MXene Conductive Layer for Cathode Adhesion and Cycle Stability
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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 degradation of battery capacity and cycle life due to loose material particles during charge-discharge cycles.
Innovation Solution
Incorporating a conductive layer between the current collector and the active material layer with an MXene material, which includes transition metal carbides and/or nitrides, to enhance electrical conductivity and strengthen adhesion through hydrogen bonding with functional groups, thereby improving the peel force and long-term cycle stability of the battery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If carbon coating is applied to aluminum current collector to enhance conductivity, then conductive performance is improved, but adhesion between current collector and active material layer deteriorates
Solution Approach 1:
The patent divides the coating into two distinct layers: a conductive layer containing carbon material applied first to enhance electrical conductivity, and an adhesive layer containing adhesive material applied second to strengthen bonding with the active material layer. This segmentation allows each layer to perform its specialized function without compromising the other, resolving the contradiction between conductivity and adhesion.
Solution Approach 2:
The patent employs a composite coating structure combining carbon material and adhesive material in distinct layers. The conductive layer provides electrical pathways while the adhesive layer provides bonding functionality, creating a composite system that simultaneously achieves both conductivity enhancement and adhesion improvement that neither material could achieve alone.
2Reliability
If carbon coating is applied to aluminum current collector, then conductive performance is improved, but battery cycle life deteriorates due to loose material particles
Solution Approach 1:
The patent segments the coating into conductive and adhesive layers, where the adhesive layer specifically addresses particle detachment during charge-discharge cycles. This segmentation allows the adhesive layer to secure material particles firmly to the current collector, preventing loosening during cycling while the conductive layer maintains electrical performance, thus extending battery cycle life.
Solution Approach 2:
The adhesive layer acts as a protective cushioning layer applied beforehand to prevent particle detachment during subsequent charge-discharge cycles. This prior protective measure ensures material particles remain firmly bonded throughout the battery's operational life, preventing the loosening that would otherwise occur and reduce cycle life.
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 the conductive performance and stability of the battery while increasing the adhesion between the current collector and active material layer, ensuring higher battery capacity and improved long-term cycle stability without adversely affecting the battery's electrical performance.
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 and stability of the battery
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.