Li-Ion Electrode Truss Structure for Mechanical Integrity
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Solution Overview
Problem
Lithium ion secondary batteries face challenges in achieving optimal electrical conductivity, mechanical integrity, and specific energy capacity due to limitations in the structure and composition of their electrodes, which affect their performance and operating life.
Innovation Solution
A method of forming a lithium ion secondary battery electrode involves combining a binder and active particles with carbon fibers, cutting the carbon fibers to create a truss structure, and inserting them into a mixture layer on a substrate, resulting in a cured mixture layer that accommodates lithium ion incorporation and release while maintaining mechanical integrity and conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If carbon fibers are used to form a truss structure in the electrode, then mechanical integrity and flexibility are improved, but device complexity increases
Solution Approach 1:
The electrode combines carbon fibers with binder and active particles to create a composite truss structure. The carbon fibers provide mechanical strength and conductivity while the binder matrix holds the structure together, creating a composite material that achieves both mechanical integrity and flexibility without requiring complex separate components.
Solution Approach 2:
The patent transitions from traditional planar electrode structures to a three-dimensional truss architecture. By arranging carbon fibers in a 3D network with specific orientation angles (30-60 degrees from the electrode surface), the structure gains mechanical strength and volumetric flexibility without significantly increasing manufacturing complexity.
2Strength
If the electrode structure is made rigid to maintain mechanical integrity, then strength is improved, but adaptability to volumetric changes during charging and discharging deteriorates
Solution Approach 1:
The truss structure employs carbon fibers arranged at specific angles (30-60 degrees) that allow the electrode to dynamically adapt its volume during charging and discharging. The angled fiber orientation enables the structure to flex and expand/contract in response to active particle volume changes while maintaining overall mechanical integrity through the truss architecture.
Solution Approach 2:
The patent optimizes the carbon fiber orientation angle as a key parameter to balance mechanical strength and volumetric flexibility. By setting fibers at 30-60 degrees from the electrode surface rather than perpendicular or parallel orientations, the structure achieves optimal compromise between rigidity and adaptability to volume changes during battery operation.
3Adaptability or versatility
If carbon fibers are inserted in random orientation, then adaptability to volumetric changes is improved, but manufacturing precision deteriorates
Solution Approach 1:
Instead of truly random orientation, the patent specifies a controlled angular range (30-60 degrees from the electrode surface) for carbon fiber insertion. This parameter-based approach provides sufficient volumetric flexibility while maintaining manufacturability through controlled insertion processes, avoiding the need for precise individual fiber positioning.
Solution Approach 2:
The carbon fiber orientation is controlled locally within specific angular ranges rather than requiring uniform precision throughout the entire electrode. This allows different regions to have varying fiber angles within the 30-60 degree range, providing local adaptability while maintaining overall manufacturing feasibility through less stringent precision requirements.
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 resulting electrode exhibits excellent electrical conductivity, mechanical integrity, specific energy capacity, and operating life, with the truss structure allowing for flexible volumetric changes during charging and discharging, enhancing the battery's performance and lifespan.
Implementation Method 1
The cured mixture layer is configured for incorporating a plurality of lithium ions during charging of the lithium ion secondary battery to a lithiated state, and releasing the plurality of lithium ions during the discharging of the lithium ion secondary battery to a non-lithiated state
Implementation Method 2
The cured mixture layer includes a binder and a plurality of carbon fibers coated by the binder
Implementation Method 3
heating the preform to form a cured mixture layer disposed on the surface and thereby form the electrode of the lithium ion secondary battery
Data Source
AI summary
A method of forming an electrode of a lithium ion secondary battery includes combining a binder and active particles to form a mixture, coating a surface with the mixture to form a coated article, translating the article along a first plane, cutting a first plurality of carbon fibers, each having a first average length, to form a second plurality of carbon fibers, each having a longitudinal axis and a second average length that is shorter than the first average length, inserting the second plurality of fibers into the mixture layer so that the longitudinal axis of each of at least a portion of the second plurality of fibers is not parallel to the first plane to form a preform, wherein the second plurality of fibers forms a truss structure disposed in three dimensions within the mixture layer, and heating the preform to form the electrode. An electrode is also disclosed.