In:
Advanced Functional Materials, Wiley, Vol. 28, No. 1 ( 2018-01)
Abstract:
Rechargeable magnesium/sulfur (Mg/S) and magnesium/selenium (Mg/Se) batteries are characterized by high energy density, inherent safety, and economical effectiveness, and therefore, are of great scientific and technological interest. However, elusive challenges, including the limited charge storage capacity, low Coulombic efficiency, and short cycle life, have been encountered due to the sluggish electrochemical kinetics and severe shuttles of ploysulfides (polyselenide). Taking selenium as model paradigm, a new and reliable Mg‐Se chemistry is proposed through designing binary selenium‐copper (Se‐Cu) cathodes. An intriguing effect of Cu powders on the electrochemical reaction pathways of the active Se microparticles is revealed in a way of forming Cu 3 Se 2 intermediates, which induces an unconventional yet reversible two‐stage magnesiation mechanism: Mg‐ions first insert into Cu 3 Se 2 phases; in a second step Cu‐ions in the Mg 2 x Cu 3 Se 2 lattice exchange with Mg‐ions. As expected, binary Se‐Cu electrodes show significantly improved reversibility and elongated cycle life. More bracingly, Se/C nanostructures fabricated by facile blade coating Se nanorodes onto copper foils exhibit high output power and capacity (696.0 mAh g −1 at 67.9 mA g −1 ), which outperforms all previously reported Mg/Se batteries. This work envisions a facile and reliable strategy to achieve better reversibility and long‐term durability of selenium (sulfur) electrodes.
Type of Medium:
Online Resource
ISSN:
1616-301X
,
1616-3028
DOI:
10.1002/adfm.201701718
Language:
English
Publisher:
Wiley
Publication Date:
2018
detail.hit.zdb_id:
2029061-5
detail.hit.zdb_id:
2039420-2
SSG:
11
