Anode Pre-Lithiation Reactor Spacing for Stable SEI Formation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing pre-lithiation methods for negative electrodes in secondary batteries result in inefficient SEI film composition due to varying distances between lithium metal and the negative electrode, leading to reduced battery capacity and cycle lifespan.
Innovation Solution
A pre-lithiation apparatus and method that adjusts the separation distance between a lithium metal counter electrode and the negative electrode to 7 to 15 mm, using a roll-to-roll process, to form an optimized SEI film with a higher inorganic content, preventing reactions with oxygen and carbon dioxide.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the distance between lithium metal and negative electrode is not controlled, then the pre-lithiation process is simple, but the SEI film composition deteriorates and battery performance decreases
Solution Approach 1:
The patent applies parameter changes by precisely controlling the separation distance between the lithium metal counter electrode and the negative electrode structure within 7-15 mm. This distance parameter optimization enables the formation of an SEI film with appropriate inorganic content, preventing reactions with oxygen and carbon dioxide, thereby improving initial efficiency and cycle characteristics without requiring complex additional components
2Productivity
If lithium metal directly contacts negative electrode, then pre-lithiation is efficient, but SEI film composition becomes uncontrolled and battery capacity reduces
Solution Approach 1:
The patent uses the electrolyte solution as an intermediary medium between the lithium metal counter electrode and the negative electrode structure. By maintaining a separation distance of 7-15 mm in the electrolyte solution, the system enables efficient lithium ion transfer while preventing direct contact that would cause uncontrolled SEI film formation, thus resolving the contradiction between pre-lithiation efficiency and SEI film composition control
Solution Approach 2:
The patent optimizes the separation distance parameter to 7-15 mm, which balances the need for efficient lithium ion transfer (pre-lithiation efficiency) with the need for controlled SEI film formation. This parameter optimization ensures that lithium ions can reach the negative electrode effectively while the controlled distance prevents direct metal contact that would lead to uncontrolled SEI composition
3Productivity
If separation distance is too small, then pre-lithiation is efficient, but SEI film quality deteriorates due to reactions with oxygen and carbon dioxide
Solution Approach 1:
The patent optimizes the separation distance parameter to 7-15 mm, which is sufficient to prevent harmful reactions with oxygen and carbon dioxide while maintaining efficient pre-lithiation. This parameter optimization resolves the contradiction by finding the optimal balance point where productivity is maintained and harmful effects are eliminated
4Reliability
If separation distance is increased, then SEI film quality improves, but pre-lithiation efficiency decreases
Solution Approach 1:
The patent optimizes the separation distance to 7-15 mm, which is the optimal range that maintains both high SEI film quality and efficient pre-lithiation. This parameter optimization resolves the contradiction by identifying the sweet spot where increased distance improves quality without excessively reducing productivity
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
Improves initial efficiency and cycle characteristics of the battery by forming an optimized SEI film, enhancing the stability and performance of the negative electrode.
Implementation Method 1
pre-lithiating the negative electrode structure by arranging a lithium metal counter electrode, which is disposed to be spaced apart from the negative electrode structure, in a pre-lithiation section, and electrochemically charging the negative electrode structure
Implementation Method 2
impregnating the negative electrode structure with the pre-lithiation solution while moving the negative electrode structure in the impregnation section
Implementation Method 3
impregnating the negative electrode structure with the pre-lithiation solution
Implementation Method 4
the aging section is configured for aging the pre-lithiated negative electrode structure by leaving the pre-lithiated negative electrode structure unattended in the pre-lithiation solution for a predetermined time
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present technology relates to an apparatus and method for pre-lithiating a negative electrode, and the apparatus includes: a pre-lithiation reactor which is sequentially divided into an impregnation section, a pre-lithiation section and an aging section, and accommodates a pre-lithiation solution in which a negative electrode structure is moved; a negative electrode roll which is arranged outside the pre-lithiation solution and on which the negative electrode structure before being moved is wound; a lithium metal counter electrode which is arranged in the pre-lithiation solution in the pre-lithiation section and is spaced apart from the negative electrode structure by a predetermined distance to face the negative electrode structure which is moved in the pre-lithiation solution; and a charge and discharge unit which is connected to the negative electrode structure and the lithium metal counter electrode, in which a separation distance between the lithium metal counter electrode and the negative electrode structure is in a range of 7 to 15 mm.