Interleaved Electrode Battery Merging Cell Types
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Solution Overview
Problem
High capacity lithium ion batteries face instability issues leading to internal shorts, thermal runaway, and safety concerns due to decreasing output resistance, which limits the capacity of individual cells and poses risks of fire and explosion.
Innovation Solution
The solution involves merging at least two different cell types in a stack, sharing electrodes of one polarity and interleaving electrodes of another polarity, with connective tabs located uniquely to prevent short circuits and enhance heat sinking capacity for cooling, thereby limiting short circuit current and preventing thermal runaway.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the capacity of individual battery cells is increased, then the battery can provide higher energy storage, but the output resistance decreases leading to internal shorts and thermal runaway risks
Solution Approach 1:
The battery is divided into multiple smaller cells (first cell type and second cell type) that are connected in parallel. Each cell maintains its own electrodes and separator, preventing internal shorts while collectively providing high capacity. The segmentation isolates potential failure points, so a short in one cell does not affect others.
Solution Approach 2:
A common electrode of opposite polarity is introduced as an intermediary between the positive electrodes of different cell types. This common electrode shares connective tabs and provides a distributed current collection path, reducing current density and heat generation at any single point, thereby preventing thermal runaway.
2Device complexity
If multiple cells are merged into fewer cells to increase capacity, then the number of cells is reduced, but internal shorts and thermal runaway risks increase
Solution Approach 1:
The battery maintains distinct cell structures (first cell type with first positive electrode, second cell type with second positive electrode) rather than merging into a single homogeneous cell. Each cell type retains its separator and electrode configuration, preserving safety boundaries while reducing the total cell count through parallel connection of cell types.
Solution Approach 2:
Different cell types are designed with different capacities and characteristics. The first and second positive electrodes have different capacities, allowing optimization of local regions. This heterogeneous structure distributes energy density and current flow, preventing hot spots that could lead to thermal runaway.
3Ease of manufacture
If electrodes are shared between cell types, then manufacturing efficiency is improved, but short circuit risks may increase
Solution Approach 1:
The common electrode of opposite polarity acts as an intermediary that is shared between first and second cell types. It includes connective tabs that are electrically connected to both cell types, providing a controlled current path that prevents direct contact between like electrodes while enabling efficient current collection and distribution.
Solution Approach 2:
Instead of sharing electrodes in the same spatial plane (which would risk short circuits), the common electrode is positioned in a different dimensional arrangement as a shared opposite-polarity electrode. This spatial reconfiguration allows multiple cell types to share current collection infrastructure without creating short circuit pathways.
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 approach effectively reduces heat generation at short circuit locations, increases the safety threshold, and allows for higher capacity batteries while minimizing the number of cells, thus enhancing safety and efficiency.
Implementation Method 1
interleaving electrodes of another polarity, with connective tabs located uniquely to prevent short circuits and enhance heat sinking capacity for cooling, thereby limiting short circuit current and preventing thermal runaway
Data Source
Figure 1a~1d
Figure 2a~2d
Figure 3
AI summary
A battery having the electrodes of multiple cell types interleaved to prevent thermal runaway by cooling a shorted region between electrodes. The battery includes multiple cell types where each cell type has multiple electrodes a first polarity. The electrodes of each of the cell types share a pair of the common electrodes having a second polarity. The electrodes of the multiple cell types and the multiple common electrodes are interleaved such that if the electrodes of the multiple cell types and the adjacent common electrodes of one or more cell types short together, the current within the shorted cells is sufficiently small to prevent thermal runaway and the electrodes of the adjacent cells of the other cell types of the first polarity and the common electrodes of the second polarity not having short circuits provide heat sinking for the heat generated by the short circuit to prevent thermal runaway.