Wound Electrode Assembly Layout for Lithium Plating Suppression
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Solution Overview
Problem
Lithium plating in lithium-ion batteries reduces electrical performance and poses safety hazards due to dendrite formation, which existing technologies have not effectively addressed.
Innovation Solution
A wound electrode assembly design where the positive electrode winding starting section is not provided with tabs, increasing internal resistance and reducing ion separation, thereby lowering the likelihood of lithium plating. This design also includes optimized tab arrangements and heat dissipation structures to manage temperature and ion flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the positive electrode sheet is designed with uniform tab distribution, then current collection is optimized, but lithium plating risk increases due to excessive ion separation at the winding starting section
Solution Approach 1:
The patent applies local quality by creating a non-uniform tab distribution where the winding starting section has reduced or no tabs, while other sections maintain normal tab density. This localized modification reduces ion separation at the critical winding starting section where lithium plating occurs, without compromising current collection in other areas. The selective placement of tabs addresses the specific problem location rather than applying a uniform solution throughout the electrode sheet.
2Reliability
If the positive electrode winding starting section has tabs for current collection, then electrical conductivity is improved, but internal resistance decreases making lithium plating more likely
Solution Approach 1:
The patent changes the parameter of tab distribution by reducing or eliminating tabs at the winding starting section compared to other sections. This parameter modification increases the internal resistance specifically at the winding starting section, which slows down ion separation and reduces the likelihood of lithium plating. The parameter change is localized to the critical area rather than affecting the entire electrode uniformly.
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
Significantly reduces the risk of lithium plating and associated safety hazards, improving both electrical performance and safety of lithium-ion batteries by controlling ion separation and temperature distribution.
Implementation Method 1
the positive electrode winding starting section has no tab for directly guiding out currents in the positive electrode winding starting section, which is equivalent to increasing an internal resistance corresponding to the positive electrode winding starting section
Implementation Method 2
This design also includes optimized tab arrangements and heat dissipation structures to manage temperature and ion flow
Data Source
AI summary
A wound electrode assembly includes a positive electrode sheet including a positive electrode winding starting section not provided with positive electrode tabs and a positive electrode winding extension section provided with a positive electrode tab. The positive electrode winding starting section and the positive electrode winding extension section are connected, and the positive electrode winding starting section is wound at least one circle.