In:
Journal of The Electrochemical Society, The Electrochemical Society, Vol. 168, No. 12 ( 2021-12-01), p. 120549-
Abstract:
Birnessite MnO 2 is a promising cathode material for aqueous Mg-ion batteries due to its layered structure with large interlayer distance. However, the two-dimensional growth mode of birnessite induces nanosheet morphology with preferred growth of inactive (001) planes with sluggish ion transport kinetics. In this work, a high Mg content birnessite with hierarchical nanowall arrays morphology is prepared by in situ electro-conversion using spinel Mn 3 O 4 nanowall arrays. The electro-conversion Mg-birnessite (ECMB) nanowall arrays are assembled by ultrasmall nanosheets with reduced (001) planes but increased active (010) planes, affording enriched open intercalation channels and shortened Mg 2+ diffusion length. Consequently, the ECMB cathode exhibits a large specific reversible capacity of about 255.1 mAh g −1 at a current density of 200 mA g −1 , and outstanding cycling stability with 73.6% capacity retention after 3000 cycles. Finally, a 2.2 V aqueous full cell is constructed by using ECMB as positive electrode and polyimide as negative electrode, which achieves a high energy density of 65.2 Wh kg −1 at a power density of 96 W kg −1 . This work demonstrates effective crystal plane modulation for Mg-birnessite to achieve superior Mg 2+ storage in aqueous batteries.
Type of Medium:
Online Resource
ISSN:
0013-4651
,
1945-7111
DOI:
10.1149/1945-7111/ac4548
Language:
Unknown
Publisher:
The Electrochemical Society
Publication Date:
2021
