Irregular Silicon Anode Lamination for Battery Strain
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Solution Overview
Problem
Conventional battery electrodes are costly, cumbersome, and inefficient, limiting battery lifetime due to complex and time-consuming implementation processes, and they struggle with the large volume changes of silicon-based anodes during lithiation and delithiation, which lead to electrical isolation and capacity loss.
Innovation Solution
The method involves using overlapped irregularly shaped active material for electrode lamination, where silicon-dominant anodes are formed with a mosaic of irregular shapes on a current collector, allowing for improved electrical contact and strain absorption during lithiation, and the roll-press lamination process reduces processing time and waste while maintaining performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional battery electrode methods are used, then manufacturing complexity and cost are reduced, but battery lifetime and performance are limited
Solution Approach 1:
The electrode is segmented into multiple discrete irregularly shaped active material pieces rather than using continuous conventional electrode structures. This segmentation allows each piece to independently accommodate volume changes during lithiation, preventing electrical isolation and maintaining battery lifetime while simplifying the manufacturing process through direct placement on current collectors.
Solution Approach 2:
The patent inverts the conventional approach by using irregularly shaped active material pieces instead of traditional continuous electrode foils. This inversion allows the active material to naturally accommodate volume expansion and contraction, resolving the contradiction between improving battery lifetime and reducing manufacturing complexity.
2Use of energy by moving object
If silicon-based anodes are used, then energy density is improved, but volume changes during lithiation cause electrical isolation and capacity loss
Solution Approach 1:
The silicon-based anode is divided into multiple small irregularly shaped pieces rather than using large continuous structures. This segmentation allows each piece to independently expand and contract during lithiation without causing electrical isolation, maintaining both high energy density and stable electrical contact throughout the battery cycle life.
Solution Approach 2:
Each irregularly shaped active material piece has locally optimized geometry that accommodates volume changes during lithiation. The irregular shapes provide local quality variations that allow different regions of the electrode to expand and contract differently, preventing stress concentration and maintaining electrical contact stability while utilizing silicon's high energy density.
3Productivity
If regular processing methods are used, then manufacturing consistency is maintained, but processing time and material waste increase
Solution Approach 1:
The active material pieces are prepared in advance with irregular shapes that are optimized for their function. This preliminary action allows the pieces to be directly placed and laminated onto current collectors without requiring additional processing steps, significantly reducing processing time and minimizing material waste while maintaining manufacturing consistency.
Solution Approach 2:
The patent changes the geometric parameters of the active material from regular shapes to irregular shapes, and changes the processing parameters from conventional electrode fabrication to direct lamination. These parameter changes enable faster processing and reduce material waste while maintaining the necessary manufacturing consistency for battery production.
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 enhances the energy density and cycle life of lithium-ion batteries by stabilizing the silicon anodes, reducing the impact of volume changes and maintaining electrochemical reactivity, while also simplifying the manufacturing process and reducing costs.
Implementation Method 1
an adhesive layer extending over a surface of the metal current collector
Implementation Method 2
the roll-press lamination process reduces processing time and waste
Data Source
AI summary
Systems and methods for electrode lamination using overlapped irregular shaped active material may include a battery having a cathode, an electrolyte, and an anode, with the anode including an active material on a metal current collector. The active material may include a plurality of irregularly shaped pieces bonded to the metal current collector, and may include silicon, carbon, and a pyrolyzed polymer. The active material may include more than 50% silicon by weight. The plurality of irregularly shaped pieces may be roll press laminated to the metal current collector. Gaps may remain between some of the irregularly shaped pieces of active material. The gaps may absorb strain in the active material during lithiation of the anode. The metal current collector may include a copper or nickel foil. Portions of the metal current collector not covered by active material may be protected by an adhesive or inorganic layer.