1,3-Dioxane Electrolyte for High-Voltage Battery Stability
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Solution Overview
Problem
Lithium secondary batteries face issues with charging storage and discharging storage properties when operated in high-temperature and high-voltage environments, leading to increased interfacial resistance, self-discharge, and metal elution, which degrade electrochemical characteristics.
Innovation Solution
A nonaqueous electrolytic solution containing a compound with two alkyl substituents at the 5-position of 1,3-dioxane, dissolved in a solvent, which enhances charging and discharging storage properties by promoting surface film formation and reducing metal elution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional nonaqueous electrolytic solutions are used in high-temperature and high-voltage environments, then initial capacity and basic cycle properties can be maintained, but charging storage properties and discharging storage properties deteriorate due to oxidative decomposition of the solvent
Solution Approach 1:
The patent introduces a specific compound (1,3-dioxane with two alkyl substituents at the 5-position) as an intermediary substance in the electrolytic solution. This compound acts as a mediator that forms protective surface films on the positive electrode, preventing direct contact and oxidative decomposition between the conventional electrolyte components and the electrode at high temperatures and voltages. The intermediary compound thus resolves the contradiction by stabilizing the electrolyte composition while maintaining reliable charging storage properties.
Solution Approach 2:
The patent modifies the chemical composition parameters of the electrolytic solution by incorporating a specific compound with defined structural characteristics (1,3-dioxane with two alkyl substituents at the 5-position). This parameter change in the electrolyte composition enables the formation of stable surface films that prevent oxidative decomposition, thereby improving both charging storage properties and composition stability simultaneously.
2Quantity of substance
If lithium secondary batteries are kept in a charged state in high-temperature and high-voltage environments, then energy storage capacity is maintained, but interfacial resistance increases due to deposition of decomposed products and electrolyte depletion
Solution Approach 1:
The patent applies preliminary action by having the specific compound (1,3-dioxane with two alkyl substituents at the 5-position) form protective surface films on the positive electrode before oxidative decomposition can occur. This preliminary film formation prevents the generation of decomposed products and electrolyte depletion that would otherwise increase interfacial resistance during prolonged charging storage in high-temperature and high-voltage environments, thus maintaining both energy storage capacity and low interfacial resistance.
3Area of stationary object
If lithium secondary batteries are kept in a discharged state after high-voltage usage in high-temperature environments, then active surface area is increased, but self-discharge accelerates due to reaction with nonaqueous solvent
Solution Approach 1:
The patent converts the potentially harmful reaction between the exposed active surface and nonaqueous solvent into a beneficial process. The specific compound (1,3-dioxane with two alkyl substituents at the 5-position) facilitates the formation of a stable surface film on the negative electrode that prevents harmful self-discharge reactions while allowing the active surface area to remain exposed for normal operation. This transforms the harmful effect of increased active surface area into a benefit by controlling the surface chemistry to prevent energy loss.
4Quantity of substance
If high-voltage charging is performed to increase capacity, then energy storage capacity is improved, but oxidative decomposition of solvent occurs at potentials above 4.3 V
Solution Approach 1:
The patent introduces the specific compound (1,3-dioxane with two alkyl substituents at the 5-position) as an intermediary that forms protective surface films on the positive electrode. This intermediary layer enables high-voltage charging operations by preventing direct oxidative decomposition between the electrolyte solvent and the electrode at potentials above 4.3 V, thus allowing increased energy storage capacity without the harmful effects of solvent decomposition.
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 significantly improves charging and discharging storage properties and reduces metal elution in lithium batteries, maintaining electrochemical stability even at high temperatures and voltages.
Implementation Method 1
when the nonaqueous electrolytic solution contains a compound having two alkyl substituents at the 5-position of 1,3-dioxane, the charging storage properties and the discharging storage properties of an energy storage device are remarkably improved
Implementation Method 2
a compound having two alkyl substituents at the 5-position of 1,3-dioxane, which promotes surface film formation and reducing metal elution
Implementation Method 3
a nonaqueous electrolytic solution having an electrolyte salt dissolved in a nonaqueous solvent
Implementation Method 4
a lithium ion secondary battery and a lithium ion capacitor have been recently watched as a power source
Data Source
AI summary
The present invention relates to a nonaqueous electrolytic solution having an electrolyte salt dissolved in a nonaqueous solvent, the nonaqueous electrolytic solution containing 0.1 to 5% by mass of a compound represented by the following general formula (I) and an energy storage device including the foregoing nonaqueous electrolytic solution. This nonaqueous electrolytic solution is able to improve charging storage properties and discharging storage properties of an energy storage device when used in the high-temperature and high-voltage environment.In the formula, R1 and R2 each independently represent an alkyl group having 1 to 4 carbon atoms.