Composite Electrolyte Battery Cell for Anode Expansion Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Batteries with silicon and lithium metal as anode materials face volume expansion issues that lead to squeezing-induced leakage of liquid electrolytes, compromising cycling performance.
Innovation Solution
A battery cell design incorporating a combination of solid and liquid electrolytes, with specific ratios of solid electrolyte mass to total electrolyte mass, and a heat-curable electrolyte formation process, to balance cycling performance and capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If silicon and lithium metal are used as anode materials to achieve ultra-high theoretical gram capacities, then energy density is improved, but volume expansion during cycling causes squeezing-induced leakage of liquid electrolytes and deteriorates cycling performance
Solution Approach 1:
The patent employs a composite electrolyte system combining solid electrolyte and liquid electrolyte in specific ratios. The solid electrolyte component suppresses volume expansion of the silicon-based negative electrode during cycling, while the liquid electrolyte maintains good ionic conductivity, thereby resolving the contradiction between energy density and cycling performance
Solution Approach 2:
The patent optimizes the mass ratio parameters of solid electrolyte to total electrolyte (y=5-50%) and controls the negative electrode volume expansion ratio (x≤20%), establishing quantitative relationships between these parameters and battery performance to achieve both high energy density and reliable cycling
2Reliability
If the negative electrode volume expansion ratio is controlled to reduce electrolyte leakage, then cycling performance is improved, but capacity performance may be limited
Solution Approach 1:
The patent applies different electrolyte components to different functional needs: solid electrolyte primarily at the negative electrode interface to handle volume expansion, and liquid electrolyte distributed throughout to ensure bulk ionic conductivity and capacity, achieving localized optimization of electrode-electrolyte interaction
3Reliability
If solid electrolyte content is increased to suppress volume expansion, then cycling performance is improved, but lithium ion transmission rate may decrease
Solution Approach 1:
The patent creates a composite electrolyte where solid electrolyte (5-50% by mass) provides structural stability and volume expansion suppression, while liquid electrolyte (50-95% by mass) provides high ionic conductivity, achieving synergistic effect that balances cycling performance and lithium ion transmission rate
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
Reduces electrolyte leakage and enhances lithium ion transmission, maintaining battery capacity and cycling performance by leveraging the strengths of both electrolyte types.
Implementation Method 1
The solid electrolyte is a heat-curable electrolyte solution. The heat-curable electrolyte can be cured under heating conditions to form a solid electrolyte.
Data Source
AI summary
A battery cell comprises a negative electrode plate and an electrolyte, and the electrolyte comprises a solid electrolyte and a liquid electrolyte. The ratio of the thickness of the fully charged negative electrode plate to the thickness of the uncharged negative electrode plate is x, and the ratio of the mass of the solid electrolyte in the electrolyte to the mass of the electrolyte is y. When x≤20%, 0<y≤50%. When 20%<x<80%, 50%<y<90%. when x≥80%, 90%≤y≤96%.