Highly Flexible K‐Intercalated MnO₂/Carbon Membrane for High‐Performance Aqueous Zinc‐Ion Battery Cathode

Abstract

The layered MnO2 is intensively investigated as one of the most promising cathode materials for aqueous zinc‐ion batteries (AZIBs), but its commercialization is severely impeded by the challenging issues of the inferior intrinsic electronic conductivity and undesirable structural stability during the charge–discharge cycles. Herein, the lab‐prepared flexible carbon membrane with highly electrical conductivity is first used as the matrix to generate ultrathin δ‐MnO2 with an enlarged interlayer spacing induced by the K+‐intercalation to potentially alleviate the structural damage caused by H+/Zn2+ co‐intercalation, resulting in a high reversible capacity of 190 mAh g−1 at 3 A g−1 over 1000 cycles. The in situ/ex‐situ characterizations and electrochemical analysis confirm that the enlarged interlayer spacing can provide free space for the reversible deintercalation/intercalation of H+/Zn2+ in the structure of δ‐MnO2, and H+/Zn2+ co‐intercalation mechanism contributes to the enhanced charge storage in the layered K+‐intercalated δ‐MnO2. This work provides a plausible way to construct a flexible carbon membrane‐based cathode for high‐performance AZIBs.

N-doped carbon fibers protection boost electrochemical performance of MnO-based cathode in rate capability and cycling-life

“…However, the C-ZM system shows no characteristic peak of ZSH in its XRD spectrum after initial discharge process (Figure S7), and moreover, the GCD curves of discharge-charge and charge-discharge (different sequence, which blocks the influence of ZSH, since it is the byproduct of H + -insertion during the discharge process) process exhibit almost overlap in C-ZM system (Figure S8). More importantly, the reduced specific capacity of MnOC-ZM in Figure S9 (70.0 mAh g -1 ) with the restricted voltage window of 0.9-1.7 V proves that the oxidation reaction at 1.7~1.8 V (not 1.3 V, different from ZSH as reported 15,18,33 ) is vital in the whole energy storage process, demonstrating the ZSH-assisted deposition-dissolution reaction model might not suit to apply in MnO-based cathode.…”

Trace Amounts of Triple-Functional Additives Enable Reversible Aqueous Zinc-Ion Batteries from a Comprehensive Perspective

“…A better rate performance was achieved in DE, which further proving the better redox reaction kinetic behaviors in DE (Fig. 5 c) [ 55 , 56 ]. Figure 5 d displays the comparison of long cycling stability evaluations in different electrolytes at 0.5 A g −1 , in which a very low capacity retention performance of 55% was delivered along with a small specific capacity of 38.3 mAh g −1 after 700 cycles in BE.…”

Dynamic compensation of MnOOH to mitigate the irregular dissolution of MnO2in rechargeable aqueous Zn/MnO2batteries

“…4b and S14 †). Furthermore, beneting from the dynamic [34][35][36][37][38][39][40] compensation of MnOOH, the Zn/MnO 2 battery with the Zn-Ce electrolyte achieved reversible capacity retention of 97.4% and a capacity of 130.1 mA h g −1 at 1 A g −1 aer 1000 cycles (vs. 40.5% and 75.8 mA h g −1 for the Zn/MnO 2 battery with the basic electrolyte), and identical results were obtained at a current density of 0.5 A g −1 (Fig. 4c and d).…”

“…(c and d) Long cycling performance of Zn/MnO 2 batteries with the basic electrolyte and Zn-Ce electrolyte at 0.5 and 1.0 A g −1 . (e) Comparison of electrochemical performance of the Zn/MnO 2 battery based on the Zn-Ce electrolyte with other Zn/MnO 2 batteries reported previously [34][35][36][37][38][39][40].…”