Intercalation of Mg into a Few-Layer Phyllomanganate in Non-aqueous Electrolytes at Room Temperature

(a) STEM-HAADF image of MnOx, (b) elemental maps of magnesiated MnOx nanoparticles, (c) potential versus capacity profiles of MnOx paired with a Mg metal anode at room temperature, (d) synchrotron XRD patterns, (e) Mn K-edge spectra and (f) Mn L-edge spectra of pristine (black), discharged (red) and charged (blue) MnOx electrode.

Scientific Achievement

Nanocrystals of a few-layer manganese oxide are shown to have considerable electrochemical activity toward Mg2+ intercalation even at room temperature, where they delivered ~190 mAh/g in full Mg metal batteries.

Significance and Impact

These observations constitute a foundational step toward Mg batteries with high energy density, which require oxide cathodes. So far, all oxides explored have shown fundamental barriers toward extensive Mg2+ intercalation at room temperature, and, thus, very low capacity. This work bridges this gap, paving the way to new avenues of materials design.

Research Details

  • Few-layer nanoscrolls of a manganese oxide showed high electrochemical activity in non-aqueous electrolytes developed by JCESR for full cells with Mg metal.
  • High capacity was reached at a high potential of at ~1.9 V (vs Mg/Mg2+)
  • A suite of analyses with techniques showing different chemical and structural sensitivity supported the existence and reversibility of Mg2+ intercalation into the oxide.
  • Compared with other reports that showed no intercalation, our few-layer manganese oxide contained interlayer defects, which points at novel avenues of design of materials complexity tailored for Mg2+ intercalation.

Download this highlight

DOI: 10.1021/acs.chemmater.0c01305

Latest Updates

See All