Supporting information Role of Chloride for a Simple, Non-Grignard ...
Supporting information
Role of Chloride for a Simple, Non-Grignard Mg Electrolyte in Ether Based Solvents Niya Sa,*1,2 Baofei Pan,1,2 Anumita Saha-Shah,3 Aude A. Hubaud,1,2 John T. Vaughey,1,2 Lane A. Baker,3 Chen Liao,1,2 Anthony K. Burrell*1,2 1
Joint Center for Energy Storage Research (JCESR), Argonne National Laboratory, Lemont, IL 60439, USA 2
Chemical Science and Engineering Division, Argonne National Laboratory, Lemont, IL 60439, USA 3
Department of Chemistry, Indiana University, Bloomington, Indiana 47405, USA
*
corresponding author: Anthony K. Burrell, email: [email protected] (A.K.B.), phone: 630-252-2629 Niya Sa, email: [email protected], phone: 630-252-2045 Joint Center for Energy Storage Research (JCESR), Argonne National Lab, Lemont, IL 60439, USA.
Stability of the Mg(TFSI)2-MgCl2 electrolyte, in G2 and THF solvent, to the stainless steel current collector is investigated by linear scan voltammetry (LSV) as shown in Figure S1. Results show that the stability of the Mg(TFSI)2-MgCl2 versus stainless steel is > 2.5 V versus Mg/Mg2+. As a result, the cheverel phase cathode (cathode used in this work), ~1.2 V against Mg metal, should not be affected by the stability of the current collector in this study.
Figure S1. (a) Linear scan voltammetry (LSV) of a 0.5 M at 1:(0.5) of Mg(TFSI)2:MgCl2 in THF solvent; (b) Linear scan voltammetry (LSV) of a 0.5 M at 1:(0.5) of Mg(TFSI)2:MgCl2 in G2
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solvent; Continuous scan of the first 3 cycles were shown. CV was performed on a three electrode setup with Pt disk (2 mm in diameter, CH Instruments, Austin, TX) as working electrode, and mechanically polished Mg ribbons (99.9% purity, Sigma-Aldrich) as reference and counter electrode. Experiment was carried out in a glove box under pure argon atmosphere with H2O and O2 levels less than 1 ppm. Scan rate of 25 mV/sec was used. Cathode results for the Mg(TFSI)2:MgCl2 in G2 is shown in Figure 2S, where reversible Mg insertion into Mo6S8 was not observed. Although the Mg(TFSI)2:MgCl2 in G2 electrolyte showed nice performance for reversible Mg deposition, however, we believe it is electrolyte selective to make reversible Mg interaction happen at cathode. According to a recent published simulation work, one of the possible explanations is that THF solvated MgxCly+ species is critical to permit Mg intercalation with the open Mo sites at the Chevrel Phase cathode.1
Figure S2. Galvanostatic cycling of the Mo6S8 cathode in 0.5 M 1: (0.5) Mg(TFSI)2-MgCl2 in G2 electrolyte. Left: a typical charge-discharge profile; Right: Capacity vs cycle number.
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Figure S3. Cyclic voltammetry (CV) of a 0.5 M Mg(TFSI)2: MgCl2 in DME solvent. Continuous scan of the first 3 cycles were shown. CV was performed on a three electrode setup with Pt disk electrode (2 mm in diameter, CH Instruments, Austin, TX) as working electrode, and mechanically polished Mg ribbons (99.9% purity, Sigma-Aldrich) as reference and counter electrode. Experiment was carried out in a glove box under pure argon atmosphere with H2O and O2 levels less than 1 ppm. Scan rate of 25 mV/sec was applied in this study.
References 1. Wan, L. F.; Perdue, B. R.; Apblett, C. A.; Prendergast, D., Mg Desolvation and Intercalation Mechanism at the Mo6S8 Chevrel Phase Surface. Chem. Mater. 2015, 27, 5932-5940.
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Role of Chloride for a Simple, Non-Grignard Mg Electrolyte in Ether Based Solvents Niya Sa,*1,2 Baofei Pan,1,2 Anumita Saha-Shah,3 Aude A. Hubaud,1,2 John T. Vaughey,1,2 Lane A. Baker,3 Chen Liao,1,2 Anthony K. Burrell*1,2 1
Joint Center for Energy Storage Research (JCESR), Argonne National Laboratory, Lemont, IL 60439, USA 2
Chemical Science and Engineering Division, Argonne National Laboratory, Lemont, IL 60439, USA 3
Department of Chemistry, Indiana University, Bloomington, Indiana 47405, USA
*
corresponding author: Anthony K. Burrell, email: [email protected] (A.K.B.), phone: 630-252-2629 Niya Sa, email: [email protected], phone: 630-252-2045 Joint Center for Energy Storage Research (JCESR), Argonne National Lab, Lemont, IL 60439, USA.
Stability of the Mg(TFSI)2-MgCl2 electrolyte, in G2 and THF solvent, to the stainless steel current collector is investigated by linear scan voltammetry (LSV) as shown in Figure S1. Results show that the stability of the Mg(TFSI)2-MgCl2 versus stainless steel is > 2.5 V versus Mg/Mg2+. As a result, the cheverel phase cathode (cathode used in this work), ~1.2 V against Mg metal, should not be affected by the stability of the current collector in this study.
Figure S1. (a) Linear scan voltammetry (LSV) of a 0.5 M at 1:(0.5) of Mg(TFSI)2:MgCl2 in THF solvent; (b) Linear scan voltammetry (LSV) of a 0.5 M at 1:(0.5) of Mg(TFSI)2:MgCl2 in G2
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solvent; Continuous scan of the first 3 cycles were shown. CV was performed on a three electrode setup with Pt disk (2 mm in diameter, CH Instruments, Austin, TX) as working electrode, and mechanically polished Mg ribbons (99.9% purity, Sigma-Aldrich) as reference and counter electrode. Experiment was carried out in a glove box under pure argon atmosphere with H2O and O2 levels less than 1 ppm. Scan rate of 25 mV/sec was used. Cathode results for the Mg(TFSI)2:MgCl2 in G2 is shown in Figure 2S, where reversible Mg insertion into Mo6S8 was not observed. Although the Mg(TFSI)2:MgCl2 in G2 electrolyte showed nice performance for reversible Mg deposition, however, we believe it is electrolyte selective to make reversible Mg interaction happen at cathode. According to a recent published simulation work, one of the possible explanations is that THF solvated MgxCly+ species is critical to permit Mg intercalation with the open Mo sites at the Chevrel Phase cathode.1
Figure S2. Galvanostatic cycling of the Mo6S8 cathode in 0.5 M 1: (0.5) Mg(TFSI)2-MgCl2 in G2 electrolyte. Left: a typical charge-discharge profile; Right: Capacity vs cycle number.
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Figure S3. Cyclic voltammetry (CV) of a 0.5 M Mg(TFSI)2: MgCl2 in DME solvent. Continuous scan of the first 3 cycles were shown. CV was performed on a three electrode setup with Pt disk electrode (2 mm in diameter, CH Instruments, Austin, TX) as working electrode, and mechanically polished Mg ribbons (99.9% purity, Sigma-Aldrich) as reference and counter electrode. Experiment was carried out in a glove box under pure argon atmosphere with H2O and O2 levels less than 1 ppm. Scan rate of 25 mV/sec was applied in this study.
References 1. Wan, L. F.; Perdue, B. R.; Apblett, C. A.; Prendergast, D., Mg Desolvation and Intercalation Mechanism at the Mo6S8 Chevrel Phase Surface. Chem. Mater. 2015, 27, 5932-5940.
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