Magnesium-Sodium Hybrid Battery With High Voltage, Capacity and Cyclability.

Oscar Tutusaus,Ruigang Zhang,Rana Mohtadi,Chen Ling

doi:10.3389/fchem.2018.00611

Abstract

Rechargeable magnesium battery has been widely considered as a potential alternative to current Li-ion technology. However, the lack of appropriate cathode with high-energy density and good sustainability hinders the realization of competitive magnesium cells. Recently, a new concept of hybrid battery coupling metal magnesium anode with a cathode undergoing the electrochemical cycling of a secondary ion has received increased attention. Mg-Na hybrid battery, for example, utilizes the dendritic-free deposition of magnesium at the anode and fast Na+-intercalation at the cathode to reversibly store and harvest energy. In the current work, the principles that take the full advantage of metal Mg anode and Na-battery cathode to construct high-performance Mg-Na hybrid battery are described. By rationally applying such design principle, we constructed a Mg-NaCrO2 hybrid battery using metal Mg anode, NaCrO2 cathode and a mixture of all-phenyl complex (PhMgCl-AlCl3, Mg-APC) and sodium carba-closo-dodecaborate (NaCB11H12) as dual-salt electrolyte. The Mg-NaCrO2 cell delivered an energy density of 183 Wh kg−1 at the voltage of 2.3 V averaged in 50 cycles. We found that the amount of electrolyte can be reduced by using solid MgCl2 as additional magnesium reservoir while maintaining comparable electrochemical performance. A hypothetical MgCl2-NaCrO2 hybrid battery is therefore proposed with energy density estimated to be 215 Wh kg−1 and the output voltage over 2 V.

Highlights

Since the first commercialization in 1991, lithium-ion battery (LIB) has become the dominating power source in the market of portable electronics
The theoretical study was based on density functional theory (DFT) calculations performed with the Vienna ab initio Simulation Package (VASP) using projector-augmented waves (PAW) pseudopotentials and the exchange-correlation functionals parametrized by Perdew, Burke, and Ernzerhof for the generalized gradient approximation (GGA) (Kresse and Hafner, 1994; Kresse and Furthmuller, 1996; Kresse and Joubert, 1999)
We demonstrated that the Mg-NaCrO2 cell operated via Na-intercalation at the cathode and Mg deposition/dissolution at the anode

Summary

Introduction

Since the first commercialization in 1991, lithium-ion battery (LIB) has become the dominating power source in the market of portable electronics. While expanding the territory of current Li-ion technology into larger scale devices faces challenges on the energy density, high materials cost, safety issues and potential supply risk, great efforts have been devoted to developing beyond Li-ion chemistries One of such non-Li-based candidates is rechargeable magnesium battery (Yoo et al, 2013; Muldoon et al, 2014). The deposition of magnesium forms non-dendritic morphology (Matsui, 2011; Ling et al, 2012), overcoming one of the major safety risks of dendritic lithium plating Encouraged by these significant benefits, the research of magnesium battery has gained much attention and several breakthroughs have been made in the past few years (Yoo et al, 2013; Canepa et al, 2017). At this moment the biggest challenge toward the realization of a competitive magnesium battery is to marry metal magnesium anode

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Results

Conclusion