US-12620622-B2 - Compound including sulfur-containing heterocyclic cation and bis(oxolato)borate anion, electrolytic solution and electrochemical device including the same

US12620622B2US 12620622 B2US12620622 B2US 12620622B2US-12620622-B2

Abstract

An electrolytic solution containing: a compound (1) represented by the following formula (1): wherein R 101 is a C2-C7 organic group and optionally includes at least one selected from the group consisting of a hetero atom and an unsaturated bond; and R 102 is a C1-C3 organic group and optionally includes at least one selected from the group consisting of a hetero atom and an unsaturated bond.

Inventors

Tomoya Hidaka
Yoshiko Kuwajima
Shigeaki Yamazaki
Toshiharu Shimooka
Akinori Tani

Assignees

DAIKIN INDUSTRIES, LTD.

Dates

Publication Date: 20260505
Application Date: 20221121
Priority Date: 20200522

Claims (12)

1 . A compound represented by the following formula (1): wherein R 101 is a group represented by —(CH 2 ) n —; and n is an integer of 4 to 7; and R 102 is a methyl group or an ethyl group.
2 . An electrolytic solution comprising: a cation (1-1) represented by the following formula (1-1): wherein R 101 is a group represented by —(CH 2 ) n —; and n is an integer of 4 to 7; and R 102 is a methyl group or an ethyl group; and a bis(oxalato)borate anion.
3 . An electrochemical device comprising the electrolytic solution according to claim 2 .
4 . A lithium-ion secondary battery comprising the electrolytic solution according to claim 2 .
5 . An electrolytic solution comprising: a compound (1) represented by the following formula (1): wherein R 101 is a group represented by —(CH 2 ) n —; and n is an integer of 4 to 7; and R 102 is a methyl group or an ethyl group.
6 . The electrolytic solution according to claim 5 , wherein the compound (1) is contained in an amount of 0.001 to 10% by mass relative to the electrolytic solution.
7 . An electrochemical device comprising the electrolytic solution according to claim 5 .
8 . An electrochemical device comprising the electrolytic solution according to claim 6 .
9 . A lithium-ion secondary battery comprising the electrolytic solution according to claim 5 .
10 . A lithium-ion secondary battery comprising the electrolytic solution according to claim 6 .
11 . A module comprising the electrochemical device according to claim 7 .
12 . A module comprising the lithium-ion secondary battery according to claim 9 .

Description

TECHNICAL FIELD The disclosure relates to electrolytic solutions, electrochemical devices, lithium-ion secondary batteries, modules, and compounds. BACKGROUND ART Current electric appliances demonstrate a tendency to have a reduced weight and a smaller size, which leads to development of electrochemical devices such as lithium-ion secondary batteries having a high energy density. Further, electrochemical devices such as lithium-ion secondary batteries are desired to have improved characteristics as they are applied to more various fields. Improvement in battery characteristics will become more and more important particularly when lithium-ion secondary batteries are put in use for automobiles. Capacitors have been examined to improve their characteristics. For example, Patent Literature 1 discloses an electrolytic solution for an electric double layer capacitor, containing ethyltrimethylammonium tetrafluoroborate and a specific imidazolium tetrafluoroborate. CITATION LIST Patent Literature Patent Literature 1: JP 2012-74528 A SUMMARY The disclosure relates to an electrolytic solution containing: a compound (1) represented by the following formula (1): wherein R101 is a C2-C7 organic group and optionally includes at least one selected from the group consisting of a hetero atom and an unsaturated bond; and R102 is a C1-C3 organic group and optionally includes at least one selected from the group consisting of a hetero atom and an unsaturated bond. Advantageous Effects The disclosure can provide an electrolytic solution that allows an electrochemical device to have low resistance and improved cycle characteristics and an electrochemical device, a lithium-ion secondary battery, and a module each including the electrolytic solution. The disclosure can also provide a novel compound. DESCRIPTION OF EMBODIMENTS The disclosure will be specifically described hereinbelow. The disclosure relates to an electrolytic solution (hereinafter, also referred to as a first electrolytic solution) containing a compound (1) represented by the following formula (1): wherein R101 is a C2-C7 organic group and optionally includes at least one selected from the group consisting of a hetero atom and an unsaturated bond; and R102 is a C1-C3 organic group and optionally includes at least one selected from the group consisting of a hetero atom and an unsaturated bond. The first electrolytic solution of the disclosure allows an electrochemical device such as a lithium-ion secondary battery to have low resistance and allows an electrochemical device to have improved cycle characteristics (e.g., capacity retention after cycles). These effects are presumably owing to the formation of a film of decomposition products of the electrolytic solution on electrodes of the electrochemical device. In particular, the formation of a film derived from the cation in the compound (1) on the positive electrode of the electrochemical device presumably improves the resistance and cycle characteristics. The compound (1) is represented by the formula (1): In the formula (1), R101 is a C2-C7 organic group and optionally includes at least one selected from the group consisting of a hetero atom and an unsaturated bond. The organic group for R101 is a divalent organic group. The organic group preferably has a carbon number of 3 to 7, more preferably 4 to 7, still more preferably 4 or 5, particularly preferably 4. Examples of the hetero atom in R101 include an oxygen atom (O), a sulfur atom (S), a nitrogen atom (N), a silicon atom (Si), a phosphorus atom (P), a boron atom (B), and halogen atoms. Preferred is an oxygen atom, a sulfur atom, or a nitrogen atom, more preferred is an oxygen atom or a nitrogen atom, and still more preferred is an oxygen atom. R101 optionally includes an ether bond (—O—). R101 also preferably includes no hetero atom. The unsaturated bond in R101 may be an unsaturated bond between carbon atoms, an unsaturated bond between a carbon atom and a hetero atom, or an unsaturated bond between hetero atoms. The unsaturated bond may be a double bond or a triple bond. Examples of the unsaturated bond include C═C, C≡C, C═O, C═N, C≡N, C═S, and S═O. R101 also preferably includes no unsaturated bond. The organic group for R101 preferably forms a 4- to 8-membered ring, more preferably a 5- to 8-membered ring, still more preferably a 5- or 6-membered ring, particularly preferably a 5-membered ring, together with the sulfur atom in the formula (1). In the organic group, atoms constituting a ring preferably consist only of carbon atoms. R101 is preferably a group represented by —(CY1Y2)n— where Y1 and Y2 are each independently a hydrogen atom or a C1-C3 organic group; and n is an integer of 2 to 7. The organic group for Y1 and Y2 preferably has a carbon number of 1 or 2, more preferably 1. The organic group for Y1 and Y2 is preferably an alkyl or alkoxy group having a carbon number within the above range, more preferably an alkyl group having a carbon number wi