Dielectric Coated Battery Separator for Dendrite Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current separators for high-capacity energy storage devices, such as Li-ion batteries, face limitations including susceptibility to electrical shorts due to lithium dendrite growth, complex manufacturing methods, high costs, and constraints on electrode size and weight, which hinder faster charging and higher capacity performance.
Innovation Solution
A separator comprising a porous ion-conducting polymeric substrate coated with a thin, binder-free dielectric layer, typically aluminum oxide, formed using reactive evaporation techniques, which enhances ionic conductivity and inhibits dendrite growth, allowing for thinner, more efficient separators with improved manufacturing efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high porosity separator is used to increase ionic conductivity, then ionic conductivity is improved, but electrical short susceptibility increases due to lithium dendrite formation
Solution Approach 1:
The patent applies composite materials by combining a polymeric separator substrate with a dielectric coating layer. The polymeric substrate provides high porosity for ionic conductivity, while the dielectric coating layer provides electrical insulation to prevent dendrite-induced shorts. This composite structure resolves the contradiction by integrating two materials with complementary properties.
Solution Approach 2:
The patent utilizes porous materials at multiple levels: the polymeric separator substrate has a porous structure for ion transport, and the dielectric coating layer is formed as a porous or non-porous thin film that maintains electrical insulation while allowing ion passage. The porous structure enables ionic conductivity without compromising electrical safety.
2Reliability
If traditional separator manufacturing methods are used, then separator functionality is achieved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent merges the separator manufacturing process with the dielectric coating application into a single integrated process. The dielectric coating is applied directly to the separator substrate in the same manufacturing line, eliminating the need for separate lamination steps. This reduces manufacturing complexity while maintaining functionality.
Solution Approach 2:
The patent replaces mechanical lamination processes with a deposition-based coating process. Instead of physically laminating separate separator and protective layer components, the dielectric layer is deposited directly onto the separator substrate using vapor deposition or similar techniques, simplifying the manufacturing system.
3Object-affected harmful factors
If thicker separator is used to prevent electrical shorts, then electrical safety is improved, but ionic resistance increases and charging speed decreases
Solution Approach 1:
The patent applies local quality by providing electrical insulation only where needed - as a thin dielectric coating layer on the separator surface rather than throughout the entire separator thickness. This localized approach provides short prevention without increasing overall ionic resistance, maintaining fast charging capability while ensuring electrical safety.
Solution Approach 2:
The patent uses a thin film dielectric coating layer (typically nanometer to micrometer scale) to provide electrical insulation. This thin film approach prevents electrical shorts without requiring thick separator material, thereby maintaining low ionic resistance and fast charging speed while ensuring electrical safety.
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 results in separators with reduced ionic resistance, increased energy density, superior performance, and enhanced lithium metal deposition and stripping during cycling, leading to higher voltage stability and puncture resistance, while reducing manufacturing costs and electrode size constraints.
Implementation Method 1
formed using reactive evaporation techniques
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
Implementations of the present disclosure generally relate to separators, high performance electrochemical devices, such as, batteries and capacitors, including the aforementioned separators, and methods for fabricating the same. In one implementation, a separator for a battery is provided. The separator comprises a substrate capable of conducting ions and at least one dielectric layer capable of conducting ions. The at least one dielectric layer at least partially covers the substrate and has a thickness of 1 nanometer to 2,000 nanometers.