An in-situ self-etching enabled high-power electrode for aqueous zinc-ion batteries

Sluggish storage kinetics is considered as the main bottleneck of cathode materials for fast-charging aqueous zinc-ion batteries (AZIBs). In this report, we propose a novel in-situ self-etching strategy to unlock the Palm tree-like vanadium oxide/carbon nanofiber membrane (P-VO/C) as a robust free-standing electrode. Comprehensive investigations including the finite element simulation, in-situ X-ray diffraction, and in-situ electrochemical impedance spectroscopy disclosed it an electrochemically induced phase transformation mechanism from VO to layered ZnxV2O5 & sdot;nH(2)O, as well as superior storage kinetics with ultrahigh pseudocapacitive contribution. As demonstrated, such electrode can remain a specific capacity of 285 mA h g(-1) after 100 cycles at 1 A g(-1), 144.4 mA h g(-1) after 1500 cycles at 30 A g(-1), and even 97 mA h g(-1) after 3000 cycles at 60 A g(-1), respectively. Unexpectedly, an impressive power density of 78.9 kW kg(-1) at the super-high current density of 100 A g(-1) also can be achieved. Such design concept of in-situ self-etching free-standing electrode can provide a brand-new insight into extending the pseudocapacitive storage limit, so as to promote the development of high-power energy storage devices including but not limited to AZIBs.(c) 2023 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.