Interphase-Structured Multilayer Electrodes for Energy-Power Balance
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Solution Overview
Problem
Current battery technologies face challenges in achieving a balance between energy density and power density, with existing solutions failing to effectively mitigate the trade-off between these two performance metrics, while also maintaining mechanical integrity and preventing solid electrolyte interphase (SEI) buildup.
Innovation Solution
The development of multilayer electrodes with interphase structures, comprising layers with different microstructures, porosities, and active material chemistries, where an interphase layer with a higher concentration of binder and conductive additives interpenetrates and binds the layers, enhancing mechanical and electronic connectivity and ion conduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If multilayer electrodes with different microstructures are used to increase energy density, then energy density is improved, but mechanical integrity deteriorates due to expansion and contraction mismatches between layers
Solution Approach 1:
An interphase layer is introduced as an intermediary between the first and second electrode layers. This interphase layer has a porosity intermediate between the first and second layers, and includes a non-planar boundary with interpenetrating finger-like structures that mechanically interlock the layers together, preventing delamination while maintaining the benefits of different microstructures for high energy density
Solution Approach 2:
The electrode is constructed as a composite multilayer structure with different materials and microstructures in each layer. The first layer, second layer, and interphase layer form a composite system where each layer has optimized properties, and the interphase layer acts as a transition zone that combines characteristics of both adjacent layers to ensure mechanical compatibility
2Strength
If electrode layers are tightly bound to increase mechanical integrity, then mechanical integrity is improved, but ion conduction deteriorates due to reduced porosity and increased tortuosity
Solution Approach 1:
The interphase layer exhibits local quality transitions with its porosity and microstructure varying through its thickness. The porosity is intermediate between the adjacent layers, creating a gradual transition zone that maintains ion conduction pathways while providing mechanical binding. The non-planar boundary with interpenetrating structures provides localized mechanical strength without uniformly reducing porosity throughout the entire electrode
3Ease of manufacture
If homogeneous electrode structure is used to simplify manufacturing, then ease of manufacture is improved, but performance deteriorates due to inability to balance energy density and power density
Solution Approach 1:
The electrode is segmented into multiple functional layers (first layer, second layer, and interphase layer) with distinct microstructures and properties. This segmentation allows each layer to be optimized for specific functions (energy storage, power delivery, mechanical integrity) while maintaining a systematic manufacturing process that applies the same multilayer approach consistently across production
4Productivity
If high porosity is used to improve ion conduction, then power density is improved, but energy density deteriorates due to increased volume fraction of pores
Solution Approach 1:
The solution moves from a single-layer homogeneous structure to a multilayer vertical structure with different porosity levels in different dimensions (layers). The first layer can have high porosity for ion conduction and power density, while the second layer has lower porosity for higher active material content and energy density, with the interphase layer providing mechanical integration. This dimensional arrangement allows both high power density and high energy density to coexist in different regions of the same electrode
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
This approach increases energy density without compromising power density, maintains mechanical integrity during electrode expansion and contraction, and reduces SEI buildup, thereby improving the overall performance and cycle life of electrochemical energy storage devices.
Implementation Method 1
an interphase layer adhering the first layer to the second layer, the interphase layer including an intermixing of the first active material particles and the second active material particles
Implementation Method 2
the particles are adhered together by the binder and the conductive additive, such that the particles and the conductive additive form a conductive network
Implementation Method 3
a first layer including a plurality of first active material particles and a first binder, the first active material particles having a first average particle size
Data Source
AI summary
Methods are disclosed for manufacturing an electrode for use in a device such as a secondary battery. Electrodes may include a first layer having first active particles adhered together by a binder, a second layer having second active particles adhered together by a binder, and an interphase layer interposed between the first and second layers. In some examples, the interphase layer may include an interpenetration of the first and second particles, such that substantially discrete fingers of the first layer interlock with substantially discrete fingers of the second layer.