Electrochemical Activation of Hydroxyl Polymer Cathode for High-Performance Aqueous Zinc-Organic Batteries.

The slow reaction kinetics and structural instability of organic electrode materials limit the further performance improvement of aqueous zinc-organic batteries. Herein, we have synthesized a Z-folded hydroxyl polymer polytetrafluorohydroquinone (PTFHQ) with inert hydroxyl groups that could be partially oxidized to the active carbonyl groups through the in situ activation process and then undertake the storage/release of Zn2+ . In the activated PTFHQ, the hydroxyl groups and S atoms enlarge the electronegativity region near the electrochemically active carbonyl groups, enhancing their electrochemical activity. Simultaneously, the residual hydroxyl groups could act as hydrophilic groups to enhance the electrolyte wettability while ensuring the stability of the polymer chain in the electrolyte. Also, the Z-folded structure of PTFHQ plays an important role in reversible binding with Zn2+ and fast ion diffusion. All these benefits make the activated PTFHQ exhibit a high specific capacity of 215 mAh g-1 at 0.1 A g-1 , over 3400 stable cycles with a capacity retention of 92 %, and an outstanding rate capability of 196 mAh g-1 at 20 A g-1 .

A Sulfur Heterocyclic Quinone Cathode Towards High-Rate and Long-Cycle Aqueous Zn-Organic Batteries.

Organic materials have attracted much attention in aqueous zinc-ion batteries (AZIBs) due to their sustainability and structure-designable, but their further development is hindered by the high solubility, poor conductivity, and low utilization of active groups, resulting in poor cycling stability, terrible rate capability, and low capacity. In order to solve these three major obstacles, a novel organic host, benzo[b]naphtho[2',3':5,6][1,4]dithiino[2,3-i]thianthrene-5,7,9,14,16,18-hexone (BNDTH), with abundant electroactive groups and stable extended π-conjugated structure is synthesized and composited with reduced graphene oxide (RGO) through a solvent exchange composition method to act as the cathode material for AZIBs. The well-designed BNDTH/RGO composite exhibits a high capacity of 296 mAh g-1 (nearly a full utilization of the active groups), superior rate capability of 120 mAh g-1 , and a long lifetime of 58 000 cycles with a capacity retention of 65% at 10 A g-1 . Such excellent performance can be attributed to the ingenious structural design of the active molecule, as well as the unique solvent exchange composition strategy that enables effective dispersion of excess charge on the active molecule during discharge/charge process. This work provides important insights for the rational design of organic cathode materials and has significant guidance for realizing ideal high performance in AZIBs.

A dendrite-free and anticaustic Zn anode enabled by high current-induced reconstruction of the electrical double layer.

Aqueous Zn-based batteries deliver thousands of cycles at high rates but poor recyclability at low rates. Herein, we reveal that this illogical phenomenon is attributed to the reconstructed electrode/electrolyte interface at high rates, wherein the condensed electrical double layer (EDL) and the tightly absorbed Zn2+ ions on the Zn electrode surface afford compact and corrosion-resistant Zn deposits.

High-intensity ultrasound improved the physicochemical and gelling properties of Litopenaeus vannamei myofibrillar protein.

The effects of high-intensity ultrasound on the physicochemical and gelling properties of Litopenaeus vannamei (L. vannamei) myofibrillar protein (MP) were investigated. MP solutions were subjected to ultrasound treatment (power 100 W, 300 W, and 500 W). It was found that the carbonyl and free amino contents of MP increased significantly with increasing ultrasound power, accompanied by enhanced emulsification properties. The increase of free radical and carbonyl content indicated that ultrasound induced the oxidation of MP. With the increase of ultrasound power, it was found that the total sulfhydryl content of the shrimp MP decreased, but the surface hydrophobicity increased significantly, which might be closely related to the conformational changes of MP. Meanwhile, a significant increase of ß-sheet but a decrease of α-helix in the secondary structure of MP was observed with increasing ultrasound power, indicating that ultrasound treatment induced the stretching and flexibility of MP molecules. SDS-PAGE showed that L. vannamei MP consisted of myosin heavy chain, actin, myosin light chain, paramyosin and tropomyosin. Ultrasound treatment could lead to some degree of oxidative aggregation of MP. The results of rheological properties indicated that ultrasound treatment enhanced the viscoelasticity of MP and further improved the gel strength of MP gel. This study can provide a theoretical basis for the functional modification of shrimp MP and the processing of its surimi products.