An Aqueous Mg 2+ -Based Dual-Ion Battery with High Power Density

Yunpei Zhu, Jun Yin, Abdul-Hamid Emwas, Omar F. Mohammed, Husam N. Alshareef

Research output: Contribution to journalArticlepeer-review

Abstract

Rechargeable Mg batteries promise low-cost, safe, and high-energy alternatives to Li-ion batteries. However, the high polarization strength of Mg2+ leads to its strong interaction with electrode materials and electrolyte molecules, resulting in sluggish Mg2+ dissociation and diffusion as well as insufficient power density and cycling stability. Here an aqueous Mg2+-based dual-ion battery is reported to bypass the penalties of slow dissociation and solid-state diffusion. This battery chemistry utilizes fast redox reactions on the polymer electrodes, i.e., anion (de)doping on the polyaniline (PANI) cathode and (de)enolization upon incorporating Mg2+ on the polyimide anode. The kinetically favored and stable electrodes depend on designing a saturated aqueous electrolyte of 4.5 m Mg(NO3)2. The concentrated electrolyte suppresses the irreversible deprotonation reaction of the PANI cathode to enable excellent stability (a lifespan of over 10 000 cycles) and rate performance (33% capacity retention at 500 C) and avoids the anodic parasitic reaction of nitrate reduction to deliver the stable polyimide anode (86.2% capacity retention after 6000 cycles). The resultant full Mg2+-based dual-ion battery shows a high specific power of 10 826 W kg−1, competitive with electrochemical supercapacitors. The electrolyte and electrode chemistries elucidated in this study provide an alternative approach to developing better-performing Mg-based batteries.
Original languageEnglish (US)
Pages (from-to)2107523
JournalAdvanced Functional Materials
DOIs
StatePublished - Sep 13 2021

ASJC Scopus subject areas

  • Biomaterials
  • Electrochemistry
  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

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