Solid electrolyte, electrode, power storage device, and method for producing solid electrolytes

Patent metadata

Field	Value
Publication number	US-11710850-B2
Application number	US-201816481814-A
Country	US
Kind code	B2
Filing date	Oct 31, 2018
Priority date	Nov 2, 2017
Publication date	Jul 25, 2023
Grant date	Jul 25, 2023

Abstract

A solid electrolyte ( 10 ) of the present disclosure includes porous silica ( 11 ) having a plurality of pores ( 12 ) interconnected mutually and an electrolyte ( 13 ) coating inner surfaces of the plurality of pores ( 12 ). The electrolyte ( 13 ) includes 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide represented by EMI-TFSI and a lithium salt dissolved in the EMI-TFSI. A molar ratio of the EMI-TFSI to the porous silica ( 11 ) is larger than 1.5 and less than 2.0.

First claim

The invention claimed is:

1. A solid electrolyte comprising:
mesoporous silica having a plurality of pores interconnected mutually; and
an electrolyte coating inner surfaces of the plurality of pores and forming a three-dimensional network, wherein the electrolyte comprises 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide represented by EMI-TFSI and a lithium salt dissolved in the EMI-TFSI, the lithium salt comprising lithium bis(trifluoromethanesulfonyl)imide, and
wherein a molar ratio of the EMI-TFSI to a silicon alkoxide that forms the mesoporous silica is 1.7 or more and 1.8 or less.

2. The solid electrolyte according to claim 1 , wherein
the electrolyte comprises a first electrolyte layer having contact with the inner surfaces of the plurality of pores,
the first electrolyte layer comprises a first anion layer, a first cation layer, and a second anion layer,
the first anion layer comprises a plurality of first bis(trifluoromethanesulfonyl)imide ions adsorbed to the inner surfaces of the plurality of pores of the mesoporous silica,
the first cation layer comprises a plurality of 1-ethyl-3-methylimidazolium ions ionically bonded to the plurality of first bis(trifluoromethanesulfonyl)imide ions respectively, and
the second anion layer comprises a plurality of second bis(trifluoromethanesulfonyl)imide ions ionically bonded to the plurality of 1-ethyl-3-methylimidazolium ions respectively.

3. The solid electrolyte according to claim 1 , wherein
the mesoporous silica forms a single layer, and an outer boundary of the solid electrolyte is defined by the mesoporous silica.

4. The solid electrolyte according to claim 1 , wherein the silicon alkoxide comprises at least one selected from tetraethyl orthosilicate, a substituted tetraethyl orthosilicate, and tetramethyl orthosilicate.

5. The solid electrolyte according to claim 4 , wherein the silicon alkoxide comprises tetraethyl orthosilicate.

6. An electrode, comprising:
the solid electrolyte according to claim 1 ; and
an electrode active material.

7. The electrode according to claim 6 , further comprising at least one selected from a conductive agent and a binder.

8. The electrode according to claim 6 , further comprising a conductive agent, wherein
a plurality of first particles made of the electrode active material and a plurality of second particles made of the conductive agent are fixed in a matrix of the solid electrolyte.

9. A power storage device, comprising:
a positive electrode;
a negative electrode; and the solid electrolyte according to claim 1 .

10. A power storage device, comprising:
a positive electrode; and
a negative electrode, wherein
at least one selected from the positive electrode and the negative electrode is the electrode according to claim 6 .

11. A method for producing a solid electrolyte, comprising:
mixing a silicon alkoxide, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (EMI-TFSI), lithium bis(trifluoromethanesulfonyl)imide, water, and an organic solvent to prepare a liquid mixture;
causing gelation of the liquid mixture to form a gel mixture; and
drying the gel mixture to form a solid electrolyte, the solid electrolyte comprising mesoporous silica having a plurality of pores interconnected mutually and an electrolyte coating inner surfaces of the plurality of pores and forming a three-dimensional network, wherein the molar ratio of the EMI-TFSI to the silicon alkoxide forming the mesoporous silica is 1.7 or more and 1.8 or less.

12. The method according to claim 11 , wherein the silicon alkoxide comprises at least one selected from tetraethyl orthosilicate, a substituted tetraethyl orthosilicate, and tetramethyl orthosilicate.

13. A solid electrolyte comprising:
mesoporous silica having a plurality of pores interconnected mutually; and
an electrolyte coating inner surfaces of the plurality of pores and forming a three-dimensional network, wherein the electrolyte comprises 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide represented by EMI-TFSI and a lithium salt dissolved in the EMI-TFSI, the lithium salt comprising lithium bis(trifluoromethanesulfonyl)imide,
wherein a molar ratio of the EMI-TFSI to a silicon alkoxide that forms the mesoporous silica is 1.7 or more and 1.8 or less, and
wherein the electrolyte comprises a first electrolyte layer having contact with the inner surfaces of the plurality of pores,
the first electrolyte layer comprises a first anion layer, a first cation layer, and a second anion layer,
the first anion layer comprises a plurality of first bis(trifluoromethanesulfonyl)imide ions adsorbed to the inner surfaces of the plurality of pores of the mesoporous silica,
the first cation layer comprises a plurality of 1-ethyl-3-methylimidazolium ions ionically bonded to the plurality of first bis(trifluoromethanesulfonyl)imide ions respectively, and
the second anion layer comprises a plurality of second bis(trifluoromethanesulfonyl)imide ions ionically bonded to the plurality of 1-ethyl-3-methylimidazolium ions respectively.

Assignees

• Imec Vzw
• Panasonic Corp

Inventors

• Vereecken Philippe
• Mees Maarten
• GANDRUD Knut Bjarne
• Sagara Akihiko
• Murata Mitsuhiro
• Kaneko Yukihiro
• Tomiyama Morio
• Shimada Mikinari

Classifications

• H01M10/0562 Primary

  Solid materials · CPC title

• H01B1/12

  organic substances {(organic macromolecular compounds or compositions C08)} · CPC title

• H01M4/13

  Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof · CPC title

• H01M4/62

  Selection of inactive substances as ingredients for active masses, e.g. binders, fillers · CPC title

• H01M10/052

  Li-accumulators · CPC title