High-Performance Aqueous Zinc Batteries Based on Organic/Organic Cathodes Integrating Multiredox Centers.

Organic cathode materials with redox-active sites and flexible structure are promising for developing aqueous zinc ion batteries with high capacity and large output power. However, the energy storage of most organic hosts relies on the coordination/incoordination reaction between Zn2+ /H+ and a single functional group, which result in inferior capacity, low discharge platform, and structural instability. Here, the lead is taken in in situ electrodepositing stable poly(1,5-naphthalenediamine, 1,5-NAPD) as interlayer and excellent conductive poly(para-aminophenol, pAP) skin onto nanoporous carbon in sequence for the structural optimization of organic/organic cathodes, designated as C@multi-layer polymer. In situ analyses, electrochemical measurements, and theoretical calculation prove that both CO and CN active groups can act as a strong electron donor as well as Zn2+ host during the discharging process. Benefiting from the synergistic effect of the double organic layers, C@multi-layer polymer delivers high capacity, long lifespan, and excellent capacity reservation even at large discharge current and commercial mass loading (>10 mg cm-2 ). Introducing multiredox centers into one organic composites will provide new insights into designing advanced Zn-organic batteries.

Zhao Y ，Huang Y ，Wu F ，Chen R ，Li L ... -  《-》

Tailoring double-layer aromatic polymers with multi-active sites towards high performance aqueous Zn-organic batteries.

Zhao Y ，Huang Y ，Chen R ，Wu F ，Li L ... -  《-》

2,3-diaminophenazine as a high-rate rechargeable aqueous zinc-ion batteries cathode.

Organic materials are attracting extensive attention as promising cathodes for rechargeable aqueous zinc-ion batteries (ZIBs). However, most of them fail to implement the requirement of batteries with combined high-rate and long-cycle performance. Herein, we report a flexible organic molecule 2,3-diaminophenazine (DAP) which exhibits ultrahigh rate performance up to 500C and high capacity retention of 80% after 10,000 cycles at 100C (25.5 A g-1). Moreover, the Zn2+ storage mechanism in the DAP electrode is revealed by ex-situ characterization technologies and theoretical calculation, and the redox active centers CN participate in the reversible electrochemical reaction process. Furthermore, electrochemical analyses show that surface-controlled electrochemical behavior contributes to the high-rate performance of DAP cathodes. Besides, its excellent long-cycle performance can be ascribed to the suppressed DAP dissolubility by using a modified glass fiber separator with carbon nanotubes (CNT) film. Our work provides useful insight into the design of high-rate and long-life ZIBs.

Liang J ，Tang M ，Cheng L ，Zhu Q ，Ji R ，Liu X ，Zhang Q ，Wang H ，Liu Z ... -  《-》

Naphthoquinone-Based Composite Cathodes for Aqueous Rechargeable Zinc-Ion Batteries.

Kumankuma-Sarpong J ，Tang S ，Guo W ，Fu Y ... -  《-》

MXene-Boosted Imine Cathodes with Extended Conjugated Structure for Aqueous Zinc-Ion Batteries.

Organic molecules have been considered promising energy-storage materials in aqueous zinc-ion batteries (ZIBs), but are plagued by poor conductivity and structural instability because of the short-range conjugated structure and low molecular weight. Herein, an imine-based tris(aza)pentacene (TAP) with extended conjugated effects along the CN backbones is proposed, which is in situ injected into layered MXene to form a TAP/Ti3 C2 Tx cathode. Theoretical and electrochemical analyses reveal a selective H+ /Zn2+ co-insertion/extraction mechanism in TAP, which is ascribed to the steric effect on the availability of active CN sites. Moreover, Ti3 C2 Tx , as a conductive scaffold, favors fast Zn2+ diffusion to boost the electrode kinetics of TAP. Close electronic interactions between TAP and Ti3 C2 Tx preserve the structural integrity of TAP/Ti3 C2 Tx during the repeated charge/discharge. Accordingly, the TAP/Ti3 C2 Tx cathode delivers a high reversible capacity of 303 mAh g-1 at 0.04 A g-1 in aqueous ZIBs, which also realizes an ultralong lifetime over 10 000 cycles with a capacity retention of 81.6%. Furthermore, flexible Zn||TAP/Ti3 C2 Tx batteries with a quasi-solid-state electrolyte demonstrate potential application in wearable electronic devices. This work offers pivotal guidance to create highly stable organic electrodes for advanced ZIBs.

Wang X ，Liu Y ，Wei Z ，Hong J ，Liang H ，Song M ，Zhou Y ，Huang X ... -  《-》