KR-102963551-B1 - Non-aqueous electrolyte and non-aqueous electrolyte battery using the same

Abstract

The present invention relates to [1] a non-aqueous electrolyte containing a compound (A) represented by general formula (1) and an anion (B) represented by general formula (2), with a mass ratio [(A)/(B)] of 0.01 or more and 1.2 or less, and [2] a positive electrode, a negative electrode having a positive electrode active material capable of absorbing and releasing lithium ions, and a non-aqueous electrolyte having said non-aqueous electrolyte.

Inventors

• 후카미즈, 고지
• 미요시, 가즈히로

Assignees

• 엠유 아이오닉 솔류션즈 주식회사

Dates

Publication Date

20260513

Application Date

20220325

Priority Date

20210326

Claims (6)

1. A non-aqueous electrolyte containing a compound (A) represented by the following general formula (1) and an anion (B) represented by the following general formula (2), wherein the mass ratio [(A)/(B)] of the content of the compound (A) to the content of the anion (B) is 0.01 or greater and 1.2 or less. [In Formula (1), X1 and X2 each represent an aliphatic hydrocarbon group having 1 to 3 carbon atoms that may be independently substituted with a hydrogen atom or a halogen atom. Y1 is a divalent atomic group selected from the structural group represented by Formula (1-1) below. Z1 represents an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, or a monovalent substituent represented by the following formula (1-3). [In Equation (1-1), * indicates the bonding location with the oxygen atom in Equation (1).] [In Formula (1-3), Z₂ represents an alkyl group or alkoxy group having 1 to 3 carbon atoms that may be substituted with a halogen atom, or an alkoxyalkyl group having 2 to 4 carbon atoms that may be substituted with a halogen atom. X₃ and X₄ each independently represent a hydrogen atom or a halogen atom, and n represents an integer from 1 to 5. Additionally, ** in Formula (1-3) indicates a bonding site with Y₁ in Formula (1).] [In Formula (2), Z3 represents a fluorine atom, an alkyl group or alkoxy group having 1 to 4 carbon atoms that may be substituted with a halogen atom, or an alkenyl group or alkenyloxy group having 2 to 4 carbon atoms that may be substituted with a halogen atom.]
2. A non-aqueous electrolyte in which Y1 in general formula (1) is a divalent atomic group represented by the following formula (1-2). [In Equation (1-2), * indicates the bonding location with the oxygen atom in Equation (1).]
3. A non-aqueous electrolyte in which Z3 in general formula (2) is a fluorine atom, in claim 1 or 2.
4. A non-aqueous electrolyte according to claim 1 or 2, additionally containing a chain carboxylic acid ester.
5. A non-aqueous electrolyte battery characterized by having a positive electrode, a negative electrode, and a non-aqueous electrolyte as described in claim 1 or 2, wherein the positive electrode active material capable of absorbing and releasing lithium ions.
6. In claim 5, the above positive electrode is a non-aqueous electrolyte battery containing a lithium transition metal composite oxide represented by the following general formula (13) as a positive electrode active material. Li a1 Ni b1 M c1 O 2 (13) [In Equation (13), a1, b1, and c1 are 0.90≤a1≤1.10, 0.65≤b1≤0.98, and 0≤c1≤0.20, respectively, and b1+c1=1. M represents at least one element selected from the group consisting of Co, Mn, Al, Mg, Zr, Fe, Ti, and Er.]

Description

Non-aqueous electrolyte and non-aqueous electrolyte battery using the same The present invention relates to a non-aqueous electrolyte and a non-aqueous electrolyte battery using the same. Non-aqueous electrolyte batteries, such as lithium-ion secondary batteries, have been commercialized for a wide range of applications, from so-called civilian power sources like mobile phones and notebook computers to onboard power sources for vehicles such as automobiles. However, in recent years, the demand for high performance in non-aqueous electrolyte batteries has been increasing, and improvements in various battery characteristics are desired, particularly regarding high capacity, low-temperature usage characteristics, high-temperature storage characteristics, cycle characteristics, and safety during overcharging. To date, numerous technologies have been examined regarding active materials for the positive and negative electrodes, as well as various battery components including non-aqueous electrolytes, as means to improve the high-temperature storage characteristics or cycle characteristics of non-aqueous electrolyte secondary batteries. Patent Document 1 discloses a non-aqueous electrolyte containing specific amounts of vinylene carbonate and 2-propynylmethyl carbonate as a non-aqueous electrolyte for manufacturing a lithium secondary battery with excellent cycle characteristics. Patent Document 2 discloses a non-aqueous electrolyte that can improve electrochemical properties under high temperature and also reduce the discharge capacity retention rate and electrode thickness increase rate after a high-temperature cycle test, and contains a specific diisocyanato compound and also contains a specific amount of at least one selected from a specific phosphate ester compound, a cyclic sulfonic acid ester compound, an isocyanato compound, and a triple bond-containing compound. [1. Non-aqueous electrolyte] The non-aqueous electrolyte of the present invention is a non-aqueous electrolyte for a non-aqueous electrolyte battery containing an electrolyte and a non-aqueous solvent, and is characterized by containing a compound (A) represented by the following general formula (1) and an anion (B) represented by the following general formula (2), and having a mass ratio [(A)/(B)] of the content of the compound (A) to the content of the anion (B) being 0.01 or more and 1.2 or less. [In Formula (1), X1 and X2 each represent an aliphatic hydrocarbon group having 1 to 3 carbon atoms that may be independently substituted with a hydrogen atom or a halogen atom. Y1 is a divalent atomic group selected from the structural group represented by Formula (1-1) below. Z1 represents an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, or a monovalent substituent represented by the following formula (1-3). [In Equation (1-1), * indicates the bonding location with the oxygen atom in Equation (1).] [In Formula (1-3), Z₂ represents an alkyl group or alkoxy group having 1 to 3 carbon atoms that may be substituted with a halogen atom, or an alkoxyalkyl group having 2 to 4 carbon atoms that may be substituted with a halogen atom. X₃ and X₄ each independently represent a hydrogen atom or a halogen atom, and n represents an integer from 1 to 5. Additionally, ** in Formula (1-3) indicates a bonding site with Y₁ in Formula (1).] [In Formula (2), Z3 represents a fluorine atom, an alkyl group or alkoxy group having 1 to 4 carbon atoms that may be substituted with a halogen atom, or an alkenyl group or alkenyloxy group having 2 to 4 carbon atoms that may be substituted with a halogen atom.] A non-aqueous electrolyte battery manufactured using the non-aqueous electrolyte of the present invention can improve discharge power capacity by suppressing the malfunction of the battery's current cutoff valve. Although the operation and principle are not necessarily clear, they are presumed as follows. However, the present invention is not limited to the operation and principle described below. Compound (A) represented by general formula (1) has terminal alkyne sites with low steric hindrance, so it coordinates to transition metal elements present in the positive electrode. Because of this, it can suppress contact between other electrolyte components on the surface of the positive electrode, thereby suppressing the oxidative decomposition reaction of the electrolyte. However, when the battery becomes overcharged and the positive electrode potential returns to a level lower than the normal operating potential, the compound (A) coordinated to the positive electrode itself undergoes oxidative decomposition, causing gas generation. Here, it may be thought that if the pressure of the current cutoff valve is set appropriately, the current cutoff valve can be operated in the event of abnormalities such as overcharging while suppressing the malfunction of the current cutoff valve during normal use. However, since the above compound (A) has a