Nonaqueous Battery Electrolyte Composition for Stable High-Temperature Storage
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Solution Overview
Problem
Nonaqueous secondary batteries experience increased direct-current resistance and decreased discharge capacity when stored in high-temperature environments due to insoluble acesulfame compounds in the electrolyte solution, leading to potential short circuits and inadequate electrode impregnation.
Innovation Solution
A nonaqueous secondary battery design incorporating a nonaqueous electrolyte solution with acesulfame compounds at specific concentrations, along with a positive electrode active material and a negative electrode, to inhibit the formation of a solid electrolyte interphase (SEI) film thickening and metal ion elution, thereby maintaining battery performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If acesulfame Li is added to the nonaqueous electrolyte solution at 1% by mass or more, then the discharge capacity is improved, but the acesulfame Li does not dissolve completely, leaving insoluble components that may cause short circuits and inadequate electrode impregnation
Solution Approach 1:
The patent changes the concentration parameter of acesulfame Li from 1% by mass or more (comparative example) to 0.01% by mass or more but less than 1% by mass (invention). This parameter adjustment ensures complete dissolution of acesulfame Li in the nonaqueous electrolyte solution, preventing insoluble components while maintaining the ability to inhibit SEI film thickening and metal ion elution during high-temperature storage.
2Duration of action of stationary object
If the battery is stored in a high-temperature environment (60°C) over an extended period (14 days) in a fully-charged state, then the discharge capacity increases, but the direct-current resistance increases and discharge capacity decreases
Solution Approach 1:
The patent applies a preliminary action by adding a specific amount of acesulfame Li (0.01% by mass or more but less than 1% by mass) to the nonaqueous electrolyte solution before battery assembly and storage. This preliminary addition creates a protective effect that prevents SEI film thickening and metal ion elution during subsequent high-temperature storage, thereby maintaining low direct-current resistance and high discharge capacity even after extended storage periods.
3Reliability
If the content of acesulfame Li is increased to inhibit SEI film thickening, then the battery performance is improved, but the acesulfame Li becomes insoluble in the electrolyte solution
Solution Approach 1:
The patent identifies and applies the optimal concentration parameter range for acesulfame Li in the nonaqueous electrolyte solution. By setting the content to 0.01% by mass or more but less than 1% by mass, the invention achieves complete dissolution of acesulfame Li, ensuring electrolyte solution homogeneity while maintaining sufficient effectiveness in inhibiting SEI film thickening and preventing metal ion elution during high-temperature storage.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively prevents the increase in direct-current resistance and decrease in discharge capacity, ensuring stable battery performance even after high-temperature long-term storage by maintaining the integrity of the SEI film and preventing metal ion deposition.
Implementation Method 1
inhibit the formation of a solid electrolyte interphase (SEI) film thickening
Implementation Method 2
preventing metal ion elution
Implementation Method 3
The negative electrode is formed of lithium or a negative electrode material capable of occluding and releasing lithium
Data Source
AI summary
Provided is a nonaqueous secondary battery including: a nonaqueous electrolyte solution that contains a compound (A) represented by the following Formula (I); a positive electrode that contains a positive electrode active material containing a compound (B) represented by the following Formula (II); and a negative electrode. The content of the compound (A) is more than 0% by mass but less than 1.0% by mass with respect to a total amount of the nonaqueous electrolyte solution. In Formula (I), X+ represents a hydrogen ion, a lithium ion, a sodium ion, or a potassium ion. In Formula (II), 0.1≤a<1.3, 0.1<(1-b-c)<1.0, 0<b<0.6, and 0<c<0.6.