MXene Conductive Layer for Li-Ion Cathode Adhesion and Cycling
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Solution Overview
Problem
Existing carbon coating formulations for aluminum current collectors in lithium-ion batteries enhance conductive performance but fail to improve the adhesion between the current collector and the active material layer, leading to reduced bonding force and rapid capacity degradation during long-term charge-discharge cycles.
Innovation Solution
Incorporating a conductive layer with an MXene material between the current collector and the active material layer, which includes transition metal carbides and/or nitrides, to enhance electrical conductivity and strengthen adhesion through hydrogen bonding with functional groups, thereby improving peel force and cycle stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If carbon coating is applied to aluminum current collector to enhance conductive performance, then electrical conductivity is improved, but adhesion between current collector and active material layer cannot be elevated
Solution Approach 1:
The patent uses a composite coating layer containing both carbon particles and silane-modified polyacrylic acid on the aluminum current collector. The carbon particles provide electrical conductivity while the silane-modified polyacrylic acid forms strong chemical bonds with the active material layer, achieving both conductive performance and adhesion simultaneously
Solution Approach 2:
The silane-modified polyacrylic acid acts as an intermediary substance between the aluminum current collector and the active material layer. It forms a bridging layer that chemically bonds to both surfaces, enhancing adhesion while the embedded carbon particles maintain electrical conductivity
2Reliability
If conventional carbon coating is used to improve conductivity, then electrical performance is enhanced, but bonding force decreases leading to rapid capacity degradation
Solution Approach 1:
The patent modifies the chemical parameters of the coating layer by using silane-modified polyacrylic acid instead of conventional binders. This chemical modification enables the coating to form strong chemical bonds with the active material, significantly improving bonding force and capacity stability while maintaining conductivity through carbon particle incorporation
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 MXene material enhances both conductive performance and adhesion, increasing battery capacity and stability by reducing internal resistance and maintaining structural integrity during cycling.
Implementation Method 1
the conductive layer includes an MXene material... By adding the MXene material in the conductive layer, it is possible to elevate the conductive performance
Implementation Method 2
strengthen the adhesion between the current collector and the active material layer... through hydrogen bonding with functional groups
Data Source
AI summary
Disclosed are a positive electrode and a preparation method thereof and a battery. The positive electrode includes a current collector, an active material layer, and a conductive layer disposed between the current collector and the active material layer. The conductive layer includes an MXene material. Adding the MXene material in the conductive layer may elevate the conductive performance and stability of the battery, and may also strengthen the adhesion between the current collector and the active material layer, enhance the peel force of the positive electrode, and improve the long-term cycle stability of the battery. In addition, since the addition of the MXene material enhances the adhesion between the current collector and the active material layer, under the condition that the peel strength of the electrode sheet is ensured, the content of binder in the active material layer may be reduced.