Battery Separator Coating for Nail Penetration Safety
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium-ion batteries face challenges in safety and reliability under harsh conditions such as impact and nail penetration, requiring improved safety performance.
Innovation Solution
A separator comprising a porous substrate with a porous layer containing inorganic particles and a binder, with a specific ratio of puncture elongation to puncture force, and controlled tensile strength differences, enhancing the battery's ability to prevent short-circuits and thermal runaway.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the separator uses conventional materials and structure, then the manufacturing cost is low and ease of manufacture is good, but the safety performance under harsh conditions (impact, nail penetration, hot box) is insufficient
Solution Approach 1:
The separator comprises a porous substrate and a porous layer containing inorganic particles (such as aluminum oxide, silicon dioxide, magnesium oxide) and binder. This composite structure combines the mechanical properties of the substrate with the protective and thermal properties of the inorganic particles, significantly improving safety performance under harsh conditions including impact, nail penetration, and hot box tests while maintaining manufacturing feasibility.
Solution Approach 2:
The porous layer is selectively applied to specific surfaces of the porous substrate, creating localized functional zones. The inorganic particles and binder are concentrated in the porous layer rather than throughout the entire separator, providing enhanced protection where needed while maintaining overall structural integrity and controlling complexity.
2Reliability
If the separator uses conventional materials and structure, then the device complexity is low and ease of manufacture is good, but the ability to prevent short-circuits and thermal runaway is insufficient
Solution Approach 1:
The combination of porous substrate, inorganic particles, and binder creates a multi-functional separator that simultaneously provides mechanical strength, thermal stability, and short-circuit prevention. The inorganic particles act as physical barriers and heat sinks, while the porous structure maintains ion conductivity, achieving superior short-circuit prevention without excessive complexity.
Solution Approach 2:
Both the substrate and the coating layer are porous, allowing efficient lithium ion transport while maintaining structural integrity. The porous structure prevents densification under stress and maintains ion pathways even when the separator is subjected to harsh conditions, enhancing short-circuit prevention capability.
Data Source
AI summary
An electrochemical device includes a cathode, an anode and a separator, the separator being disposed between the cathode and the anode, the separator including a porous substrate and a porous layer, and the porous layer being disposed on a surface of the porous substrate and including inorganic particles and a binder, where a ratio of a puncture elongation of the porous substrate to a puncture force of the porous substrate is about 1.5 mm/N to about 25 mm/N. A lithium-ion battery including the separator, provided by the present application, improves the safety performance of the lithium-ion battery.