Electrode Polymer Coating for High-Temperature Capacity Retention
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Solution Overview
Problem
Secondary batteries experience a decrease in storage capacity and an increase in resistance after storage at high temperatures and repeated charge and discharge cycles, which existing polymer layer technologies fail to adequately address.
Innovation Solution
A polymer layer containing a copolymer with a fluoromonomer unit and an amide bond-containing monomer unit, along with an inorganic particle, is formed on the electrode active material layer to enhance the battery's performance by preventing capacity loss and resistance increase.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional polymer layer is used on the electrode, then the battery can operate, but the storage capacity decreases after high-temperature storage
Solution Approach 1:
The patent uses a composite polymer layer containing both fluorinated polymer units and carboxyl-containing polymer units. The fluorinated polymer provides thermal stability and resistance to high-temperature degradation, while the carboxyl-containing polymer enhances adhesion to the electrode active material and stabilizes the electrode-electrolyte interface. This composite structure resolves the contradiction by combining materials with complementary properties that simultaneously address storage capacity retention and high-temperature stability.
Solution Approach 2:
The patent modifies the chemical composition parameters of the polymer layer by incorporating specific functional groups (fluorinated groups and carboxyl groups) in controlled ratios. The fluorinated content and carboxyl content are adjusted as compositional parameters to optimize performance. This parameter change approach allows the polymer layer to maintain structural integrity at high temperatures while preserving electrochemical activity, thereby resolving the contradiction between temperature stability and capacity retention.
2Reliability
If a conventional polymer layer is used on the electrode, then the battery can operate, but the resistance increases after repeated charge and discharge
Solution Approach 1:
The composite polymer layer combines fluorinated polymers (which provide chemical inertness and resistance to electrolyte decomposition) with carboxyl-containing polymers (which provide strong binding to electrode materials and stabilize the solid electrolyte interface). This composite structure prevents polymer layer degradation during repeated charge-discharge cycles, maintaining low resistance over extended cycle life and resolving the contradiction between resistance stability and duration of action.
Solution Approach 2:
The polymer layer acts as a sacrificial protective layer that stabilizes the interface between the electrode active material and the electrolyte. By providing a stable, protective interface that prevents direct contact and degradation between reactive components, the polymer layer extends the operational life of the battery without requiring the electrode materials themselves to be perfectly stable, thus resolving the contradiction through interface engineering.
3Reliability
If the polymer layer composition is optimized for high-temperature stability, then storage capacity is maintained, but the manufacturing complexity increases
Solution Approach 1:
The patent defines specific compositional parameters (fluorinated polymer content, carboxyl-containing polymer content, molecular weight ranges) that can be controlled through standard polymerization processes. By establishing clear parameter ranges rather than requiring complex multi-component systems, the patent achieves high-temperature stability while keeping the manufacturing process relatively simple. The solution involves tuning compositional parameters within defined ranges rather than introducing additional processing steps or complex architectures.
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 proposed solution effectively maintains the secondary battery's storage capacity and prevents resistance increase even after high-temperature storage and repeated charge-discharge cycles, improving the battery's overall performance and longevity.
Implementation Method 1
the polymer layer contains a copolymer containing a fluoromonomer unit and an amide bond-containing monomer unit
Implementation Method 2
a polymer layer containing a copolymer with a fluoromonomer unit and an amide bond-containing monomer unit, along with an inorganic particle, is formed on the electrode active material layer to enhance the battery's performance by preventing capacity loss and resistance increase
Implementation Method 3
an inorganic particle is provided
Data Source
AI summary
Provided is an electrode comprising an electrode active material layer and a polymer layer formed on the electrode active material layer, wherein the polymer layer comprises a copolymer comprising a fluoromonomer unit and an amide bond-containing monomer unit, and an inorganic particle.