Battery Pack Filler Structure for Cell Position and Resistance Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium ion batteries face issues with resin current collectors having low electron mobility, leading to increased internal resistance due to deviations in cell positions caused by external vibrations and gas generation during storage, transportation, and use at high temperatures.
Innovation Solution
A battery pack design with filler materials in gaps between cells and the exterior body to maintain close contact between resin current collectors, using gas adsorption particles to absorb generated gases and prevent positional deviations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If resin current collectors are used to achieve high energy density and output density, then the battery can achieve high energy density, but the electron mobility is low leading to increased internal resistance
Solution Approach 1:
A resin current collector sheet with higher conductivity is introduced as an intermediary between the resin current collectors of adjacent cells. This mediator improves electron mobility and reduces contact resistance without requiring direct metal current collectors, thus maintaining high energy density while reducing internal resistance.
2Reliability
If cells are laminated closely to improve conductivity, then electron mobility improves, but external vibrations cause positional deviations increasing internal resistance
Solution Approach 1:
A resin current collector sheet is placed beforehand between adjacent resin current collectors to cushion and absorb the effects of external vibrations. This prevents direct contact loss between cells while maintaining electrical connectivity, thus preserving both conductivity and positional stability.
3Ease of manufacture
If gas is generated during storage at high temperatures, then internal pressure increases causing cell position deviation, but deaeration is insufficient to prevent this
Solution Approach 1:
The resin current collector sheet acts as a compressible intermediary layer that absorbs internal pressure increases from gas generation. This mediator prevents direct transmission of pressure to the cell structure, maintaining positional stability even when deaeration is insufficient.
4Reliability
If metal current collectors are used instead of resin, then conductivity improves, but energy density decreases due to weight and volume
Solution Approach 1:
Different materials are used in different locations: resin current collectors are used within cells for high energy density, while a more conductive resin current collector sheet is used between cells for improved conductivity. This local differentiation optimizes both energy density and conductivity without requiring metal current collectors throughout.
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 maintains close contact between resin current collectors, preventing positional deviations and increases in internal resistance, while also adsorbing gases generated during lithium ion battery operation, thus enhancing the stability and performance of the battery pack.
Implementation Method 1
using gas adsorption particles to absorb generated gases and prevent positional deviations
Data Source
AI summary
A battery pack having two or more cells provided with a lamination unit composed of a single set of a positive electrode resin current collector, a positive electrode active material layer, a separator, a negative electrode active material layer and a negative electrode resin current collector sequentially laminated together, the two or more cells being sealed in an exterior body, in which filler materials are provided in gaps between the cells and/or gaps between the cell and the exterior body.