Current Collector Coating to Reduce Battery Gas Generation
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Solution Overview
Problem
Secondary batteries experience performance decline and safety hazards due to interfacial chemical properties deterioration from side reactions between the electrode and electrolyte solution during charge-discharge cycles, leading to gas generation and capacity fading.
Innovation Solution
A current collector with a thin surface modification layer, not exceeding 50 nm, acts as an artificial solid electrolyte interface, blocking direct contact between the negative electrode metal and electrolyte, prepared by atomic layer deposition, and optionally combined with a deposition-inducing layer to enhance ion transmission and mechanical stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a coating layer is applied to block side reactions between electrode and electrolyte, then safety performance is improved, but interface resistance increases and ion transmission efficiency decreases
Solution Approach 1:
The patent applies a thin film coating layer with controlled thickness (5-50 nm) on the current collector surface. This thin film acts as a protective barrier that blocks side reactions between the electrode and electrolyte while maintaining sufficient ion transmission capability. The specific thickness range is optimized to balance protection function with ion conductivity, preventing excessive interface resistance.
Solution Approach 2:
The patent changes the thickness parameter of the coating layer to an optimal range (5-50 nm) to resolve the contradiction. By precisely controlling the coating thickness within this range, the patent achieves both adequate protection against side reactions (improving safety) and sufficient ion transmission (maintaining low interface resistance).
2Reliability
If a thick coating layer is used to provide adequate protection, then safety is improved, but ion transmission efficiency and electronic conductivity deteriorate
Solution Approach 1:
The patent employs a thin film coating (5-50 nm) that provides adequate protective function while allowing efficient ion transmission. The thin film structure ensures that the coating is thin enough to maintain high ion transmission efficiency and electronic conductivity, yet thick enough to provide necessary protection against side reactions.
Solution Approach 2:
The patent uses a composite structure consisting of the current collector and the coating layer formed by atomic layer deposition. This composite structure combines the high conductivity of the metal current collector with the protective and ion-conductive properties of the coating material, achieving both safety and high ion transmission efficiency.
3Duration of action of stationary object
If a coating layer is applied to prevent side reactions, then cycle performance is improved, but manufacturing complexity increases
Solution Approach 1:
The patent replaces traditional multi-step coating methods with atomic layer deposition (ALD) technology. ALD is a vapor-phase deposition process that can precisely control coating thickness at the nanometer scale in a single step, eliminating the need for multiple mechanical coating steps and subsequent processing, thus reducing manufacturing complexity while achieving superior cycle performance.
Solution Approach 2:
The patent changes the manufacturing approach by using ALD to precisely control the coating thickness parameter (5-50 nm). This precise parameter control enables the formation of a uniform, defect-free coating in a single process step, improving cycle performance while keeping the manufacturing process relatively simple and controllable.
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 solution effectively reduces gas production, improves safety, and enhances cycle performance by maintaining low interface resistance and mechanical strength, ensuring efficient ion and electron transmission while preventing side reactions.
Implementation Method 1
The coating includes at least a surface modification layer... The surface modification layer on one side of the current collector can serve as an artificial solid electrolyte interface to effectively block direct contact between a negative electrode metal and an electrolyte solution constituent
Implementation Method 2
The surface modification layer disclosed herein is extremely thin, and can maximally ensure efficient transmission of ions and a low interface resistance of the battery
Implementation Method 3
the current collector is ensured to be of high electronic conductivity, thereby facilitating transmission of electrons between components of the battery
Data Source
AI summary
This application provides a current collector with a coating, a secondary battery, a battery module, a battery pack, and an electrical device. The coating includes at least a surface modification layer. The coating is formed on at least one side of the current collector. A thickness of the surface modification layer is not greater than 50 nm. The coating formed on at least one side of the current collector can effectively block direct contact between a negative electrode metal and an electrolyte solution constituent, thereby reducing side reactions between the negative electrode metal and the electrolyte solution, significantly reducing gas generated by the battery during a long period of cycling, and improving the cycle performance and safety of the battery.