Battery Cell Insulation Structure for High-Voltage Breakdown Resistance
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Solution Overview
Problem
High-voltage breakdown susceptibility of battery cell shells in lithium-ion batteries leads to lithium plating corrosion, heat generation, and a risk of combustion and explosion due to high voltage formation between the positive/negative terminal posts and the shell.
Innovation Solution
A battery cell design incorporating a first insulating protective layer on the inner wall of the shell and a second insulating protective layer enveloping the electrode assembly, increasing the creepage distance and providing insulating protection to enhance breakdown voltage resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If multiple battery cells are connected in series to form a battery pack, then high voltage is generated, but the shell becomes susceptible to high-voltage breakdown and lithium plating corrosion
Solution Approach 1:
An insulating protective layer is introduced as an intermediary between the electrode assembly and the shell. This protective layer acts as a mediator that prevents direct contact and electrical breakdown, allowing the battery to operate at high voltages without compromising shell reliability
Solution Approach 2:
The battery structure employs composite material design by combining the conductive electrode assembly with an insulating protective layer and the shell, creating a multi-material system that simultaneously achieves high voltage operation and enhanced breakdown resistance
2Device complexity
If the shell is directly in contact with the electrolyte solution, then the structure is simple, but the shell undergoes lithium plating corrosion breakdown under high voltage
Solution Approach 1:
The insulating protective layer serves as an intermediary barrier between the shell and the electrolyte solution, preventing direct contact and thereby eliminating lithium plating corrosion while maintaining structural simplicity
Solution Approach 2:
A thin film insulating protective layer is applied to the shell interior, providing corrosion protection without significantly increasing structural complexity or volume
3Use of energy by moving object
If the electrolyte solution contacts the shell under high voltage, then heat is generated through oxidation, but the probability of combustion and explosion increases
Solution Approach 1:
The insulating protective layer acts as a mediator that prevents direct contact between the electrolyte solution and the shell under high voltage conditions, thereby eliminating the oxidation reaction that generates heat and prevents combustion and explosion risks
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 insulating protective layers effectively improve the high-voltage breakdown resistance of the shell, reducing the probability of combustion or explosion by separating the shell from the electrode assembly and enhancing insulation.
Implementation Method 1
the first insulating protective layer is disposed on an inner wall of the shell; and the second insulating protective layer is configured to envelop at least a portion of the electrode assembly
Data Source
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AI summary
The present application provides a battery cell (20), a battery (100), and an electrical device. The battery cell (20) includes a shell (21), an electrode assembly (22), a first insulating protective layer (23), and a second insulating protective layer (24). The first insulating protective layer (23) is disposed on an inner wall of the shell (21), and the second insulating protective layer (24) is configured to envelop at least a portion of the electrode assembly (22). The battery cell (20) provided in the embodiments of the present application uses the first insulating protective layer (23) and the second insulating protective layer (24) to separate the shell (21) from the electrode assembly (22), thereby increasing the creepage distance between the shell (21) and the electrode assembly (22). This can achieve the purpose of improving the breakdown voltage resistance between the shell (21) and the electrode assembly (22), thereby effectively enhancing the high-voltage breakdown resistance of the shell (21), and consequently reducing the probability of combustion or explosion of the battery cell (20).