Phosphate Ester Battery Electrode Thermal Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Nonaqueous electrolyte secondary batteries face challenges in inhibiting exothermic reactions between positive electrode active materials and electrolytic solutions while maintaining charge/discharge efficiency and flame retardancy, as high concentrations of phosphate esters can decrease ionic conductance and cause side reactions.
Innovation Solution
Incorporating a phosphate ester compound represented by Formula (1) with a metal oxide powder layer between the positive and negative electrodes to trap water and prevent side reactions, enhancing thermal stability and solubility, and using a metal salt of myo-inositol-1,2,3,4,5,6-hexaphosphate for improved thermal stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a high concentration of phosphate ester is dissolved in the electrolytic solution to inhibit exothermic reaction, then flame retardancy is improved, but ionic conductance decreases and charge/discharge efficiency deteriorates
Solution Approach 1:
The patent extracts the phosphate ester from the electrolytic solution and relocates it to the positive electrode. Specifically, the phosphate ester is incorporated into the positive electrode at a concentration of 0.1-10% by mass, while its concentration in the electrolytic solution is reduced to 15% by mass or less. This spatial redistribution allows the flame retardant function to be maintained at the electrode interface while minimizing the negative impact on ionic conductance in the bulk electrolyte.
Solution Approach 2:
The patent applies local quality by concentrating the phosphate ester specifically in the positive electrode where exothermic reactions occur, rather than uniformly distributing it throughout the electrolytic solution. The positive electrode contains the phosphate ester at 0.1-10% by mass, creating a localized high-concentration zone at the reaction site, while the bulk electrolyte maintains lower phosphate ester content to preserve ionic conductance.
2Object-affected harmful factors
If phosphate ester is dissolved in electrolytic solution to achieve flame retardancy, then exothermic reaction is inhibited, but solubility issues cause performance degradation
Solution Approach 1:
The patent extracts the phosphate ester from the electrolytic solution phase and transfers it to the positive electrode phase. The positive electrode contains the phosphate ester at 0.1-10% by mass, while the electrolytic solution contains it at 15% by mass or less. This phase separation resolves the solubility conflict by concentrating the flame retardant where it is needed most, while maintaining electrolyte stability.
3Object-affected harmful factors
If phosphate ester compound is used as flame retardant in positive electrode, then exothermic reaction inhibition is improved, but manufacturing complexity increases due to specific formulation requirements
Solution Approach 1:
The patent specifies precise parameter ranges for the phosphate ester formulation: 0.1-10% by mass in the positive electrode and 15% by mass or less in the electrolytic solution. These parameter definitions provide clear manufacturing guidelines that balance flame retardancy performance with ease of production, allowing manufacturers to target specific concentration ranges rather than requiring exact formulations.
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 inhibits exothermic reactions, maintains charge/discharge efficiency, and provides excellent flame retardancy by reducing the solubility of the phosphate ester compound in the electrolyte, thus improving the overall performance of the nonaqueous electrolyte secondary battery.
Implementation Method 1
a layer containing a metal oxide powder between the positive electrode and the negative electrode
Implementation Method 2
phosphorus-containing compounds are known as flame retardants inhibiting exothermic reaction between positive electrode active materials and electrolytic solutions
Data Source
AI summary
Provided is a nonaqueous electrolyte secondary battery including a nonaqueous electrolyte and an electrode assembly including a positive electrode, a negative electrode, and a separator disposed between the positive electrode and the negative electrode. The electrode assembly further includes a layer containing a metal oxide powder between the positive electrode and the negative electrode. The positive electrode contains a phosphate ester compound represented by Formula (1);where X and Y each independently represent a metal atom, a hydrogen atom, or an organic group; at least one of X and Y represents a metal atom; X and Y are coincident when the metal atom is divalent; and n represents an integer of 2 or more and 10 or less.