ChemInform Abstract: Nonaqueous Electrochemistry of Magnesium. Applications to Energy Storage.

Abstract

ChemInform Abstract Various solvents, Mg compounds, and host materials for Mg intercalation (transition metal oxides, sulfides, and borides) are studied in order to develop an ambient temp. rechargeable magnesium battery based on organic electrolytes and cathodes capable of reversible Mg intercalation. The only electrolytes which allow Mg dissolution and deposition are solutions of organomagnesium compounds in ethers or tertiary amines. However, many of these solutions are unstable in the presence of transition metal oxides or sulfides, which are found to function acceptably as intercalation electrodes. Possible directions for future research which could lead to an improvement of battery performance are discussed.

Sponge-Like Porous Manganese(II,III) Oxide as a Highly Efficient Cathode Material for Rechargeable Magnesium Ion Batteries

“…41,42 Several studies have claimed intercalation of Mg 2+ ions into spinel-structured Mn2O4 (λ-MnO2) in aqueous environments. 43 45,46 Mn3O4 as cathode material for MIB could host about 0.66 Mg ions per formula unit, corresponding to the theoretical capacity of 154 mAh g -1 . Thus, in this work, 1C = 154 mA g -1 .…”

Reversible Deposition and Dissolution of Magnesium from Imidazolium-Based Ionic Liquids

“…Due to higher theoretical capacity (2205 mAh/g), higher negative potential (about −2 V versus standard hydrogen electrode in aprotic solutions), low cost, safe to handle and environmentally friendly nature, metallic magnesium is an attractive candidate for the active material of high energy density batteries [2][3][4]. But in many nonaqueous solutions, a reversible process of electrochemical deposition and dissolution of magnesium is hard to achieve because of the formation of compact passive film [5].…”

“…But in many nonaqueous solutions, a reversible process of electrochemical deposition and dissolution of magnesium is hard to achieve because of the formation of compact passive film [5]. It is known that electrochemical Mg deposition is impossible from solutions containing simple ionic Mg salts (such as MgCl 2 , Mg(ClO 4 ) 2 , etc.) in commonly used aprotic solvents (such as alkyl carbonates, esters, and acetonitrile) [6,7].…”

“…in commonly used aprotic solvents (such as alkyl carbonates, esters, and acetonitrile) [6,7]. However, magnesium can be reversibly deposited electrochemically in the systems without the passivating phenomena, such as ethereal solutions of Grignard reagents (RMgX, R = alkyl, aryl groups; X = halide: Cl, Br) [7][8][9][10], amidomagnesium halides [11,12], Mg(BR 2 R 2 ) 2 (R = alkyl and R = aryl group) [2,11], Mg(AX 4−n R n R n ) 2 (A = Al, B; X = Cl, Br; R, R = alkyl or aryl groups, and n + n = n) [13,14], and PhMgCl-AlCl 3 [15]. However, those electrolyte systems still suffer from the problems of safety and reliability due to the flammability and high vapor pressure of the ethereal solvents.…”

Interface-Induced Renormalization of Electrolyte Energy Levels in Magnesium Batteries

“…10 The stability of the anode/electrolyte interface also remains a point of concern: In contrast to Li-ion systems, where the formation of an SEI limits the rate of electrode corrosion and electrolyte decomposition, the existence and desirability of an SEI on the surface of a Mg anode remains a matter of debate. [11][12][18][19][20] Aurbach has argued that an SEI is undesirable in Mg batteries since the resulting film is not amenable to facile Mg-ion transport. 8 Figure 1 and the preceding discussion highlight the importance of the electrolyte's electronic structure (i.e., HOMO-LUMO positions) in controlling electrolyte decomposition and the tendency for SEI formation.…”