Pre-Lithiation Chamber Moisture Capture for SEI Stability
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Solution Overview
Problem
Existing pre-lithiation processes struggle to control water content in the dry room environment, leading to the formation of byproducts that damage the solid electrolyte interphase (SEI) film on the negative electrode, causing the electrode to revert to a non-lithiated state.
Innovation Solution
A pre-lithiation reaction chamber apparatus with a water-capturing member and a position-changing member to manage water content below 10 ppm, using water-capturing powder and rotating or vibrating mechanisms to maintain the integrity of the SEI film.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If pre-lithiation is carried out in a dry room environment, then the process can be performed in a readily available facility, but the water content cannot be controlled below 10 ppm due to room introduction processes
Solution Approach 1:
A water-capturing member is introduced as an intermediary substance between the external environment and the pre-lithiation reaction vessel. This member actively captures and removes water molecules from the atmosphere inside the reaction chamber, enabling water content control below 10 ppm without requiring the entire dry room to be hermetically sealed or maintained at ultra-low humidity.
Solution Approach 2:
The invention creates a localized inert atmosphere within the reaction chamber by combining the water-capturing member with a nitrogen gas supply system. The nitrogen gas flows through the chamber to displace moisture-laden air, while the water-capturing member continuously removes any remaining water vapor, together establishing a water-free environment suitable for pre-lithiation.
2Device complexity
If water content is not controlled below 10 ppm, then the pre-lithiation process can proceed without additional water control measures, but byproducts form that damage the SEI film and cause the negative electrode to revert to non-lithiated state
Solution Approach 1:
The water-capturing member performs preliminary anti-action by proactively removing water from the reaction chamber atmosphere before water can react with lithium salts to form harmful byproducts. This preventive approach stops the harmful chemical reactions before they can occur, protecting the SEI film integrity without requiring complex real-time monitoring or intervention systems.
3Manufacturing precision
If water-capturing powder is used to control humidity, then water content can be reduced, but the powder settles at the bottom and loses effectiveness over time
Solution Approach 1:
The water-capturing member is designed with dynamic characteristics through the position-changing member that actively moves the water-capturing powder between different positions in the container. This dynamic movement prevents the powder from settling and forming a depleted layer at the bottom, continuously exposing fresh powder surfaces to capture water vapor and maintaining effectiveness throughout the pre-lithiation process.
Solution Approach 2:
The water-capturing member incorporates vibration functionality that mechanically agitates the water-capturing powder during operation. This vibration prevents powder settling and promotes uniform distribution, ensuring continuous contact between the powder and water vapor in the atmosphere, thereby maintaining water-capturing effectiveness throughout the process duration.
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 apparatus ensures homogeneous pre-lithiation of the negative electrode, enhancing initial coulombic efficiency and cycle capacity retention of lithium secondary batteries.
Implementation Method 1
a water-capturing member, wherein the water-capturing member includes water-capturing powder
Data Source
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AI summary
The present disclosure provides a pre-lithiation reaction chamber apparatus including a pre-lithiation reaction vessel which can prevent harmful effects caused by water that may be generated during pre-lithiation, wherein the pre-lithiation reaction vessel includes an electrolyte, a negative electrode for a lithium secondary battery and a lithium ion-supplying member, each of the negative electrode for a lithium secondary battery and the lithium ion-supplying member is at least partially in contact with the electrolyte, the electrolyte includes a lithium salt, the pre-lithiation reaction chamber apparatus further includes a water-capturing member, and the water-capturing member includes: water-capturing powder; a container configured to receive the water-capturing powder; and a position-changing member configured to change the position of the water-capturing powder in the container.