Conductive-Coated Current Collector for Corrosion-Resistant Li-Ion Electrodes
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Solution Overview
Problem
Current lithium-ion battery technology faces issues with corrosion of current collectors due to reactions with water-based slurries, especially when using nickel-containing cathode active materials, and high interfacial resistance between the electrode layer and the current collector, leading to poor electrochemical performance.
Innovation Solution
A modified current collector is introduced, comprising a substrate with a conductive layer applied on one side or both sides. The conductive layer consists of a conductive material and a binder material, where the binder material includes a copolymer with specific structural units that provide adhesion and resistance to re-dissolution in aqueous solvents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If water-based slurry is used to manufacture lithium-ion batteries, then safety and environmental friendliness are improved, but current collector corrosion occurs due to basic solution formation from nickel-containing cathode materials
Solution Approach 1:
The patent introduces an organic acid cross-linking agent as an intermediary substance between the water-based slurry and the current collector. This cross-linking agent forms a protective layer that mediates the interaction, preventing direct contact between the basic solution from nickel-containing cathode materials and the current collector, thus eliminating corrosion while maintaining the safety and environmental benefits of water-based slurries
Solution Approach 2:
The patent applies preliminary anti-action by using the organic acid cross-linking agent to preemptively counteract the harmful basic solution formation. The cross-linking agent reacts with the basic solution before it can corrode the current collector, forming a protective complex that neutralizes the corrosive effect and prevents damage to the current collector
2Device complexity
If conventional current collector structure is used, then manufacturing simplicity is maintained, but high interfacial resistance between electrode layer and current collector leads to poor electrochemical performance
Solution Approach 1:
The patent applies composite materials by creating a multi-layered current collector structure consisting of a metal foil substrate combined with an organic acid cross-linked binder layer. This composite structure combines the electrical conductivity of the metal foil with the adhesion and corrosion resistance properties of the cross-linked organic acid layer, achieving both low interfacial resistance and high reliability in electrochemical performance
3Strength
If organic acid cross-linking agent is added to facilitate adherence of conductive particles, then adhesion strength is improved, but corrosion of underlying metal foil occurs over time
Solution Approach 1:
The patent converts the harmful effect of organic acid corrosion into a beneficial protective mechanism. The organic acid cross-linking agent initially provides strong adhesion, and its gradual reaction with the basic solution from nickel-containing cathode materials forms a protective complex that actually protects the metal foil from corrosion over time, turning the potential harm into long-term protection
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 modified current collector acts as a physical barrier to prevent corrosion of the substrate and reduces interfacial resistance, enhancing the electrochemical performance of lithium-ion batteries by improving the adhesion and mechanical strength of the electrode layer.
Implementation Method 1
the binder material comprises a copolymer comprising a structural unit (a)... providing adhesion and mechanical strength
Implementation Method 2
The conductive layer of the modified current collector can act as a physical barrier between the substrate and the alkaline electrode active material in the electrode layer. This prevents the corrosion of the substrate
Implementation Method 3
the binder material includes a copolymer with specific structural units that provide adhesion and resistance to re-dissolution in aqueous solvents
Data Source
AI summary
The invention discloses a modified current collector for a secondary battery, comprising a substrate and a conductive layer applied on one side or both sides of the substrate, wherein the conductive layer comprises a conductive material and binder material, wherein the binder material comprises a copolymer. Also provided herein is an electrode for a secondary battery, comprising the modified current collector and an electrode layer, wherein the electrode layer is located on the surface of the conductive layer(s). Within an electrode comprising the modified current collector of the present invention, the presence of conductive layer inhibits corrosion of the substrate and reduces interfacial resistance between the electrode layer and the substrate. Consequently, batteries comprising an electrode prepared using the modified current collector disclosed herein exhibit exceptional electrochemical performance.