In-situ growth of co-intercalated MnO2 on 3D lignin-based carbon nanoflowers endows high-performance aqueous zinc-ion batteries cathode
Yiwen Zhang, Ying Han, Xing Wang, Pengfei Lian, Zihao Ma
Abstract
The electrochemical kinetics, conductivity, and lifespan of MnO 2 are significant challenges that impede its commercialization as a cathode material for aqueous zinc-ion batteries (AZIBs). In this study, carbon nanoflowers (NFCs) were prepared from lignin as a carbon source, and the dissolution behaviour of MnO 2 during cycling was inhibited by uniformly loading nanoflower-like δ-MnO 2 (MnO 2 @NFC) on NFCs in situ. Additionally, Co-intercalated δ-MnO 2 /lignin-based carbon nanoflowers (Co-MnO 2 @NFC) were prepared and used as the cathode for rechargeable AZIBs. The initial discharge capacity of the AZIBs using Co-MnO 2 @NFC as the cathode material is as high as 340 mAh·g −1 at a specific current density of 0.1 A·g −1 , and the capacity retention rate reaches 88.1 % after 1000 cycles at 1.0 A·g −1 . Co-MnO 2 @NFC exhibits excellent conductivity compared to δ-MnO 2 and MnO 2 @NFC. Through electrochemical analysis and ex-situ characterization, the energy storage mechanism of Co-MnO 2 @NFC is identified as H + /Zn 2+ co-insertion/extraction. This work enhances the stability of MnO 2 by loading it onto NFC carriers. It improves the specific capacity of the material by intercalating Co ion , providing a new approach for the controllable design of cathodes for AZIBs.