High-Rate Cell Formation for Silicon Anode Expansion Directionality
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Solution Overview
Problem
Conventional battery anode technologies are costly, cumbersome, and inefficient, limiting battery lifetime and performance.
Innovation Solution
A method and system for high-speed formation of cells to configure anisotropic expansion of silicon-dominant anodes, utilizing varying charge rates during the formation process to control anode expansion in specific directions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional battery anode technologies are used, then manufacturing cost and complexity are reduced, but battery lifetime and performance are limited
Solution Approach 1:
The patent changes the formation charge rate parameter from conventional low rates to high rates (e.g., 1C, 2C, 3C, 4C, or higher), which fundamentally alters the expansion behavior of silicon-dominant anodes during formation. This parameter change enables controlled anisotropic expansion that improves battery lifetime while maintaining manufacturing efficiency
Solution Approach 2:
The patent introduces dynamic control of the formation process by adjusting charge rates at different stages. The formation process uses varying charge rates (e.g., initial high rate followed by lower rates) to dynamically manage anode expansion, achieving both high performance and manufacturing feasibility
2Productivity
If high charge rates are used during formation, then manufacturing speed and productivity are improved, but control over anode expansion becomes more difficult
Solution Approach 1:
The patent employs periodic action by using a multi-stage formation process with different charge rates. The process alternates between high charge rates (for speed) and lower charge rates (for precision control), creating a periodic pattern that achieves both high productivity and precise expansion control
Solution Approach 2:
The patent applies preliminary action by conducting formation at high charge rates before the anode is fully lithiated. This preliminary high-rate formation establishes the desired anisotropic expansion pattern early in the process, making subsequent control easier and maintaining high overall productivity
3Quantity of substance
If silicon-dominant anodes are used, then energy density is improved, but anode expansion during formation becomes uncontrolled
Solution Approach 1:
The patent exploits asymmetry by inducing anisotropic expansion where the anode expands differently in different directions (x-y plane versus z-direction). This asymmetric expansion pattern, controlled through high charge rate formation, stabilizes the anode composition by directing expansion along favorable crystallographic planes while maintaining high energy density
Solution Approach 2:
The patent applies preliminary anti-action by using high charge rate formation to pre-configur the anode expansion before normal operation. This preliminary action creates internal stresses and structural arrangements that counteract uncontrolled expansion during subsequent cycling, stabilizing the anode composition
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
Enables efficient and controlled anode expansion, reducing x-y expansion while increasing z-direction expansion, thereby improving cycle performance and energy density of silicon-dominant anodes without compromising manufacturing speed or cost.
Implementation Method 1
configuring anisotropic expansion of silicon-dominant anodes
Implementation Method 2
anode expansion during lithiation
Data Source
AI summary
Systems and methods for high speed formation of cells for configuring anisotropic expansion of silicon-dominant anodes may include a cathode, an electrolyte, and an anode, where the anode may include a current collector and an active material on the current collector. An expansion of the anode may be configured by a charge rate during formation of the battery. The expansion of the anode may be less than 1.5% in lateral dimensions of the anode for higher charge rates during formation with the active material being more than 50% silicon, where the higher charge rate may be 1 C or higher, and perpendicular expansion may be higher for charge rates below 1 C during formation. The expansion of the anode may be lower in lateral dimensions for thicker current collectors, which may be 10 μm or thicker, and may be lower in lateral dimensions for more rigid materials for the current collector.