Enhanced cycling stability achieved by the nitrogen doped carbon coating layer for electrodeposited Mn3O4 in aqueous zinc ion batteries
Zixiang Zhou, Shuling Liu, Jie Wang, Yili Wu, Yifan Yang, Yvpei Li, Jinlian Wang, Chao Wang
Abstract
Aqueous rechargeable Zn-ion batteries (ZIBs) are promising candidates for large scale energy storage. Unfortunately, their application is hindered by the quick capacity fading. Herein, the Mn3O4@N-doped carbon coated carbon cloth electrodes (Mn3O4@NC/CC) are prepared by electrodeposition and calcination and are used as the cathode for ZIBs. The thickness of the electrodeposited Mn3O4 is ∼ 200 nm, and the NC layer is ∼ 10 nm. The ZIB with Mn3O4@NC/CC displays the capacity of 265.8 mAh g−1 at 0.2 A g−1, and has a high reversible capacity of 165.6 mAh g−1 after 2000 charged − discharged cycles at 3 A g−1. The capacitive-controlled processes contribute mainly to the charge storage mechanism. The introduction of NC layer can effectively prevent the disintegration of active material during charge-discharge cycling. The NC layer can also hinder the diffusion of Zn2+ and enhance Rct, that leads to suppressed Zn ion insertion/extraction and possibly milder change in crystal structure. Ex-situ characterization shows that the Mn3O4 is irreversibly converted to R-MnO2 after multiple charge − discharge cycles, and both H+ and Zn2+ participate in the charge storage processes.