Nonaqueous Battery Electrolyte Segmentation for CID Gas Generation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Nonaqueous electrolyte secondary batteries face challenges in maintaining low battery resistance during normal use while ensuring sufficient gas generation for current interrupt devices (CID) operation during overcharge, as excessive amounts of cyclohexylbenzene as a gas generation additive can increase resistance and limit gas generation.
Innovation Solution
Incorporating graphite particles and a gas generant like cyclohexylbenzene into the positive-electrode active material layer, with an α solute in the electrolyte solution that decreases at a specific electric potential, allowing for controlled gas generation and reduced battery resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the additive amount of cyclohexylbenzene (CHB) used as the gas generation additive is increased, then the gas generation amount at overcharge is improved, but the battery resistance in normal use area increases
Solution Approach 1:
The gas generant (cyclohexylbenzene) is segmented into two locations: incorporated into the positive-electrode active material layer and added to the electrolyte solution. This segmentation allows controlled gas generation at the electrode during overcharge while maintaining lower concentrations in the electrolyte to minimize resistance increase during normal use.
Solution Approach 2:
Different regions of the battery are given different qualities: the positive-electrode active material layer contains a higher concentration of gas generant for effective CID operation, while the electrolyte solution contains a controlled amount to balance gas generation and resistance management. This local differentiation optimizes both safety and performance.
2Reliability
If the additive amount of cyclohexylbenzene (CHB) used as the gas generation additive is increased, then the CID operation smoothness is improved, but the gas amount increase becomes limited beyond a given amount
Solution Approach 1:
By segmenting the gas generant distribution between the positive-electrode active material layer and electrolyte solution, the system achieves more efficient gas generation. The electrode-incorporated portion provides immediate gas generation for CID operation, while the electrolyte portion supplements gas generation, preventing saturation and ensuring reliable CID operation across different overcharge conditions.
3Quantity of substance
If an α solute is added to the electrolyte solution to manage viscosity and gas generation, then the gas generant deployment is improved, but the electrolyte solution composition becomes more complex
Solution Approach 1:
The α solute modifies the electrolyte solution's physical parameters (viscosity, solubility) to enhance gas generant deployment. By adjusting the concentration and type of α solute, the system optimizes gas generation efficiency while managing the complexity of the electrolyte composition through controlled parameter selection.
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
This configuration enables smooth operation of the CID during overcharge with enhanced gas generation while maintaining low battery resistance in normal use, by ensuring the gas generant is effectively deployed and the electrolyte solution's viscosity is managed.
Implementation Method 1
cyclohexylbenzene is added, as a gas generation additive, to an electrolyte solution... at which the gas generant begins to generate gas
Implementation Method 2
an electric potential Y at which an amount of the α solute in the electrolyte solution begins to decrease due to the graphite particles
Data Source
AI summary
A nonaqueous electrolyte secondary battery proposed herein is configured such that a positive-electrode active material layer includes graphite particles and a gas generant. Further, an electrolyte solution includes an α solute. Here, a relationship between an upper limit electric potential X of a positive electrode in a predetermined normal use area, an electric potential Y at which an amount of the α solute in the electrolyte solution begins to decrease due to the graphite particles, and an electric potential Z at which the gas generant begins to generate gas is X<Y<Z.