Epoxy Powder Coating Composition for Electrolyte-Resistant Battery Insulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing powder coatings for electric vehicle batteries are vulnerable to damage and loss of insulation properties when exposed to electrolytes, which are highly corrosive, leading to issues such as discolouration, loss of adhesion, and reduced electrical insulation.
Innovation Solution
A particulate coating composition comprising an epoxy resin, a curing agent with an imidazoline ring, a filler, and a degassing agent, preferably benzoin, with an epoxy binder system ranging from 40-99 wt%, which forms a durable coating that maintains insulation and adhesion even after contact with electrolytes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If powder coating is applied to battery cells, then adhesion to aluminium substrate and structural glue is improved, but electrolyte resistance deteriorates due to chemical corrosion from LiPF6 and other electrolyte components
Solution Approach 1:
The patent modifies the chemical composition parameters of the powder coating by incorporating specific epoxy resins (e.g., bisphenol A-based epoxy with EEW 700-900 g/eq), curing agents (e.g., dicyandiamide, phenolic resins), and functional additives in controlled ratios. This chemical parameter optimization enables the coating to achieve both strong adhesion to aluminium substrates and structural glues while maintaining resistance to electrolyte corrosion through enhanced cross-linking density and chemical stability.
Solution Approach 2:
The invention creates a composite coating formulation combining multiple materials with complementary properties: epoxy resin provides adhesion and flexibility, curing agents create cross-linked networks for chemical resistance, fillers enhance mechanical strength, and functional additives provide corrosion protection. This multi-material composite approach allows the single coating layer to simultaneously satisfy adhesion requirements and electrolyte resistance demands.
2Ease of manufacture
If coating is exposed to electrolyte at curing temperatures of 120-130°C, then coating forms properly, but electrolyte is damaged and coating loses insulative properties
Solution Approach 1:
The patent applies powder coating to battery cells before electrolyte filling, allowing the coating to form its protective layer in advance. The coating is cured at controlled temperatures to establish its insulative properties and chemical resistance barrier before any electrolyte contact occurs, preventing subsequent damage from high-temperature electrolyte exposure.
Solution Approach 2:
The coating acts as a sacrificial protective layer that absorbs any potential damage from electrolyte exposure during filling operations. By positioning the coating as the first line of defense, the system allows the coating to bear the brunt of any thermal or chemical stress, protecting the underlying battery cell and maintaining overall system reliability.
3Ease of manufacture
If PET tape is used for insulation, then manufacturing is simple, but bonding strength to aluminium substrate is insufficient for CTP technology
Solution Approach 1:
The patent replaces the mechanical adhesive system of PET tape with a chemically-bonded powder coating system. The powder coating, when cured, forms a cross-linked polymer network that creates strong chemical bonds with the aluminium substrate and structural glue, providing superior bonding strength compared to the mechanical adhesion of PET tape, while maintaining ease of application through powder coating processes.
4Ease of operation
If PET tape is used at high temperatures, then application is easy, but size stabilization is lost and adhesion deteriorates
Solution Approach 1:
The patent changes the thermal stability parameters of the insulation material by using powder coating with a cured polymer matrix that maintains its dimensional stability and adhesion properties at high temperatures. Unlike PET tape which softens and loses stability above its glass transition temperature, the cross-linked epoxy-based powder coating maintains its mechanical properties and size stability in the high-temperature environment of battery cells.
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 coating composition provides enhanced resistance to electrolytes, maintaining insulation and adhesion, preventing discolouration, and ensuring the coating's integrity under extreme conditions.
Implementation Method 1
a degassing agent, preferably benzoin
Implementation Method 2
comprising an epoxy resin, a curing agent comprising an imidazoline ring
Data Source
AI summary
A particulate coating composition, and preferably a powder coating composition, is disclosed. The particulate coating composition includes an epoxy resin and a curing agent, wherein the curing agent comprises an imidazoline ring. Additionally, the particulate coating composition includes a filler and a degassing agent, preferably benzoin, wherein the total amount of epoxy binder system, and wherein said system includes the epoxy resin and the curing agent, is 40-99 wt %, based on the total weight of the particulate coating composition.