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High Areal Capacity Hybrid Magnesium–Lithium-Ion Battery with 99.9% Coulombic Efficiency for Large-Scale Energy Storage
journal contribution
posted on 2015-04-01, 00:00 authored by Hyun Deog Yoo, Yanliang Liang, Yifei Li, Yan YaoHybrid magnesium–lithium-ion
batteries (MLIBs) featuring dendrite-free deposition of Mg anode and
Li-intercalation cathode are safe alternatives to Li-ion batteries
for large-scale energy storage. Here we report for the first time
the excellent stability of a high areal capacity MLIB cell and dendrite-free
deposition behavior of Mg under high current density (2 mA cm–2). The hybrid cell showed no capacity loss for 100
cycles with Coulombic efficiency as high as 99.9%, whereas the control
cell with a Li-metal anode only retained 30% of its original capacity
with Coulombic efficiency well below 90%. The use of TiS2 as a cathode enabled the highest specific capacity and one of the
best rate performances among reported MLIBs. Postmortem analysis of
the cycled cells revealed dendrite-free Mg deposition on a Mg anode
surface, while mossy Li dendrites were observed covering the Li surface
and penetrated into separators in the Li cell. The energy density
of a MLIB could be further improved by developing electrolytes with
higher salt concentration and wider electrochemical window, leading
to new opportunities for its application in large-scale energy storage.