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CN-122003751-A - Nonaqueous electrolyte secondary battery

CN122003751ACN 122003751 ACN122003751 ACN 122003751ACN-122003751-A

Abstract

A nonaqueous electrolyte secondary battery includes a positive electrode, a negative electrode, a separator, and a nonaqueous electrolyte. The positive electrode contains LiMn （1‑y） Fe y PO 4 (wherein 0< y < 1) as a positive electrode active material, and the nonaqueous electrolytic solution contains a compound represented by formula (1). In formula (1), Q represents an alkylene group, an alkenylene group, or the like, and X represents a group represented by formula (2 a) or formula (2 b). R 1 represents an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a hydroxyl group, a lithiated group, or the like.

Inventors

  • Dao Honghui
  • Kono yuu

Assignees

  • 住友精化株式会社

Dates

Publication Date
20260508
Application Date
20240919
Priority Date
20231019

Claims (7)

  1. 1. A nonaqueous electrolyte secondary battery comprising a positive electrode, a negative electrode, a separator and a nonaqueous electrolyte, wherein, The positive electrode contains LiMn （1-y） Fe y PO 4 as a positive electrode active material, y is a value satisfying 0< y <1, The nonaqueous electrolyte contains a compound represented by the following formula (1), In the formula (1), Q represents a group which forms a ring structure together with a sulfur atom of a sulfonyl group and is selected from an alkylene group having 4 to 6 carbon atoms which may have 1 or more substituents and an alkenylene group having 4 to 6 carbon atoms which may have 1 or more substituents, X represents a group represented by the following formula (2 a) or the following formula (2 b), In the formula (2 a) and the formula (2 b), R 1 represents an alkyl group having 1 to 4 carbon atoms which may have a fluorine atom as a substituent, an alkenyl group having 2 to 4 carbon atoms which may have a fluorine atom as a substituent, an alkynyl group having 2 to 4 carbon atoms which may have a fluorine atom as a substituent, an aryl group having 6 to 10 carbon atoms which may have a fluorine atom as a substituent, a hydroxyl group, or a lithiated group.
  2. 2. The nonaqueous electrolyte secondary battery according to claim 1, wherein, In formula (1), Q is an alkylene group having 4 carbon atoms which may have 1 or more substituents, or an alkenylene group having 4 carbon atoms which may have 1 or more substituents.
  3. 3. The nonaqueous electrolyte secondary battery according to claim 1 or 2, wherein, In the formulas (2 a) and (2 b), R 1 is an alkyl group having 1 to 2 carbon atoms which may have a fluorine atom as a substituent, an alkenyl group having 2 to 4 carbon atoms which may have a fluorine atom as a substituent, an alkynyl group having 3 to 4 carbon atoms which may have a fluorine atom as a substituent, or a phenyl group which may have a fluorine atom as a substituent.
  4. 4. The nonaqueous electrolyte secondary battery according to claim 1 or 2, wherein, X is a group represented by formula (2 a).
  5. 5. The nonaqueous electrolyte secondary battery according to claim 1 or 2, wherein, X is a group represented by formula (2 b).
  6. 6. The nonaqueous electrolyte secondary battery according to claim 1 or 2, wherein, The compound represented by the formula (1) is a compound represented by the following formula (1 a), In the formula (1 a), the meaning of X is the same as that of X in the formula (1).
  7. 7. The nonaqueous electrolyte secondary battery according to claim 1 or 2, wherein, The compound represented by the formula (1) is a compound represented by the following formula (1 b), In the formula (1 b), the meaning of X is the same as that of X in the formula (1).

Description

Nonaqueous electrolyte secondary battery Technical Field The present invention relates to a nonaqueous electrolyte secondary battery. Background With growing interest in solving environmental problems and realizing sustainable cycle society, research into nonaqueous electrolyte secondary batteries typified by lithium ion batteries is being extensively conducted. Lithium ion batteries have high voltage and energy density, and thus are used as power sources for notebook computers, mobile phones, electric vehicles, and the like. In lithium ion batteries, a method of adding various additives to an electrolyte is generally used for the purpose of improving battery performance and the like. As such an additive, for example, an additive is known which is decomposed at the time of initial charge and discharge and forms a coating film called a Solid Electrolyte Interface (SEI) on the surface of the anode. It is considered that the formation of SEI plays an important role in suppressing degradation of secondary batteries upon repeated charge and discharge cycles and improving various battery performances. For example, patent document 1 discloses a method in which 1, 3-propane sultone and/or 1, 4-butane sultone are added to an electrolyte solution as additives in a lithium secondary battery using lithium cobaltate or lithium manganate as a positive electrode active material, thereby improving cycle characteristics and the like. Patent document 2 discloses a method of improving storage stability at high temperature by adding a cyclic sulfonate compound as an additive to an electrolyte in a power storage device including a lithium NCM composite metal oxide as a positive electrode active material. Patent document 3 discloses a method of improving storage stability at high temperatures by adding 1, 3-dioxane as an additive to an electrolyte in a power storage device containing a lithium NCM composite metal oxide or a lithium-containing olivine-type phosphate as a positive electrode active material. Technical literature of the prior art Patent literature Patent document 1 Japanese patent No. 3978881 Patent document 2 International publication No. 2012/147818 Patent document 3 International publication No. 2018/116879 Disclosure of Invention Technical problem to be solved by the invention Recently, as a positive electrode active material, lithium manganese iron phosphate having more excellent stability among the above-mentioned lithium-containing olivine-type phosphates has been attracting attention. However, a nonaqueous electrolyte secondary battery containing the lithium iron manganese phosphate as a positive electrode active material has not yet been established as a formulation suitable for improving storage stability at high temperatures. An aspect of the present invention relates to a method of improving the storage stability at high temperatures of a nonaqueous electrolyte secondary battery containing lithium manganese iron phosphate as a positive electrode active material. Means for solving the technical problems One aspect of the present invention relates to a nonaqueous electrolyte secondary battery including the following. Item 1. A nonaqueous electrolyte secondary battery comprising a positive electrode, a negative electrode, a separator and a nonaqueous electrolyte, wherein, The positive electrode contains LiMn （1-y）FeyPO4 as a positive electrode active material, y is a value satisfying 0< y <1, The nonaqueous electrolyte contains a compound represented by the following formula (1), In the formula (1), Q represents a group which forms a ring structure together with a sulfur atom of a sulfonyl group and is selected from an alkylene group having 4 to 6 carbon atoms which may have 1 or more substituents and an alkenylene group having 4 to 6 carbon atoms which may have 1 or more substituents, X is a group represented by the following formula (2 a) or the following formula (2 b), In the formula (2 a) and the formula (2 b), R 1 represents an alkyl group having 1 to 4 carbon atoms which may have a fluorine atom as a substituent, an alkenyl group having 2 to 4 carbon atoms which may have a fluorine atom as a substituent, an alkynyl group having 2 to 4 carbon atoms which may have a fluorine atom as a substituent, an aryl group having 6 to 10 carbon atoms which may have a fluorine atom as a substituent, a hydroxyl group, or a lithiated group. Item 2. The nonaqueous electrolyte secondary battery according to claim 1, wherein, In formula (1), Q is an alkylene group having 4 carbon atoms which may have 1 or more substituents, or an alkenylene group having 4 carbon atoms which may have 1 or more substituents. Item 3. The nonaqueous electrolyte secondary battery according to item 1 or 2, wherein, In the formulas (2 a) and (2 b), R 1 is an alkyl group having 1 to 2 carbon atoms which may have a fluorine atom as a substituent, an alkenyl group having 2 to 4 carbon atoms which may have a fluorine atom as a substituent, an alkyn