Electrolyte salts for rechargeable magnesium-ion batteries

Patent metadata

Field	Value
Publication number	US-10868335-B2
Application number	US-201816133278-A
Country	US
Kind code	B2
Filing date	Sep 17, 2018
Priority date	Sep 17, 2018
Publication date	Dec 15, 2020
Grant date	Dec 15, 2020

Abstract

Magnesium salts suitable for use in an electrolyte for a magnesium ion electrochemical cell are described herein. The salts are magnesium tetra(perfluoroalkoxy)metalates, optionally solvated with up to seven ether molecules coordinated to the magnesium ion thereof. In one embodiment, the salt has the empirical formula: Mg(Z) n 2+ [M(OCR 3 ) 4 − ] 2 (Formula (I)) wherein Z is an ether; n is 0 to about 7; M is Al or B; and each R independently is a perfluoroalkyl group (e.g., C 1 to C 10 perfluoroalkyl). The magnesium salts of Formula (I) are suitable for use as electrolyte salts for magnesium ion batteries (e.g., 5 V class magnesium batteries) and exhibit a wide redox window that is particularly compatible with magnesium anode. The salts are relatively cost effective to prepare by methods described herein, which are conveniently scalable to levels suitable for commercial production.

First claim

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. An electrochemical cell comprising
an anode;
a cathode;
and a magnesium ion-containing electrolyte contacting the anode and the cathode; wherein the anode comprises metallic magnesium and the cathode comprises at least one compound selected from the group consisting of MoS 2 , Mo 6 S 8 , MoO 3 , TiS 2 , Ti 2 S 4 , V 2 O 5 , MnO 2 , MgM a 2 O 4 , MgM b XO 4 , Mg 0.5 M c 2 (PO 4 ) 3 , and Mg x M d (CN) 6 •yH 2 O; wherein:
M a is one or more metal selected from the group consisting of Mn, Fe, Co, Ni, and Cr;
M b is one or more metal selected from the group consisting of Fe, Mn, Co, and Ni;
M c is one or more metal selected from the group consisting of Ti, Zr, V, and Fe;
M d is one or more metal selected from the group consisting of Fe and Ni;
X is one or more element selected from the group consisting of Si, P, and S;
x is 0 or 1; and
y is in the range of 0 to 9;
the electrolyte comprises a magnesium salt dissolved in a nonaqueous solvent;
the magnesium salt comprises a salt of Formula (I): Mg(Z) n 2+ [M(OCR 3 ) 4 − ] 2 ;
Z is an ether;
n is 0 to 7;
M is Al or B; and
each R independently is a perfluoroalkyl group.

2. A battery comprising a plurality of the electrochemical cell of claim 1 electrically connected together.

3. The electrochemical cell of claim 1 , wherein Z comprises at least one ether selected from the group consisting of a dialkyl ether and a cyclic ether.

4. The electrochemical cell of claim 1 , wherein Z comprises at least one ether selected from the group consisting of diethyl ether and tetrahydrofuran.

5. The electrochemical cell of claim 1 , wherein n is 7.

6. The electrochemical cell of claim 1 , wherein M is Al.

7. The electrochemical cell of claim 1 , wherein M is B.

8. The electrochemical cell of claim 1 , wherein each R independently is a C 1 to C 10 perfluoroalkyl.

9. The electrochemical cell of claim 1 , wherein each R is trifluoromethyl.

10. The electrochemical cell of claim 1 , wherein M is Al, and each R is trifluoromethyl.

11. The electrochemical cell of claim 1 , wherein M is Al, each R is trifluoromethyl, and Z is selected from the group consisting of diethyl ether and tetrahydrofuran.

12. The electrochemical cell of claim 1 , wherein M is Al, each R is trifluoromethyl, Z is tetrahydrofuran, and n is 7.

13. The electrochemical cell of claim 1 , wherein the nonaqueous organic solvent comprises at least one solvent selected from the group consisting of diethyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, 2,5-dimethyltetrahydrofuran, dimethoxyethane, diglyme, triglyme, tetraglyme, sulfolane, 3-methylsulfolane, acetonitrile, propylene carbonate, butyrolactone, valerolactone, and glutaronitrile.

Assignees

• Uchicago Argonne Llc

Inventors

• Lau Ka-Cheong
• Liao Chen

Classifications

• C07F5/061 Primary

  with C-aluminium linkage · CPC title

• H01M2300/0028

  characterised by the solvent · CPC title

• H01M4/505

  of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy · CPC title

• H01M10/0569

  characterised by the solvents · CPC title

• C07F5/022

  without C-boron linkages · CPC title