Flame-Retardant Electrode Coating for Battery Short-Circuit Suppression
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Solution Overview
Problem
Secondary batteries face safety issues due to short circuits and initial heat generation during abnormal operations like internal/external short circuits, overcharge, or overdischarge, which can lead to explosions.
Innovation Solution
The electrode assembly incorporates a flame retardant coating between active material coating and non-coating portions on the cathode and anode collectors, preventing direct contact and suppressing initial heat generation through heat absorption reactions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the separator contracts due to generated heat during abnormal operations, then the cathode and anode directly contact each other causing short circuit, but the battery structure remains simple without additional protective layers
Solution Approach 1:
The patent introduces a non-conductive coating portion containing flame retardant as an intermediary layer between the active material coating portion and the active material non-coating portion. This coating acts as a mediator that prevents direct contact between cathode and anode even when separator contracts, thereby preventing short circuit while maintaining relatively simple battery structure
Solution Approach 2:
The patent applies different properties to different parts of the electrode: the active material coating portion maintains high conductivity for normal operation, while the non-conductive coating portion containing flame retardant provides insulation and heat absorption at specific locations (between active material coating and non-coating portions). This local differentiation prevents short circuit without requiring complete structural redesign
2Reliability
If high current flows during electrical malfunction, then rapid electron transfer occurs causing heat generation, but the thermal conductivity of the collector is low leading to temperature increase
Solution Approach 1:
The patent converts the harmful effect of heat generation into a beneficial effect by incorporating flame retardant in the non-conductive coating portion. When heat is generated during abnormal operations, the flame retardant absorbs the heat through endothermic decomposition reactions, transforming the harmful thermal energy into chemical energy storage, thereby preventing thermal runaway and reducing collector temperature
Solution Approach 2:
The patent changes the thermal and chemical parameters of the electrode structure by adding flame retardant materials to the non-conductive coating portion. This modification alters the heat absorption capacity and thermal stability parameters, enabling the electrode to withstand high temperatures during electrical malfunctions without excessive temperature rise
3Reliability
If the separator contracts due to heat, then direct contact between cathode and anode increases short circuit possibility, but adding protective coatings increases manufacturing complexity
Solution Approach 1:
The patent merges multiple functions into a single non-conductive coating portion: it provides electrical insulation to prevent short circuit, contains flame retardant for heat absorption, and creates a physical barrier between active material coating and non-coating portions. This consolidation achieves short circuit prevention without proportionally increasing manufacturing complexity
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 design effectively prevents short circuits and suppresses initial heat generation, enhancing the safety of secondary batteries during abnormal operations by using halogen-based, phosphorus-based, or inorganic compound flame retardants in the coating portions.
Implementation Method 1
initial heat generation is suppressed through heat absorption reaction of a flame retardant
Data Source
AI summary
An electrode includes: an active material coating portion coated with an electrode active material on at least one surface of an electrode collector; an active material non-coating portion which is formed on one side of the active material coating portion and is not coated with the electrode active material; and an electrode coating portion which is coated between the active material coating portion and the active material non-coating portion and contains a flame retardant.