Advanced Functional Materials
Advanced Functional Materials
5 years ago

Self-Established Rapid Magnesiation/De-Magnesiation Pathways in Binary Selenium–Copper Mixtures with Significantly Enhanced Mg-Ion Storage Reversibility

Self-Established Rapid Magnesiation/De-Magnesiation Pathways in Binary Selenium–Copper Mixtures with Significantly Enhanced Mg-Ion Storage Reversibility
Qingfu Wang, Aobing Du, Jun Ma, Shanmu Dong, Guanglei Cui, Zhonghua Zhang, Huimin Xu, Zili Cui, Xinhong Zhou, Bingbing Chen
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 Cu3Se2 intermediates, which induces an unconventional yet reversible two-stage magnesiation mechanism: Mg-ions first insert into Cu3Se2 phases; in a second step Cu-ions in the Mg2xCu3Se2 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. Binary microsized Se-Cu electrodes show an unconventional yet reversible process occurring in a way of two-stage magnesiation mechanism: one step is the Mg-ions inserting into the Cu3Se2 phases; in the second step Cu-ions in the Mg2xCu3Se2 lattice exchange with Mg-ions forming the final products of MgSe nanoparticles and metallic Cu nanowires, resulting in excellent Mg-ion storage properties.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/adfm.201701718

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.