Patterned Silicon Anodes to Prevent Expansion-Induced Disconnection
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Solution Overview
Problem
Lithium-ion batteries face challenges with silicon anodes due to significant volume expansion during lithium insertion and extraction, leading to pulverization and electrical disconnection, which limits their practical application despite silicon's higher theoretical storage capacity compared to carbon-based anodes.
Innovation Solution
A patterned anode structure is developed, featuring a current collector with a metal layer and a metal oxide layer in a specific pattern, overlaid with a continuous porous lithium storage layer formed by chemical vapor deposition, which selectively adheres to the patterned metal oxide layer, enhancing stability and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If silicon is used as anode material to replace carbon-based anodes, then charge capacity is improved, but volume expansion during lithium insertion and extraction causes pulverization and electrical disconnection
Solution Approach 1:
The silicon anode is divided into discrete islands separated by spacing, rather than using continuous bulk silicon. This segmentation allows each island to independently accommodate volume expansion during lithiation while maintaining electrical connection to the current collector, preventing pulverization and disconnection despite the high charge capacity of silicon
Solution Approach 2:
The silicon islands are embedded within a carbon-based matrix structure, creating a nested configuration where silicon is contained within the larger anode architecture. This nesting provides structural support and maintains electrical connectivity while allowing the silicon to expand and contract during lithium insertion and extraction cycles
2Reliability
If nano- or micro-structured silicon is used to reduce pulverization, then stability is improved, but manufacturing complexity increases
Solution Approach 1:
The invention changes the morphological parameters of silicon from bulk continuous structures to discrete islands with specific size ranges (50 nm to 50 µm) and controlled spacing. These parameter changes provide stability by preventing crack propagation while maintaining compatibility with existing manufacturing processes like chemical vapor deposition, avoiding the need for complex nanofabrication techniques
3Ease of manufacture
If continuous porous lithium storage layer is formed by chemical vapor deposition, then manufacturing simplicity is improved, but control over silicon distribution and morphology becomes more challenging
Solution Approach 1:
A patterned metal oxide layer is introduced as an intermediary between the current collector and the silicon-forming process. This intermediary layer guides the chemical vapor deposition to form silicon islands in specific locations, providing both manufacturing simplicity through a single-step deposition process and precise control over silicon distribution and morphology
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 solution provides improved stability at aggressive charging rates, higher areal charge capacity, increased charge capacity per gram of silicon, improved physical durability, and a simplified, more reproducible manufacturing process, addressing the issues of volume expansion and electrical disconnection.
Implementation Method 1
a metal oxide layer provided in a first pattern overlaying the metal layer
Implementation Method 2
A continuous porous lithium storage layer is selectively formed by chemical vapor deposition by exposing the current collector to at least one lithium storage material precursor gas
Data Source
Figure 1A~1C
Figure 2
Figure 3
AI summary
An anode for an energy storage device includes a current collector having a metal layer; and a metal oxide layer provided in a first pattern overlaying the metal layer. The anode further includes a patterned lithium storage structure having a continuous porous lithium storage layer selectively overlaying at least a portion of the first pattern of metal oxide. A method of making an anode for use in an energy storage device includes providing a current collector having a metal layer and a metal oxide layer provided in a first pattern overlaying the metal layer. A continuous porous lithium storage layer is selectively formed by chemical vapor deposition by exposing the current collector to at least one lithium storage material precursor gas.