Lithium Layer Anode with Primer for Pre-lithiation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium secondary batteries face significant irreversible capacity loss due to the formation of a Solid Electrolyte Interface (SEI) film on the negative electrode active material, leading to reduced capacity and increased risk of internal short circuits during pre-lithiation processes.
Innovation Solution
A negative electrode design for lithium secondary batteries featuring a lithium layer positioned between the current collector and the active material layer, along with a primer layer to facilitate easier lithium adhesion and controlled moisture management, allowing for effective pre-lithiation without the risk of subsequent internal short circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a lithium layer is directly deposited on the negative electrode current collector to achieve pre-lithiation, then irreversible capacity loss is reduced, but internal short circuits may occur due to poor adhesion control and moisture sensitivity
Solution Approach 1:
A primer layer is introduced as an intermediary between the current collector and the lithium layer. This primer layer mediates the interaction between these two components, providing controlled adhesion and moisture management that prevents direct harmful contact while enabling effective lithium deposition for pre-lithiation
Solution Approach 2:
The primer layer is applied in advance before lithium deposition to prepare the surface for controlled lithium adhesion. This preliminary action establishes the proper interface conditions that prevent subsequent internal short circuits while enabling effective pre-lithiation
2Quantity of substance
If metal lithium is used as the negative electrode active material to achieve high theoretical capacity, then capacity is improved, but separator damage occurs due to lithium atom growth during charging and discharging
Solution Approach 1:
Pre-lithiation is performed in advance by depositing a controlled lithium layer on the current collector before assembling the battery. This preliminary lithium supply compensates for the lithium consumed during SEI formation, allowing the use of high-capacity materials like silicon or graphite without requiring excess lithium metal that would grow and damage the separator
Solution Approach 2:
The invention changes the state and distribution of lithium from bulk metal lithium that grows during cycling to a controlled thin film deposited in advance. This parameter change from bulk to thin-film morphology prevents the harmful growth behavior while maintaining the high capacity benefits
3Manufacturing precision
If a primer layer is added to improve lithium adhesion and control moisture, then pre-lithiation effectiveness is improved, but device complexity increases
Solution Approach 1:
The primer layer serves as a functional intermediary that combines multiple benefits: improving lithium adhesion, managing moisture, and providing a controlled deposition surface. This single intermediate layer consolidates multiple functions that would otherwise require separate components or process steps
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
This design enables reduced irreversible capacity loss and improved capacity characteristics by ensuring precise control over lithium distribution and adhesion, enhancing the pre-lithiation process and overall battery performance.
Implementation Method 1
lithium ions of the positive electrode active material of the positive electrode are intercalated into/de intercalated from the negative electrode active material of the negative electrode
Implementation Method 2
the SEI film formed at the beginning of charging prevents the reaction between the lithium ions and a negative electrode or other materials during charging and discharging, and functions as an ion tunnel to pass only the lithium ions therethrough
Data Source
Figure 1
AI summary
The present invention relates to a negative electrode for a lithium secondary battery including a negative electrode current collector, a negative electrode active material layer, a lithium layer positioned between the negative electrode current collector and the negative electrode active material layer, and a primer layer positioned between the negative electrode current collector and the lithium layer, and a manufacturing method thereof.