Battery Electrode Insulating Layer for Pressure-Balanced Tab Regions
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium-ion batteries used in portable electronic devices face safety issues due to pressure imbalances and increased local resistance in regions where active material is removed, leading to potential swelling and safety hazards like fire or explosion.
Innovation Solution
The battery design includes insulating layers in regions where active material is not applied, ensuring uniform thickness and preventing local resistance, with insulating layers disposed in portions of the negative electrode substrate to align with positive electrode tabs, and vice versa, to maintain even pressure distribution and prevent dendrite formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If active material is removed from the facing region to prevent short circuits, then safety is improved, but pressure imbalance and local resistance increase occur
Solution Approach 1:
The patent applies different treatments to different regions of the electrode substrate. The facing region (where tabs are located) has active material removed to prevent short circuits, while other regions maintain active material for normal battery function. This local differentiation resolves the contradiction by applying the safety measure only where necessary rather than uniformly across the entire electrode.
Solution Approach 2:
The patent introduces an insulating layer as an intermediary component in the facing region where active material is removed. This insulating layer prevents direct contact between tabs and active material (avoiding short circuits) while also providing structural support to maintain uniform pressure distribution during battery assembly, thereby addressing both safety and pressure balance concerns.
2Reliability
If active material is removed from the facing region, then short circuit prevention is improved, but local resistance increases
Solution Approach 1:
The insulating layer serves as a mediator that maintains electrical isolation in the facing region while providing a uniform surface that prevents localized resistance spikes. By controlling the thickness and material properties of this insulating layer, the patent achieves both short circuit prevention and resistance uniformity.
Solution Approach 2:
The patent controls the thickness of the insulating layer in the facing region to match the thickness of the active material layer in other regions. This parameter matching ensures uniform pressure distribution and consistent electrical characteristics across the entire electrode assembly, preventing local resistance increases while maintaining short circuit prevention.
3Stress or pressure
If facing region thickness is made uniform with other regions, then pressure balance is improved, but manufacturing complexity increases
Solution Approach 1:
The patent controls the thickness parameter of the insulating layer in the facing region to be equal to the thickness of the active material layer in other regions. This simple parameter specification (matching thicknesses) achieves uniform pressure distribution without requiring complex multi-step manufacturing processes, as the insulating layer can be applied in a single step during electrode fabrication.
Data Source
AI summary
A battery includes: a positive electrode including a positive electrode substrate having a first surface and a second surface, a positive active material applied to the first surface of the positive electrode substrate, and a positive electrode tab attached to the first surface of the positive electrode substrate; a negative electrode including a negative electrode substrate having a first surface and a second surface, a negative active material applied to the first surface of the negative electrode substrate, and a negative electrode tab attached to the first surface of the negative electrode substrate; and a separator provided between the positive electrode and the negative electrode, wherein the first surface of the negative electrode substrate includes a first region to which the negative active material is not applied and which faces the positive electrode tab, the first surface of the negative electrode substrate includes a second region to which the negative active material is applied and which is adjacent to the first region in a longitudinal direction of the positive electrode tab, and the negative electrode includes an insulating layer disposed in at least a portion of the first region.