Prismatic Battery Spark Prevention via Insulation Design
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Solution Overview
Problem
High-power, high-capacity prismatic secondary batteries used in electric vehicles and stationary storage systems face a risk of spark generation inside the battery after the current disconnection mechanism is activated, potentially damaging the outer structure due to increased pressure and electrolyte-related conductive routes.
Innovation Solution
A prismatic secondary battery design with a specific configuration, including a distance of at least 2.4 mm between conductive members along the surface of insulation members, and insulation materials that are 100% gasified at high temperatures to prevent spark generation, inhibiting the formation of low-resistance conductive routes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the current disconnection mechanism is activated to disconnect electric connection when battery pressure increases, then safety is improved, but spark generation occurs inside the battery due to high voltage applied to electrolytic solution on the insulation member surface
Solution Approach 1:
A resin layer is coated on the surface of the insulation member to serve as an intermediary substance. This resin layer prevents direct contact between the electrolytic solution and the insulation member surface, thereby eliminating the conductive path that causes spark generation while maintaining the current disconnection mechanism's safety function
Solution Approach 2:
The surface properties of the insulation member are changed by coating it with a resin layer. This modification alters the electrical and chemical parameters of the surface, making it non-conductive to electrolytic solution and preventing the formation of low-resistance conductive routes that lead to sparks
2Quantity of substance
If a large number of batteries are connected in series to achieve high capacity and high power, then energy storage capability is improved, but the risk of spark generation and damage to outer structure increases
Solution Approach 1:
The resin layer on the insulation member surface acts as a protective intermediary that prevents spark generation even in high-voltage battery packs with multiple batteries connected in series, thereby protecting the outer structure from damage while maintaining high energy storage capability
Solution Approach 2:
The resin coating is applied in advance to the insulation member surface to prevent potential spark generation before it can occur. This preventive measure cushions against the harmful effects of sparks that could damage the battery outer structure in high-voltage applications
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
Prevents spark generation and damage to the battery structure by ensuring insulation materials are effective at high temperatures, maintaining safety and reliability in high-voltage applications.
Implementation Method 1
at least one of the first insulation member and the second insulation member is formed from a material having a weight reduction percentage of 100% at a thermo gravimetric measurement under conditions of a measurement temperature of 25° C.-600° C.
Implementation Method 2
a material having a weight reduction percentage of 100% at a thermo gravimetric measurement under conditions of a measurement temperature of 25° C.-600° C.
Implementation Method 3
the inversion plate is deformed when a pressure in the prismatic outer structure becomes greater than or equal to a predetermined value, to disconnect a conductive route between the electrode structure and the external terminal
Implementation Method 4
Because the electrical resistance of this route is very high, when current flows in this route, heat is generated
Implementation Method 5
the temperature of the insulation member surface is further increased by electrolysis of the electrolytic solution, the surface of the insulation member or the electrolytic solution existing on the surface of the insulation member is carbonized
Data Source
AI summary
A prismatic secondary battery of one configuration has a current disconnection mechanism, and a distance from a first conductive member to a second conductive member along a surface of a first insulation member and passing an outer periphery of the first insulation member is greater than or equal to 2.4 mm. At least one of the first insulation member and a second insulation member is formed from a material having a weight reduction percentage of 100% in thermo gravimetric measurement under conditions of a measurement temperature of 25° C.-600° C., a temperature increase rate of 5° C.±0.5° C./min, a measurement atmosphere of inert gas flow, and an amount of measurement sample of 10 mg±5 mg.