Battery and module
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Solution Overview
Problem
Existing lithium-ion secondary batteries face the risk of short-circuiting due to the degradation of the short-circuit prevention layer under high-temperature conditions, leading to a reduction in film thickness and potential electrical insulation failure.
Innovation Solution
A battery design incorporating an electrically insulating layer with a binder, such as polyvinylidene fluoride, and an electrically insulating filler, like alumina or zirconia beads, is applied to the positive electrode lead part. This layer maintains electrical insulation even when exposed to high temperatures, preventing short-circuiting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a resin short-circuit prevention layer is used on the positive electrode lead part, then short-circuit prevention function is provided, but the film thickness is reduced over time due to creep under high-temperature conditions
Solution Approach 1:
The patent changes the material composition parameters of the prevention layer by incorporating inorganic filler particles (such as alumina, silica, or boehmite) into the resin matrix. This composite structure modifies the thermal and mechanical properties, reducing creep deformation under high-temperature conditions while maintaining the short-circuit prevention function.
Solution Approach 2:
The patent creates a composite material system combining organic resin with inorganic filler particles. The inorganic particles provide structural support and dimensional stability at high temperatures, preventing the film thickness reduction that occurs with pure resin layers, while the resin provides the necessary flexibility and adhesion.
2Temperature
If the positive electrode lead part is exposed to high-temperature environment during charging and discharging, then electrical insulation is maintained, but the prevention layer degrades and may cause short-circuiting
Solution Approach 1:
The patent modifies the thermal stability parameters by selecting resins with high glass transition temperatures and incorporating inorganic fillers that are stable at elevated temperatures. This allows the prevention layer to maintain its structural integrity and electrical insulation properties even when exposed to high-temperature environments during battery operation.
Solution Approach 2:
The composite structure of resin and inorganic filler creates a material that combines the thermal stability of inorganic particles with the flexibility and electrical insulation properties of the resin matrix, ensuring reliable short-circuit prevention under thermal stress.
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 proposed solution effectively suppresses the occurrence of short-circuiting by ensuring the electrically insulating layer retains its thickness and functionality, even under high-temperature conditions, thereby enhancing the battery's reliability and performance.
Implementation Method 1
owing to creep, the film thickness of the short-circuit prevention layer tends to be reduced over time
Data Source
AI summary
A battery includes: a layer-type electrode body including a positive electrode sheet and a negative electrode sheet, the positive negative electrode sheets being alternately layered in a layering direction via a separator sheet; a laminate exterior body accommodating the electrode body; a positive electrode tab that projects from the laminate exterior body toward a first direction orthogonal to the layering direction, and that is electrically connected to the positive electrode sheets; a negative electrode tab that projects from the laminate exterior body toward another side in the first direction, and that is electrically connected to the negative electrode sheets; and an electrically insulating layer, wherein: the positive electrode current collector includes a positive electrode lead part, the electrically insulating layer is disposed at a surface of the positive electrode lead part, and the electrically insulating layer includes a binder and an electrically insulating filler.